Fix: apply edited `DragValue` when it looses focus (#3776)

* Closes https://github.com/emilk/egui/issues/2877
* Closes https://github.com/emilk/egui/pull/3451

crates/egui/src/context.rs

@@ -1608,8 +1608,7 @@ impl ContextImpl {
 
         viewport.repaint.frame_nr += 1;
 
-        self.memory
+        self.memory.end_frame(&viewport.frame_state.used_ids);
-            .end_frame(&viewport.input, &viewport.frame_state.used_ids);
 
         if let Some(fonts) = self.fonts.get(&pixels_per_point.into()) {
             let tex_mngr = &mut self.tex_manager.0.write();

crates/egui/src/memory.rs

@@ -5,8 +5,7 @@ use epaint::{emath::Rangef, vec2, Vec2};
 use crate::{
     area,
     window::{self, WindowInteraction},
-    EventFilter, Id, IdMap, InputState, LayerId, Pos2, Rect, Style, ViewportId, ViewportIdMap,
+    EventFilter, Id, IdMap, LayerId, Pos2, Rect, Style, ViewportId, ViewportIdMap, ViewportIdSet,
-    ViewportIdSet,
 };
 
 // ----------------------------------------------------------------------------
@@ -79,9 +78,6 @@ pub struct Memory {
     #[cfg_attr(feature = "persistence", serde(skip))]
     pub(crate) viewport_id: ViewportId,
 
-    #[cfg_attr(feature = "persistence", serde(skip))]
-    pub(crate) drag_value: crate::widgets::drag_value::MonoState,
-
     /// Which popup-window is open (if any)?
     /// Could be a combo box, color picker, menu etc.
     #[cfg_attr(feature = "persistence", serde(skip))]
@@ -111,7 +107,6 @@ impl Default for Memory {
             interactions: Default::default(),
             viewport_id: Default::default(),
             window_interactions: Default::default(),
-            drag_value: Default::default(),
             areas: Default::default(),
             popup: Default::default(),
             everything_is_visible: Default::default(),
@@ -587,11 +582,10 @@ impl Memory {
         }
     }
 
-    pub(crate) fn end_frame(&mut self, input: &InputState, used_ids: &IdMap<Rect>) {
+    pub(crate) fn end_frame(&mut self, used_ids: &IdMap<Rect>) {
         self.caches.update();
         self.areas_mut().end_frame();
         self.interaction_mut().focus.end_frame(used_ids);
-        self.drag_value.end_frame(input);
     }
 
     pub(crate) fn set_viewport_id(&mut self, viewport_id: ViewportId) {

crates/egui/src/util/id_type_map.rs

@@ -476,13 +476,22 @@ impl IdTypeMap {
         }
     }
 
-    /// Remove the state of this type an id.
+    /// Remove the state of this type and id.
     #[inline]
     pub fn remove<T: 'static>(&mut self, id: Id) {
         let hash = hash(TypeId::of::<T>(), id);
         self.map.remove(&hash);
     }
 
+    /// Remove and fetch the state of this type and id.
+    #[inline]
+    pub fn remove_temp<T: 'static + Clone>(&mut self, id: Id) -> Option<T> {
+        let hash = hash(TypeId::of::<T>(), id);
+        self.map
+            .remove(&hash)
+            .and_then(|element| element.get_temp().cloned())
+    }
+
     /// Note all state of the given type.
     pub fn remove_by_type<T: 'static>(&mut self) {
         let key = TypeId::of::<T>();

crates/egui/src/widgets/drag_value.rs

@@ -6,28 +6,6 @@ use crate::*;
 
 // ----------------------------------------------------------------------------
 
-/// Same state for all [`DragValue`]s.
-#[derive(Clone, Debug, Default)]
-pub(crate) struct MonoState {
-    last_dragged_id: Option<Id>,
-    last_dragged_value: Option<f64>,
-
-    /// For temporary edit of a [`DragValue`] value.
-    /// Couples with the current focus id.
-    edit_string: Option<String>,
-}
-
-impl MonoState {
-    pub(crate) fn end_frame(&mut self, input: &InputState) {
-        if input.pointer.any_pressed() || input.pointer.any_released() {
-            self.last_dragged_id = None;
-            self.last_dragged_value = None;
-        }
-    }
-}
-
-// ----------------------------------------------------------------------------
-
 type NumFormatter<'a> = Box<dyn 'a + Fn(f64, RangeInclusive<usize>) -> String>;
 type NumParser<'a> = Box<dyn 'a + Fn(&str) -> Option<f64>>;
 
@@ -402,13 +380,13 @@ impl<'a> Widget for DragValue<'a> {
         // screen readers.
         let is_kb_editing = ui.memory_mut(|mem| {
             mem.interested_in_focus(id);
-            let is_kb_editing = mem.has_focus(id);
+            mem.has_focus(id)
-            if mem.gained_focus(id) {
-                mem.drag_value.edit_string = None;
-            }
-            is_kb_editing
         });
 
+        if ui.memory_mut(|mem| mem.gained_focus(id)) {
+            ui.data_mut(|data| data.remove::<String>(id));
+        }
+
         let old_value = get(&mut get_set_value);
         let mut value = old_value;
         let aim_rad = ui.input(|i| i.aim_radius() as f64);
@@ -467,7 +445,7 @@ impl<'a> Widget for DragValue<'a> {
         value = clamp_to_range(value, clamp_range.clone());
         if old_value != value {
             set(&mut get_set_value, value);
-            ui.memory_mut(|mem| mem.drag_value.edit_string = None);
+            ui.data_mut(|data| data.remove::<String>(id));
         }
 
         let value_text = match custom_formatter {
@@ -483,11 +461,27 @@ impl<'a> Widget for DragValue<'a> {
 
         let text_style = ui.style().drag_value_text_style.clone();
 
+        if ui.memory(|mem| mem.lost_focus(id)) {
+            let value_text = ui.data_mut(|data| data.remove_temp::<String>(id));
+            if let Some(value_text) = value_text {
+                // We were editing the value as text last frame, but lost focus.
+                // Make sure we applied the last text value:
+                let parsed_value = match &custom_parser {
+                    Some(parser) => parser(&value_text),
+                    None => value_text.parse().ok(),
+                };
+                if let Some(parsed_value) = parsed_value {
+                    let parsed_value = clamp_to_range(parsed_value, clamp_range.clone());
+                    set(&mut get_set_value, parsed_value);
+                }
+            }
+        }
+
         // some clones below are redundant if AccessKit is disabled
         #[allow(clippy::redundant_clone)]
         let mut response = if is_kb_editing {
             let mut value_text = ui
-                .memory_mut(|mem| mem.drag_value.edit_string.take())
+                .data_mut(|data| data.remove_temp::<String>(id))
                 .unwrap_or_else(|| value_text.clone());
             let response = ui.add(
                 TextEdit::singleline(&mut value_text)
@@ -509,7 +503,7 @@ impl<'a> Widget for DragValue<'a> {
                 response.lost_focus()
             };
             if update {
-                let parsed_value = match custom_parser {
+                let parsed_value = match &custom_parser {
                     Some(parser) => parser(&value_text),
                     None => value_text.parse().ok(),
                 };
@@ -518,7 +512,7 @@ impl<'a> Widget for DragValue<'a> {
                     set(&mut get_set_value, parsed_value);
                 }
             }
-            ui.memory_mut(|mem| mem.drag_value.edit_string = Some(value_text));
+            ui.data_mut(|data| data.insert_temp(id, value_text));
             response
         } else {
             let button = Button::new(
@@ -533,7 +527,7 @@ impl<'a> Widget for DragValue<'a> {
             let mut response = response.on_hover_cursor(CursorIcon::ResizeHorizontal);
 
             if ui.style().explanation_tooltips {
-                response = response .on_hover_text(format!(
+                response = response.on_hover_text(format!(
                     "{}{}{}\nDrag to edit or click to enter a value.\nPress 'Shift' while dragging for better control.",
                     prefix,
                     value as f32, // Show full precision value on-hover. TODO(emilk): figure out f64 vs f32
@@ -541,15 +535,18 @@ impl<'a> Widget for DragValue<'a> {
                 ));
             }
 
+            if ui.input(|i| i.pointer.any_pressed() || i.pointer.any_released()) {
+                // Reset memory of preciely dagged value.
+                ui.data_mut(|data| data.remove::<f64>(id));
+            }
+
             if response.clicked() {
-                ui.memory_mut(|mem| {
+                ui.data_mut(|data| data.remove::<String>(id));
-                    mem.drag_value.edit_string = None;
+                ui.memory_mut(|mem| mem.request_focus(id));
-                    mem.request_focus(id);
-                });
                 let mut state = TextEdit::load_state(ui.ctx(), id).unwrap_or_default();
                 state.set_ccursor_range(Some(text::CCursorRange::two(
-                    epaint::text::cursor::CCursor::default(),
+                    text::CCursor::default(),
-                    epaint::text::cursor::CCursor::new(value_text.chars().count()),
+                    text::CCursor::new(value_text.chars().count()),
                 )));
                 state.store(ui.ctx(), response.id);
             } else if response.dragged() {
@@ -563,28 +560,22 @@ impl<'a> Widget for DragValue<'a> {
                 let delta_value = delta_points as f64 * speed;
 
                 if delta_value != 0.0 {
-                    let mut drag_state = ui.memory_mut(|mem| std::mem::take(&mut mem.drag_value));
-
                     // Since we round the value being dragged, we need to store the full precision value in memory:
-                    let stored_value = (drag_state.last_dragged_id == Some(response.id))
+                    let precise_value = ui.data_mut(|data| data.get_temp::<f64>(id));
-                        .then_some(drag_state.last_dragged_value)
+                    let precise_value = precise_value.unwrap_or(value);
-                        .flatten();
+                    let precise_value = precise_value + delta_value;
-                    let stored_value = stored_value.unwrap_or(value);
-                    let stored_value = stored_value + delta_value;
 
                     let aim_delta = aim_rad * speed;
                     let rounded_new_value = emath::smart_aim::best_in_range_f64(
-                        stored_value - aim_delta,
+                        precise_value - aim_delta,
-                        stored_value + aim_delta,
+                        precise_value + aim_delta,
                     );
                     let rounded_new_value =
                         emath::round_to_decimals(rounded_new_value, auto_decimals);
                     let rounded_new_value = clamp_to_range(rounded_new_value, clamp_range.clone());
                     set(&mut get_set_value, rounded_new_value);
 
-                    drag_state.last_dragged_id = Some(response.id);
+                    ui.data_mut(|data| data.insert_temp::<f64>(id, precise_value));
-                    drag_state.last_dragged_value = Some(stored_value);
-                    ui.memory_mut(|mem| mem.drag_value = drag_state);
                 }
             }
 

crates/egui_extras/src/table.rs

@@ -634,11 +634,8 @@ impl<'a> Table<'a> {
             // Hide first-frame-jitters when auto-sizing.
             ui.add_visible_ui(!first_frame_auto_size_columns, |ui| {
                 let hovered_row_index_id = self.state_id.with("__table_hovered_row");
-                let hovered_row_index = ui.memory_mut(|w| {
+                let hovered_row_index =
-                    let hovered_row = w.data.get_temp(hovered_row_index_id);
+                    ui.data_mut(|data| data.remove_temp::<usize>(hovered_row_index_id));
-                    w.data.remove::<usize>(hovered_row_index_id);
-                    hovered_row
-                });
 
                 let layout = StripLayout::new(ui, CellDirection::Horizontal, cell_layout, sense);