Clips in timeline

lightningbeam-ui/lightningbeam-core/src/actions/add_layer.rs

@@ -0,0 +1,126 @@
+//! Add layer action
+//!
+//! Handles adding a new layer to the document.
+
+use crate::action::Action;
+use crate::document::Document;
+use crate::layer::{AnyLayer, VectorLayer};
+use uuid::Uuid;
+
+/// Action that adds a new layer to the document
+pub struct AddLayerAction {
+    /// The layer to add
+    layer: AnyLayer,
+
+    /// ID of the created layer (set after execution)
+    created_layer_id: Option<Uuid>,
+}
+
+impl AddLayerAction {
+    /// Create a new add layer action with a vector layer
+    ///
+    /// # Arguments
+    ///
+    /// * `name` - The name for the new layer
+    pub fn new_vector(name: impl Into<String>) -> Self {
+        let layer = VectorLayer::new(name);
+        Self {
+            layer: AnyLayer::Vector(layer),
+            created_layer_id: None,
+        }
+    }
+
+    /// Create a new add layer action with any layer type
+    ///
+    /// # Arguments
+    ///
+    /// * `layer` - The layer to add
+    pub fn new(layer: AnyLayer) -> Self {
+        Self {
+            layer,
+            created_layer_id: None,
+        }
+    }
+
+    /// Get the ID of the created layer (after execution)
+    pub fn created_layer_id(&self) -> Option<Uuid> {
+        self.created_layer_id
+    }
+}
+
+impl Action for AddLayerAction {
+    fn execute(&mut self, document: &mut Document) {
+        // Add layer to the document's root
+        let layer_id = document.root_mut().add_child(self.layer.clone());
+
+        // Store the ID for rollback
+        self.created_layer_id = Some(layer_id);
+    }
+
+    fn rollback(&mut self, document: &mut Document) {
+        // Remove the created layer if it exists
+        if let Some(layer_id) = self.created_layer_id {
+            document.root_mut().remove_child(&layer_id);
+
+            // Clear the stored ID
+            self.created_layer_id = None;
+        }
+    }
+
+    fn description(&self) -> String {
+        match &self.layer {
+            AnyLayer::Vector(_) => "Add vector layer",
+            AnyLayer::Audio(_) => "Add audio layer",
+            AnyLayer::Video(_) => "Add video layer",
+        }
+        .to_string()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_add_vector_layer() {
+        let mut document = Document::new("Test");
+        assert_eq!(document.root.children.len(), 0);
+
+        // Create and execute action
+        let mut action = AddLayerAction::new_vector("New Layer");
+        action.execute(&mut document);
+
+        // Verify layer was added
+        assert_eq!(document.root.children.len(), 1);
+        let layer = &document.root.children[0];
+        assert_eq!(layer.layer().name, "New Layer");
+        assert!(matches!(layer, AnyLayer::Vector(_)));
+
+        // Rollback
+        action.rollback(&mut document);
+
+        // Verify layer was removed
+        assert_eq!(document.root.children.len(), 0);
+    }
+
+    #[test]
+    fn test_add_layer_description() {
+        let action = AddLayerAction::new_vector("Test");
+        assert_eq!(action.description(), "Add vector layer");
+    }
+
+    #[test]
+    fn test_add_multiple_layers() {
+        let mut document = Document::new("Test");
+
+        let mut action1 = AddLayerAction::new_vector("Layer 1");
+        let mut action2 = AddLayerAction::new_vector("Layer 2");
+
+        action1.execute(&mut document);
+        action2.execute(&mut document);
+
+        assert_eq!(document.root.children.len(), 2);
+        assert_eq!(document.root.children[0].layer().name, "Layer 1");
+        assert_eq!(document.root.children[1].layer().name, "Layer 2");
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/add_shape.rs

@@ -5,13 +5,13 @@
 use crate::action::Action;
 use crate::document::Document;
 use crate::layer::AnyLayer;
-use crate::object::Object;
+use crate::object::ShapeInstance;
 use crate::shape::Shape;
 use uuid::Uuid;
 
 /// Action that adds a shape and object to a vector layer
 ///
-/// This action creates both a Shape (the path/geometry) and an Object
+/// This action creates both a Shape (the path/geometry) and an ShapeInstance
 /// (the instance with transform). Both are added to the layer.
 pub struct AddShapeAction {
     /// Layer ID to add the shape to
@@ -21,7 +21,7 @@ pub struct AddShapeAction {
     shape: Shape,
 
     /// The object to add (references the shape with transform)
-    object: Object,
+    object: ShapeInstance,
 
     /// ID of the created shape (set after execution)
     created_shape_id: Option<Uuid>,
@@ -38,7 +38,7 @@ impl AddShapeAction {
     /// * `layer_id` - The layer to add the shape to
     /// * `shape` - The shape to add
     /// * `object` - The object instance referencing the shape
-    pub fn new(layer_id: Uuid, shape: Shape, object: Object) -> Self {
+    pub fn new(layer_id: Uuid, shape: Shape, object: ShapeInstance) -> Self {
         Self {
             layer_id,
             shape,
@@ -110,7 +110,7 @@ mod tests {
         let rect = Rect::new(0.0, 0.0, 100.0, 50.0);
         let path = rect.to_path(0.1);
         let shape = Shape::new(path).with_fill(ShapeColor::rgb(255, 0, 0));
-        let object = Object::new(shape.id).with_position(50.0, 50.0);
+        let object = ShapeInstance::new(shape.id).with_position(50.0, 50.0);
 
         // Create and execute action
         let mut action = AddShapeAction::new(layer_id, shape, object);
@@ -119,9 +119,9 @@ mod tests {
         // Verify shape and object were added
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
             assert_eq!(layer.shapes.len(), 1);
-            assert_eq!(layer.objects.len(), 1);
+            assert_eq!(layer.shape_instances.len(), 1);
 
-            let added_object = &layer.objects[0];
+            let added_object = &layer.shape_instances[0];
             assert_eq!(added_object.transform.x, 50.0);
             assert_eq!(added_object.transform.y, 50.0);
         } else {
@@ -134,7 +134,7 @@ mod tests {
         // Verify shape and object were removed
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
             assert_eq!(layer.shapes.len(), 0);
-            assert_eq!(layer.objects.len(), 0);
+            assert_eq!(layer.shape_instances.len(), 0);
         }
     }
 
@@ -149,7 +149,7 @@ mod tests {
         let path = circle.to_path(0.1);
         let shape = Shape::new(path)
             .with_fill(ShapeColor::rgb(0, 255, 0));
-        let object = Object::new(shape.id);
+        let object = ShapeInstance::new(shape.id);
 
         let mut action = AddShapeAction::new(layer_id, shape, object);
 
@@ -161,7 +161,7 @@ mod tests {
 
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
             assert_eq!(layer.shapes.len(), 1);
-            assert_eq!(layer.objects.len(), 1);
+            assert_eq!(layer.shape_instances.len(), 1);
         }
     }
 
@@ -174,7 +174,7 @@ mod tests {
         let rect = Rect::new(0.0, 0.0, 50.0, 50.0);
         let path = rect.to_path(0.1);
         let shape = Shape::new(path);
-        let object = Object::new(shape.id);
+        let object = ShapeInstance::new(shape.id);
 
         let mut action = AddShapeAction::new(layer_id, shape, object);
 
@@ -185,7 +185,7 @@ mod tests {
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
             // Should have 2 shapes and 2 objects
             assert_eq!(layer.shapes.len(), 2);
-            assert_eq!(layer.objects.len(), 2);
+            assert_eq!(layer.shape_instances.len(), 2);
         }
     }
 }

lightningbeam-ui/lightningbeam-core/src/actions/mod.rs

@@ -3,12 +3,20 @@
 //! This module contains all the concrete action types that can be executed
 //! through the action system.
 
+pub mod add_layer;
 pub mod add_shape;
+pub mod move_clip_instances;
 pub mod move_objects;
 pub mod paint_bucket;
+pub mod transform_clip_instances;
 pub mod transform_objects;
+pub mod trim_clip_instances;
 
+pub use add_layer::AddLayerAction;
 pub use add_shape::AddShapeAction;
-pub use move_objects::MoveObjectsAction;
+pub use move_clip_instances::MoveClipInstancesAction;
+pub use move_objects::MoveShapeInstancesAction;
 pub use paint_bucket::PaintBucketAction;
-pub use transform_objects::TransformObjectsAction;
+pub use transform_clip_instances::TransformClipInstancesAction;
+pub use transform_objects::TransformShapeInstancesAction;
+pub use trim_clip_instances::{TrimClipInstancesAction, TrimData, TrimType};

lightningbeam-ui/lightningbeam-core/src/actions/move_clip_instances.rs

@@ -0,0 +1,143 @@
+//! Move clip instances action
+//!
+//! Handles moving one or more clip instances along the timeline.
+
+use crate::action::Action;
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use std::collections::HashMap;
+use uuid::Uuid;
+
+/// Action that moves clip instances to new timeline positions
+pub struct MoveClipInstancesAction {
+    /// Map of layer IDs to vectors of (clip_instance_id, old_timeline_start, new_timeline_start)
+    layer_moves: HashMap<Uuid, Vec<(Uuid, f64, f64)>>,
+}
+
+impl MoveClipInstancesAction {
+    /// Create a new move clip instances action
+    ///
+    /// # Arguments
+    ///
+    /// * `layer_moves` - Map of layer IDs to vectors of (clip_instance_id, old_timeline_start, new_timeline_start)
+    pub fn new(layer_moves: HashMap<Uuid, Vec<(Uuid, f64, f64)>>) -> Self {
+        Self { layer_moves }
+    }
+}
+
+impl Action for MoveClipInstancesAction {
+    fn execute(&mut self, document: &mut Document) {
+        for (layer_id, moves) in &self.layer_moves {
+            let layer = match document.get_layer_mut(layer_id) {
+                Some(l) => l,
+                None => continue,
+            };
+
+            // Get mutable reference to clip_instances for this layer type
+            let clip_instances = match layer {
+                AnyLayer::Vector(vl) => &mut vl.clip_instances,
+                AnyLayer::Audio(al) => &mut al.clip_instances,
+                AnyLayer::Video(vl) => &mut vl.clip_instances,
+            };
+
+            // Update timeline_start for each clip instance
+            for (clip_id, _old, new) in moves {
+                if let Some(clip_instance) = clip_instances.iter_mut().find(|ci| ci.id == *clip_id)
+                {
+                    clip_instance.timeline_start = *new;
+                }
+            }
+        }
+    }
+
+    fn rollback(&mut self, document: &mut Document) {
+        for (layer_id, moves) in &self.layer_moves {
+            let layer = match document.get_layer_mut(layer_id) {
+                Some(l) => l,
+                None => continue,
+            };
+
+            // Get mutable reference to clip_instances for this layer type
+            let clip_instances = match layer {
+                AnyLayer::Vector(vl) => &mut vl.clip_instances,
+                AnyLayer::Audio(al) => &mut al.clip_instances,
+                AnyLayer::Video(vl) => &mut vl.clip_instances,
+            };
+
+            // Restore original timeline_start for each clip instance
+            for (clip_id, old, _new) in moves {
+                if let Some(clip_instance) = clip_instances.iter_mut().find(|ci| ci.id == *clip_id)
+                {
+                    clip_instance.timeline_start = *old;
+                }
+            }
+        }
+    }
+
+    fn description(&self) -> String {
+        let total_count: usize = self.layer_moves.values().map(|v| v.len()).sum();
+        if total_count == 1 {
+            "Move clip instance".to_string()
+        } else {
+            format!("Move {} clip instances", total_count)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::clip::{Clip, ClipInstance, ClipType};
+    use crate::layer::VectorLayer;
+
+    #[test]
+    fn test_move_clip_instances_action() {
+        // Create a document with a test clip instance
+        let mut document = Document::new("Test");
+
+        let clip = Clip::new(ClipType::Vector, "Test Clip", None);
+        let clip_id = clip.id;
+
+        let mut vector_layer = VectorLayer::new("Layer 1");
+        vector_layer.clips.push(clip);
+
+        let mut clip_instance = ClipInstance::new(clip_id);
+        clip_instance.timeline_start = 1.0; // Start at 1 second
+        let instance_id = clip_instance.id;
+        vector_layer.clip_instances.push(clip_instance);
+
+        let layer_id = document.root.add_child(AnyLayer::Vector(vector_layer));
+
+        // Create move action: move from 1.0 to 5.0 seconds
+        let mut layer_moves = HashMap::new();
+        layer_moves.insert(layer_id, vec![(instance_id, 1.0, 5.0)]);
+
+        let mut action = MoveClipInstancesAction::new(layer_moves);
+
+        // Execute
+        action.execute(&mut document);
+
+        // Verify position changed
+        if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
+            let instance = layer
+                .clip_instances
+                .iter()
+                .find(|ci| ci.id == instance_id)
+                .unwrap();
+            assert_eq!(instance.timeline_start, 5.0);
+        }
+
+        // Rollback
+        action.rollback(&mut document);
+
+        // Verify position restored
+        if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
+            let instance = layer
+                .clip_instances
+                .iter()
+                .find(|ci| ci.id == instance_id)
+                .unwrap();
+            assert_eq!(instance.timeline_start, 1.0);
+        }
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/move_objects.rs

@@ -1,6 +1,6 @@
-//! Move objects action
+//! Move shape instances action
 //!
-//! Handles moving one or more objects to new positions.
+//! Handles moving one or more shape instances to new positions.
 
 use crate::action::Action;
 use crate::document::Document;
@@ -9,31 +9,31 @@ use std::collections::HashMap;
 use uuid::Uuid;
 use vello::kurbo::Point;
 
-/// Action that moves objects to new positions
-pub struct MoveObjectsAction {
-    /// Layer ID containing the objects
+/// Action that moves shape instances to new positions
+pub struct MoveShapeInstancesAction {
+    /// Layer ID containing the shape instances
     layer_id: Uuid,
 
     /// Map of object IDs to their old and new positions
-    object_positions: HashMap<Uuid, (Point, Point)>, // (old_pos, new_pos)
+    shape_instance_positions: HashMap<Uuid, (Point, Point)>, // (old_pos, new_pos)
 }
 
-impl MoveObjectsAction {
-    /// Create a new move objects action
+impl MoveShapeInstancesAction {
+    /// Create a new move shape instances action
     ///
     /// # Arguments
     ///
-    /// * `layer_id` - The layer containing the objects
-    /// * `object_positions` - Map of object IDs to (old_position, new_position)
-    pub fn new(layer_id: Uuid, object_positions: HashMap<Uuid, (Point, Point)>) -> Self {
+    /// * `layer_id` - The layer containing the shape instances
+    /// * `shape_instance_positions` - Map of object IDs to (old_position, new_position)
+    pub fn new(layer_id: Uuid, shape_instance_positions: HashMap<Uuid, (Point, Point)>) -> Self {
         Self {
             layer_id,
-            object_positions,
+            shape_instance_positions,
         }
     }
 }
 
-impl Action for MoveObjectsAction {
+impl Action for MoveShapeInstancesAction {
     fn execute(&mut self, document: &mut Document) {
         let layer = match document.get_layer_mut(&self.layer_id) {
             Some(l) => l,
@@ -41,8 +41,8 @@ impl Action for MoveObjectsAction {
         };
 
         if let AnyLayer::Vector(vector_layer) = layer {
-            for (object_id, (_old, new)) in &self.object_positions {
-                vector_layer.modify_object_internal(object_id, |obj| {
+            for (shape_instance_id, (_old, new)) in &self.shape_instance_positions {
+                vector_layer.modify_object_internal(shape_instance_id, |obj| {
                     obj.transform.x = new.x;
                     obj.transform.y = new.y;
                 });
@@ -57,8 +57,8 @@ impl Action for MoveObjectsAction {
         };
 
         if let AnyLayer::Vector(vector_layer) = layer {
-            for (object_id, (old, _new)) in &self.object_positions {
-                vector_layer.modify_object_internal(object_id, |obj| {
+            for (shape_instance_id, (old, _new)) in &self.shape_instance_positions {
+                vector_layer.modify_object_internal(shape_instance_id, |obj| {
                     obj.transform.x = old.x;
                     obj.transform.y = old.y;
                 });
@@ -67,11 +67,11 @@ impl Action for MoveObjectsAction {
     }
 
     fn description(&self) -> String {
-        let count = self.object_positions.len();
+        let count = self.shape_instance_positions.len();
         if count == 1 {
-            "Move object".to_string()
+            "Move shape instance".to_string()
         } else {
-            format!("Move {} objects", count)
+            format!("Move {} shape instances", count)
         }
     }
 }
@@ -80,40 +80,40 @@ impl Action for MoveObjectsAction {
 mod tests {
     use super::*;
     use crate::layer::VectorLayer;
-    use crate::object::Object;
+    use crate::object::ShapeInstance;
     use crate::shape::Shape;
     use vello::kurbo::{Circle, Shape as KurboShape};
 
     #[test]
-    fn test_move_objects_action() {
+    fn test_move_shape_instances_action() {
         // Create a document with a test object
         let mut document = Document::new("Test");
 
         let circle = Circle::new((100.0, 100.0), 50.0);
         let path = circle.to_path(0.1);
         let shape = Shape::new(path);
-        let object = Object::new(shape.id).with_position(50.0, 50.0);
+        let object = ShapeInstance::new(shape.id).with_position(50.0, 50.0);
 
         let mut vector_layer = VectorLayer::new("Layer 1");
         vector_layer.add_shape(shape);
-        let object_id = vector_layer.add_object(object);
+        let shape_instance_id = vector_layer.add_object(object);
         let layer_id = document.root.add_child(AnyLayer::Vector(vector_layer));
 
         // Create move action
         let mut positions = HashMap::new();
         positions.insert(
-            object_id,
+            shape_instance_id,
             (Point::new(50.0, 50.0), Point::new(150.0, 200.0))
         );
 
-        let mut action = MoveObjectsAction::new(layer_id, positions);
+        let mut action = MoveShapeInstancesAction::new(layer_id, positions);
 
         // Execute
         action.execute(&mut document);
 
         // Verify position changed
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
-            let obj = layer.get_object(&object_id).unwrap();
+            let obj = layer.get_object(&shape_instance_id).unwrap();
             assert_eq!(obj.transform.x, 150.0);
             assert_eq!(obj.transform.y, 200.0);
         }
@@ -123,7 +123,7 @@ mod tests {
 
         // Verify position restored
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
-            let obj = layer.get_object(&object_id).unwrap();
+            let obj = layer.get_object(&shape_instance_id).unwrap();
             assert_eq!(obj.transform.x, 50.0);
             assert_eq!(obj.transform.y, 50.0);
         }

lightningbeam-ui/lightningbeam-core/src/actions/paint_bucket.rs

@@ -8,7 +8,7 @@ use crate::curve_segment::CurveSegment;
 use crate::document::Document;
 use crate::gap_handling::GapHandlingMode;
 use crate::layer::AnyLayer;
-use crate::object::Object;
+use crate::object::ShapeInstance;
 use crate::planar_graph::PlanarGraph;
 use crate::shape::ShapeColor;
 use uuid::Uuid;
@@ -34,8 +34,8 @@ pub struct PaintBucketAction {
     /// ID of the created shape (set after execution)
     created_shape_id: Option<Uuid>,
 
-    /// ID of the created object (set after execution)
-    created_object_id: Option<Uuid>,
+    /// ID of the created shape instance (set after execution)
+    created_shape_instance_id: Option<Uuid>,
 }
 
 impl PaintBucketAction {
@@ -62,7 +62,7 @@ impl PaintBucketAction {
             tolerance,
             gap_mode,
             created_shape_id: None,
-            created_object_id: None,
+            created_shape_instance_id: None,
         }
     }
 }
@@ -74,10 +74,10 @@ impl Action for PaintBucketAction {
         // Optimization: Check if we're clicking on an existing shape first
         // This is much faster than building a planar graph
         if let Some(AnyLayer::Vector(vector_layer)) = document.get_layer_mut(&self.layer_id) {
-            // Iterate through objects in reverse order (topmost first)
-            for object in vector_layer.objects.iter().rev() {
-                // Find the corresponding shape
-                if let Some(shape) = vector_layer.shapes.iter().find(|s| s.id == object.shape_id) {
+            // Iterate through shape instances in reverse order (topmost first)
+            for shape_instance in vector_layer.shape_instances.iter().rev() {
+                // Find the corresponding shape (O(1) HashMap lookup)
+                if let Some(shape) = vector_layer.shapes.get(&shape_instance.shape_id) {
                     // Skip shapes without fill color (e.g., lines with only stroke)
                     if shape.fill_color.is_none() {
                         continue;
@@ -92,8 +92,8 @@ impl Action for PaintBucketAction {
                         continue;
                     }
 
-                    // Apply the object's transform to get the transformed path
-                    let transform_affine = object.transform.to_affine();
+                    // Apply the shape instance's transform to get the transformed path
+                    let transform_affine = shape_instance.transform.to_affine();
 
                     // Transform the click point to shape's local coordinates (inverse transform)
                     let inverse_transform = transform_affine.inverse();
@@ -110,8 +110,8 @@ impl Action for PaintBucketAction {
                         // Store the shape ID before the immutable borrow ends
                         let shape_id = shape.id;
 
-                        // Find mutable reference to the shape and update its fill
-                        if let Some(shape_mut) = vector_layer.shapes.iter_mut().find(|s| s.id == shape_id) {
+                        // Find mutable reference to the shape and update its fill (O(1) HashMap lookup)
+                        if let Some(shape_mut) = vector_layer.shapes.get_mut(&shape_id) {
                             shape_mut.fill_color = Some(self.fill_color);
                             println!("Updated shape fill color");
                         }
@@ -154,20 +154,20 @@ impl Action for PaintBucketAction {
 
             println!("DEBUG: Face shape created with fill_color: {:?}", face_shape.fill_color);
 
-            let face_object = Object::new(face_shape.id);
+            let face_shape_instance = ShapeInstance::new(face_shape.id);
 
             // Store the created IDs for rollback
             self.created_shape_id = Some(face_shape.id);
-            self.created_object_id = Some(face_object.id);
+            self.created_shape_instance_id = Some(face_shape_instance.id);
 
             if let Some(AnyLayer::Vector(vector_layer)) = document.get_layer_mut(&self.layer_id) {
                 let shape_id_for_debug = face_shape.id;
                 vector_layer.add_shape_internal(face_shape);
-                vector_layer.add_object_internal(face_object);
+                vector_layer.add_object_internal(face_shape_instance);
                 println!("DEBUG: Added filled shape");
 
-                // Verify the shape still has the fill color after being added
-                if let Some(added_shape) = vector_layer.shapes.iter().find(|s| s.id == shape_id_for_debug) {
+                // Verify the shape still has the fill color after being added (O(1) HashMap lookup)
+                if let Some(added_shape) = vector_layer.shapes.get(&shape_id_for_debug) {
                     println!("DEBUG: After adding to layer, shape fill_color = {:?}", added_shape.fill_color);
                 }
             }
@@ -180,7 +180,7 @@ impl Action for PaintBucketAction {
 
     fn rollback(&mut self, document: &mut Document) {
         // Remove the created shape and object if they exist
-        if let (Some(shape_id), Some(object_id)) = (self.created_shape_id, self.created_object_id) {
+        if let (Some(shape_id), Some(object_id)) = (self.created_shape_id, self.created_shape_instance_id) {
             let layer = match document.get_layer_mut(&self.layer_id) {
                 Some(l) => l,
                 None => return,
@@ -192,7 +192,7 @@ impl Action for PaintBucketAction {
             }
 
             self.created_shape_id = None;
-            self.created_object_id = None;
+            self.created_shape_instance_id = None;
         }
     }
 
@@ -219,11 +219,11 @@ fn extract_curves_from_all_shapes(
 
     // Extract curves only from this vector layer
     if let AnyLayer::Vector(vector_layer) = layer {
-        println!("Extracting curves from {} objects in layer", vector_layer.objects.len());
+        println!("Extracting curves from {} objects in layer", vector_layer.shape_instances.len());
         // Extract curves from each object (which applies transforms to shapes)
-        for (obj_idx, object) in vector_layer.objects.iter().enumerate() {
-            // Find the shape for this object
-            let shape = match vector_layer.shapes.iter().find(|s| s.id == object.shape_id) {
+        for (obj_idx, object) in vector_layer.shape_instances.iter().enumerate() {
+            // Find the shape for this object (O(1) HashMap lookup)
+            let shape = match vector_layer.shapes.get(&object.shape_id) {
                 Some(s) => s,
                 None => continue,
             };
@@ -313,12 +313,12 @@ mod tests {
         let rect = Rect::new(0.0, 0.0, 100.0, 100.0);
         let path = rect.to_path(0.1);
         let shape = Shape::new(path);
-        let object = Object::new(shape.id);
+        let shape_instance = ShapeInstance::new(shape.id);
 
         // Add the boundary shape
         if let Some(AnyLayer::Vector(layer)) = document.get_layer_mut(&layer_id) {
             layer.add_shape_internal(shape);
-            layer.add_object_internal(object);
+            layer.add_object_internal(shape_instance);
         }
 
         // Create and execute paint bucket action
@@ -336,7 +336,7 @@ mod tests {
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
             // Should have original shape + filled shape
             assert!(layer.shapes.len() >= 1);
-            assert!(layer.objects.len() >= 1);
+            assert!(layer.shape_instances.len() >= 1);
         } else {
             panic!("Layer not found or not a vector layer");
         }
@@ -347,7 +347,7 @@ mod tests {
         if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
             // Should only have original shape
             assert_eq!(layer.shapes.len(), 1);
-            assert_eq!(layer.objects.len(), 1);
+            assert_eq!(layer.shape_instances.len(), 1);
         }
     }
 

lightningbeam-ui/lightningbeam-core/src/actions/transform_clip_instances.rs

@@ -0,0 +1,80 @@
+//! Transform clip instances action
+//!
+//! Handles spatial transformation (move, scale, rotate) of clip instances on the stage.
+
+use crate::action::Action;
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use crate::object::Transform;
+use std::collections::HashMap;
+use uuid::Uuid;
+
+/// Action that transforms clip instances spatially on the stage
+pub struct TransformClipInstancesAction {
+    layer_id: Uuid,
+    /// Map of clip instance ID to (old transform, new transform)
+    clip_instance_transforms: HashMap<Uuid, (Transform, Transform)>,
+}
+
+impl TransformClipInstancesAction {
+    pub fn new(
+        layer_id: Uuid,
+        clip_instance_transforms: HashMap<Uuid, (Transform, Transform)>,
+    ) -> Self {
+        Self {
+            layer_id,
+            clip_instance_transforms,
+        }
+    }
+}
+
+impl Action for TransformClipInstancesAction {
+    fn execute(&mut self, document: &mut Document) {
+        let layer = match document.get_layer_mut(&self.layer_id) {
+            Some(l) => l,
+            None => return,
+        };
+
+        // Get mutable reference to clip_instances for this layer type
+        let clip_instances = match layer {
+            AnyLayer::Vector(vl) => &mut vl.clip_instances,
+            AnyLayer::Audio(al) => &mut al.clip_instances,
+            AnyLayer::Video(vl) => &mut vl.clip_instances,
+        };
+
+        // Apply new transforms
+        for (clip_id, (_old, new)) in &self.clip_instance_transforms {
+            if let Some(clip_instance) = clip_instances.iter_mut().find(|ci| ci.id == *clip_id) {
+                clip_instance.transform = new.clone();
+            }
+        }
+    }
+
+    fn rollback(&mut self, document: &mut Document) {
+        let layer = match document.get_layer_mut(&self.layer_id) {
+            Some(l) => l,
+            None => return,
+        };
+
+        // Get mutable reference to clip_instances for this layer type
+        let clip_instances = match layer {
+            AnyLayer::Vector(vl) => &mut vl.clip_instances,
+            AnyLayer::Audio(al) => &mut al.clip_instances,
+            AnyLayer::Video(vl) => &mut vl.clip_instances,
+        };
+
+        // Restore old transforms
+        for (clip_id, (old, _new)) in &self.clip_instance_transforms {
+            if let Some(clip_instance) = clip_instances.iter_mut().find(|ci| ci.id == *clip_id) {
+                clip_instance.transform = old.clone();
+            }
+        }
+    }
+
+    fn description(&self) -> String {
+        format!(
+            "Transform {} clip instance(s)",
+            self.clip_instance_transforms.len()
+        )
+    }
+}

lightningbeam-ui/lightningbeam-core/src/actions/transform_objects.rs

@@ -1,6 +1,6 @@
-//! Transform objects action
+//! Transform shape instances action
 //!
-//! Applies scale, rotation, and other transformations to objects with undo/redo support.
+//! Applies scale, rotation, and other transformations to shape instances with undo/redo support.
 
 use crate::action::Action;
 use crate::document::Document;
@@ -9,32 +9,32 @@ use crate::object::Transform;
 use std::collections::HashMap;
 use uuid::Uuid;
 
-/// Action to transform multiple objects
-pub struct TransformObjectsAction {
+/// Action to transform multiple shape instances
+pub struct TransformShapeInstancesAction {
     layer_id: Uuid,
-    /// Map of object ID to (old transform, new transform)
-    object_transforms: HashMap<Uuid, (Transform, Transform)>,
+    /// Map of shape instance ID to (old transform, new transform)
+    shape_instance_transforms: HashMap<Uuid, (Transform, Transform)>,
 }
 
-impl TransformObjectsAction {
+impl TransformShapeInstancesAction {
     /// Create a new transform action
     pub fn new(
         layer_id: Uuid,
-        object_transforms: HashMap<Uuid, (Transform, Transform)>,
+        shape_instance_transforms: HashMap<Uuid, (Transform, Transform)>,
     ) -> Self {
         Self {
             layer_id,
-            object_transforms,
+            shape_instance_transforms,
         }
     }
 }
 
-impl Action for TransformObjectsAction {
+impl Action for TransformShapeInstancesAction {
     fn execute(&mut self, document: &mut Document) {
         if let Some(layer) = document.get_layer_mut(&self.layer_id) {
             if let AnyLayer::Vector(vector_layer) = layer {
-                for (object_id, (_old, new)) in &self.object_transforms {
-                    vector_layer.modify_object_internal(object_id, |obj| {
+                for (shape_instance_id, (_old, new)) in &self.shape_instance_transforms {
+                    vector_layer.modify_object_internal(shape_instance_id, |obj| {
                         obj.transform = new.clone();
                     });
                 }
@@ -45,8 +45,8 @@ impl Action for TransformObjectsAction {
     fn rollback(&mut self, document: &mut Document) {
         if let Some(layer) = document.get_layer_mut(&self.layer_id) {
             if let AnyLayer::Vector(vector_layer) = layer {
-                for (object_id, (old, _new)) in &self.object_transforms {
-                    vector_layer.modify_object_internal(object_id, |obj| {
+                for (shape_instance_id, (old, _new)) in &self.shape_instance_transforms {
+                    vector_layer.modify_object_internal(shape_instance_id, |obj| {
                         obj.transform = old.clone();
                     });
                 }
@@ -55,6 +55,6 @@ impl Action for TransformObjectsAction {
     }
 
     fn description(&self) -> String {
-        format!("Transform {} object(s)", self.object_transforms.len())
+        format!("Transform {} shape instance(s)", self.shape_instance_transforms.len())
     }
 }

lightningbeam-ui/lightningbeam-core/src/actions/trim_clip_instances.rs

@@ -0,0 +1,271 @@
+//! Trim clip instances action
+//!
+//! Handles trimming one or more clip instances by adjusting trim_start and/or trim_end.
+
+use crate::action::Action;
+use crate::document::Document;
+use crate::layer::AnyLayer;
+use std::collections::HashMap;
+use uuid::Uuid;
+
+/// Type of trim operation
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum TrimType {
+    /// Trim from the start (adjust trim_start and timeline_start)
+    TrimLeft,
+    /// Trim from the end (adjust trim_end)
+    TrimRight,
+}
+
+/// Action that trims clip instances
+pub struct TrimClipInstancesAction {
+    /// Map of layer IDs to vectors of (clip_instance_id, trim_type, old_values, new_values)
+    /// For TrimLeft: (old_trim_start, old_timeline_start, new_trim_start, new_timeline_start)
+    /// For TrimRight: (old_trim_end, new_trim_end) - stored as Option<f64>
+    layer_trims: HashMap<Uuid, Vec<(Uuid, TrimType, TrimData, TrimData)>>,
+}
+
+/// Trim data that can represent either left or right trim values
+#[derive(Debug, Clone)]
+pub struct TrimData {
+    /// For TrimLeft: trim_start value
+    /// For TrimRight: trim_end value (Option because it can be None)
+    pub trim_value: Option<f64>,
+    /// For TrimLeft: timeline_start value (where the clip appears on timeline)
+    /// For TrimRight: unused (None)
+    pub timeline_start: Option<f64>,
+}
+
+impl TrimData {
+    /// Create TrimData for left trim
+    pub fn left(trim_start: f64, timeline_start: f64) -> Self {
+        Self {
+            trim_value: Some(trim_start),
+            timeline_start: Some(timeline_start),
+        }
+    }
+
+    /// Create TrimData for right trim
+    pub fn right(trim_end: Option<f64>) -> Self {
+        Self {
+            trim_value: trim_end,
+            timeline_start: None,
+        }
+    }
+}
+
+impl TrimClipInstancesAction {
+    /// Create a new trim clip instances action
+    pub fn new(layer_trims: HashMap<Uuid, Vec<(Uuid, TrimType, TrimData, TrimData)>>) -> Self {
+        Self { layer_trims }
+    }
+}
+
+impl Action for TrimClipInstancesAction {
+    fn execute(&mut self, document: &mut Document) {
+        for (layer_id, trims) in &self.layer_trims {
+            let layer = match document.get_layer_mut(layer_id) {
+                Some(l) => l,
+                None => continue,
+            };
+
+            // Get mutable reference to clip_instances for this layer type
+            let clip_instances = match layer {
+                AnyLayer::Vector(vl) => &mut vl.clip_instances,
+                AnyLayer::Audio(al) => &mut al.clip_instances,
+                AnyLayer::Video(vl) => &mut vl.clip_instances,
+            };
+
+            // Apply trims
+            for (clip_id, trim_type, _old, new) in trims {
+                if let Some(clip_instance) = clip_instances.iter_mut().find(|ci| ci.id == *clip_id)
+                {
+                    match trim_type {
+                        TrimType::TrimLeft => {
+                            if let (Some(new_trim), Some(new_timeline)) =
+                                (new.trim_value, new.timeline_start)
+                            {
+                                clip_instance.trim_start = new_trim;
+                                clip_instance.timeline_start = new_timeline;
+                            }
+                        }
+                        TrimType::TrimRight => {
+                            clip_instance.trim_end = new.trim_value;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    fn rollback(&mut self, document: &mut Document) {
+        for (layer_id, trims) in &self.layer_trims {
+            let layer = match document.get_layer_mut(layer_id) {
+                Some(l) => l,
+                None => continue,
+            };
+
+            // Get mutable reference to clip_instances for this layer type
+            let clip_instances = match layer {
+                AnyLayer::Vector(vl) => &mut vl.clip_instances,
+                AnyLayer::Audio(al) => &mut al.clip_instances,
+                AnyLayer::Video(vl) => &mut vl.clip_instances,
+            };
+
+            // Restore original trim values
+            for (clip_id, trim_type, old, _new) in trims {
+                if let Some(clip_instance) = clip_instances.iter_mut().find(|ci| ci.id == *clip_id)
+                {
+                    match trim_type {
+                        TrimType::TrimLeft => {
+                            if let (Some(old_trim), Some(old_timeline)) =
+                                (old.trim_value, old.timeline_start)
+                            {
+                                clip_instance.trim_start = old_trim;
+                                clip_instance.timeline_start = old_timeline;
+                            }
+                        }
+                        TrimType::TrimRight => {
+                            clip_instance.trim_end = old.trim_value;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    fn description(&self) -> String {
+        let total_count: usize = self.layer_trims.values().map(|v| v.len()).sum();
+        if total_count == 1 {
+            "Trim clip instance".to_string()
+        } else {
+            format!("Trim {} clip instances", total_count)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::clip::{Clip, ClipInstance, ClipType};
+    use crate::layer::VectorLayer;
+
+    #[test]
+    fn test_trim_left_action() {
+        let mut document = Document::new("Test");
+
+        let clip = Clip::new(ClipType::Vector, "Test Clip", Some(10.0));
+        let clip_id = clip.id;
+
+        let mut vector_layer = VectorLayer::new("Layer 1");
+        vector_layer.clips.push(clip);
+
+        let mut clip_instance = ClipInstance::new(clip_id);
+        clip_instance.timeline_start = 0.0;
+        clip_instance.trim_start = 0.0;
+        let instance_id = clip_instance.id;
+        vector_layer.clip_instances.push(clip_instance);
+
+        let layer_id = document.root.add_child(AnyLayer::Vector(vector_layer));
+
+        // Create trim action: trim 2 seconds from left
+        let mut layer_trims = HashMap::new();
+        layer_trims.insert(
+            layer_id,
+            vec![(
+                instance_id,
+                TrimType::TrimLeft,
+                TrimData::left(0.0, 0.0),
+                TrimData::left(2.0, 2.0),
+            )],
+        );
+
+        let mut action = TrimClipInstancesAction::new(layer_trims);
+
+        // Execute
+        action.execute(&mut document);
+
+        // Verify trim applied
+        if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
+            let instance = layer
+                .clip_instances
+                .iter()
+                .find(|ci| ci.id == instance_id)
+                .unwrap();
+            assert_eq!(instance.trim_start, 2.0);
+            assert_eq!(instance.timeline_start, 2.0);
+        }
+
+        // Rollback
+        action.rollback(&mut document);
+
+        // Verify restored
+        if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
+            let instance = layer
+                .clip_instances
+                .iter()
+                .find(|ci| ci.id == instance_id)
+                .unwrap();
+            assert_eq!(instance.trim_start, 0.0);
+            assert_eq!(instance.timeline_start, 0.0);
+        }
+    }
+
+    #[test]
+    fn test_trim_right_action() {
+        let mut document = Document::new("Test");
+
+        let clip = Clip::new(ClipType::Vector, "Test Clip", Some(10.0));
+        let clip_id = clip.id;
+
+        let mut vector_layer = VectorLayer::new("Layer 1");
+        vector_layer.clips.push(clip);
+
+        let mut clip_instance = ClipInstance::new(clip_id);
+        clip_instance.trim_end = None; // Full duration
+        let instance_id = clip_instance.id;
+        vector_layer.clip_instances.push(clip_instance);
+
+        let layer_id = document.root.add_child(AnyLayer::Vector(vector_layer));
+
+        // Create trim action: trim to 8 seconds from right
+        let mut layer_trims = HashMap::new();
+        layer_trims.insert(
+            layer_id,
+            vec![(
+                instance_id,
+                TrimType::TrimRight,
+                TrimData::right(None),
+                TrimData::right(Some(8.0)),
+            )],
+        );
+
+        let mut action = TrimClipInstancesAction::new(layer_trims);
+
+        // Execute
+        action.execute(&mut document);
+
+        // Verify trim applied
+        if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
+            let instance = layer
+                .clip_instances
+                .iter()
+                .find(|ci| ci.id == instance_id)
+                .unwrap();
+            assert_eq!(instance.trim_end, Some(8.0));
+        }
+
+        // Rollback
+        action.rollback(&mut document);
+
+        // Verify restored
+        if let Some(AnyLayer::Vector(layer)) = document.get_layer(&layer_id) {
+            let instance = layer
+                .clip_instances
+                .iter()
+                .find(|ci| ci.id == instance_id)
+                .unwrap();
+            assert_eq!(instance.trim_end, None);
+        }
+    }
+}

lightningbeam-ui/lightningbeam-core/src/clip.rs

@@ -0,0 +1,621 @@
+//! Clip system for Lightningbeam
+//!
+//! Clips are reusable compositions that can contain layers and be instantiated multiple times.
+//! Similar to MovieClips in Flash or Compositions in After Effects.
+//!
+//! ## Architecture
+//!
+//! - **Clip**: The reusable definition (VectorClip, VideoClip, AudioClip)
+//! - **ClipInstance**: An instance of a clip with its own transform, timing, and playback properties
+//!
+//! Multiple ClipInstances can reference the same Clip, each with different positions,
+//! timing windows, and playback speeds.
+
+use crate::layer::AnyLayer;
+use crate::layer_tree::LayerTree;
+use crate::object::Transform;
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+/// Vector clip containing nested layers
+///
+/// A VectorClip is a composition that contains its own layer hierarchy.
+/// Multiple ClipInstances can reference the same VectorClip, each with
+/// their own transform and timing properties.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct VectorClip {
+    /// Unique identifier
+    pub id: Uuid,
+
+    /// Clip name
+    pub name: String,
+
+    /// Canvas width in pixels
+    pub width: f64,
+
+    /// Canvas height in pixels
+    pub height: f64,
+
+    /// Duration in seconds
+    pub duration: f64,
+
+    /// Nested layer hierarchy
+    pub layers: LayerTree<AnyLayer>,
+}
+
+impl VectorClip {
+    /// Create a new vector clip
+    pub fn new(name: impl Into<String>, width: f64, height: f64, duration: f64) -> Self {
+        Self {
+            id: Uuid::new_v4(),
+            name: name.into(),
+            width,
+            height,
+            duration,
+            layers: LayerTree::new(),
+        }
+    }
+
+    /// Create with a specific ID
+    pub fn with_id(
+        id: Uuid,
+        name: impl Into<String>,
+        width: f64,
+        height: f64,
+        duration: f64,
+    ) -> Self {
+        Self {
+            id,
+            name: name.into(),
+            width,
+            height,
+            duration,
+            layers: LayerTree::new(),
+        }
+    }
+}
+
+/// Video clip referencing an external video file
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct VideoClip {
+    /// Unique identifier
+    pub id: Uuid,
+
+    /// Clip name
+    pub name: String,
+
+    /// Path to video file
+    pub file_path: String,
+
+    /// Video width in pixels
+    pub width: f64,
+
+    /// Video height in pixels
+    pub height: f64,
+
+    /// Duration in seconds (from video metadata)
+    pub duration: f64,
+
+    /// Frame rate (from video metadata)
+    pub frame_rate: f64,
+}
+
+impl VideoClip {
+    /// Create a new video clip
+    pub fn new(
+        name: impl Into<String>,
+        file_path: impl Into<String>,
+        width: f64,
+        height: f64,
+        duration: f64,
+        frame_rate: f64,
+    ) -> Self {
+        Self {
+            id: Uuid::new_v4(),
+            name: name.into(),
+            file_path: file_path.into(),
+            width,
+            height,
+            duration,
+            frame_rate,
+        }
+    }
+}
+
+/// MIDI event representing a single MIDI message
+///
+/// Compatible with daw-backend's MidiEvent structure
+#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
+pub struct MidiEvent {
+    /// Time position within the clip in seconds
+    pub timestamp: f64,
+    /// MIDI status byte (includes channel)
+    pub status: u8,
+    /// First data byte (note number, CC number, etc.)
+    pub data1: u8,
+    /// Second data byte (velocity, CC value, etc.)
+    pub data2: u8,
+}
+
+impl MidiEvent {
+    /// Create a new MIDI event
+    pub fn new(timestamp: f64, status: u8, data1: u8, data2: u8) -> Self {
+        Self {
+            timestamp,
+            status,
+            data1,
+            data2,
+        }
+    }
+
+    /// Create a note on event
+    pub fn note_on(timestamp: f64, channel: u8, note: u8, velocity: u8) -> Self {
+        Self {
+            timestamp,
+            status: 0x90 | (channel & 0x0F),
+            data1: note,
+            data2: velocity,
+        }
+    }
+
+    /// Create a note off event
+    pub fn note_off(timestamp: f64, channel: u8, note: u8, velocity: u8) -> Self {
+        Self {
+            timestamp,
+            status: 0x80 | (channel & 0x0F),
+            data1: note,
+            data2: velocity,
+        }
+    }
+}
+
+/// Audio clip type
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum AudioClipType {
+    /// Sampled audio from a file
+    ///
+    /// References audio data in a shared AudioPool (managed by daw-backend).
+    /// Compatible with daw-backend's Clip structure.
+    Sampled {
+        /// Index into the audio pool (references AudioFile)
+        /// This allows sharing audio data between multiple clip instances
+        audio_pool_index: usize,
+    },
+    /// MIDI sequence
+    ///
+    /// Compatible with daw-backend's MidiClip structure.
+    Midi {
+        /// MIDI events with timestamps
+        events: Vec<MidiEvent>,
+        /// Whether the clip loops
+        loop_enabled: bool,
+    },
+}
+
+/// Audio clip
+///
+/// This is compatible with daw-backend's audio system:
+/// - Sampled audio references data in AudioPool (managed externally)
+/// - MIDI audio stores events directly in the clip
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct AudioClip {
+    /// Unique identifier
+    pub id: Uuid,
+
+    /// Clip name
+    pub name: String,
+
+    /// Duration in seconds
+    /// For sampled audio, this can be set to trim the audio shorter than the source file
+    pub duration: f64,
+
+    /// Audio clip type (sampled or MIDI)
+    pub clip_type: AudioClipType,
+}
+
+impl AudioClip {
+    /// Create a new sampled audio clip
+    ///
+    /// # Arguments
+    /// * `name` - Clip name
+    /// * `audio_pool_index` - Index into the AudioPool (from daw-backend)
+    /// * `duration` - Clip duration (can be shorter than source file for trimming)
+    pub fn new_sampled(name: impl Into<String>, audio_pool_index: usize, duration: f64) -> Self {
+        Self {
+            id: Uuid::new_v4(),
+            name: name.into(),
+            duration,
+            clip_type: AudioClipType::Sampled { audio_pool_index },
+        }
+    }
+
+    /// Create a new MIDI clip
+    pub fn new_midi(
+        name: impl Into<String>,
+        duration: f64,
+        events: Vec<MidiEvent>,
+        loop_enabled: bool,
+    ) -> Self {
+        Self {
+            id: Uuid::new_v4(),
+            name: name.into(),
+            duration,
+            clip_type: AudioClipType::Midi {
+                events,
+                loop_enabled,
+            },
+        }
+    }
+
+    /// Get the audio pool index if this is a sampled audio clip
+    pub fn audio_pool_index(&self) -> Option<usize> {
+        match &self.clip_type {
+            AudioClipType::Sampled { audio_pool_index } => Some(*audio_pool_index),
+            _ => None,
+        }
+    }
+
+    /// Get MIDI events if this is a MIDI clip
+    pub fn midi_events(&self) -> Option<&[MidiEvent]> {
+        match &self.clip_type {
+            AudioClipType::Midi { events, .. } => Some(events),
+            _ => None,
+        }
+    }
+}
+
+/// Unified clip enum for polymorphic handling
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub enum AnyClip {
+    Vector(VectorClip),
+    Video(VideoClip),
+    Audio(AudioClip),
+}
+
+impl AnyClip {
+    /// Get the clip ID
+    pub fn id(&self) -> Uuid {
+        match self {
+            AnyClip::Vector(c) => c.id,
+            AnyClip::Audio(c) => c.id,
+            AnyClip::Video(c) => c.id,
+        }
+    }
+
+    /// Get the clip name
+    pub fn name(&self) -> &str {
+        match self {
+            AnyClip::Vector(c) => &c.name,
+            AnyClip::Audio(c) => &c.name,
+            AnyClip::Video(c) => &c.name,
+        }
+    }
+
+    /// Get the clip duration
+    pub fn duration(&self) -> f64 {
+        match self {
+            AnyClip::Vector(c) => c.duration,
+            AnyClip::Audio(c) => c.duration,
+            AnyClip::Video(c) => c.duration,
+        }
+    }
+}
+
+/// Clip instance with transform, timing, and playback properties
+///
+/// References a clip and provides instance-specific properties:
+/// - Transform (position, rotation, scale)
+/// - Timeline placement (when this instance appears on the parent layer's timeline)
+/// - Trimming (trim_start, trim_end within the clip's internal content)
+/// - Playback speed (time remapping)
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct ClipInstance {
+    /// Unique identifier for this instance
+    pub id: Uuid,
+
+    /// The clip this instance references
+    pub clip_id: Uuid,
+
+    /// Transform (position, rotation, scale, skew)
+    pub transform: Transform,
+
+    /// Opacity (0.0 to 1.0)
+    pub opacity: f64,
+
+    /// Optional name for this instance
+    pub name: Option<String>,
+
+    /// When this instance starts on the timeline (in seconds, relative to parent layer)
+    /// This is the external positioning - where the instance appears on the timeline
+    /// Default: 0.0 (start at beginning of layer)
+    pub timeline_start: f64,
+
+    /// How long this instance appears on the timeline (in seconds)
+    /// If timeline_duration > (trim_end - trim_start), the trimmed content will loop
+    /// Default: None (use trimmed clip duration, no looping)
+    pub timeline_duration: Option<f64>,
+
+    /// Trim start: offset into the clip's internal content (in seconds)
+    /// Allows trimming the beginning of the clip
+    /// - For audio: offset into the audio file
+    /// - For video: offset into the video file
+    /// - For vector: offset into the animation timeline
+    /// Default: 0.0 (start at beginning of clip)
+    pub trim_start: f64,
+
+    /// Trim end: offset into the clip's internal content (in seconds)
+    /// Allows trimming the end of the clip
+    /// Default: None (use full clip duration)
+    pub trim_end: Option<f64>,
+
+    /// Playback speed multiplier
+    /// 1.0 = normal speed, 0.5 = half speed, 2.0 = double speed
+    /// Default: 1.0
+    pub playback_speed: f64,
+
+    /// Clip-level gain/volume (for audio clips)
+    /// Compatible with daw-backend's Clip.gain
+    /// Default: 1.0
+    pub gain: f32,
+}
+
+impl ClipInstance {
+    /// Create a new clip instance
+    pub fn new(clip_id: Uuid) -> Self {
+        Self {
+            id: Uuid::new_v4(),
+            clip_id,
+            transform: Transform::default(),
+            opacity: 1.0,
+            name: None,
+            timeline_start: 0.0,
+            timeline_duration: None,
+            trim_start: 0.0,
+            trim_end: None,
+            playback_speed: 1.0,
+            gain: 1.0,
+        }
+    }
+
+    /// Create with a specific ID
+    pub fn with_id(id: Uuid, clip_id: Uuid) -> Self {
+        Self {
+            id,
+            clip_id,
+            transform: Transform::default(),
+            opacity: 1.0,
+            name: None,
+            timeline_start: 0.0,
+            timeline_duration: None,
+            trim_start: 0.0,
+            trim_end: None,
+            playback_speed: 1.0,
+            gain: 1.0,
+        }
+    }
+
+    /// Set the transform
+    pub fn with_transform(mut self, transform: Transform) -> Self {
+        self.transform = transform;
+        self
+    }
+
+    /// Set the position
+    pub fn with_position(mut self, x: f64, y: f64) -> Self {
+        self.transform.x = x;
+        self.transform.y = y;
+        self
+    }
+
+    /// Set the opacity
+    pub fn with_opacity(mut self, opacity: f64) -> Self {
+        self.opacity = opacity;
+        self
+    }
+
+    /// Set the name
+    pub fn with_name(mut self, name: impl Into<String>) -> Self {
+        self.name = Some(name.into());
+        self
+    }
+
+    /// Set timeline position
+    pub fn with_timeline_start(mut self, timeline_start: f64) -> Self {
+        self.timeline_start = timeline_start;
+        self
+    }
+
+    /// Set trimming (start and end time within the clip's internal content)
+    pub fn with_trimming(mut self, trim_start: f64, trim_end: Option<f64>) -> Self {
+        self.trim_start = trim_start;
+        self.trim_end = trim_end;
+        self
+    }
+
+    /// Set playback speed
+    pub fn with_playback_speed(mut self, speed: f64) -> Self {
+        self.playback_speed = speed;
+        self
+    }
+
+    /// Set gain/volume (for audio)
+    pub fn with_gain(mut self, gain: f32) -> Self {
+        self.gain = gain;
+        self
+    }
+
+    /// Get the effective duration of this instance (accounting for trimming and looping)
+    /// If timeline_duration is set, returns that (enabling content looping)
+    /// Otherwise returns the trimmed content duration
+    pub fn effective_duration(&self, clip_duration: f64) -> f64 {
+        // If timeline_duration is explicitly set, use that (for looping)
+        if let Some(timeline_dur) = self.timeline_duration {
+            return timeline_dur;
+        }
+
+        // Otherwise, return the trimmed content duration
+        let end = self.trim_end.unwrap_or(clip_duration);
+        (end - self.trim_start).max(0.0)
+    }
+
+    /// Remap timeline time to clip content time
+    ///
+    /// Takes a global timeline time and returns the corresponding time within this
+    /// clip's content, accounting for:
+    /// - Instance position (timeline_start)
+    /// - Playback speed
+    /// - Trimming (trim_start, trim_end)
+    /// - Looping (if timeline_duration > content window)
+    ///
+    /// Returns None if the clip instance is not active at the given timeline time.
+    pub fn remap_time(&self, timeline_time: f64, clip_duration: f64) -> Option<f64> {
+        // Check if clip instance is active at this time
+        let instance_end = self.timeline_start + self.effective_duration(clip_duration);
+        if timeline_time < self.timeline_start || timeline_time >= instance_end {
+            return None;
+        }
+
+        // Calculate relative time within the instance (0.0 = start of instance)
+        let relative_time = timeline_time - self.timeline_start;
+
+        // Account for playback speed
+        let content_time = relative_time * self.playback_speed;
+
+        // Get the content window size (the portion of clip we're sampling)
+        let trim_end = self.trim_end.unwrap_or(clip_duration);
+        let content_window = (trim_end - self.trim_start).max(0.0);
+
+        // If content_window is zero, can't sample anything
+        if content_window == 0.0 {
+            return Some(self.trim_start);
+        }
+
+        // Apply looping if content exceeds the window
+        let looped_time = if content_time > content_window {
+            content_time % content_window
+        } else {
+            content_time
+        };
+
+        // Add trim_start offset to get final clip time
+        Some(self.trim_start + looped_time)
+    }
+
+    /// Convert to affine transform
+    pub fn to_affine(&self) -> vello::kurbo::Affine {
+        self.transform.to_affine()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_vector_clip_creation() {
+        let clip = VectorClip::new("My Composition", 1920.0, 1080.0, 10.0);
+        assert_eq!(clip.name, "My Composition");
+        assert_eq!(clip.width, 1920.0);
+        assert_eq!(clip.height, 1080.0);
+        assert_eq!(clip.duration, 10.0);
+    }
+
+    #[test]
+    fn test_video_clip_creation() {
+        let clip = VideoClip::new("My Video", "/path/to/video.mp4", 1920.0, 1080.0, 30.0, 24.0);
+        assert_eq!(clip.name, "My Video");
+        assert_eq!(clip.file_path, "/path/to/video.mp4");
+        assert_eq!(clip.duration, 30.0);
+        assert_eq!(clip.frame_rate, 24.0);
+    }
+
+    #[test]
+    fn test_audio_clip_sampled() {
+        let clip = AudioClip::new_sampled("Background Music", 0, 180.0);
+        assert_eq!(clip.name, "Background Music");
+        assert_eq!(clip.duration, 180.0);
+        assert_eq!(clip.audio_pool_index(), Some(0));
+    }
+
+    #[test]
+    fn test_audio_clip_midi() {
+        let events = vec![MidiEvent::note_on(0.0, 0, 60, 100)];
+        let clip = AudioClip::new_midi("Piano Melody", 60.0, events.clone(), false);
+        assert_eq!(clip.name, "Piano Melody");
+        assert_eq!(clip.duration, 60.0);
+        assert_eq!(clip.midi_events().map(|e| e.len()), Some(1));
+    }
+
+    #[test]
+    fn test_midi_event_creation() {
+        let event = MidiEvent::note_on(1.5, 0, 60, 100);
+        assert_eq!(event.timestamp, 1.5);
+        assert_eq!(event.status, 0x90); // Note on, channel 0
+        assert_eq!(event.data1, 60); // Middle C
+        assert_eq!(event.data2, 100); // Velocity
+    }
+
+    #[test]
+    fn test_any_clip_enum() {
+        let vector_clip = VectorClip::new("Comp", 1920.0, 1080.0, 10.0);
+        let any_clip = AnyClip::Vector(vector_clip.clone());
+
+        assert_eq!(any_clip.id(), vector_clip.id);
+        assert_eq!(any_clip.name(), "Comp");
+        assert_eq!(any_clip.duration(), 10.0);
+    }
+
+    #[test]
+    fn test_clip_instance_creation() {
+        let clip_id = Uuid::new_v4();
+        let instance = ClipInstance::new(clip_id);
+
+        assert_eq!(instance.clip_id, clip_id);
+        assert_eq!(instance.opacity, 1.0);
+        assert_eq!(instance.timeline_start, 0.0);
+        assert_eq!(instance.trim_start, 0.0);
+        assert_eq!(instance.trim_end, None);
+        assert_eq!(instance.playback_speed, 1.0);
+        assert_eq!(instance.gain, 1.0);
+    }
+
+    #[test]
+    fn test_clip_instance_trimming() {
+        let clip_id = Uuid::new_v4();
+        let instance = ClipInstance::new(clip_id)
+            .with_trimming(2.0, Some(8.0));
+
+        assert_eq!(instance.trim_start, 2.0);
+        assert_eq!(instance.trim_end, Some(8.0));
+        assert_eq!(instance.effective_duration(10.0), 6.0);
+    }
+
+    #[test]
+    fn test_clip_instance_no_end_trim() {
+        let clip_id = Uuid::new_v4();
+        let instance = ClipInstance::new(clip_id)
+            .with_trimming(2.0, None);
+
+        assert_eq!(instance.trim_start, 2.0);
+        assert_eq!(instance.trim_end, None);
+        assert_eq!(instance.effective_duration(10.0), 8.0);
+    }
+
+    #[test]
+    fn test_clip_instance_builder() {
+        let clip_id = Uuid::new_v4();
+        let instance = ClipInstance::new(clip_id)
+            .with_position(100.0, 200.0)
+            .with_opacity(0.5)
+            .with_name("My Instance")
+            .with_playback_speed(2.0)
+            .with_gain(0.8);
+
+        assert_eq!(instance.transform.x, 100.0);
+        assert_eq!(instance.transform.y, 200.0);
+        assert_eq!(instance.opacity, 0.5);
+        assert_eq!(instance.name, Some("My Instance".to_string()));
+        assert_eq!(instance.playback_speed, 2.0);
+        assert_eq!(instance.gain, 0.8);
+    }
+}

lightningbeam-ui/lightningbeam-core/src/document.rs

@@ -3,9 +3,11 @@
 //! The Document represents a complete animation project with settings
 //! and a root graphics object containing the scene graph.
 
+use crate::clip::{AudioClip, VideoClip, VectorClip};
 use crate::layer::AnyLayer;
 use crate::shape::ShapeColor;
 use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
 use uuid::Uuid;
 
 /// Root graphics object containing all layers in the scene
@@ -91,6 +93,16 @@ pub struct Document {
     /// Root graphics object containing all layers
     pub root: GraphicsObject,
 
+    /// Clip libraries - reusable clip definitions
+    /// VectorClips can be instantiated multiple times with different transforms/timing
+    pub vector_clips: HashMap<Uuid, VectorClip>,
+
+    /// Video clip library - references to video files
+    pub video_clips: HashMap<Uuid, VideoClip>,
+
+    /// Audio clip library - sampled audio and MIDI clips
+    pub audio_clips: HashMap<Uuid, AudioClip>,
+
     /// Current playback time in seconds
     #[serde(skip)]
     pub current_time: f64,
@@ -107,6 +119,9 @@ impl Default for Document {
             framerate: 60.0,
             duration: 10.0,
             root: GraphicsObject::default(),
+            vector_clips: HashMap::new(),
+            video_clips: HashMap::new(),
+            audio_clips: HashMap::new(),
             current_time: 0.0,
         }
     }
@@ -159,15 +174,12 @@ impl Document {
         self.current_time = time.max(0.0).min(self.duration);
     }
 
-    /// Get visible layers at the current time from the root graphics object
+    /// Get visible layers from the root graphics object
     pub fn visible_layers(&self) -> impl Iterator<Item = &AnyLayer> {
         self.root
             .children
             .iter()
-            .filter(|layer| {
-                let layer = layer.layer();
-                layer.visible && layer.contains_time(self.current_time)
-            })
+            .filter(|layer| layer.layer().visible)
     }
 
     /// Get a layer by ID
@@ -192,6 +204,74 @@ impl Document {
     pub fn get_layer_mut(&mut self, id: &Uuid) -> Option<&mut AnyLayer> {
         self.root.get_child_mut(id)
     }
+
+    // === CLIP LIBRARY METHODS ===
+
+    /// Add a vector clip to the library
+    pub fn add_vector_clip(&mut self, clip: VectorClip) -> Uuid {
+        let id = clip.id;
+        self.vector_clips.insert(id, clip);
+        id
+    }
+
+    /// Add a video clip to the library
+    pub fn add_video_clip(&mut self, clip: VideoClip) -> Uuid {
+        let id = clip.id;
+        self.video_clips.insert(id, clip);
+        id
+    }
+
+    /// Add an audio clip to the library
+    pub fn add_audio_clip(&mut self, clip: AudioClip) -> Uuid {
+        let id = clip.id;
+        self.audio_clips.insert(id, clip);
+        id
+    }
+
+    /// Get a vector clip by ID
+    pub fn get_vector_clip(&self, id: &Uuid) -> Option<&VectorClip> {
+        self.vector_clips.get(id)
+    }
+
+    /// Get a video clip by ID
+    pub fn get_video_clip(&self, id: &Uuid) -> Option<&VideoClip> {
+        self.video_clips.get(id)
+    }
+
+    /// Get an audio clip by ID
+    pub fn get_audio_clip(&self, id: &Uuid) -> Option<&AudioClip> {
+        self.audio_clips.get(id)
+    }
+
+    /// Get a mutable vector clip by ID
+    pub fn get_vector_clip_mut(&mut self, id: &Uuid) -> Option<&mut VectorClip> {
+        self.vector_clips.get_mut(id)
+    }
+
+    /// Get a mutable video clip by ID
+    pub fn get_video_clip_mut(&mut self, id: &Uuid) -> Option<&mut VideoClip> {
+        self.video_clips.get_mut(id)
+    }
+
+    /// Get a mutable audio clip by ID
+    pub fn get_audio_clip_mut(&mut self, id: &Uuid) -> Option<&mut AudioClip> {
+        self.audio_clips.get_mut(id)
+    }
+
+    /// Remove a vector clip from the library
+    pub fn remove_vector_clip(&mut self, id: &Uuid) -> Option<VectorClip> {
+        self.vector_clips.remove(id)
+    }
+
+    /// Remove a video clip from the library
+    pub fn remove_video_clip(&mut self, id: &Uuid) -> Option<VideoClip> {
+        self.video_clips.remove(id)
+    }
+
+    /// Remove an audio clip from the library
+    pub fn remove_audio_clip(&mut self, id: &Uuid) -> Option<AudioClip> {
+        self.audio_clips.remove(id)
+    }
 }
 
 #[cfg(test)]

lightningbeam-ui/lightningbeam-core/src/hit_test.rs

@@ -3,12 +3,23 @@
 //! Provides functions for testing if points or rectangles intersect with
 //! shapes and objects, taking into account transform hierarchies.
 
+use crate::clip::{ClipInstance, VectorClip, VideoClip};
 use crate::layer::VectorLayer;
-use crate::object::Object;
+use crate::object::ShapeInstance;
 use crate::shape::Shape;
+use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 use vello::kurbo::{Affine, Point, Rect, Shape as KurboShape};
 
+/// Result of a hit test operation
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum HitResult {
+    /// Hit a shape instance
+    ShapeInstance(Uuid),
+    /// Hit a clip instance
+    ClipInstance(Uuid),
+}
+
 /// Hit test a layer at a specific point
 ///
 /// Tests objects in reverse order (front to back) and returns the first hit.
@@ -31,7 +42,7 @@ pub fn hit_test_layer(
     parent_transform: Affine,
 ) -> Option<Uuid> {
     // Test objects in reverse order (back to front in Vec = front to back for hit testing)
-    for object in layer.objects.iter().rev() {
+    for object in layer.shape_instances.iter().rev() {
         // Get the shape for this object
         let shape = layer.get_shape(&object.shape_id)?;
 
@@ -127,7 +138,7 @@ pub fn hit_test_objects_in_rect(
 ) -> Vec<Uuid> {
     let mut hits = Vec::new();
 
-    for object in &layer.objects {
+    for object in &layer.shape_instances {
         // Get the shape for this object
         if let Some(shape) = layer.get_shape(&object.shape_id) {
             // Combine parent transform with object transform
@@ -161,7 +172,7 @@ pub fn hit_test_objects_in_rect(
 ///
 /// The bounding box in screen/canvas space
 pub fn get_object_bounds(
-    object: &Object,
+    object: &ShapeInstance,
     shape: &Shape,
     parent_transform: Affine,
 ) -> Rect {
@@ -170,6 +181,154 @@ pub fn get_object_bounds(
     combined_transform.transform_rect_bbox(local_bbox)
 }
 
+/// Hit test a single clip instance with a given clip bounds
+///
+/// Tests if a point hits the clip instance's bounding box.
+///
+/// # Arguments
+///
+/// * `clip_instance` - The clip instance to test
+/// * `clip_width` - The clip's width in pixels
+/// * `clip_height` - The clip's height in pixels
+/// * `point` - The point to test in screen/canvas space
+/// * `parent_transform` - Transform from parent layer/clip
+///
+/// # Returns
+///
+/// true if the point hits the clip instance, false otherwise
+pub fn hit_test_clip_instance(
+    clip_instance: &ClipInstance,
+    clip_width: f64,
+    clip_height: f64,
+    point: Point,
+    parent_transform: Affine,
+) -> bool {
+    // Create bounding rectangle for the clip
+    let clip_rect = Rect::new(0.0, 0.0, clip_width, clip_height);
+
+    // Combine parent transform with clip instance transform
+    let combined_transform = parent_transform * clip_instance.transform.to_affine();
+
+    // Transform the bounding rectangle to screen space
+    let transformed_rect = combined_transform.transform_rect_bbox(clip_rect);
+
+    // Test if point is inside the transformed rectangle
+    transformed_rect.contains(point)
+}
+
+/// Get the bounding box of a clip instance in screen space
+///
+/// # Arguments
+///
+/// * `clip_instance` - The clip instance to get bounds for
+/// * `clip_width` - The clip's width in pixels
+/// * `clip_height` - The clip's height in pixels
+/// * `parent_transform` - Transform from parent layer/clip
+///
+/// # Returns
+///
+/// The bounding box in screen/canvas space
+pub fn get_clip_instance_bounds(
+    clip_instance: &ClipInstance,
+    clip_width: f64,
+    clip_height: f64,
+    parent_transform: Affine,
+) -> Rect {
+    let clip_rect = Rect::new(0.0, 0.0, clip_width, clip_height);
+    let combined_transform = parent_transform * clip_instance.transform.to_affine();
+    combined_transform.transform_rect_bbox(clip_rect)
+}
+
+/// Hit test clip instances at a specific point
+///
+/// Tests clip instances in reverse order (front to back) and returns the first hit.
+/// This function requires the clip libraries to look up clip dimensions.
+///
+/// # Arguments
+///
+/// * `clip_instances` - The clip instances to test
+/// * `vector_clips` - HashMap of vector clips for looking up dimensions
+/// * `video_clips` - HashMap of video clips for looking up dimensions
+/// * `point` - The point to test in screen/canvas space
+/// * `parent_transform` - Transform from parent layer/clip
+///
+/// # Returns
+///
+/// The UUID of the first clip instance hit, or None if no hit
+pub fn hit_test_clip_instances(
+    clip_instances: &[ClipInstance],
+    vector_clips: &std::collections::HashMap<Uuid, VectorClip>,
+    video_clips: &std::collections::HashMap<Uuid, VideoClip>,
+    point: Point,
+    parent_transform: Affine,
+) -> Option<Uuid> {
+    // Test in reverse order (front to back)
+    for clip_instance in clip_instances.iter().rev() {
+        // Try to get clip dimensions from either vector or video clips
+        let (width, height) = if let Some(vector_clip) = vector_clips.get(&clip_instance.clip_id) {
+            (vector_clip.width, vector_clip.height)
+        } else if let Some(video_clip) = video_clips.get(&clip_instance.clip_id) {
+            (video_clip.width, video_clip.height)
+        } else {
+            // Clip not found or is audio (no spatial representation)
+            continue;
+        };
+
+        if hit_test_clip_instance(clip_instance, width, height, point, parent_transform) {
+            return Some(clip_instance.id);
+        }
+    }
+
+    None
+}
+
+/// Hit test clip instances within a rectangle (for marquee selection)
+///
+/// Returns all clip instances whose bounding boxes intersect with the given rectangle.
+///
+/// # Arguments
+///
+/// * `clip_instances` - The clip instances to test
+/// * `vector_clips` - HashMap of vector clips for looking up dimensions
+/// * `video_clips` - HashMap of video clips for looking up dimensions
+/// * `rect` - The selection rectangle in screen/canvas space
+/// * `parent_transform` - Transform from parent layer/clip
+///
+/// # Returns
+///
+/// Vector of UUIDs for all clip instances that intersect the rectangle
+pub fn hit_test_clip_instances_in_rect(
+    clip_instances: &[ClipInstance],
+    vector_clips: &std::collections::HashMap<Uuid, VectorClip>,
+    video_clips: &std::collections::HashMap<Uuid, VideoClip>,
+    rect: Rect,
+    parent_transform: Affine,
+) -> Vec<Uuid> {
+    let mut hits = Vec::new();
+
+    for clip_instance in clip_instances {
+        // Try to get clip dimensions from either vector or video clips
+        let (width, height) = if let Some(vector_clip) = vector_clips.get(&clip_instance.clip_id) {
+            (vector_clip.width, vector_clip.height)
+        } else if let Some(video_clip) = video_clips.get(&clip_instance.clip_id) {
+            (video_clip.width, video_clip.height)
+        } else {
+            // Clip not found or is audio (no spatial representation)
+            continue;
+        };
+
+        // Get clip instance bounding box in screen space
+        let clip_bbox = get_clip_instance_bounds(clip_instance, width, height, parent_transform);
+
+        // Check if rectangles intersect
+        if rect.intersect(clip_bbox).area() > 0.0 {
+            hits.push(clip_instance.id);
+        }
+    }
+
+    hits
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

lightningbeam-ui/lightningbeam-core/src/layer.rs

@@ -3,9 +3,11 @@
 //! Layers organize objects and shapes, and contain animation data.
 
 use crate::animation::AnimationData;
-use crate::object::Object;
+use crate::clip::ClipInstance;
+use crate::object::ShapeInstance;
 use crate::shape::Shape;
 use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
 use uuid::Uuid;
 
 /// Layer type
@@ -21,6 +23,37 @@ pub enum LayerType {
     Automation,
 }
 
+/// Common trait for all layer types
+///
+/// Provides uniform access to common layer properties across VectorLayer,
+/// AudioLayer, VideoLayer, and their wrapper AnyLayer enum.
+pub trait LayerTrait {
+    // Identity
+    fn id(&self) -> Uuid;
+    fn name(&self) -> &str;
+    fn set_name(&mut self, name: String);
+    fn has_custom_name(&self) -> bool;
+    fn set_has_custom_name(&mut self, custom: bool);
+
+    // Visual properties
+    fn visible(&self) -> bool;
+    fn set_visible(&mut self, visible: bool);
+    fn opacity(&self) -> f64;
+    fn set_opacity(&mut self, opacity: f64);
+
+    // Audio properties (all layers can affect audio through nesting)
+    fn volume(&self) -> f64;
+    fn set_volume(&mut self, volume: f64);
+    fn muted(&self) -> bool;
+    fn set_muted(&mut self, muted: bool);
+
+    // Editor state
+    fn soloed(&self) -> bool;
+    fn set_soloed(&mut self, soloed: bool);
+    fn locked(&self) -> bool;
+    fn set_locked(&mut self, locked: bool);
+}
+
 /// Base layer structure
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Layer {
@@ -33,17 +66,26 @@ pub struct Layer {
     /// Layer name
     pub name: String,
 
+    /// Whether the name was set by user (vs auto-generated)
+    pub has_custom_name: bool,
+
     /// Whether the layer is visible
     pub visible: bool,
 
     /// Layer opacity (0.0 to 1.0)
     pub opacity: f64,
 
-    /// Start time in seconds
-    pub start_time: f64,
+    /// Audio volume (1.0 = 100%, affects nested audio layers/clips)
+    pub volume: f64,
 
-    /// End time in seconds
-    pub end_time: f64,
+    /// Audio mute state
+    pub muted: bool,
+
+    /// Solo state (for isolating layers)
+    pub soloed: bool,
+
+    /// Lock state (prevents editing)
+    pub locked: bool,
 
     /// Animation data for this layer
     pub animation_data: AnimationData,
@@ -56,10 +98,13 @@ impl Layer {
             id: Uuid::new_v4(),
             layer_type,
             name: name.into(),
+            has_custom_name: false,  // Auto-generated by default
             visible: true,
             opacity: 1.0,
-            start_time: 0.0,
-            end_time: 10.0, // Default 10 second duration
+            volume: 1.0,             // 100% volume
+            muted: false,
+            soloed: false,
+            locked: false,
             animation_data: AnimationData::new(),
         }
     }
@@ -70,36 +115,22 @@ impl Layer {
             id,
             layer_type,
             name: name.into(),
+            has_custom_name: false,
             visible: true,
             opacity: 1.0,
-            start_time: 0.0,
-            end_time: 10.0,
+            volume: 1.0,
+            muted: false,
+            soloed: false,
+            locked: false,
             animation_data: AnimationData::new(),
         }
     }
 
-    /// Set the time range
-    pub fn with_time_range(mut self, start: f64, end: f64) -> Self {
-        self.start_time = start;
-        self.end_time = end;
-        self
-    }
-
     /// Set visibility
     pub fn with_visibility(mut self, visible: bool) -> Self {
         self.visible = visible;
         self
     }
-
-    /// Get duration
-    pub fn duration(&self) -> f64 {
-        self.end_time - self.start_time
-    }
-
-    /// Check if a time is within this layer's range
-    pub fn contains_time(&self, time: f64) -> bool {
-        time >= self.start_time && time <= self.end_time
-    }
 }
 
 /// Vector layer containing shapes and objects
@@ -108,11 +139,85 @@ pub struct VectorLayer {
     /// Base layer properties
     pub layer: Layer,
 
-    /// Shapes defined in this layer
-    pub shapes: Vec<Shape>,
+    /// Shapes defined in this layer (indexed by UUID for O(1) lookup)
+    pub shapes: HashMap<Uuid, Shape>,
 
-    /// Object instances (references to shapes with transforms)
-    pub objects: Vec<Object>,
+    /// Shape instances (references to shapes with transforms)
+    pub shape_instances: Vec<ShapeInstance>,
+
+    /// Clip instances (references to vector clips with transforms)
+    /// VectorLayer can contain instances of VectorClips for nested compositions
+    pub clip_instances: Vec<ClipInstance>,
+}
+
+impl LayerTrait for VectorLayer {
+    fn id(&self) -> Uuid {
+        self.layer.id
+    }
+
+    fn name(&self) -> &str {
+        &self.layer.name
+    }
+
+    fn set_name(&mut self, name: String) {
+        self.layer.name = name;
+    }
+
+    fn has_custom_name(&self) -> bool {
+        self.layer.has_custom_name
+    }
+
+    fn set_has_custom_name(&mut self, custom: bool) {
+        self.layer.has_custom_name = custom;
+    }
+
+    fn visible(&self) -> bool {
+        self.layer.visible
+    }
+
+    fn set_visible(&mut self, visible: bool) {
+        self.layer.visible = visible;
+    }
+
+    fn opacity(&self) -> f64 {
+        self.layer.opacity
+    }
+
+    fn set_opacity(&mut self, opacity: f64) {
+        self.layer.opacity = opacity;
+    }
+
+    fn volume(&self) -> f64 {
+        self.layer.volume
+    }
+
+    fn set_volume(&mut self, volume: f64) {
+        self.layer.volume = volume;
+    }
+
+    fn muted(&self) -> bool {
+        self.layer.muted
+    }
+
+    fn set_muted(&mut self, muted: bool) {
+        self.layer.muted = muted;
+    }
+
+    fn soloed(&self) -> bool {
+        self.layer.soloed
+    }
+
+    fn set_soloed(&mut self, soloed: bool) {
+        self.layer.soloed = soloed;
+    }
+
+    fn locked(&self) -> bool {
+        self.layer.locked
+    }
+
+    fn set_locked(&mut self, locked: bool) {
+        self.layer.locked = locked;
+    }
 }
 
 impl VectorLayer {
@@ -120,43 +225,44 @@ impl VectorLayer {
     pub fn new(name: impl Into<String>) -> Self {
         Self {
             layer: Layer::new(LayerType::Vector, name),
-            shapes: Vec::new(),
-            objects: Vec::new(),
+            shapes: HashMap::new(),
+            shape_instances: Vec::new(),
+            clip_instances: Vec::new(),
         }
     }
 
     /// Add a shape to this layer
     pub fn add_shape(&mut self, shape: Shape) -> Uuid {
         let id = shape.id;
-        self.shapes.push(shape);
+        self.shapes.insert(id, shape);
         id
     }
 
     /// Add an object to this layer
-    pub fn add_object(&mut self, object: Object) -> Uuid {
+    pub fn add_object(&mut self, object: ShapeInstance) -> Uuid {
         let id = object.id;
-        self.objects.push(object);
+        self.shape_instances.push(object);
         id
     }
 
     /// Find a shape by ID
     pub fn get_shape(&self, id: &Uuid) -> Option<&Shape> {
-        self.shapes.iter().find(|s| &s.id == id)
+        self.shapes.get(id)
     }
 
     /// Find a mutable shape by ID
     pub fn get_shape_mut(&mut self, id: &Uuid) -> Option<&mut Shape> {
-        self.shapes.iter_mut().find(|s| &s.id == id)
+        self.shapes.get_mut(id)
     }
 
     /// Find an object by ID
-    pub fn get_object(&self, id: &Uuid) -> Option<&Object> {
-        self.objects.iter().find(|o| &o.id == id)
+    pub fn get_object(&self, id: &Uuid) -> Option<&ShapeInstance> {
+        self.shape_instances.iter().find(|o| &o.id == id)
     }
 
     /// Find a mutable object by ID
-    pub fn get_object_mut(&mut self, id: &Uuid) -> Option<&mut Object> {
-        self.objects.iter_mut().find(|o| &o.id == id)
+    pub fn get_object_mut(&mut self, id: &Uuid) -> Option<&mut ShapeInstance> {
+        self.shape_instances.iter_mut().find(|o| &o.id == id)
     }
 
     // === MUTATION METHODS (pub(crate) - only accessible to action module) ===
@@ -167,7 +273,7 @@ impl VectorLayer {
     /// only happen through the action system.
     pub(crate) fn add_shape_internal(&mut self, shape: Shape) -> Uuid {
         let id = shape.id;
-        self.shapes.push(shape);
+        self.shapes.insert(id, shape);
         id
     }
 
@@ -175,9 +281,9 @@ impl VectorLayer {
     ///
     /// This method is intentionally `pub(crate)` to ensure mutations
     /// only happen through the action system.
-    pub(crate) fn add_object_internal(&mut self, object: Object) -> Uuid {
+    pub(crate) fn add_object_internal(&mut self, object: ShapeInstance) -> Uuid {
         let id = object.id;
-        self.objects.push(object);
+        self.shape_instances.push(object);
         id
     }
 
@@ -187,11 +293,7 @@ impl VectorLayer {
     /// This method is intentionally `pub(crate)` to ensure mutations
     /// only happen through the action system.
     pub(crate) fn remove_shape_internal(&mut self, id: &Uuid) -> Option<Shape> {
-        if let Some(index) = self.shapes.iter().position(|s| &s.id == id) {
-            Some(self.shapes.remove(index))
-        } else {
-            None
-        }
+        self.shapes.remove(id)
     }
 
     /// Remove an object from this layer (internal, for actions only)
@@ -199,9 +301,9 @@ impl VectorLayer {
     /// Returns the removed object if found.
     /// This method is intentionally `pub(crate)` to ensure mutations
     /// only happen through the action system.
-    pub(crate) fn remove_object_internal(&mut self, id: &Uuid) -> Option<Object> {
-        if let Some(index) = self.objects.iter().position(|o| &o.id == id) {
-            Some(self.objects.remove(index))
+    pub(crate) fn remove_object_internal(&mut self, id: &Uuid) -> Option<ShapeInstance> {
+        if let Some(index) = self.shape_instances.iter().position(|o| &o.id == id) {
+            Some(self.shape_instances.remove(index))
         } else {
             None
         }
@@ -214,7 +316,7 @@ impl VectorLayer {
     /// only happen through the action system.
     pub fn modify_object_internal<F>(&mut self, id: &Uuid, f: F)
     where
-        F: FnOnce(&mut Object),
+        F: FnOnce(&mut ShapeInstance),
     {
         if let Some(object) = self.get_object_mut(id) {
             f(object);
@@ -222,14 +324,85 @@ impl VectorLayer {
     }
 }
 
-/// Audio layer (placeholder for future implementation)
+/// Audio layer containing audio clips
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct AudioLayer {
     /// Base layer properties
     pub layer: Layer,
 
-    /// Audio file path or data reference
-    pub audio_source: Option<String>,
+    /// Clip instances (references to audio clips)
+    /// AudioLayer can contain instances of AudioClips (sampled or MIDI)
+    pub clip_instances: Vec<ClipInstance>,
+}
+
+impl LayerTrait for AudioLayer {
+    fn id(&self) -> Uuid {
+        self.layer.id
+    }
+
+    fn name(&self) -> &str {
+        &self.layer.name
+    }
+
+    fn set_name(&mut self, name: String) {
+        self.layer.name = name;
+    }
+
+    fn has_custom_name(&self) -> bool {
+        self.layer.has_custom_name
+    }
+
+    fn set_has_custom_name(&mut self, custom: bool) {
+        self.layer.has_custom_name = custom;
+    }
+
+    fn visible(&self) -> bool {
+        self.layer.visible
+    }
+
+    fn set_visible(&mut self, visible: bool) {
+        self.layer.visible = visible;
+    }
+
+    fn opacity(&self) -> f64 {
+        self.layer.opacity
+    }
+
+    fn set_opacity(&mut self, opacity: f64) {
+        self.layer.opacity = opacity;
+    }
+
+    fn volume(&self) -> f64 {
+        self.layer.volume
+    }
+
+    fn set_volume(&mut self, volume: f64) {
+        self.layer.volume = volume;
+    }
+
+    fn muted(&self) -> bool {
+        self.layer.muted
+    }
+
+    fn set_muted(&mut self, muted: bool) {
+        self.layer.muted = muted;
+    }
+
+    fn soloed(&self) -> bool {
+        self.layer.soloed
+    }
+
+    fn set_soloed(&mut self, soloed: bool) {
+        self.layer.soloed = soloed;
+    }
+
+    fn locked(&self) -> bool {
+        self.layer.locked
+    }
+
+    fn set_locked(&mut self, locked: bool) {
+        self.layer.locked = locked;
+    }
 }
 
 impl AudioLayer {
@@ -237,19 +410,90 @@ impl AudioLayer {
     pub fn new(name: impl Into<String>) -> Self {
         Self {
             layer: Layer::new(LayerType::Audio, name),
-            audio_source: None,
+            clip_instances: Vec::new(),
         }
     }
 }
 
-/// Video layer (placeholder for future implementation)
+/// Video layer containing video clips
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct VideoLayer {
     /// Base layer properties
     pub layer: Layer,
 
-    /// Video file path or data reference
-    pub video_source: Option<String>,
+    /// Clip instances (references to video clips)
+    /// VideoLayer can contain instances of VideoClips
+    pub clip_instances: Vec<ClipInstance>,
+}
+
+impl LayerTrait for VideoLayer {
+    fn id(&self) -> Uuid {
+        self.layer.id
+    }
+
+    fn name(&self) -> &str {
+        &self.layer.name
+    }
+
+    fn set_name(&mut self, name: String) {
+        self.layer.name = name;
+    }
+
+    fn has_custom_name(&self) -> bool {
+        self.layer.has_custom_name
+    }
+
+    fn set_has_custom_name(&mut self, custom: bool) {
+        self.layer.has_custom_name = custom;
+    }
+
+    fn visible(&self) -> bool {
+        self.layer.visible
+    }
+
+    fn set_visible(&mut self, visible: bool) {
+        self.layer.visible = visible;
+    }
+
+    fn opacity(&self) -> f64 {
+        self.layer.opacity
+    }
+
+    fn set_opacity(&mut self, opacity: f64) {
+        self.layer.opacity = opacity;
+    }
+
+    fn volume(&self) -> f64 {
+        self.layer.volume
+    }
+
+    fn set_volume(&mut self, volume: f64) {
+        self.layer.volume = volume;
+    }
+
+    fn muted(&self) -> bool {
+        self.layer.muted
+    }
+
+    fn set_muted(&mut self, muted: bool) {
+        self.layer.muted = muted;
+    }
+
+    fn soloed(&self) -> bool {
+        self.layer.soloed
+    }
+
+    fn set_soloed(&mut self, soloed: bool) {
+        self.layer.soloed = soloed;
+    }
+
+    fn locked(&self) -> bool {
+        self.layer.locked
+    }
+
+    fn set_locked(&mut self, locked: bool) {
+        self.layer.locked = locked;
+    }
 }
 
 impl VideoLayer {
@@ -257,7 +501,7 @@ impl VideoLayer {
     pub fn new(name: impl Into<String>) -> Self {
         Self {
             layer: Layer::new(LayerType::Video, name),
-            video_source: None,
+            clip_instances: Vec::new(),
         }
     }
 }
@@ -270,6 +514,144 @@ pub enum AnyLayer {
     Video(VideoLayer),
 }
 
+impl LayerTrait for AnyLayer {
+    fn id(&self) -> Uuid {
+        match self {
+            AnyLayer::Vector(l) => l.id(),
+            AnyLayer::Audio(l) => l.id(),
+            AnyLayer::Video(l) => l.id(),
+        }
+    }
+
+    fn name(&self) -> &str {
+        match self {
+            AnyLayer::Vector(l) => l.name(),
+            AnyLayer::Audio(l) => l.name(),
+            AnyLayer::Video(l) => l.name(),
+        }
+    }
+
+    fn set_name(&mut self, name: String) {
+        match self {
+            AnyLayer::Vector(l) => l.set_name(name),
+            AnyLayer::Audio(l) => l.set_name(name),
+            AnyLayer::Video(l) => l.set_name(name),
+        }
+    }
+
+    fn has_custom_name(&self) -> bool {
+        match self {
+            AnyLayer::Vector(l) => l.has_custom_name(),
+            AnyLayer::Audio(l) => l.has_custom_name(),
+            AnyLayer::Video(l) => l.has_custom_name(),
+        }
+    }
+
+    fn set_has_custom_name(&mut self, custom: bool) {
+        match self {
+            AnyLayer::Vector(l) => l.set_has_custom_name(custom),
+            AnyLayer::Audio(l) => l.set_has_custom_name(custom),
+            AnyLayer::Video(l) => l.set_has_custom_name(custom),
+        }
+    }
+
+    fn visible(&self) -> bool {
+        match self {
+            AnyLayer::Vector(l) => l.visible(),
+            AnyLayer::Audio(l) => l.visible(),
+            AnyLayer::Video(l) => l.visible(),
+        }
+    }
+
+    fn set_visible(&mut self, visible: bool) {
+        match self {
+            AnyLayer::Vector(l) => l.set_visible(visible),
+            AnyLayer::Audio(l) => l.set_visible(visible),
+            AnyLayer::Video(l) => l.set_visible(visible),
+        }
+    }
+
+    fn opacity(&self) -> f64 {
+        match self {
+            AnyLayer::Vector(l) => l.opacity(),
+            AnyLayer::Audio(l) => l.opacity(),
+            AnyLayer::Video(l) => l.opacity(),
+        }
+    }
+
+    fn set_opacity(&mut self, opacity: f64) {
+        match self {
+            AnyLayer::Vector(l) => l.set_opacity(opacity),
+            AnyLayer::Audio(l) => l.set_opacity(opacity),
+            AnyLayer::Video(l) => l.set_opacity(opacity),
+        }
+    }
+
+    fn volume(&self) -> f64 {
+        match self {
+            AnyLayer::Vector(l) => l.volume(),
+            AnyLayer::Audio(l) => l.volume(),
+            AnyLayer::Video(l) => l.volume(),
+        }
+    }
+
+    fn set_volume(&mut self, volume: f64) {
+        match self {
+            AnyLayer::Vector(l) => l.set_volume(volume),
+            AnyLayer::Audio(l) => l.set_volume(volume),
+            AnyLayer::Video(l) => l.set_volume(volume),
+        }
+    }
+
+    fn muted(&self) -> bool {
+        match self {
+            AnyLayer::Vector(l) => l.muted(),
+            AnyLayer::Audio(l) => l.muted(),
+            AnyLayer::Video(l) => l.muted(),
+        }
+    }
+
+    fn set_muted(&mut self, muted: bool) {
+        match self {
+            AnyLayer::Vector(l) => l.set_muted(muted),
+            AnyLayer::Audio(l) => l.set_muted(muted),
+            AnyLayer::Video(l) => l.set_muted(muted),
+        }
+    }
+
+    fn soloed(&self) -> bool {
+        match self {
+            AnyLayer::Vector(l) => l.soloed(),
+            AnyLayer::Audio(l) => l.soloed(),
+            AnyLayer::Video(l) => l.soloed(),
+        }
+    }
+
+    fn set_soloed(&mut self, soloed: bool) {
+        match self {
+            AnyLayer::Vector(l) => l.set_soloed(soloed),
+            AnyLayer::Audio(l) => l.set_soloed(soloed),
+            AnyLayer::Video(l) => l.set_soloed(soloed),
+        }
+    }
+
+    fn locked(&self) -> bool {
+        match self {
+            AnyLayer::Vector(l) => l.locked(),
+            AnyLayer::Audio(l) => l.locked(),
+            AnyLayer::Video(l) => l.locked(),
+        }
+    }
+
+    fn set_locked(&mut self, locked: bool) {
+        match self {
+            AnyLayer::Vector(l) => l.set_locked(locked),
+            AnyLayer::Audio(l) => l.set_locked(locked),
+            AnyLayer::Video(l) => l.set_locked(locked),
+        }
+    }
+}
+
 impl AnyLayer {
     /// Get a reference to the base layer
     pub fn layer(&self) -> &Layer {
@@ -316,7 +698,7 @@ mod tests {
     fn test_vector_layer() {
         let vector_layer = VectorLayer::new("My Layer");
         assert_eq!(vector_layer.shapes.len(), 0);
-        assert_eq!(vector_layer.objects.len(), 0);
+        assert_eq!(vector_layer.shape_instances.len(), 0);
     }
 
     #[test]

lightningbeam-ui/lightningbeam-core/src/layer_tree.rs

@@ -0,0 +1,187 @@
+//! Hierarchical layer tree
+//!
+//! Provides a tree structure for organizing layers in a hierarchical manner.
+//! Layers can be nested within other layers for organizational purposes.
+
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+/// Node in the layer tree
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct LayerNode<T> {
+    /// The layer data
+    pub data: T,
+
+    /// Child layers
+    pub children: Vec<LayerNode<T>>,
+}
+
+impl<T> LayerNode<T> {
+    /// Create a new layer node
+    pub fn new(data: T) -> Self {
+        Self {
+            data,
+            children: Vec::new(),
+        }
+    }
+
+    /// Add a child layer
+    pub fn add_child(&mut self, child: LayerNode<T>) {
+        self.children.push(child);
+    }
+
+    /// Remove a child layer by index
+    pub fn remove_child(&mut self, index: usize) -> Option<LayerNode<T>> {
+        if index < self.children.len() {
+            Some(self.children.remove(index))
+        } else {
+            None
+        }
+    }
+
+    /// Get a reference to a child
+    pub fn get_child(&self, index: usize) -> Option<&LayerNode<T>> {
+        self.children.get(index)
+    }
+
+    /// Get a mutable reference to a child
+    pub fn get_child_mut(&mut self, index: usize) -> Option<&mut LayerNode<T>> {
+        self.children.get_mut(index)
+    }
+
+    /// Get number of children
+    pub fn child_count(&self) -> usize {
+        self.children.len()
+    }
+}
+
+/// Layer tree root
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct LayerTree<T> {
+    /// Root layers (no parent)
+    pub roots: Vec<LayerNode<T>>,
+}
+
+impl<T> LayerTree<T> {
+    /// Create a new empty layer tree
+    pub fn new() -> Self {
+        Self { roots: Vec::new() }
+    }
+
+    /// Add a root layer and return its index
+    pub fn add_root(&mut self, data: T) -> usize {
+        let node = LayerNode::new(data);
+        let index = self.roots.len();
+        self.roots.push(node);
+        index
+    }
+
+    /// Remove a root layer by index
+    pub fn remove_root(&mut self, index: usize) -> Option<LayerNode<T>> {
+        if index < self.roots.len() {
+            Some(self.roots.remove(index))
+        } else {
+            None
+        }
+    }
+
+    /// Get a reference to a root layer
+    pub fn get_root(&self, index: usize) -> Option<&LayerNode<T>> {
+        self.roots.get(index)
+    }
+
+    /// Get a mutable reference to a root layer
+    pub fn get_root_mut(&mut self, index: usize) -> Option<&mut LayerNode<T>> {
+        self.roots.get_mut(index)
+    }
+
+    /// Get number of root layers
+    pub fn root_count(&self) -> usize {
+        self.roots.len()
+    }
+
+    /// Iterate over all root layers
+    pub fn iter(&self) -> impl Iterator<Item = &LayerNode<T>> {
+        self.roots.iter()
+    }
+
+    /// Iterate over all root layers mutably
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut LayerNode<T>> {
+        self.roots.iter_mut()
+    }
+}
+
+impl<T> Default for LayerTree<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_layer_tree_creation() {
+        let tree: LayerTree<i32> = LayerTree::new();
+        assert_eq!(tree.root_count(), 0);
+    }
+
+    #[test]
+    fn test_add_root_layers() {
+        let mut tree = LayerTree::new();
+        tree.add_root(1);
+        tree.add_root(2);
+        tree.add_root(3);
+
+        assert_eq!(tree.root_count(), 3);
+        assert_eq!(tree.get_root(0).unwrap().data, 1);
+        assert_eq!(tree.get_root(1).unwrap().data, 2);
+        assert_eq!(tree.get_root(2).unwrap().data, 3);
+    }
+
+    #[test]
+    fn test_nested_layers() {
+        let mut tree = LayerTree::new();
+        let root_idx = tree.add_root("Root");
+
+        let root = tree.get_root_mut(root_idx).unwrap();
+        root.add_child(LayerNode::new("Child 1"));
+        root.add_child(LayerNode::new("Child 2"));
+
+        assert_eq!(root.child_count(), 2);
+        assert_eq!(root.get_child(0).unwrap().data, "Child 1");
+        assert_eq!(root.get_child(1).unwrap().data, "Child 2");
+    }
+
+    #[test]
+    fn test_remove_root() {
+        let mut tree = LayerTree::new();
+        tree.add_root(1);
+        tree.add_root(2);
+        tree.add_root(3);
+
+        let removed = tree.remove_root(1);
+        assert_eq!(removed.unwrap().data, 2);
+        assert_eq!(tree.root_count(), 2);
+        assert_eq!(tree.get_root(0).unwrap().data, 1);
+        assert_eq!(tree.get_root(1).unwrap().data, 3);
+    }
+
+    #[test]
+    fn test_remove_child() {
+        let mut tree = LayerTree::new();
+        let root_idx = tree.add_root("Root");
+
+        let root = tree.get_root_mut(root_idx).unwrap();
+        root.add_child(LayerNode::new("Child 1"));
+        root.add_child(LayerNode::new("Child 2"));
+        root.add_child(LayerNode::new("Child 3"));
+
+        let removed = root.remove_child(1);
+        assert_eq!(removed.unwrap().data, "Child 2");
+        assert_eq!(root.child_count(), 2);
+        assert_eq!(root.get_child(0).unwrap().data, "Child 1");
+        assert_eq!(root.get_child(1).unwrap().data, "Child 3");
+    }
+}

lightningbeam-ui/lightningbeam-core/src/lib.rs

@@ -10,6 +10,8 @@ pub mod path_fitting;
 pub mod shape;
 pub mod object;
 pub mod layer;
+pub mod layer_tree;
+pub mod clip;
 pub mod document;
 pub mod renderer;
 pub mod action;

lightningbeam-ui/lightningbeam-core/src/object.rs

@@ -8,6 +8,7 @@ use uuid::Uuid;
 use vello::kurbo::Shape as KurboShape;
 
 /// 2D transform for an object
+/// Contains only geometric transformations (position, rotation, scale, skew)
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Transform {
     /// X position
@@ -24,8 +25,6 @@ pub struct Transform {
     pub skew_x: f64,
     /// Y skew in degrees
     pub skew_y: f64,
-    /// Opacity (0.0 to 1.0)
-    pub opacity: f64,
 }
 
 impl Default for Transform {
@@ -38,7 +37,6 @@ impl Default for Transform {
             scale_y: 1.0,
             skew_x: 0.0,
             skew_y: 0.0,
-            opacity: 1.0,
         }
     }
 }
@@ -119,39 +117,46 @@ impl Transform {
     }
 }
 
-/// An object instance (shape with transform)
+/// A shape instance (shape with transform)
+/// Represents an instance of a Shape with its own transform properties.
+/// Multiple instances can reference the same shape.
 #[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Object {
+pub struct ShapeInstance {
     /// Unique identifier
     pub id: Uuid,
 
     /// Reference to the shape this object uses
     pub shape_id: Uuid,
 
-    /// Transform properties
+    /// Transform properties (position, rotation, scale, skew)
     pub transform: Transform,
 
+    /// Opacity (0.0 to 1.0, separate from geometric transform)
+    pub opacity: f64,
+
     /// Name for display in UI
     pub name: Option<String>,
 }
 
-impl Object {
-    /// Create a new object for a shape
+impl ShapeInstance {
+    /// Create a new shape instance for a shape
     pub fn new(shape_id: Uuid) -> Self {
         Self {
             id: Uuid::new_v4(),
             shape_id,
             transform: Transform::default(),
+            opacity: 1.0,
             name: None,
         }
     }
 
-    /// Create a new object with a specific ID
+    /// Create a new shape instance with a specific ID
     pub fn with_id(id: Uuid, shape_id: Uuid) -> Self {
         Self {
             id,
             shape_id,
             transform: Transform::default(),
+            opacity: 1.0,
             name: None,
         }
     }
@@ -174,15 +179,15 @@ impl Object {
         self
     }
 
-    /// Convert object transform to affine matrix
+    /// Convert shape instance transform to affine matrix
     pub fn to_affine(&self) -> kurbo::Affine {
         self.transform.to_affine()
     }
 
-    /// Get the bounding box of this object given its shape
+    /// Get the bounding box of this shape instance given its shape
     ///
-    /// Returns the bounding box in the object's parent coordinate space
-    /// (i.e., with the object's transform applied).
+    /// Returns the bounding box in the instance's parent coordinate space
+    /// (i.e., with the instance's transform applied).
     pub fn bounding_box(&self, shape: &crate::shape::Shape) -> kurbo::Rect {
         let path_bbox = shape.path().bounding_box();
         self.to_affine().transform_rect_bbox(path_bbox)
@@ -214,11 +219,11 @@ mod tests {
     }
 
     #[test]
-    fn test_object_creation() {
+    fn test_shape_instance_creation() {
         let shape_id = Uuid::new_v4();
-        let object = Object::new(shape_id);
+        let shape_instance = ShapeInstance::new(shape_id);
 
-        assert_eq!(object.shape_id, shape_id);
-        assert_eq!(object.transform.x, 0.0);
+        assert_eq!(shape_instance.shape_id, shape_id);
+        assert_eq!(shape_instance.transform.x, 0.0);
     }
 }

lightningbeam-ui/lightningbeam-core/src/renderer.rs

@@ -5,6 +5,7 @@
 use crate::animation::TransformProperty;
 use crate::document::Document;
 use crate::layer::{AnyLayer, VectorLayer};
+use crate::object::ShapeInstance;
 use kurbo::{Affine, Shape};
 use vello::kurbo::Rect;
 use vello::peniko::Fill;
@@ -21,8 +22,9 @@ pub fn render_document_with_transform(document: &Document, scene: &mut Scene, ba
     // 1. Draw background
     render_background(document, scene, base_transform);
 
-    // 2. Recursively render the root graphics object
-    render_graphics_object(document, scene, base_transform);
+    // 2. Recursively render the root graphics object at current time
+    let time = document.current_time;
+    render_graphics_object(document, time, scene, base_transform);
 }
 
 /// Draw the document background
@@ -42,17 +44,17 @@ fn render_background(document: &Document, scene: &mut Scene, base_transform: Aff
 }
 
 /// Recursively render the root graphics object and its children
-fn render_graphics_object(document: &Document, scene: &mut Scene, base_transform: Affine) {
+fn render_graphics_object(document: &Document, time: f64, scene: &mut Scene, base_transform: Affine) {
     // Render all visible layers in the root graphics object
     for layer in document.visible_layers() {
-        render_layer(document, layer, scene, base_transform);
+        render_layer(document, time, layer, scene, base_transform);
     }
 }
 
 /// Render a single layer
-fn render_layer(document: &Document, layer: &AnyLayer, scene: &mut Scene, base_transform: Affine) {
+fn render_layer(document: &Document, time: f64, layer: &AnyLayer, scene: &mut Scene, base_transform: Affine) {
     match layer {
-        AnyLayer::Vector(vector_layer) => render_vector_layer(document, vector_layer, scene, base_transform),
+        AnyLayer::Vector(vector_layer) => render_vector_layer(document, time, vector_layer, scene, base_transform),
         AnyLayer::Audio(_) => {
             // Audio layers don't render visually
         }
@@ -62,28 +64,65 @@ fn render_layer(document: &Document, layer: &AnyLayer, scene: &mut Scene, base_t
     }
 }
 
-/// Render a vector layer with all its objects
-fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Scene, base_transform: Affine) {
-    let time = document.current_time;
+/// Render a clip instance (recursive rendering for nested compositions)
+fn render_clip_instance(
+    document: &Document,
+    time: f64,
+    clip_instance: &crate::clip::ClipInstance,
+    _parent_opacity: f64,
+    scene: &mut Scene,
+    base_transform: Affine,
+) {
+    // Try to find the clip in the document's clip libraries
+    // For now, only handle VectorClips (VideoClip and AudioClip rendering not yet implemented)
+    let Some(vector_clip) = document.vector_clips.get(&clip_instance.clip_id) else {
+        return; // Clip not found or not a vector clip
+    };
+
+    // Remap timeline time to clip's internal time
+    let Some(clip_time) = clip_instance.remap_time(time, vector_clip.duration) else {
+        return; // Clip instance not active at this time
+    };
+
+    // Build transform for this clip instance
+    let instance_transform = base_transform * clip_instance.to_affine();
+
+    // TODO: Properly handle clip instance opacity by threading opacity through rendering pipeline
+    // Currently clip_instance.opacity is not being applied to nested layers
+
+    // Recursively render all root layers in the clip at the remapped time
+    for layer_node in vector_clip.layers.iter() {
+        // TODO: Filter by visibility and time range once LayerNode exposes that data
+        render_layer(document, clip_time, &layer_node.data, scene, instance_transform);
+    }
+}
+
+/// Render a vector layer with all its clip instances and shape instances
+fn render_vector_layer(document: &Document, time: f64, layer: &VectorLayer, scene: &mut Scene, base_transform: Affine) {
 
     // Get layer-level opacity
     let layer_opacity = layer.layer.opacity;
 
-    // Render each object in the layer
-    for object in &layer.objects {
-        // Get the shape for this object
-        let Some(shape) = layer.get_shape(&object.shape_id) else {
+    // Render clip instances first (they appear under shape instances)
+    for clip_instance in &layer.clip_instances {
+        render_clip_instance(document, time, clip_instance, layer_opacity, scene, base_transform);
+    }
+
+    // Render each shape instance in the layer
+    for shape_instance in &layer.shape_instances {
+        // Get the shape for this instance
+        let Some(shape) = layer.get_shape(&shape_instance.shape_id) else {
             continue;
         };
 
         // Evaluate animated properties
-        let transform = &object.transform;
+        let transform = &shape_instance.transform;
         let x = layer
             .layer
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::X,
                 },
                 time,
@@ -94,7 +133,7 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::Y,
                 },
                 time,
@@ -105,7 +144,7 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::Rotation,
                 },
                 time,
@@ -116,7 +155,7 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::ScaleX,
                 },
                 time,
@@ -127,7 +166,7 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::ScaleY,
                 },
                 time,
@@ -138,7 +177,7 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::SkewX,
                 },
                 time,
@@ -149,7 +188,7 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::SkewY,
                 },
                 time,
@@ -160,11 +199,11 @@ fn render_vector_layer(document: &Document, layer: &VectorLayer, scene: &mut Sce
             .animation_data
             .eval(
                 &crate::animation::AnimationTarget::Object {
-                    id: object.id,
+                    id: shape_instance.id,
                     property: TransformProperty::Opacity,
                 },
                 time,
-                transform.opacity,
+                shape_instance.opacity,
             );
 
         // Check if shape has morphing animation
@@ -276,7 +315,7 @@ mod tests {
     use super::*;
     use crate::document::Document;
     use crate::layer::{AnyLayer, VectorLayer};
-    use crate::object::Object;
+    use crate::object::ShapeInstance;
     use crate::shape::{Shape, ShapeColor};
     use kurbo::{Circle, Shape as KurboShape};
 
@@ -298,13 +337,13 @@ mod tests {
         let path = circle.to_path(0.1);
         let shape = Shape::new(path).with_fill(ShapeColor::rgb(255, 0, 0));
 
-        // Create an object for the shape
-        let object = Object::new(shape.id);
+        // Create a shape instance for the shape
+        let shape_instance = ShapeInstance::new(shape.id);
 
         // Create a vector layer
         let mut vector_layer = VectorLayer::new("Layer 1");
         vector_layer.add_shape(shape);
-        vector_layer.add_object(object);
+        vector_layer.add_object(shape_instance);
 
         // Add to document
         doc.root.add_child(AnyLayer::Vector(vector_layer));

lightningbeam-ui/lightningbeam-core/src/selection.rs

@@ -1,63 +1,67 @@
 //! Selection state management
 //!
-//! Tracks selected objects and shapes for editing operations.
+//! Tracks selected shape instances, clip instances, and shapes for editing operations.
 
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
 /// Selection state for the editor
 ///
-/// Maintains sets of selected objects and shapes.
+/// Maintains sets of selected shape instances, clip instances, and shapes.
 /// This is separate from the document to make it easy to
 /// pass around for UI rendering without needing mutable access.
 #[derive(Clone, Debug, Default, Serialize, Deserialize)]
 pub struct Selection {
-    /// Currently selected objects (instances)
-    selected_objects: Vec<Uuid>,
+    /// Currently selected shape instances
+    selected_shape_instances: Vec<Uuid>,
 
     /// Currently selected shapes (definitions)
     selected_shapes: Vec<Uuid>,
+
+    /// Currently selected clip instances
+    selected_clip_instances: Vec<Uuid>,
 }
 
 impl Selection {
     /// Create a new empty selection
     pub fn new() -> Self {
         Self {
-            selected_objects: Vec::new(),
+            selected_shape_instances: Vec::new(),
             selected_shapes: Vec::new(),
+            selected_clip_instances: Vec::new(),
         }
     }
 
-    /// Add an object to the selection
-    pub fn add_object(&mut self, id: Uuid) {
-        if !self.selected_objects.contains(&id) {
-            self.selected_objects.push(id);
+    /// Add a shape instance to the selection
+    pub fn add_shape_instance(&mut self, id: Uuid) {
+        if !self.selected_shape_instances.contains(&id) {
+            self.selected_shape_instances.push(id);
         }
     }
 
-    /// Add a shape to the selection
+    /// Add a shape definition to the selection
     pub fn add_shape(&mut self, id: Uuid) {
         if !self.selected_shapes.contains(&id) {
             self.selected_shapes.push(id);
         }
     }
 
-    /// Remove an object from the selection
-    pub fn remove_object(&mut self, id: &Uuid) {
-        self.selected_objects.retain(|&x| x != *id);
+    /// Remove a shape instance from the selection
+    pub fn remove_shape_instance(&mut self, id: &Uuid) {
+        self.selected_shape_instances.retain(|&x| x != *id);
     }
 
-    /// Remove a shape from the selection
+    /// Remove a shape definition from the selection
     pub fn remove_shape(&mut self, id: &Uuid) {
         self.selected_shapes.retain(|&x| x != *id);
     }
 
-    /// Toggle an object's selection state
-    pub fn toggle_object(&mut self, id: Uuid) {
-        if self.contains_object(&id) {
-            self.remove_object(&id);
+    /// Toggle a shape instance's selection state
+    pub fn toggle_shape_instance(&mut self, id: Uuid) {
+        if self.contains_shape_instance(&id) {
+            self.remove_shape_instance(&id);
         } else {
-            self.add_object(id);
+            self.add_shape_instance(id);
         }
     }
 
@@ -70,15 +74,37 @@ impl Selection {
         }
     }
 
+    /// Add a clip instance to the selection
+    pub fn add_clip_instance(&mut self, id: Uuid) {
+        if !self.selected_clip_instances.contains(&id) {
+            self.selected_clip_instances.push(id);
+        }
+    }
+
+    /// Remove a clip instance from the selection
+    pub fn remove_clip_instance(&mut self, id: &Uuid) {
+        self.selected_clip_instances.retain(|&x| x != *id);
+    }
+
+    /// Toggle a clip instance's selection state
+    pub fn toggle_clip_instance(&mut self, id: Uuid) {
+        if self.contains_clip_instance(&id) {
+            self.remove_clip_instance(&id);
+        } else {
+            self.add_clip_instance(id);
+        }
+    }
+
     /// Clear all selections
     pub fn clear(&mut self) {
-        self.selected_objects.clear();
+        self.selected_shape_instances.clear();
         self.selected_shapes.clear();
+        self.selected_clip_instances.clear();
     }
 
     /// Clear only object selections
-    pub fn clear_objects(&mut self) {
-        self.selected_objects.clear();
+    pub fn clear_shape_instances(&mut self) {
+        self.selected_shape_instances.clear();
     }
 
     /// Clear only shape selections
@@ -86,9 +112,14 @@ impl Selection {
         self.selected_shapes.clear();
     }
 
+    /// Clear only clip instance selections
+    pub fn clear_clip_instances(&mut self) {
+        self.selected_clip_instances.clear();
+    }
+
     /// Check if an object is selected
-    pub fn contains_object(&self, id: &Uuid) -> bool {
-        self.selected_objects.contains(id)
+    pub fn contains_shape_instance(&self, id: &Uuid) -> bool {
+        self.selected_shape_instances.contains(id)
     }
 
     /// Check if a shape is selected
@@ -96,14 +127,21 @@ impl Selection {
         self.selected_shapes.contains(id)
     }
 
+    /// Check if a clip instance is selected
+    pub fn contains_clip_instance(&self, id: &Uuid) -> bool {
+        self.selected_clip_instances.contains(id)
+    }
+
     /// Check if selection is empty
     pub fn is_empty(&self) -> bool {
-        self.selected_objects.is_empty() && self.selected_shapes.is_empty()
+        self.selected_shape_instances.is_empty()
+            && self.selected_shapes.is_empty()
+            && self.selected_clip_instances.is_empty()
     }
 
     /// Get the selected objects
-    pub fn objects(&self) -> &[Uuid] {
-        &self.selected_objects
+    pub fn shape_instances(&self) -> &[Uuid] {
+        &self.selected_shape_instances
     }
 
     /// Get the selected shapes
@@ -112,8 +150,8 @@ impl Selection {
     }
 
     /// Get the number of selected objects
-    pub fn object_count(&self) -> usize {
-        self.selected_objects.len()
+    pub fn shape_instance_count(&self) -> usize {
+        self.selected_shape_instances.len()
     }
 
     /// Get the number of selected shapes
@@ -121,10 +159,20 @@ impl Selection {
         self.selected_shapes.len()
     }
 
+    /// Get the selected clip instances
+    pub fn clip_instances(&self) -> &[Uuid] {
+        &self.selected_clip_instances
+    }
+
+    /// Get the number of selected clip instances
+    pub fn clip_instance_count(&self) -> usize {
+        self.selected_clip_instances.len()
+    }
+
     /// Set selection to a single object (clears previous selection)
-    pub fn select_only_object(&mut self, id: Uuid) {
+    pub fn select_only_shape_instance(&mut self, id: Uuid) {
         self.clear();
-        self.add_object(id);
+        self.add_shape_instance(id);
     }
 
     /// Set selection to a single shape (clears previous selection)
@@ -133,11 +181,17 @@ impl Selection {
         self.add_shape(id);
     }
 
+    /// Set selection to a single clip instance (clears previous selection)
+    pub fn select_only_clip_instance(&mut self, id: Uuid) {
+        self.clear();
+        self.add_clip_instance(id);
+    }
+
     /// Set selection to multiple objects (clears previous selection)
-    pub fn select_objects(&mut self, ids: &[Uuid]) {
-        self.clear_objects();
+    pub fn select_shape_instances(&mut self, ids: &[Uuid]) {
+        self.clear_shape_instances();
         for &id in ids {
-            self.add_object(id);
+            self.add_shape_instance(id);
         }
     }
 
@@ -148,6 +202,14 @@ impl Selection {
             self.add_shape(id);
         }
     }
+
+    /// Set selection to multiple clip instances (clears previous selection)
+    pub fn select_clip_instances(&mut self, ids: &[Uuid]) {
+        self.clear_clip_instances();
+        for &id in ids {
+            self.add_clip_instance(id);
+        }
+    }
 }
 
 #[cfg(test)]
@@ -158,7 +220,7 @@ mod tests {
     fn test_selection_creation() {
         let selection = Selection::new();
         assert!(selection.is_empty());
-        assert_eq!(selection.object_count(), 0);
+        assert_eq!(selection.shape_instance_count(), 0);
         assert_eq!(selection.shape_count(), 0);
     }
 
@@ -168,17 +230,17 @@ mod tests {
         let id1 = Uuid::new_v4();
         let id2 = Uuid::new_v4();
 
-        selection.add_object(id1);
-        assert_eq!(selection.object_count(), 1);
-        assert!(selection.contains_object(&id1));
+        selection.add_shape_instance(id1);
+        assert_eq!(selection.shape_instance_count(), 1);
+        assert!(selection.contains_shape_instance(&id1));
 
-        selection.add_object(id2);
-        assert_eq!(selection.object_count(), 2);
+        selection.add_shape_instance(id2);
+        assert_eq!(selection.shape_instance_count(), 2);
 
-        selection.remove_object(&id1);
-        assert_eq!(selection.object_count(), 1);
-        assert!(!selection.contains_object(&id1));
-        assert!(selection.contains_object(&id2));
+        selection.remove_shape_instance(&id1);
+        assert_eq!(selection.shape_instance_count(), 1);
+        assert!(!selection.contains_shape_instance(&id1));
+        assert!(selection.contains_shape_instance(&id2));
     }
 
     #[test]
@@ -186,11 +248,11 @@ mod tests {
         let mut selection = Selection::new();
         let id = Uuid::new_v4();
 
-        selection.toggle_object(id);
-        assert!(selection.contains_object(&id));
+        selection.toggle_shape_instance(id);
+        assert!(selection.contains_shape_instance(&id));
 
-        selection.toggle_object(id);
-        assert!(!selection.contains_object(&id));
+        selection.toggle_shape_instance(id);
+        assert!(!selection.contains_shape_instance(&id));
     }
 
     #[test]
@@ -199,20 +261,20 @@ mod tests {
         let id1 = Uuid::new_v4();
         let id2 = Uuid::new_v4();
 
-        selection.add_object(id1);
-        selection.add_object(id2);
-        assert_eq!(selection.object_count(), 2);
+        selection.add_shape_instance(id1);
+        selection.add_shape_instance(id2);
+        assert_eq!(selection.shape_instance_count(), 2);
 
-        selection.select_only_object(id1);
-        assert_eq!(selection.object_count(), 1);
-        assert!(selection.contains_object(&id1));
-        assert!(!selection.contains_object(&id2));
+        selection.select_only_shape_instance(id1);
+        assert_eq!(selection.shape_instance_count(), 1);
+        assert!(selection.contains_shape_instance(&id1));
+        assert!(!selection.contains_shape_instance(&id2));
     }
 
     #[test]
     fn test_clear() {
         let mut selection = Selection::new();
-        selection.add_object(Uuid::new_v4());
+        selection.add_shape_instance(Uuid::new_v4());
         selection.add_shape(Uuid::new_v4());
 
         assert!(!selection.is_empty());

lightningbeam-ui/lightningbeam-editor/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 lightningbeam-core = { path = "../lightningbeam-core" }
+daw-backend = { path = "../../daw-backend" }
 
 # UI Framework
 eframe = { workspace = true }

lightningbeam-ui/lightningbeam-editor/src/main.rs

@@ -266,6 +266,9 @@ struct EditorApp {
     draw_simplify_mode: lightningbeam_core::tool::SimplifyMode, // Current simplification mode for draw tool
     rdp_tolerance: f64, // RDP simplification tolerance (default: 10.0)
     schneider_max_error: f64, // Schneider curve fitting max error (default: 30.0)
+    // Audio engine integration
+    audio_controller: Option<daw_backend::EngineController>, // Audio engine controller for playback
+    audio_event_rx: Option<rtrb::Consumer<daw_backend::AudioEvent>>, // Audio event receiver
 }
 
 impl EditorApp {
@@ -282,14 +285,14 @@ impl EditorApp {
 
         // Add a test layer with a simple shape to visualize
         use lightningbeam_core::layer::{AnyLayer, VectorLayer};
-        use lightningbeam_core::object::Object;
+        use lightningbeam_core::object::ShapeInstance;
         use lightningbeam_core::shape::{Shape, ShapeColor};
         use vello::kurbo::{Circle, Shape as KurboShape};
 
         let circle = Circle::new((200.0, 150.0), 50.0);
         let path = circle.to_path(0.1);
         let shape = Shape::new(path).with_fill(ShapeColor::rgb(100, 150, 250));
-        let object = Object::new(shape.id);
+        let object = ShapeInstance::new(shape.id);
 
         let mut vector_layer = VectorLayer::new("Layer 1");
         vector_layer.add_shape(shape);
@@ -464,8 +467,17 @@ impl EditorApp {
 
             // Layer menu
             MenuAction::AddLayer => {
-                println!("Menu: Add Layer");
-                // TODO: Implement add layer
+                // Create a new vector layer with a default name
+                let layer_count = self.action_executor.document().root.children.len();
+                let layer_name = format!("Layer {}", layer_count + 1);
+
+                let action = lightningbeam_core::actions::AddLayerAction::new_vector(layer_name);
+                self.action_executor.execute(Box::new(action));
+
+                // Select the newly created layer (last child in the document)
+                if let Some(last_layer) = self.action_executor.document().root.children.last() {
+                    self.active_layer_id = Some(last_layer.id());
+                }
             }
             MenuAction::AddVideoLayer => {
                 println!("Menu: Add Video Layer");
@@ -479,6 +491,65 @@ impl EditorApp {
                 println!("Menu: Add MIDI Track");
                 // TODO: Implement add MIDI track
             }
+            MenuAction::AddTestClip => {
+                // Require an active layer
+                if let Some(layer_id) = self.active_layer_id {
+                    // Create a test vector clip (5 second duration)
+                    use lightningbeam_core::clip::{VectorClip, ClipInstance};
+                    use lightningbeam_core::layer::{VectorLayer, AnyLayer};
+                    use lightningbeam_core::shape::{Shape, ShapeColor};
+                    use lightningbeam_core::object::ShapeInstance;
+                    use kurbo::{Circle, Rect, Shape as KurboShape};
+
+                    let mut test_clip = VectorClip::new("Test Clip", 400.0, 400.0, 5.0);
+
+                    // Create a layer with some shapes
+                    let mut layer = VectorLayer::new("Test Layer");
+
+                    // Create a red circle shape
+                    let circle_path = Circle::new((100.0, 100.0), 50.0).to_path(0.1);
+                    let mut circle_shape = Shape::new(circle_path);
+                    circle_shape.fill_color = Some(ShapeColor::rgb(255, 0, 0));
+                    let circle_id = circle_shape.id;
+                    layer.add_shape(circle_shape);
+
+                    // Create a blue rectangle shape
+                    let rect_path = Rect::new(200.0, 50.0, 350.0, 150.0).to_path(0.1);
+                    let mut rect_shape = Shape::new(rect_path);
+                    rect_shape.fill_color = Some(ShapeColor::rgb(0, 0, 255));
+                    let rect_id = rect_shape.id;
+                    layer.add_shape(rect_shape);
+
+                    // Add shape instances
+                    layer.shape_instances.push(ShapeInstance::new(circle_id));
+                    layer.shape_instances.push(ShapeInstance::new(rect_id));
+
+                    // Add the layer to the clip
+                    test_clip.layers.add_root(AnyLayer::Vector(layer));
+
+                    // Add to document's clip library
+                    let clip_id = self.action_executor.document_mut().add_vector_clip(test_clip);
+
+                    // Create clip instance at current time
+                    let current_time = self.action_executor.document().current_time;
+                    let instance = ClipInstance::new(clip_id)
+                        .with_timeline_start(current_time)
+                        .with_name("Test Instance");
+
+                    // Add to layer (only vector layers can have clip instances)
+                    if let Some(layer) = self.action_executor.document_mut().get_layer_mut(&layer_id) {
+                        use lightningbeam_core::layer::AnyLayer;
+                        if let AnyLayer::Vector(vector_layer) = layer {
+                            vector_layer.clip_instances.push(instance);
+                            println!("Added test clip instance with red circle and blue rectangle at time {}", current_time);
+                        } else {
+                            println!("Can only add clip instances to vector layers");
+                        }
+                    }
+                } else {
+                    println!("No active layer selected");
+                }
+            }
             MenuAction::DeleteLayer => {
                 println!("Menu: Delete Layer");
                 // TODO: Implement delete layer
@@ -678,7 +749,7 @@ impl eframe::App for EditorApp {
                 &self.theme,
                 &mut self.action_executor,
                 &mut self.selection,
-                &self.active_layer_id,
+                &mut self.active_layer_id,
                 &mut self.tool_state,
                 &mut pending_actions,
                 &mut self.draw_simplify_mode,
@@ -769,7 +840,7 @@ fn render_layout_node(
     theme: &Theme,
     action_executor: &mut lightningbeam_core::action::ActionExecutor,
     selection: &mut lightningbeam_core::selection::Selection,
-    active_layer_id: &Option<Uuid>,
+    active_layer_id: &mut Option<Uuid>,
     tool_state: &mut lightningbeam_core::tool::ToolState,
     pending_actions: &mut Vec<Box<dyn lightningbeam_core::action::Action>>,
     draw_simplify_mode: &mut lightningbeam_core::tool::SimplifyMode,
@@ -1121,7 +1192,7 @@ fn render_pane(
     theme: &Theme,
     action_executor: &mut lightningbeam_core::action::ActionExecutor,
     selection: &mut lightningbeam_core::selection::Selection,
-    active_layer_id: &Option<Uuid>,
+    active_layer_id: &mut Option<Uuid>,
     tool_state: &mut lightningbeam_core::tool::ToolState,
     pending_actions: &mut Vec<Box<dyn lightningbeam_core::action::Action>>,
     draw_simplify_mode: &mut lightningbeam_core::tool::SimplifyMode,

lightningbeam-ui/lightningbeam-editor/src/menu.rs

@@ -164,6 +164,7 @@ pub enum MenuAction {
     AddVideoLayer,
     AddAudioTrack,
     AddMidiTrack,
+    AddTestClip, // For testing: adds a test clip instance to the current layer
     DeleteLayer,
     ToggleLayerVisibility,
 
@@ -254,6 +255,7 @@ impl MenuItemDef {
     const ADD_VIDEO_LAYER: Self = Self { label: "Add Video Layer", action: MenuAction::AddVideoLayer, shortcut: None };
     const ADD_AUDIO_TRACK: Self = Self { label: "Add Audio Track", action: MenuAction::AddAudioTrack, shortcut: None };
     const ADD_MIDI_TRACK: Self = Self { label: "Add MIDI Track", action: MenuAction::AddMidiTrack, shortcut: None };
+    const ADD_TEST_CLIP: Self = Self { label: "Add Test Clip", action: MenuAction::AddTestClip, shortcut: None };
     const DELETE_LAYER: Self = Self { label: "Delete Layer", action: MenuAction::DeleteLayer, shortcut: None };
     const TOGGLE_LAYER_VISIBILITY: Self = Self { label: "Hide/Show Layer", action: MenuAction::ToggleLayerVisibility, shortcut: None };
 
@@ -364,6 +366,8 @@ impl MenuItemDef {
                     MenuDef::Item(&Self::ADD_AUDIO_TRACK),
                     MenuDef::Item(&Self::ADD_MIDI_TRACK),
                     MenuDef::Separator,
+                    MenuDef::Item(&Self::ADD_TEST_CLIP),
+                    MenuDef::Separator,
                     MenuDef::Item(&Self::DELETE_LAYER),
                     MenuDef::Item(&Self::TOGGLE_LAYER_VISIBILITY),
                 ],

lightningbeam-ui/lightningbeam-editor/src/panes/mod.rs

@@ -64,7 +64,7 @@ pub struct SharedPaneState<'a> {
     /// Current selection state (mutable for tools to modify)
     pub selection: &'a mut lightningbeam_core::selection::Selection,
     /// Currently active layer ID
-    pub active_layer_id: &'a Option<uuid::Uuid>,
+    pub active_layer_id: &'a mut Option<uuid::Uuid>,
     /// Current tool interaction state (mutable for tools to modify)
     pub tool_state: &'a mut lightningbeam_core::tool::ToolState,
     /// Actions to execute after rendering completes (two-phase dispatch)

lightningbeam-ui/lightningbeam-editor/src/panes/stage.rs

@@ -332,7 +332,7 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                     // 1. Draw selection outlines around selected objects
                     // NOTE: Skip this if Transform tool is active (it has its own handles)
                     if !self.selection.is_empty() && !matches!(self.selected_tool, Tool::Transform) {
-                        for &object_id in self.selection.objects() {
+                        for &object_id in self.selection.shape_instances() {
                             if let Some(object) = vector_layer.get_object(&object_id) {
                                 if let Some(shape) = vector_layer.get_shape(&object.shape_id) {
                                     // Get shape bounding box
@@ -385,6 +385,66 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                                 }
                             }
                         }
+
+                        // Also draw selection outlines for clip instances
+                        for &clip_id in self.selection.clip_instances() {
+                            if let Some(clip_instance) = vector_layer.clip_instances.iter().find(|ci| ci.id == clip_id) {
+                                // Get clip dimensions from document
+                                let (width, height) = if let Some(vector_clip) = self.document.get_vector_clip(&clip_instance.clip_id) {
+                                    (vector_clip.width, vector_clip.height)
+                                } else if let Some(video_clip) = self.document.get_video_clip(&clip_instance.clip_id) {
+                                    (video_clip.width, video_clip.height)
+                                } else {
+                                    continue; // Clip not found or is audio
+                                };
+
+                                // Create bounding box from clip dimensions
+                                let bbox = KurboRect::new(0.0, 0.0, width, height);
+
+                                // Apply clip instance transform and camera transform
+                                let clip_transform = clip_instance.transform.to_affine();
+                                let combined_transform = camera_transform * clip_transform;
+
+                                // Draw selection outline with different color for clip instances
+                                let clip_selection_color = Color::rgb8(255, 120, 0); // Orange
+                                scene.stroke(
+                                    &Stroke::new(stroke_width),
+                                    combined_transform,
+                                    clip_selection_color,
+                                    None,
+                                    &bbox,
+                                );
+
+                                // Draw corner handles (4 circles at corners)
+                                let handle_radius = (6.0 / self.zoom.max(0.5) as f64).max(4.0);
+                                let corners = [
+                                    (bbox.x0, bbox.y0),
+                                    (bbox.x1, bbox.y0),
+                                    (bbox.x1, bbox.y1),
+                                    (bbox.x0, bbox.y1),
+                                ];
+
+                                for (x, y) in corners {
+                                    let corner_circle = Circle::new((x, y), handle_radius);
+                                    // Fill with orange
+                                    scene.fill(
+                                        Fill::NonZero,
+                                        combined_transform,
+                                        clip_selection_color,
+                                        None,
+                                        &corner_circle,
+                                    );
+                                    // White outline
+                                    scene.stroke(
+                                        &Stroke::new(1.0),
+                                        combined_transform,
+                                        Color::rgb8(255, 255, 255),
+                                        None,
+                                        &corner_circle,
+                                    );
+                                }
+                            }
+                        }
                     }
 
                     // 2. Draw marquee selection rectangle
@@ -673,9 +733,9 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                         // For single object: use object-aligned (rotated) bounding box
                         // For multiple objects: use axis-aligned bounding box (simpler for now)
 
-                        if self.selection.objects().len() == 1 {
+                        if self.selection.shape_instances().len() == 1 {
                             // Single object - draw rotated bounding box
-                            let object_id = *self.selection.objects().iter().next().unwrap();
+                            let object_id = *self.selection.shape_instances().iter().next().unwrap();
 
                             if let Some(object) = vector_layer.get_object(&object_id) {
                                 if let Some(shape) = vector_layer.get_shape(&object.shape_id) {
@@ -863,7 +923,7 @@ impl egui_wgpu::CallbackTrait for VelloCallback {
                             // Multiple objects - use axis-aligned bbox (existing code)
                             let mut combined_bbox: Option<KurboRect> = None;
 
-                            for &object_id in self.selection.objects() {
+                            for &object_id in self.selection.shape_instances() {
                                 if let Some(object) = vector_layer.get_object(&object_id) {
                                     if let Some(shape) = vector_layer.get_shape(&object.shape_id) {
                                         let shape_bbox = shape.path().bounding_box();
@@ -1178,7 +1238,7 @@ impl StagePane {
             None => return, // No active layer
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => return,
         };
@@ -1194,25 +1254,43 @@ impl StagePane {
         // Mouse down: start interaction (use drag_started for immediate feedback)
         if response.drag_started() || response.clicked() {
             // Hit test at click position
-            let hit = hit_test::hit_test_layer(vector_layer, point, 5.0, Affine::IDENTITY);
+            // Test clip instances first (they're on top of shapes)
+            let document = shared.action_executor.document();
+            let clip_hit = hit_test::hit_test_clip_instances(
+                &vector_layer.clip_instances,
+                &document.vector_clips,
+                &document.video_clips,
+                point,
+                Affine::IDENTITY,
+            );
 
-            if let Some(object_id) = hit {
-                // Object was hit
+            let hit_result = if let Some(clip_id) = clip_hit {
+                Some(hit_test::HitResult::ClipInstance(clip_id))
+            } else {
+                // No clip hit, test shape instances
+                hit_test::hit_test_layer(vector_layer, point, 5.0, Affine::IDENTITY)
+                    .map(|id| hit_test::HitResult::ShapeInstance(id))
+            };
+
+            if let Some(hit) = hit_result {
+                match hit {
+                    hit_test::HitResult::ShapeInstance(object_id) => {
+                        // Shape instance was hit
                         if shift_held {
                             // Shift: toggle selection
-                    shared.selection.toggle_object(object_id);
+                            shared.selection.toggle_shape_instance(object_id);
                         } else {
                             // No shift: replace selection
-                    if !shared.selection.contains_object(&object_id) {
-                        shared.selection.select_only_object(object_id);
+                            if !shared.selection.contains_shape_instance(&object_id) {
+                                shared.selection.select_only_shape_instance(object_id);
                             }
                         }
 
                         // If object is now selected, prepare for dragging
-                if shared.selection.contains_object(&object_id) {
+                        if shared.selection.contains_shape_instance(&object_id) {
                             // Store original positions of all selected objects
                             let mut original_positions = std::collections::HashMap::new();
-                    for &obj_id in shared.selection.objects() {
+                            for &obj_id in shared.selection.shape_instances() {
                                 if let Some(obj) = vector_layer.get_object(&obj_id) {
                                     original_positions.insert(
                                         obj_id,
@@ -1227,6 +1305,42 @@ impl StagePane {
                                 original_positions,
                             };
                         }
+                    }
+                    hit_test::HitResult::ClipInstance(clip_id) => {
+                        // Clip instance was hit
+                        if shift_held {
+                            // Shift: toggle selection
+                            shared.selection.toggle_clip_instance(clip_id);
+                        } else {
+                            // No shift: replace selection
+                            if !shared.selection.contains_clip_instance(&clip_id) {
+                                shared.selection.select_only_clip_instance(clip_id);
+                            }
+                        }
+
+                        // If clip instance is now selected, prepare for dragging
+                        if shared.selection.contains_clip_instance(&clip_id) {
+                            // Store original positions of all selected clip instances
+                            let mut original_positions = std::collections::HashMap::new();
+                            for &clip_inst_id in shared.selection.clip_instances() {
+                                // Find the clip instance in the layer
+                                if let Some(clip_inst) = vector_layer.clip_instances.iter()
+                                    .find(|ci| ci.id == clip_inst_id) {
+                                    original_positions.insert(
+                                        clip_inst_id,
+                                        Point::new(clip_inst.transform.x, clip_inst.transform.y),
+                                    );
+                                }
+                            }
+
+                            *shared.tool_state = ToolState::DraggingSelection {
+                                start_pos: point,
+                                start_mouse: point,
+                                original_positions,
+                            };
+                        }
+                    }
+                }
             } else {
                 // Nothing hit - start marquee selection
                 if !shift_held {
@@ -1266,24 +1380,56 @@ impl StagePane {
                     let delta = point - start_mouse;
 
                     if delta.x.abs() > 0.01 || delta.y.abs() > 0.01 {
-                        // Create move action with new positions
+                        // Create move actions with new positions
                         use std::collections::HashMap;
-                        let mut object_positions = HashMap::new();
 
-                        for (object_id, original_pos) in original_positions {
+                        // Separate shape instances from clip instances
+                        use lightningbeam_core::object::Transform;
+                        let mut shape_instance_positions = HashMap::new();
+                        let mut clip_instance_transforms = HashMap::new();
+
+                        for (id, original_pos) in original_positions {
                             let new_pos = Point::new(
                                 original_pos.x + delta.x,
                                 original_pos.y + delta.y,
                             );
-                            object_positions.insert(object_id, (original_pos, new_pos));
+
+                            // Check if this is a shape instance or clip instance
+                            if shared.selection.contains_shape_instance(&id) {
+                                shape_instance_positions.insert(id, (original_pos, new_pos));
+                            } else if shared.selection.contains_clip_instance(&id) {
+                                // For clip instances, we need to get the full Transform
+                                // Find the clip instance in the layer
+                                if let Some(clip_inst) = vector_layer.clip_instances.iter()
+                                    .find(|ci| ci.id == id) {
+                                    let mut old_transform = clip_inst.transform.clone();
+                                    old_transform.x = original_pos.x;
+                                    old_transform.y = original_pos.y;
+
+                                    let mut new_transform = clip_inst.transform.clone();
+                                    new_transform.x = new_pos.x;
+                                    new_transform.y = new_pos.y;
+
+                                    clip_instance_transforms.insert(id, (old_transform, new_transform));
+                                }
+                            }
                         }
 
-                        // Create and submit the action
-                        use lightningbeam_core::actions::MoveObjectsAction;
-                        let action = MoveObjectsAction::new(*active_layer_id, object_positions);
+                        // Create and submit move action for shape instances
+                        if !shape_instance_positions.is_empty() {
+                            use lightningbeam_core::actions::MoveShapeInstancesAction;
+                            let action = MoveShapeInstancesAction::new(*active_layer_id, shape_instance_positions);
                             shared.pending_actions.push(Box::new(action));
                         }
 
+                        // Create and submit transform action for clip instances
+                        if !clip_instance_transforms.is_empty() {
+                            use lightningbeam_core::actions::TransformClipInstancesAction;
+                            let action = TransformClipInstancesAction::new(*active_layer_id, clip_instance_transforms);
+                            shared.pending_actions.push(Box::new(action));
+                        }
+                    }
+
                     // Reset tool state
                     *shared.tool_state = ToolState::Idle;
                 }
@@ -1296,24 +1442,49 @@ impl StagePane {
 
                     let selection_rect = KurboRect::new(min_x, min_y, max_x, max_y);
 
-                    // Hit test all objects in rectangle
-                    let hits = hit_test::hit_test_objects_in_rect(
+                    // Hit test clip instances in rectangle
+                    let document = shared.action_executor.document();
+                    let clip_hits = hit_test::hit_test_clip_instances_in_rect(
+                        &vector_layer.clip_instances,
+                        &document.vector_clips,
+                        &document.video_clips,
+                        selection_rect,
+                        Affine::IDENTITY,
+                    );
+
+                    // Hit test shape instances in rectangle
+                    let shape_hits = hit_test::hit_test_objects_in_rect(
                         vector_layer,
                         selection_rect,
                         Affine::IDENTITY,
                     );
 
-                    // Add to selection
-                    for obj_id in hits {
+                    // Add clip instances to selection
+                    for clip_id in clip_hits {
                         if shift_held {
-                            shared.selection.add_object(obj_id);
+                            shared.selection.add_clip_instance(clip_id);
                         } else {
                             // First hit replaces selection
                             if shared.selection.is_empty() {
-                                shared.selection.add_object(obj_id);
+                                shared.selection.add_clip_instance(clip_id);
                             } else {
                                 // Subsequent hits add to selection
-                                shared.selection.add_object(obj_id);
+                                shared.selection.add_clip_instance(clip_id);
+                            }
+                        }
+                    }
+
+                    // Add shape instances to selection
+                    for obj_id in shape_hits {
+                        if shift_held {
+                            shared.selection.add_shape_instance(obj_id);
+                        } else {
+                            // First hit replaces selection
+                            if shared.selection.is_empty() {
+                                shared.selection.add_shape_instance(obj_id);
+                            } else {
+                                // Subsequent hits add to selection
+                                shared.selection.add_shape_instance(obj_id);
                             }
                         }
                     }
@@ -1340,12 +1511,12 @@ impl StagePane {
         use vello::kurbo::Point;
 
         // Check if we have an active vector layer
-        let active_layer_id = match shared.active_layer_id {
+        let active_layer_id = match *shared.active_layer_id {
             Some(id) => id,
             None => return,
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => return,
         };
@@ -1428,7 +1599,7 @@ impl StagePane {
                 // Only create shape if rectangle has non-zero size
                 if width > 1.0 && height > 1.0 {
                     use lightningbeam_core::shape::{Shape, ShapeColor};
-                    use lightningbeam_core::object::Object;
+                    use lightningbeam_core::object::ShapeInstance;
                     use lightningbeam_core::actions::AddShapeAction;
 
                     // Create shape with rectangle path (built from lines)
@@ -1436,10 +1607,10 @@ impl StagePane {
                     let shape = Shape::new(path).with_fill(ShapeColor::from_egui(*shared.fill_color));
 
                     // Create object at the calculated position
-                    let object = Object::new(shape.id).with_position(position.x, position.y);
+                    let object = ShapeInstance::new(shape.id).with_position(position.x, position.y);
 
                     // Create and execute action immediately
-                    let action = AddShapeAction::new(*active_layer_id, shape, object);
+                    let action = AddShapeAction::new(active_layer_id, shape, object);
                     shared.action_executor.execute(Box::new(action));
 
                     // Clear tool state to stop preview rendering
@@ -1463,12 +1634,12 @@ impl StagePane {
         use vello::kurbo::Point;
 
         // Check if we have an active vector layer
-        let active_layer_id = match shared.active_layer_id {
+        let active_layer_id = match *shared.active_layer_id {
             Some(id) => id,
             None => return,
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => return,
         };
@@ -1545,7 +1716,7 @@ impl StagePane {
                 // Only create shape if ellipse has non-zero size
                 if rx > 1.0 && ry > 1.0 {
                     use lightningbeam_core::shape::{Shape, ShapeColor};
-                    use lightningbeam_core::object::Object;
+                    use lightningbeam_core::object::ShapeInstance;
                     use lightningbeam_core::actions::AddShapeAction;
 
                     // Create shape with ellipse path (built from bezier curves)
@@ -1553,10 +1724,10 @@ impl StagePane {
                     let shape = Shape::new(path).with_fill(ShapeColor::from_egui(*shared.fill_color));
 
                     // Create object at the calculated position
-                    let object = Object::new(shape.id).with_position(position.x, position.y);
+                    let object = ShapeInstance::new(shape.id).with_position(position.x, position.y);
 
                     // Create and execute action immediately
-                    let action = AddShapeAction::new(*active_layer_id, shape, object);
+                    let action = AddShapeAction::new(active_layer_id, shape, object);
                     shared.action_executor.execute(Box::new(action));
 
                     // Clear tool state to stop preview rendering
@@ -1580,12 +1751,12 @@ impl StagePane {
         use vello::kurbo::Point;
 
         // Check if we have an active vector layer
-        let active_layer_id = match shared.active_layer_id {
+        let active_layer_id = match *shared.active_layer_id {
             Some(id) => id,
             None => return,
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => return,
         };
@@ -1626,7 +1797,7 @@ impl StagePane {
                 // Only create shape if line has reasonable length
                 if length > 1.0 {
                     use lightningbeam_core::shape::{Shape, ShapeColor, StrokeStyle};
-                    use lightningbeam_core::object::Object;
+                    use lightningbeam_core::object::ShapeInstance;
                     use lightningbeam_core::actions::AddShapeAction;
 
                     // Create shape with line path
@@ -1643,10 +1814,10 @@ impl StagePane {
                         );
 
                     // Create object at the start point
-                    let object = Object::new(shape.id).with_position(start_point.x, start_point.y);
+                    let object = ShapeInstance::new(shape.id).with_position(start_point.x, start_point.y);
 
                     // Create and execute action immediately
-                    let action = AddShapeAction::new(*active_layer_id, shape, object);
+                    let action = AddShapeAction::new(active_layer_id, shape, object);
                     shared.action_executor.execute(Box::new(action));
 
                     // Clear tool state to stop preview rendering
@@ -1670,12 +1841,12 @@ impl StagePane {
         use vello::kurbo::Point;
 
         // Check if we have an active vector layer
-        let active_layer_id = match shared.active_layer_id {
+        let active_layer_id = match *shared.active_layer_id {
             Some(id) => id,
             None => return,
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => return,
         };
@@ -1718,7 +1889,7 @@ impl StagePane {
                 // Only create shape if polygon has reasonable size
                 if radius > 5.0 {
                     use lightningbeam_core::shape::{Shape, ShapeColor};
-                    use lightningbeam_core::object::Object;
+                    use lightningbeam_core::object::ShapeInstance;
                     use lightningbeam_core::actions::AddShapeAction;
 
                     // Create shape with polygon path
@@ -1726,10 +1897,10 @@ impl StagePane {
                     let shape = Shape::new(path).with_fill(ShapeColor::from_egui(*shared.fill_color));
 
                     // Create object at the center point
-                    let object = Object::new(shape.id).with_position(center.x, center.y);
+                    let object = ShapeInstance::new(shape.id).with_position(center.x, center.y);
 
                     // Create and execute action immediately
-                    let action = AddShapeAction::new(*active_layer_id, shape, object);
+                    let action = AddShapeAction::new(active_layer_id, shape, object);
                     shared.action_executor.execute(Box::new(action));
 
                     // Clear tool state to stop preview rendering
@@ -1893,12 +2064,12 @@ impl StagePane {
         use vello::kurbo::Point;
 
         // Check if we have an active vector layer
-        let active_layer_id = match shared.active_layer_id {
+        let active_layer_id = match *shared.active_layer_id {
             Some(id) => id,
             None => return,
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => return,
         };
@@ -1944,7 +2115,7 @@ impl StagePane {
                         simplify_rdp, fit_bezier_curves, RdpConfig, SchneiderConfig,
                     };
                     use lightningbeam_core::shape::{Shape, ShapeColor};
-                    use lightningbeam_core::object::Object;
+                    use lightningbeam_core::object::ShapeInstance;
                     use lightningbeam_core::actions::AddShapeAction;
 
                     // Convert points to the appropriate path based on simplify mode
@@ -2003,10 +2174,10 @@ impl StagePane {
                             );
 
                         // Create object at the calculated position
-                        let object = Object::new(shape.id).with_position(position.x, position.y);
+                        let object = ShapeInstance::new(shape.id).with_position(position.x, position.y);
 
                         // Create and execute action immediately
-                        let action = AddShapeAction::new(*active_layer_id, shape, object);
+                        let action = AddShapeAction::new(active_layer_id, shape, object);
                         shared.action_executor.execute(Box::new(action));
                     }
                 }
@@ -2037,7 +2208,7 @@ impl StagePane {
             }
         };
 
-        let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+        let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
             Some(layer) => layer,
             None => {
                 println!("Paint bucket: Layer not found");
@@ -2071,6 +2242,57 @@ impl StagePane {
         }
     }
 
+    /// Decompose an affine matrix into transform components
+    /// Returns (translation_x, translation_y, rotation_deg, scale_x, scale_y, skew_x_deg, skew_y_deg)
+    fn decompose_affine(affine: kurbo::Affine) -> (f64, f64, f64, f64, f64, f64, f64) {
+        let coeffs = affine.as_coeffs();
+        let a = coeffs[0];
+        let b = coeffs[1];
+        let c = coeffs[2];
+        let d = coeffs[3];
+        let e = coeffs[4]; // translation_x
+        let f = coeffs[5]; // translation_y
+
+        // Extract translation
+        let tx = e;
+        let ty = f;
+
+        // Decompose linear part [[a, c], [b, d]] into rotate * scale * skew
+        // Using QR-like decomposition
+
+        // Extract rotation
+        let rotation_rad = b.atan2(a);
+        let cos_r = rotation_rad.cos();
+        let sin_r = rotation_rad.sin();
+
+        // Remove rotation to get scale * skew
+        // R^(-1) * M where M = [[a, c], [b, d]]
+        let m11 = a * cos_r + b * sin_r;
+        let m12 = c * cos_r + d * sin_r;
+        let m21 = -a * sin_r + b * cos_r;
+        let m22 = -c * sin_r + d * cos_r;
+
+        // Now [[m11, m12], [m21, m22]] = scale * skew
+        // scale * skew = [[sx, 0], [0, sy]] * [[1, tan(skew_y)], [tan(skew_x), 1]]
+        //              = [[sx, sx*tan(skew_y)], [sy*tan(skew_x), sy]]
+
+        let scale_x = m11;
+        let scale_y = m22;
+
+        let skew_x_rad = if scale_y.abs() > 0.001 { (m21 / scale_y).atan() } else { 0.0 };
+        let skew_y_rad = if scale_x.abs() > 0.001 { (m12 / scale_x).atan() } else { 0.0 };
+
+        (
+            tx,
+            ty,
+            rotation_rad.to_degrees(),
+            scale_x,
+            scale_y,
+            skew_x_rad.to_degrees(),
+            skew_y_rad.to_degrees(),
+        )
+    }
+
     /// Apply transform preview to objects based on current mouse position
     fn apply_transform_preview(
         vector_layer: &mut lightningbeam_core::layer::VectorLayer,
@@ -2169,12 +2391,15 @@ impl StagePane {
             }
 
             TransformMode::ScaleEdge { axis, origin } => {
-                // Calculate scale along one axis
+                // UNIFIED MATRIX APPROACH: Calculate bounding box transform, then apply to each object
+
+                // Step 1: Calculate the bounding box transform (world-space scale from origin)
+                // Preserve sign to allow flipping when dragging past the origin
                 let (scale_x_world, scale_y_world) = match axis {
                     Axis::Horizontal => {
-                        let start_dist = (start_mouse.x - origin.x).abs();
-                        let current_dist = (current_mouse.x - origin.x).abs();
-                        let scale = if start_dist > 0.001 {
+                        let start_dist = start_mouse.x - origin.x;
+                        let current_dist = current_mouse.x - origin.x;
+                        let scale = if start_dist.abs() > 0.001 {
                             current_dist / start_dist
                         } else {
                             1.0
@@ -2182,9 +2407,9 @@ impl StagePane {
                         (scale, 1.0)
                     }
                     Axis::Vertical => {
-                        let start_dist = (start_mouse.y - origin.y).abs();
-                        let current_dist = (current_mouse.y - origin.y).abs();
-                        let scale = if start_dist > 0.001 {
+                        let start_dist = start_mouse.y - origin.y;
+                        let current_dist = current_mouse.y - origin.y;
+                        let scale = if start_dist.abs() > 0.001 {
                             current_dist / start_dist
                         } else {
                             1.0
@@ -2193,36 +2418,59 @@ impl StagePane {
                     }
                 };
 
-                // Apply scale to all selected objects
+                // Build the bounding box transform: translate to origin, scale, translate back
+                use kurbo::Affine;
+                let bbox_transform = Affine::translate((origin.x, origin.y))
+                    * Affine::scale_non_uniform(scale_x_world, scale_y_world)
+                    * Affine::translate((-origin.x, -origin.y));
+
+                // Step 2: Apply to each object using matrix composition
                 for (object_id, original_transform) in original_transforms {
+                    // Get original opacity (now separate from transform)
+                    let original_opacity = if let Some(obj) = vector_layer.get_object(object_id) {
+                        obj.opacity
+                    } else {
+                        1.0
+                    };
+
+                    // New position: transform the object's position through bbox_transform
+                    let new_pos = bbox_transform * kurbo::Point::new(original_transform.x, original_transform.y);
+
+                    // Transform bbox operation to object's local space
+                    // local_transform = R^(-1) * bbox_transform * R
+                    let rotation = Affine::rotate(original_transform.rotation.to_radians());
+                    let rotation_inv = Affine::rotate(-original_transform.rotation.to_radians());
+
+                    // Extract just the linear part of bbox_transform (no translation)
+                    let bbox_linear = Affine::scale_non_uniform(scale_x_world, scale_y_world);
+
+                    // Transform to local space
+                    let local_transform = rotation_inv * bbox_linear * rotation;
+
+                    // Extract scale and skew directly from the 2x2 matrix
+                    // Matrix form: [[a, c], [b, d]] = [[sx, sx*tan(ky)], [sy*tan(kx), sy]]
+                    let coeffs = local_transform.as_coeffs();
+                    let a = coeffs[0];
+                    let b = coeffs[1];
+                    let c = coeffs[2];
+                    let d = coeffs[3];
+
+                    // Direct extraction (no rotation assumed in local space)
+                    let local_sx = a;
+                    let local_sy = d;
+                    let local_skew_x = if d.abs() > 0.001 { (b / d).atan().to_degrees() } else { 0.0 };
+                    let local_skew_y = if a.abs() > 0.001 { (c / a).atan().to_degrees() } else { 0.0 };
+
+                    // Apply to object
                     vector_layer.modify_object_internal(object_id, |obj| {
-                        // Get object's rotation in radians
-                        let rotation_rad = original_transform.rotation.to_radians();
-                        let cos_r = rotation_rad.cos();
-                        let sin_r = rotation_rad.sin();
-
-                        // Transform scale from world space to local space (same as corner mode)
-                        let cos_r_sq = cos_r * cos_r;
-                        let sin_r_sq = sin_r * sin_r;
-                        let sx_abs = scale_x_world.abs();
-                        let sy_abs = scale_y_world.abs();
-
-                        let local_scale_x = (cos_r_sq * sx_abs * sx_abs + sin_r_sq * sy_abs * sy_abs).sqrt();
-                        let local_scale_y = (sin_r_sq * sx_abs * sx_abs + cos_r_sq * sy_abs * sy_abs).sqrt();
-
-                        // Scale position relative to origin in world space
-                        let rel_x = original_transform.x - origin.x;
-                        let rel_y = original_transform.y - origin.y;
-
-                        obj.transform.x = origin.x + rel_x * scale_x_world;
-                        obj.transform.y = origin.y + rel_y * scale_y_world;
-
-                        // Apply local-space scale
-                        obj.transform.scale_x = original_transform.scale_x * local_scale_x;
-                        obj.transform.scale_y = original_transform.scale_y * local_scale_y;
-
-                        // Keep rotation unchanged
-                        obj.transform.rotation = original_transform.rotation;
+                        obj.transform.x = new_pos.x;
+                        obj.transform.y = new_pos.y;
+                        obj.transform.rotation = original_transform.rotation; // Preserve rotation
+                        obj.transform.scale_x = original_transform.scale_x * local_sx;
+                        obj.transform.scale_y = original_transform.scale_y * local_sy;
+                        obj.transform.skew_x = original_transform.skew_x + local_skew_x;
+                        obj.transform.skew_y = original_transform.skew_y + local_skew_y;
+                        obj.opacity = original_opacity; // Preserve opacity (now separate from transform)
                     });
                 }
             }
@@ -2492,14 +2740,14 @@ impl StagePane {
         use vello::kurbo::Point;
 
         // Check if we have an active vector layer
-        let active_layer_id = match shared.active_layer_id {
+        let active_layer_id = match *shared.active_layer_id {
             Some(id) => id,
             None => return,
         };
 
         // Only work on VectorLayer - just check type, don't hold reference
         {
-            let active_layer = match shared.action_executor.document().get_layer(active_layer_id) {
+            let active_layer = match shared.action_executor.document().get_layer(&active_layer_id) {
                 Some(layer) => layer,
                 None => return,
             };
@@ -2518,17 +2766,17 @@ impl StagePane {
 
         // For single object: use rotated bounding box
         // For multiple objects: use axis-aligned bounding box
-        if shared.selection.objects().len() == 1 {
+        if shared.selection.shape_instances().len() == 1 {
             // Single object - rotated bounding box
-            self.handle_transform_single_object(ui, response, point, active_layer_id, shared);
+            self.handle_transform_single_object(ui, response, point, &active_layer_id, shared);
         } else {
             // Multiple objects - axis-aligned bounding box
             // Calculate combined bounding box for handle hit testing
             let mut combined_bbox: Option<vello::kurbo::Rect> = None;
 
             // Get immutable reference just for bbox calculation
-            if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(active_layer_id) {
-                for &object_id in shared.selection.objects() {
+            if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(&active_layer_id) {
+                for &object_id in shared.selection.shape_instances() {
                     if let Some(object) = vector_layer.get_object(&object_id) {
                         if let Some(shape) = vector_layer.get_shape(&object.shape_id) {
                             // Get shape's local bounding box
@@ -2603,8 +2851,8 @@ impl StagePane {
                 use std::collections::HashMap;
                 let mut original_transforms = HashMap::new();
 
-                if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(active_layer_id) {
-                    for &object_id in shared.selection.objects() {
+                if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(&active_layer_id) {
+                    for &object_id in shared.selection.shape_instances() {
                         if let Some(object) = vector_layer.get_object(&object_id) {
                             original_transforms.insert(object_id, object.transform.clone());
                         }
@@ -2661,12 +2909,12 @@ impl StagePane {
             if response.drag_stopped() || (ui.input(|i| i.pointer.any_released()) && matches!(shared.tool_state, ToolState::Transforming { .. })) {
                 if let ToolState::Transforming { original_transforms, .. } = shared.tool_state.clone() {
                     use std::collections::HashMap;
-                    use lightningbeam_core::actions::TransformObjectsAction;
+                    use lightningbeam_core::actions::TransformShapeInstancesAction;
 
                     let mut object_transforms = HashMap::new();
 
                     // Get current transforms and pair with originals
-                    if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(active_layer_id) {
+                    if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(&active_layer_id) {
                         for (object_id, original) in original_transforms {
                             if let Some(object) = vector_layer.get_object(&object_id) {
                                 let new_transform = object.transform.clone();
@@ -2676,7 +2924,7 @@ impl StagePane {
                     }
 
                     if !object_transforms.is_empty() {
-                        let action = TransformObjectsAction::new(*active_layer_id, object_transforms);
+                        let action = TransformShapeInstancesAction::new(active_layer_id, object_transforms);
                         shared.pending_actions.push(Box::new(action));
                     }
 
@@ -2699,11 +2947,11 @@ impl StagePane {
         use lightningbeam_core::layer::AnyLayer;
         use vello::kurbo::Affine;
 
-        let object_id = *shared.selection.objects().iter().next().unwrap();
+        let object_id = *shared.selection.shape_instances().iter().next().unwrap();
 
         // Calculate rotated bounding box corners
         let (local_bbox, world_corners, obj_transform, object) = {
-            if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(active_layer_id) {
+            if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(&active_layer_id) {
                 if let Some(object) = vector_layer.get_object(&object_id) {
                     if let Some(shape) = vector_layer.get_shape(&object.shape_id) {
                         let local_bbox = shape.path().bounding_box();
@@ -3303,11 +3551,11 @@ impl StagePane {
         if response.drag_stopped() || (ui.input(|i| i.pointer.any_released()) && matches!(shared.tool_state, ToolState::Transforming { .. })) {
             if let ToolState::Transforming { original_transforms, .. } = shared.tool_state.clone() {
                 use std::collections::HashMap;
-                use lightningbeam_core::actions::TransformObjectsAction;
+                use lightningbeam_core::actions::TransformShapeInstancesAction;
 
                 let mut object_transforms = HashMap::new();
 
-                if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(active_layer_id) {
+                if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(&active_layer_id) {
                     for (obj_id, original) in original_transforms {
                         if let Some(object) = vector_layer.get_object(&obj_id) {
                             object_transforms.insert(obj_id, (original, object.transform.clone()));
@@ -3316,7 +3564,7 @@ impl StagePane {
                 }
 
                 if !object_transforms.is_empty() {
-                    let action = TransformObjectsAction::new(*active_layer_id, object_transforms);
+                    let action = TransformShapeInstancesAction::new(*active_layer_id, object_transforms);
                     shared.pending_actions.push(Box::new(action));
                 }
 
@@ -3356,8 +3604,8 @@ impl StagePane {
                                     object_positions.insert(object_id, (original_pos, new_pos));
                                 }
 
-                                use lightningbeam_core::actions::MoveObjectsAction;
-                                let action = MoveObjectsAction::new(*active_layer_id, object_positions);
+                                use lightningbeam_core::actions::MoveShapeInstancesAction;
+                                let action = MoveShapeInstancesAction::new(*active_layer_id, object_positions);
                                 shared.pending_actions.push(Box::new(action));
                             }
                         }
@@ -3372,7 +3620,7 @@ impl StagePane {
                         use lightningbeam_core::hit_test;
                         use vello::kurbo::{Rect as KurboRect, Affine};
 
-                        if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(active_layer_id) {
+                        if let Some(AnyLayer::Vector(vector_layer)) = shared.action_executor.document().get_layer(&active_layer_id) {
                             // Create selection rectangle
                             let min_x = start.x.min(current.x);
                             let min_y = start.y.min(current.y);
@@ -3390,7 +3638,7 @@ impl StagePane {
 
                             // Add to selection
                             for obj_id in hits {
-                                shared.selection.add_object(obj_id);
+                                shared.selection.add_shape_instance(obj_id);
                             }
                         }
                     }

lightningbeam-ui/lightningbeam-editor/src/panes/timeline.rs

@@ -14,6 +14,15 @@ const LAYER_HEIGHT: f32 = 60.0;
 const LAYER_HEADER_WIDTH: f32 = 200.0;
 const MIN_PIXELS_PER_SECOND: f32 = 20.0;
 const MAX_PIXELS_PER_SECOND: f32 = 500.0;
+const EDGE_DETECTION_PIXELS: f32 = 8.0; // Distance from edge to detect trim handles
+
+/// Type of clip drag operation
+#[derive(Debug, Clone, Copy, PartialEq)]
+enum ClipDragType {
+    Move,
+    TrimLeft,
+    TrimRight,
+}
 
 pub struct TimelinePane {
     /// Current playback time in seconds
@@ -38,11 +47,15 @@ pub struct TimelinePane {
     is_panning: bool,
     last_pan_pos: Option<egui::Pos2>,
 
+    /// Clip drag state (None if not dragging)
+    clip_drag_state: Option<ClipDragType>,
+    drag_offset: f64,  // Time offset being applied during drag (for preview)
+
+    /// Cached mouse position from mousedown (used for edge detection when drag starts)
+    mousedown_pos: Option<egui::Pos2>,
+
     /// Is playback currently active?
     is_playing: bool,
-
-    /// Currently selected/active layer index
-    active_layer: usize,
 }
 
 impl TimelinePane {
@@ -51,12 +64,14 @@ impl TimelinePane {
             current_time: 0.0,
             pixels_per_second: 100.0,
             viewport_start_time: 0.0,
-            active_layer: 0,
             viewport_scroll_y: 0.0,
             duration: 10.0,  // Default 10 seconds
             is_scrubbing: false,
             is_panning: false,
             last_pan_pos: None,
+            clip_drag_state: None,
+            drag_offset: 0.0,
+            mousedown_pos: None,
             is_playing: false,
         }
     }
@@ -74,6 +89,83 @@ impl TimelinePane {
         }
     }
 
+    /// Detect which clip is under the pointer and what type of drag would occur
+    ///
+    /// Returns (drag_type, clip_id) if pointer is over a clip, None otherwise
+    fn detect_clip_at_pointer(
+        &self,
+        pointer_pos: egui::Pos2,
+        document: &lightningbeam_core::document::Document,
+        content_rect: egui::Rect,
+        header_rect: egui::Rect,
+    ) -> Option<(ClipDragType, uuid::Uuid)> {
+        let layer_count = document.root.children.len();
+
+        // Check if pointer is in valid area
+        if pointer_pos.y < header_rect.min.y {
+            return None;
+        }
+        if pointer_pos.x < content_rect.min.x {
+            return None;
+        }
+
+        let hover_time = self.x_to_time(pointer_pos.x - content_rect.min.x);
+        let relative_y = pointer_pos.y - header_rect.min.y + self.viewport_scroll_y;
+        let hovered_layer_index = (relative_y / LAYER_HEIGHT) as usize;
+
+        if hovered_layer_index >= layer_count {
+            return None;
+        }
+
+        let layers: Vec<_> = document.root.children.iter().rev().collect();
+        let layer = layers.get(hovered_layer_index)?;
+        let layer_data = layer.layer();
+
+        let clip_instances = match layer {
+            lightningbeam_core::layer::AnyLayer::Vector(vl) => &vl.clip_instances,
+            lightningbeam_core::layer::AnyLayer::Audio(al) => &al.clip_instances,
+            lightningbeam_core::layer::AnyLayer::Video(vl) => &vl.clip_instances,
+        };
+
+        // Check each clip instance
+        for clip_instance in clip_instances {
+            let clip_duration = match layer {
+                lightningbeam_core::layer::AnyLayer::Vector(_) => {
+                    document.get_vector_clip(&clip_instance.clip_id).map(|c| c.duration)
+                }
+                lightningbeam_core::layer::AnyLayer::Audio(_) => {
+                    document.get_audio_clip(&clip_instance.clip_id).map(|c| c.duration)
+                }
+                lightningbeam_core::layer::AnyLayer::Video(_) => {
+                    document.get_video_clip(&clip_instance.clip_id).map(|c| c.duration)
+                }
+            }?;
+
+            let instance_duration = clip_instance.effective_duration(clip_duration);
+            let instance_start = clip_instance.timeline_start;
+            let instance_end = instance_start + instance_duration;
+
+            if hover_time >= instance_start && hover_time <= instance_end {
+                let start_x = self.time_to_x(instance_start);
+                let end_x = self.time_to_x(instance_end);
+                let mouse_x = pointer_pos.x - content_rect.min.x;
+
+                // Determine drag type based on edge proximity (check both sides of edge)
+                let drag_type = if (mouse_x - start_x).abs() <= EDGE_DETECTION_PIXELS {
+                    ClipDragType::TrimLeft
+                } else if (end_x - mouse_x).abs() <= EDGE_DETECTION_PIXELS {
+                    ClipDragType::TrimRight
+                } else {
+                    ClipDragType::Move
+                };
+
+                return Some((drag_type, clip_instance.id));
+            }
+        }
+
+        None
+    }
+
     /// Zoom in by a fixed increment
     pub fn zoom_in(&mut self, center_x: f32) {
         self.apply_zoom_at_point(0.2, center_x);
@@ -243,7 +335,14 @@ impl TimelinePane {
     }
 
     /// Render layer header column (left side with track names and controls)
-    fn render_layer_headers(&self, ui: &mut egui::Ui, rect: egui::Rect, theme: &crate::theme::Theme) {
+    fn render_layer_headers(
+        &self,
+        ui: &mut egui::Ui,
+        rect: egui::Rect,
+        theme: &crate::theme::Theme,
+        document: &lightningbeam_core::document::Document,
+        active_layer_id: &Option<uuid::Uuid>,
+    ) {
         let painter = ui.painter();
 
         // Background for header column
@@ -264,9 +363,10 @@ impl TimelinePane {
         // Get text color from theme
         let text_style = theme.style(".text-primary", ui.ctx());
         let text_color = text_style.text_color.unwrap_or(egui::Color32::from_gray(200));
+        let secondary_text_color = egui::Color32::from_gray(150);
 
-        // Test: Draw 3 layer headers
-        for i in 0..3 {
+        // Draw layer headers from document (reversed so newest layers appear on top)
+        for (i, layer) in document.root.children.iter().rev().enumerate() {
             let y = rect.min.y + i as f32 * LAYER_HEIGHT - self.viewport_scroll_y;
 
             // Skip if layer is outside visible area
@@ -280,7 +380,8 @@ impl TimelinePane {
             );
 
             // Active vs inactive background colors
-            let bg_color = if i == self.active_layer {
+            let is_active = active_layer_id.map_or(false, |id| id == layer.id());
+            let bg_color = if is_active {
                 active_color
             } else {
                 inactive_color
@@ -288,15 +389,58 @@ impl TimelinePane {
 
             painter.rect_filled(header_rect, 0.0, bg_color);
 
+            // Get layer info
+            let layer_data = layer.layer();
+            let layer_name = &layer_data.name;
+            let (layer_type, type_color) = match layer {
+                lightningbeam_core::layer::AnyLayer::Vector(_) => ("Vector", egui::Color32::from_rgb(100, 150, 255)), // Blue
+                lightningbeam_core::layer::AnyLayer::Audio(_) => ("Audio", egui::Color32::from_rgb(100, 255, 150)), // Green
+                lightningbeam_core::layer::AnyLayer::Video(_) => ("Video", egui::Color32::from_rgb(255, 150, 100)), // Orange
+            };
+
+            // Color indicator bar on the left edge
+            let indicator_rect = egui::Rect::from_min_size(
+                header_rect.min,
+                egui::vec2(4.0, LAYER_HEIGHT),
+            );
+            painter.rect_filled(indicator_rect, 0.0, type_color);
+
             // Layer name
             painter.text(
                 header_rect.min + egui::vec2(10.0, 10.0),
                 egui::Align2::LEFT_TOP,
-                format!("Layer {}", i + 1),
+                layer_name,
                 egui::FontId::proportional(14.0),
                 text_color,
             );
 
+            // Layer type (smaller text below name with colored background)
+            let type_text_pos = header_rect.min + egui::vec2(10.0, 28.0);
+            let type_text_galley = painter.layout_no_wrap(
+                layer_type.to_string(),
+                egui::FontId::proportional(11.0),
+                secondary_text_color,
+            );
+
+            // Draw colored background for type label
+            let type_bg_rect = egui::Rect::from_min_size(
+                type_text_pos + egui::vec2(-2.0, -1.0),
+                egui::vec2(type_text_galley.size().x + 4.0, type_text_galley.size().y + 2.0),
+            );
+            painter.rect_filled(
+                type_bg_rect,
+                2.0,
+                egui::Color32::from_rgba_unmultiplied(type_color.r(), type_color.g(), type_color.b(), 60),
+            );
+
+            painter.text(
+                type_text_pos,
+                egui::Align2::LEFT_TOP,
+                layer_type,
+                egui::FontId::proportional(11.0),
+                secondary_text_color,
+            );
+
             // Separator line at bottom
             painter.line_segment(
                 [
@@ -318,7 +462,15 @@ impl TimelinePane {
     }
 
     /// Render layer rows (timeline content area)
-    fn render_layers(&self, ui: &mut egui::Ui, rect: egui::Rect, theme: &crate::theme::Theme) {
+    fn render_layers(
+        &self,
+        ui: &mut egui::Ui,
+        rect: egui::Rect,
+        theme: &crate::theme::Theme,
+        document: &lightningbeam_core::document::Document,
+        active_layer_id: &Option<uuid::Uuid>,
+        selection: &lightningbeam_core::selection::Selection,
+    ) {
         let painter = ui.painter();
 
         // Theme colors for active/inactive layers
@@ -327,8 +479,8 @@ impl TimelinePane {
         let active_color = active_style.background_color.unwrap_or(egui::Color32::from_rgb(85, 85, 85));
         let inactive_color = inactive_style.background_color.unwrap_or(egui::Color32::from_rgb(136, 136, 136));
 
-        // Test: Draw 3 layer rows
-        for i in 0..3 {
+        // Draw layer rows from document (reversed so newest layers appear on top)
+        for (i, layer) in document.root.children.iter().rev().enumerate() {
             let y = rect.min.y + i as f32 * LAYER_HEIGHT - self.viewport_scroll_y;
 
             // Skip if layer is outside visible area
@@ -342,7 +494,8 @@ impl TimelinePane {
             );
 
             // Active vs inactive background colors
-            let bg_color = if i == self.active_layer {
+            let is_active = active_layer_id.map_or(false, |id| id == layer.id());
+            let bg_color = if is_active {
                 active_color
             } else {
                 inactive_color
@@ -372,6 +525,141 @@ impl TimelinePane {
                 time += interval;
             }
 
+            // Draw clip instances for this layer
+            let clip_instances = match layer {
+                lightningbeam_core::layer::AnyLayer::Vector(vl) => &vl.clip_instances,
+                lightningbeam_core::layer::AnyLayer::Audio(al) => &al.clip_instances,
+                lightningbeam_core::layer::AnyLayer::Video(vl) => &vl.clip_instances,
+            };
+
+            for clip_instance in clip_instances {
+                // Get the clip to determine duration
+                let clip_duration = match layer {
+                    lightningbeam_core::layer::AnyLayer::Vector(_) => {
+                        document.get_vector_clip(&clip_instance.clip_id)
+                            .map(|c| c.duration)
+                    }
+                    lightningbeam_core::layer::AnyLayer::Audio(_) => {
+                        document.get_audio_clip(&clip_instance.clip_id)
+                            .map(|c| c.duration)
+                    }
+                    lightningbeam_core::layer::AnyLayer::Video(_) => {
+                        document.get_video_clip(&clip_instance.clip_id)
+                            .map(|c| c.duration)
+                    }
+                };
+
+                if let Some(clip_duration) = clip_duration {
+                    // Calculate effective duration accounting for trimming
+                    let mut instance_duration = clip_instance.effective_duration(clip_duration);
+
+                    // Instance positioned on the layer's timeline using timeline_start
+                    // The layer itself has start_time, so the absolute timeline position is:
+                    // layer.start_time + instance.timeline_start
+                    let layer_data = layer.layer();
+                    let mut instance_start = clip_instance.timeline_start;
+
+                    // Apply drag offset preview for selected clips
+                    let is_selected = selection.contains_clip_instance(&clip_instance.id);
+
+                    if let Some(drag_type) = self.clip_drag_state {
+                        if is_selected {
+                            match drag_type {
+                                ClipDragType::Move => {
+                                    // Move: shift the entire clip along the timeline
+                                    instance_start += self.drag_offset;
+                                }
+                                ClipDragType::TrimLeft => {
+                                    // Trim left: calculate new trim_start and clamp to valid range
+                                    let new_trim_start = (clip_instance.trim_start + self.drag_offset)
+                                        .max(0.0)
+                                        .min(clip_duration);
+                                    let actual_offset = new_trim_start - clip_instance.trim_start;
+
+                                    // Move start and reduce duration by actual clamped offset
+                                    instance_start = (clip_instance.timeline_start + actual_offset)
+                                        .max(0.0);
+                                    instance_duration = (clip_duration - new_trim_start).max(0.0);
+
+                                    // Adjust for existing trim_end
+                                    if let Some(trim_end) = clip_instance.trim_end {
+                                        instance_duration = (trim_end - new_trim_start).max(0.0);
+                                    }
+                                }
+                                ClipDragType::TrimRight => {
+                                    // Trim right: extend or reduce duration, clamped to available content
+                                    let max_duration = clip_duration - clip_instance.trim_start;
+                                    instance_duration = (instance_duration + self.drag_offset)
+                                        .max(0.0)
+                                        .min(max_duration);
+                                }
+                            }
+                        }
+                    }
+
+                    let instance_end = instance_start + instance_duration;
+
+                    let start_x = self.time_to_x(instance_start);
+                    let end_x = self.time_to_x(instance_end);
+
+                    // Only draw if any part is visible in viewport
+                    if end_x >= 0.0 && start_x <= rect.width() {
+                        let visible_start_x = start_x.max(0.0);
+                        let visible_end_x = end_x.min(rect.width());
+
+                        // Choose color based on layer type
+                        let (clip_color, bright_color) = match layer {
+                            lightningbeam_core::layer::AnyLayer::Vector(_) => (
+                                egui::Color32::from_rgb(100, 150, 255), // Blue
+                                egui::Color32::from_rgb(150, 200, 255), // Bright blue
+                            ),
+                            lightningbeam_core::layer::AnyLayer::Audio(_) => (
+                                egui::Color32::from_rgb(100, 255, 150), // Green
+                                egui::Color32::from_rgb(150, 255, 200), // Bright green
+                            ),
+                            lightningbeam_core::layer::AnyLayer::Video(_) => (
+                                egui::Color32::from_rgb(255, 150, 100), // Orange
+                                egui::Color32::from_rgb(255, 200, 150), // Bright orange
+                            ),
+                        };
+
+                        let clip_rect = egui::Rect::from_min_max(
+                            egui::pos2(rect.min.x + visible_start_x, y + 10.0),
+                            egui::pos2(rect.min.x + visible_end_x, y + LAYER_HEIGHT - 10.0),
+                        );
+
+                        // Draw the clip instance
+                        painter.rect_filled(
+                            clip_rect,
+                            3.0, // Rounded corners
+                            clip_color,
+                        );
+
+                        // Draw border only if selected (brighter version of clip color)
+                        if selection.contains_clip_instance(&clip_instance.id) {
+                            painter.rect_stroke(
+                                clip_rect,
+                                3.0,
+                                egui::Stroke::new(3.0, bright_color),
+                            );
+                        }
+
+                        // Draw clip name if there's space
+                        if let Some(name) = &clip_instance.name {
+                            if clip_rect.width() > 50.0 {
+                                painter.text(
+                                    clip_rect.min + egui::vec2(5.0, 5.0),
+                                    egui::Align2::LEFT_TOP,
+                                    name,
+                                    egui::FontId::proportional(11.0),
+                                    egui::Color32::WHITE,
+                                );
+                            }
+                        }
+                    }
+                }
+            }
+
             // Separator line at bottom
             painter.line_segment(
                 [
@@ -383,8 +671,20 @@ impl TimelinePane {
         }
     }
 
-    /// Handle mouse input for scrubbing, panning, and zooming
-    fn handle_input(&mut self, ui: &mut egui::Ui, full_timeline_rect: egui::Rect, ruler_rect: egui::Rect, content_rect: egui::Rect) {
+    /// Handle mouse input for scrubbing, panning, zooming, layer selection, and clip instance selection
+    fn handle_input(
+        &mut self,
+        ui: &mut egui::Ui,
+        full_timeline_rect: egui::Rect,
+        ruler_rect: egui::Rect,
+        content_rect: egui::Rect,
+        header_rect: egui::Rect,
+        layer_count: usize,
+        document: &lightningbeam_core::document::Document,
+        active_layer_id: &mut Option<uuid::Uuid>,
+        selection: &mut lightningbeam_core::selection::Selection,
+        pending_actions: &mut Vec<Box<dyn lightningbeam_core::action::Action>>,
+    ) {
         let response = ui.allocate_rect(full_timeline_rect, egui::Sense::click_and_drag());
 
         // Only process input if mouse is over the timeline pane
@@ -397,34 +697,358 @@ impl TimelinePane {
 
         let alt_held = ui.input(|i| i.modifiers.alt);
         let ctrl_held = ui.input(|i| i.modifiers.ctrl || i.modifiers.command);
+        let shift_held = ui.input(|i| i.modifiers.shift);
+
+        // Handle clip instance selection by clicking on clip rectangles
+        let mut clicked_clip_instance = false;
+        if response.clicked() && !alt_held {
+            if let Some(pos) = response.interact_pointer_pos() {
+                // Check if click is in content area (not ruler or header column)
+                if pos.y >= header_rect.min.y && pos.x >= content_rect.min.x {
+                    let relative_y = pos.y - header_rect.min.y + self.viewport_scroll_y;
+                    let clicked_layer_index = (relative_y / LAYER_HEIGHT) as usize;
+                    let click_time = self.x_to_time(pos.x - content_rect.min.x);
+
+                    // Get the layer at this index (accounting for reversed display order)
+                    if clicked_layer_index < layer_count {
+                        let layers: Vec<_> = document.root.children.iter().rev().collect();
+                        if let Some(layer) = layers.get(clicked_layer_index) {
+                            let layer_data = layer.layer();
+
+                            // Get clip instances for this layer
+                            let clip_instances = match layer {
+                                lightningbeam_core::layer::AnyLayer::Vector(vl) => &vl.clip_instances,
+                                lightningbeam_core::layer::AnyLayer::Audio(al) => &al.clip_instances,
+                                lightningbeam_core::layer::AnyLayer::Video(vl) => &vl.clip_instances,
+                            };
+
+                            // Check if click is within any clip instance
+                            for clip_instance in clip_instances {
+                                // Get the clip to determine duration
+                                let clip_duration = match layer {
+                                    lightningbeam_core::layer::AnyLayer::Vector(_) => {
+                                        document.get_vector_clip(&clip_instance.clip_id)
+                                            .map(|c| c.duration)
+                                    }
+                                    lightningbeam_core::layer::AnyLayer::Audio(_) => {
+                                        document.get_audio_clip(&clip_instance.clip_id)
+                                            .map(|c| c.duration)
+                                    }
+                                    lightningbeam_core::layer::AnyLayer::Video(_) => {
+                                        document.get_video_clip(&clip_instance.clip_id)
+                                            .map(|c| c.duration)
+                                    }
+                                };
+
+                                if let Some(clip_duration) = clip_duration {
+                                    let instance_duration = clip_instance.effective_duration(clip_duration);
+                                    let instance_start = clip_instance.timeline_start;
+                                    let instance_end = instance_start + instance_duration;
+
+                                    // Check if click is within this clip instance's time range
+                                    if click_time >= instance_start && click_time <= instance_end {
+                                        // Found a clicked clip instance!
+                                        if shift_held {
+                                            // Shift+click: add to selection
+                                            selection.add_clip_instance(clip_instance.id);
+                                        } else {
+                                            // Regular click: select only this clip
+                                            selection.select_only_clip_instance(clip_instance.id);
+                                        }
+                                        clicked_clip_instance = true;
+                                        break;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        // Cache mouse position on mousedown (before any dragging)
+        if response.hovered() && ui.input(|i| i.pointer.button_pressed(egui::PointerButton::Primary)) {
+            if let Some(pos) = response.hover_pos() {
+                self.mousedown_pos = Some(pos);
+            }
+        }
+
+        // Handle clip dragging (only if not panning or scrubbing)
+        if !alt_held && !self.is_scrubbing && !self.is_panning {
+            if response.drag_started() {
+                // Use cached mousedown position for edge detection
+                if let Some(mousedown_pos) = self.mousedown_pos {
+                    if let Some((drag_type, clip_id)) = self.detect_clip_at_pointer(
+                        mousedown_pos,
+                        document,
+                        content_rect,
+                        header_rect,
+                    ) {
+                        // If this clip is not selected, select it (respecting shift key)
+                        if !selection.contains_clip_instance(&clip_id) {
+                            if shift_held {
+                                selection.add_clip_instance(clip_id);
+                            } else {
+                                selection.select_only_clip_instance(clip_id);
+                            }
+                        }
+
+                        // Start dragging with the detected drag type
+                        self.clip_drag_state = Some(drag_type);
+                        self.drag_offset = 0.0;
+                    }
+                }
+            }
+
+            // Update drag offset during drag
+            if self.clip_drag_state.is_some() && response.dragged() {
+                let drag_delta = response.drag_delta();
+                let time_delta = drag_delta.x / self.pixels_per_second;
+                self.drag_offset += time_delta as f64;
+            }
+
+            // End drag - create action based on drag type
+            if let Some(drag_type) = self.clip_drag_state {
+                if response.drag_stopped() {
+                // Build layer_moves map for the action
+                use std::collections::HashMap;
+                let mut layer_moves: HashMap<uuid::Uuid, Vec<(uuid::Uuid, f64, f64)>> =
+                    HashMap::new();
+
+                // Iterate through all layers to find selected clip instances
+                for layer in &document.root.children {
+                    let layer_id = layer.id();
+
+                    // Get clip instances for this layer
+                    let clip_instances = match layer {
+                        lightningbeam_core::layer::AnyLayer::Vector(vl) => &vl.clip_instances,
+                        lightningbeam_core::layer::AnyLayer::Audio(al) => &al.clip_instances,
+                        lightningbeam_core::layer::AnyLayer::Video(vl) => &vl.clip_instances,
+                    };
+
+                    // Find selected clip instances in this layer
+                    for clip_instance in clip_instances {
+                        if selection.contains_clip_instance(&clip_instance.id) {
+                            let old_timeline_start = clip_instance.timeline_start;
+                            let new_timeline_start = old_timeline_start + self.drag_offset;
+
+                            // Add to layer_moves
+                            layer_moves
+                                .entry(layer_id)
+                                .or_insert_with(Vec::new)
+                                .push((clip_instance.id, old_timeline_start, new_timeline_start));
+                        }
+                    }
+                }
+
+                    // Create and add the action based on drag type
+                    match drag_type {
+                        ClipDragType::Move => {
+                            if !layer_moves.is_empty() {
+                                let action = Box::new(
+                                    lightningbeam_core::actions::MoveClipInstancesAction::new(
+                                        layer_moves,
+                                    ),
+                                );
+                                pending_actions.push(action);
+                            }
+                        }
+                        ClipDragType::TrimLeft | ClipDragType::TrimRight => {
+                            // Build layer_trims map for trim action
+                            let mut layer_trims: HashMap<
+                                uuid::Uuid,
+                                Vec<(
+                                    uuid::Uuid,
+                                    lightningbeam_core::actions::TrimType,
+                                    lightningbeam_core::actions::TrimData,
+                                    lightningbeam_core::actions::TrimData,
+                                )>,
+                            > = HashMap::new();
+
+                            // Iterate through all layers to find selected clip instances
+                            for layer in &document.root.children {
+                                let layer_id = layer.id();
+                                let layer_data = layer.layer();
+
+                                let clip_instances = match layer {
+                                    lightningbeam_core::layer::AnyLayer::Vector(vl) => {
+                                        &vl.clip_instances
+                                    }
+                                    lightningbeam_core::layer::AnyLayer::Audio(al) => {
+                                        &al.clip_instances
+                                    }
+                                    lightningbeam_core::layer::AnyLayer::Video(vl) => {
+                                        &vl.clip_instances
+                                    }
+                                };
+
+                                // Find selected clip instances in this layer
+                                for clip_instance in clip_instances {
+                                    if selection.contains_clip_instance(&clip_instance.id) {
+                                        // Get clip duration to validate trim bounds
+                                        let clip_duration = match layer {
+                                            lightningbeam_core::layer::AnyLayer::Vector(_) => {
+                                                document
+                                                    .get_vector_clip(&clip_instance.clip_id)
+                                                    .map(|c| c.duration)
+                                            }
+                                            lightningbeam_core::layer::AnyLayer::Audio(_) => {
+                                                document
+                                                    .get_audio_clip(&clip_instance.clip_id)
+                                                    .map(|c| c.duration)
+                                            }
+                                            lightningbeam_core::layer::AnyLayer::Video(_) => {
+                                                document
+                                                    .get_video_clip(&clip_instance.clip_id)
+                                                    .map(|c| c.duration)
+                                            }
+                                        };
+
+                                        if let Some(clip_duration) = clip_duration {
+                                            match drag_type {
+                                                ClipDragType::TrimLeft => {
+                                                    let old_trim_start = clip_instance.trim_start;
+                                                    let old_timeline_start =
+                                                        clip_instance.timeline_start;
+
+                                                    // New trim_start is clamped to valid range
+                                                    let new_trim_start = (old_trim_start
+                                                        + self.drag_offset)
+                                                        .max(0.0)
+                                                        .min(clip_duration);
+
+                                                    // Calculate actual offset after clamping
+                                                    let actual_offset = new_trim_start - old_trim_start;
+                                                    let new_timeline_start =
+                                                        old_timeline_start + actual_offset;
+
+                                                    layer_trims
+                                                        .entry(layer_id)
+                                                        .or_insert_with(Vec::new)
+                                                        .push((
+                                                            clip_instance.id,
+                                                            lightningbeam_core::actions::TrimType::TrimLeft,
+                                                            lightningbeam_core::actions::TrimData::left(
+                                                                old_trim_start,
+                                                                old_timeline_start,
+                                                            ),
+                                                            lightningbeam_core::actions::TrimData::left(
+                                                                new_trim_start,
+                                                                new_timeline_start,
+                                                            ),
+                                                        ));
+                                                }
+                                                ClipDragType::TrimRight => {
+                                                    let old_trim_end = clip_instance.trim_end;
+
+                                                    // Calculate new trim_end based on current duration
+                                                    let current_duration =
+                                                        clip_instance.effective_duration(clip_duration);
+                                                    let new_duration =
+                                                        (current_duration + self.drag_offset).max(0.0);
+
+                                                    // Convert new duration back to trim_end value
+                                                    let new_trim_end = if new_duration >= clip_duration {
+                                                        None // Use full clip duration
+                                                    } else {
+                                                        Some((clip_instance.trim_start + new_duration).min(clip_duration))
+                                                    };
+
+                                                    layer_trims
+                                                        .entry(layer_id)
+                                                        .or_insert_with(Vec::new)
+                                                        .push((
+                                                            clip_instance.id,
+                                                            lightningbeam_core::actions::TrimType::TrimRight,
+                                                            lightningbeam_core::actions::TrimData::right(
+                                                                old_trim_end,
+                                                            ),
+                                                            lightningbeam_core::actions::TrimData::right(
+                                                                new_trim_end,
+                                                            ),
+                                                        ));
+                                                }
+                                                _ => {}
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+
+                            // Create and add the trim action if there are any trims
+                            if !layer_trims.is_empty() {
+                                let action = Box::new(
+                                    lightningbeam_core::actions::TrimClipInstancesAction::new(
+                                        layer_trims,
+                                    ),
+                                );
+                                pending_actions.push(action);
+                            }
+                        }
+                    }
+
+                    // Reset drag state
+                    self.clip_drag_state = None;
+                    self.drag_offset = 0.0;
+                    self.mousedown_pos = None;
+                }
+            }
+        }
+
+        // Handle layer selection by clicking on layer header or content (only if no clip was clicked)
+        if response.clicked() && !alt_held && !clicked_clip_instance {
+            if let Some(pos) = response.interact_pointer_pos() {
+                // Check if click is in header or content area (not ruler)
+                if pos.y >= header_rect.min.y {
+                    let relative_y = pos.y - header_rect.min.y + self.viewport_scroll_y;
+                    let clicked_layer_index = (relative_y / LAYER_HEIGHT) as usize;
+
+                    // Get the layer at this index (accounting for reversed display order)
+                    if clicked_layer_index < layer_count {
+                        let layers: Vec<_> = document.root.children.iter().rev().collect();
+                        if let Some(layer) = layers.get(clicked_layer_index) {
+                            *active_layer_id = Some(layer.id());
+                            // Clear clip instance selection when clicking on empty layer area
+                            if !shift_held {
+                                selection.clear_clip_instances();
+                            }
+                        }
+                    }
+                }
+            }
+        }
 
         // Get mouse position relative to content area
         let mouse_pos = response.hover_pos().unwrap_or(content_rect.center());
         let mouse_x = (mouse_pos.x - content_rect.min.x).max(0.0);
 
         // Calculate max vertical scroll based on number of layers
-        // TODO: Get actual layer count from document - for now using test count of 3
-        const TEST_LAYER_COUNT: usize = 3;
-        let total_content_height = TEST_LAYER_COUNT as f32 * LAYER_HEIGHT;
+        let total_content_height = layer_count as f32 * LAYER_HEIGHT;
         let visible_height = content_rect.height();
         let max_scroll_y = (total_content_height - visible_height).max(0.0);
 
         // Scrubbing (clicking/dragging on ruler, but only when not panning)
-        if ruler_rect.contains(ui.input(|i| i.pointer.hover_pos().unwrap_or_default())) && !alt_held {
-            if response.clicked() || (response.dragged() && !self.is_panning) {
+        let cursor_over_ruler = ruler_rect.contains(ui.input(|i| i.pointer.hover_pos().unwrap_or_default()));
+
+        // Start scrubbing if cursor is over ruler and we click/drag
+        if cursor_over_ruler && !alt_held && (response.clicked() || (response.dragged() && !self.is_panning)) {
             if let Some(pos) = response.interact_pointer_pos() {
                 let x = (pos.x - content_rect.min.x).max(0.0);
-                    self.current_time = self.x_to_time(x).max(0.0).min(self.duration);
+                self.current_time = self.x_to_time(x).max(0.0);
                 self.is_scrubbing = true;
             }
-            } else if !response.dragged() {
-                self.is_scrubbing = false;
         }
-        } else {
-            if !response.dragged() {
-                self.is_scrubbing = false;
+        // Continue scrubbing while dragging, even if cursor leaves ruler
+        else if self.is_scrubbing && response.dragged() && !self.is_panning {
+            if let Some(pos) = response.interact_pointer_pos() {
+                let x = (pos.x - content_rect.min.x).max(0.0);
+                self.current_time = self.x_to_time(x).max(0.0);
             }
         }
+        // Stop scrubbing when drag ends
+        else if !response.dragged() {
+            self.is_scrubbing = false;
+        }
 
         // Distinguish between mouse wheel (discrete) and trackpad (smooth)
         let mut handled = false;
@@ -492,6 +1116,29 @@ impl TimelinePane {
                 self.last_pan_pos = None;
             }
         }
+
+        // Update cursor based on hover position (only if not scrubbing or panning)
+        if !self.is_scrubbing && !self.is_panning {
+            // If dragging a clip with trim, keep the resize cursor
+            if let Some(drag_type) = self.clip_drag_state {
+                if drag_type != ClipDragType::Move {
+                    ui.ctx().set_cursor_icon(egui::CursorIcon::ResizeHorizontal);
+                }
+            } else if let Some(hover_pos) = response.hover_pos() {
+                // Not dragging - detect hover for cursor feedback
+                if let Some((drag_type, _clip_id)) = self.detect_clip_at_pointer(
+                    hover_pos,
+                    document,
+                    content_rect,
+                    header_rect,
+                ) {
+                    // Set cursor for trim operations
+                    if drag_type != ClipDragType::Move {
+                        ui.ctx().set_cursor_icon(egui::CursorIcon::ResizeHorizontal);
+                    }
+                }
+            }
+        }
     }
 }
 
@@ -558,6 +1205,48 @@ impl PaneRenderer for TimelinePane {
         _path: &NodePath,
         shared: &mut SharedPaneState,
     ) {
+        // Sync timeline's current_time to document
+        shared.action_executor.document_mut().current_time = self.current_time;
+
+        // Get document from action executor
+        let document = shared.action_executor.document();
+        let layer_count = document.root.children.len();
+
+        // Calculate project duration from last clip endpoint across all layers
+        let mut max_endpoint: f64 = 10.0; // Default minimum duration
+        for layer in &document.root.children {
+            let clip_instances = match layer {
+                lightningbeam_core::layer::AnyLayer::Vector(vl) => &vl.clip_instances,
+                lightningbeam_core::layer::AnyLayer::Audio(al) => &al.clip_instances,
+                lightningbeam_core::layer::AnyLayer::Video(vl) => &vl.clip_instances,
+            };
+
+            for clip_instance in clip_instances {
+                // Get clip duration
+                let clip_duration = match layer {
+                    lightningbeam_core::layer::AnyLayer::Vector(_) => {
+                        document.get_vector_clip(&clip_instance.clip_id)
+                            .map(|c| c.duration)
+                    }
+                    lightningbeam_core::layer::AnyLayer::Audio(_) => {
+                        document.get_audio_clip(&clip_instance.clip_id)
+                            .map(|c| c.duration)
+                    }
+                    lightningbeam_core::layer::AnyLayer::Video(_) => {
+                        document.get_video_clip(&clip_instance.clip_id)
+                            .map(|c| c.duration)
+                    }
+                };
+
+                if let Some(clip_duration) = clip_duration {
+                    let instance_duration = clip_instance.effective_duration(clip_duration);
+                    let instance_end = clip_instance.timeline_start + instance_duration;
+                    max_endpoint = max_endpoint.max(instance_end);
+                }
+            }
+        }
+        self.duration = max_endpoint;
+
         // Split into layer header column (left) and timeline content (right)
         let header_column_rect = egui::Rect::from_min_size(
             rect.min,
@@ -605,7 +1294,7 @@ impl PaneRenderer for TimelinePane {
 
         // Render layer header column with clipping
         ui.set_clip_rect(layer_headers_rect.intersect(original_clip_rect));
-        self.render_layer_headers(ui, layer_headers_rect, shared.theme);
+        self.render_layer_headers(ui, layer_headers_rect, shared.theme, document, shared.active_layer_id);
 
         // Render time ruler (clip to ruler rect)
         ui.set_clip_rect(ruler_rect.intersect(original_clip_rect));
@@ -613,7 +1302,7 @@ impl PaneRenderer for TimelinePane {
 
         // Render layer rows with clipping
         ui.set_clip_rect(content_rect.intersect(original_clip_rect));
-        self.render_layers(ui, content_rect, shared.theme);
+        self.render_layers(ui, content_rect, shared.theme, document, shared.active_layer_id, shared.selection);
 
         // Render playhead on top (clip to timeline area)
         ui.set_clip_rect(timeline_rect.intersect(original_clip_rect));
@@ -623,7 +1312,18 @@ impl PaneRenderer for TimelinePane {
         ui.set_clip_rect(original_clip_rect);
 
         // Handle input (use full rect including header column)
-        self.handle_input(ui, rect, ruler_rect, content_rect);
+        self.handle_input(
+            ui,
+            rect,
+            ruler_rect,
+            content_rect,
+            layer_headers_rect,
+            layer_count,
+            document,
+            shared.active_layer_id,
+            shared.selection,
+            shared.pending_actions,
+        );
 
         // Register handler for pending view actions (two-phase dispatch)
         // Priority: Mouse-over (0-99) > Fallback Timeline(1001)