Misc cleanup (#3381)

* Give credit to recent big-time contributors in the main README.md

* Better named profiling scopes

* Document everything in memory.rs

* Better doc-strings

* Add a section about dependencies to the main README.md

* Improve egui_extras docs

* fix typos

README.md

@@ -87,7 +87,7 @@ On Fedora Rawhide you need to run:
 * Extensible: [easy to write your own widgets for egui](https://github.com/emilk/egui/blob/master/crates/egui_demo_lib/src/demo/toggle_switch.rs)
 * Modular: You should be able to use small parts of egui and combine them in new ways
 * Safe: there is no `unsafe` code in egui
-* Minimal dependencies: [`ab_glyph`](https://crates.io/crates/ab_glyph) [`ahash`](https://crates.io/crates/ahash) [`nohash-hasher`](https://crates.io/crates/nohash-hasher) [`parking_lot`](https://crates.io/crates/parking_lot)
+* Minimal dependencies
 
 egui is *not* a framework. egui is a library you call into, not an environment you program for.
 
@@ -99,6 +99,21 @@ egui is *not* a framework. egui is a library you call into, not an environment y
 * Native looking interface
 * Advanced and flexible layouts (that's fundamentally incompatible with immediate mode)
 
+## Dependencies
+`egui` has a minimal set of default dependencies:
+
+* [`ab_glyph`](https://crates.io/crates/ab_glyph)
+* [`ahash`](https://crates.io/crates/ahash)
+* [`nohash-hasher`](https://crates.io/crates/nohash-hasher)
+* [`parking_lot`](https://crates.io/crates/parking_lot)
+
+Heavier dependencies are kept out of `egui`, even as opt-in.
+No code that isn't fully Wasm-friendly is part of `egui`.
+
+To load images into `egui` you can use the official [`egui_extras`](https://github.com/emilk/egui/tree/master/crates/egui_extras) crate.
+
+[`eframe`](https://github.com/emilk/egui/tree/master/crates/eframe) on the other hand has a lot of dependencies, including [`winit`](https://crates.io/crates/winit), [`image`](https://crates.io/crates/image), graphics crates, clipboard crates, etc,
+
 ## Who is egui for?
 
 egui aims to be the best choice when you want a simple way to create a GUI, or you want to add a GUI to a game engine.
@@ -351,6 +366,9 @@ Notable contributions by:
 * [@t18b219k](https://github.com/t18b219k): [Port glow painter to web](https://github.com/emilk/egui/pull/868).
 * [@danielkeller](https://github.com/danielkeller): [`Context` refactor](https://github.com/emilk/egui/pull/1050).
 * [@MaximOsipenko](https://github.com/MaximOsipenko): [`Context` lock refactor](https://github.com/emilk/egui/pull/2625).
+* [@mwcampbell](https://github.com/mwcampbell): [AccessKit](https://github.com/AccessKit/accesskit) [integration](https://github.com/emilk/egui/pull/2294).
+* [@hasenbanck](https://github.com/hasenbanck), [@s-nie](https://github.com/s-nie), [@Wumpf](https://github.com/Wumpf): [`egui-wgpu`](https://github.com/emilk/egui/tree/master/crates/egui-wgpu)
+* [@jprochazk](https://github.com/jprochazk): [egui image API](https://github.com/emilk/egui/issues/3291)
 * And [many more](https://github.com/emilk/egui/graphs/contributors?type=a).
 
 egui is licensed under [MIT](LICENSE-MIT) OR [Apache-2.0](LICENSE-APACHE).

crates/eframe/src/native/run.rs

@@ -970,7 +970,7 @@ mod glow_integration {
             if window.is_minimized() == Some(true) {
                 // On Mac, a minimized Window uses up all CPU:
                 // https://github.com/emilk/egui/issues/325
-                crate::profile_scope!("bg_sleep");
+                crate::profile_scope!("minimized_sleep");
                 std::thread::sleep(std::time::Duration::from_millis(10));
             }
 
@@ -1417,7 +1417,7 @@ mod wgpu_integration {
             if window.is_minimized() == Some(true) {
                 // On Mac, a minimized Window uses up all CPU:
                 // https://github.com/emilk/egui/issues/325
-                crate::profile_scope!("bg_sleep");
+                crate::profile_scope!("minimized_sleep");
                 std::thread::sleep(std::time::Duration::from_millis(10));
             }
 

crates/egui/src/data/output.rs

@@ -84,6 +84,8 @@ pub struct PlatformOutput {
     pub mutable_text_under_cursor: bool,
 
     /// Screen-space position of text edit cursor (used for IME).
+    ///
+    /// Iff `Some`, the user is editing text.
     pub text_cursor_pos: Option<crate::Pos2>,
 
     #[cfg(feature = "accesskit")]

crates/egui/src/memory.rs

@@ -1,3 +1,5 @@
+#![warn(missing_docs)] // Let's keep this file well-documented.` to memory.rs
+
 use epaint::{emath::Rangef, vec2, Vec2};
 
 use crate::{area, window, EventFilter, Id, IdMap, InputState, LayerId, Pos2, Rect, Style};
@@ -17,6 +19,7 @@ use crate::{area, window, EventFilter, Id, IdMap, InputState, LayerId, Pos2, Rec
 #[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
 #[cfg_attr(feature = "persistence", serde(default))]
 pub struct Memory {
+    /// Global egui options.
     pub options: Options,
 
     /// This map stores some superficial state for all widgets with custom [`Id`]s.
@@ -627,21 +630,25 @@ impl Memory {
         self.interaction.focus.focused_widget = None;
     }
 
+    /// Is any widget being dragged?
     #[inline(always)]
     pub fn is_anything_being_dragged(&self) -> bool {
         self.interaction.drag_id.is_some()
     }
 
+    /// Is this specific widget being dragged?
     #[inline(always)]
     pub fn is_being_dragged(&self, id: Id) -> bool {
         self.interaction.drag_id == Some(id)
     }
 
+    /// Set which widget is being dragged.
     #[inline(always)]
     pub fn set_dragged_id(&mut self, id: Id) {
         self.interaction.drag_id = Some(id);
     }
 
+    /// Stop dragging any widget.
     #[inline(always)]
     pub fn stop_dragging(&mut self) {
         self.interaction.drag_id = None;
@@ -663,22 +670,29 @@ impl Memory {
 /// Popups are things like combo-boxes, color pickers, menus etc.
 /// Only one can be be open at a time.
 impl Memory {
+    /// Is the given popup open?
     pub fn is_popup_open(&self, popup_id: Id) -> bool {
         self.popup == Some(popup_id) || self.everything_is_visible()
     }
 
+    /// Is any popup open?
     pub fn any_popup_open(&self) -> bool {
         self.popup.is_some() || self.everything_is_visible()
     }
 
+    /// Open the given popup, and close all other.
     pub fn open_popup(&mut self, popup_id: Id) {
         self.popup = Some(popup_id);
     }
 
+    /// Close the open popup, if any.
     pub fn close_popup(&mut self) {
         self.popup = None;
     }
 
+    /// Toggle the given popup between closed and open.
+    ///
+    /// Note: at most one popup can be open at one time.
     pub fn toggle_popup(&mut self, popup_id: Id) {
         if self.is_popup_open(popup_id) {
             self.close_popup();

crates/egui_extras/README.md

@@ -7,3 +7,15 @@
 ![Apache](https://img.shields.io/badge/license-Apache-blue.svg)
 
 This is a crate that adds some features on top top of [`egui`](https://github.com/emilk/egui). This crate is for experimental features, and features that require big dependencies that do not belong in `egui`.
+
+## Images
+One thing `egui_extras` is commonly used for is to install image loaders for `egui`:
+
+```toml
+egui_extras = { version = "*", features = ["all_loaders"] }
+image = { version = "0.24", features = ["jpeg", "png"] }
+```
+
+```rs
+egui_extras::install_image_loaders(egui_ctx);
+```

crates/egui_extras/src/datepicker/button.rs

@@ -7,6 +7,7 @@ pub(crate) struct DatePickerButtonState {
     pub picker_visible: bool,
 }
 
+/// Shows a date, and will open a date picker popup when clicked.
 pub struct DatePickerButton<'a> {
     selection: &'a mut NaiveDate,
     id_source: Option<&'a str>,

crates/egui_extras/src/lib.rs

@@ -18,7 +18,7 @@ pub mod syntax_highlighting;
 #[doc(hidden)]
 pub mod image;
 mod layout;
-pub mod loaders;
+mod loaders;
 mod sizing;
 mod strip;
 mod table;

crates/emath/src/rect.rs

@@ -13,6 +13,10 @@ use crate::*;
 /// of `min` and `max` are swapped. These are usually a sign of an error.
 ///
 /// Normally the unit is points (logical pixels) in screen space coordinates.
+///
+/// `Rect` does NOT implement `Default`, because there is no obvious default value.
+/// [`Rect::ZERO`] may seem reasonable, but when used as a bounding box, [`Rect::NOTHING`]
+/// is a better default - so be explicit instead!
 #[repr(C)]
 #[derive(Clone, Copy, Eq, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]