Put everything in Context behind the same Mutex (#1050)

* Move all interior mutability from Context to CtxRef and make it a handle
* Rename `CtxRef` to `Context`
* The old `Context` is now `ContextImpl` and is non-pub
* Add benchmark Painter::rect

Co-authored-by: Daniel Keller <dklr433@gmail.com>

CHANGELOG.md

@@ -11,12 +11,21 @@ NOTE: [`epaint`](epaint/CHANGELOG.md), [`eframe`](eframe/CHANGELOG.md), [`egui_w
 * Added `Ui::add_visible` and `Ui::add_visible_ui`.
 
 ### Changed 🔧
+* ⚠️ `Context::input` and `Ui::input` now locks a mutex. This can lead to a dead-lock is used in an `if let` binding!
+  * `if let Some(pos) = ui.input().pointer.latest_pos()` and similar must now be rewritten on two lines, or with added `{}` around the righ-hand-side.
+  * Search for this problem in your code using the regex `if let .*input`.
+* Renamed `CtxRef` to `Context` ([#1050](https://github.com/emilk/egui/pull/1050)).
+* `Context` can now be cloned and stored between frames ([#1050](https://github.com/emilk/egui/pull/1050)).
 * Renamed `Ui::visible` to `Ui::is_visible`.
 * Split `Event::Text` into `Event::Text` and `Event::Paste` ([#1058](https://github.com/emilk/egui/pull/1058)).
 
 ### Fixed 🐛
 * Context menu now respects the theme ([#1043](https://github.com/emilk/egui/pull/1043))
 
+### Contributors 🙏
+* [danielkeller](https://github.com/danielkeller): [#1050](https://github.com/emilk/egui/pull/1050).
+
+
 ## 0.16.1 - 2021-12-31 - Add back `CtxRef::begin_frame,end_frame`
 
 ### Added ⭐

README.md

@@ -365,6 +365,7 @@ Notable contributions by:
 * [@AlexApps99](https://github.com/AlexApps99): [`egui_glow`](https://github.com/emilk/egui/pull/685).
 * [@mankinskin](https://github.com/mankinskin): [Context menus](https://github.com/emilk/egui/pull/543).
 * [@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).
 * 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).

eframe/examples/custom_font.rs

@@ -19,7 +19,7 @@ impl epi::App for MyApp {
 
     fn setup(
         &mut self,
-        ctx: &egui::CtxRef,
+        ctx: &egui::Context,
         _frame: &epi::Frame,
         _storage: Option<&dyn epi::Storage>,
     ) {
@@ -51,7 +51,7 @@ impl epi::App for MyApp {
         ctx.set_fonts(fonts);
     }
 
-    fn update(&mut self, ctx: &egui::CtxRef, _frame: &epi::Frame) {
+    fn update(&mut self, ctx: &egui::Context, _frame: &epi::Frame) {
         egui::CentralPanel::default().show(ctx, |ui| {
             ui.heading("egui using custom fonts");
             ui.text_edit_multiline(&mut self.text);

eframe/examples/file_dialog.rs

@@ -13,7 +13,7 @@ impl epi::App for MyApp {
         "Native file dialogs and drag-and-drop files"
     }
 
-    fn update(&mut self, ctx: &egui::CtxRef, _frame: &epi::Frame) {
+    fn update(&mut self, ctx: &egui::Context, _frame: &epi::Frame) {
         egui::CentralPanel::default().show(ctx, |ui| {
             ui.label("Drag-and-drop files onto the window!");
 
@@ -57,7 +57,7 @@ impl epi::App for MyApp {
 }
 
 impl MyApp {
-    fn detect_files_being_dropped(&mut self, ctx: &egui::CtxRef) {
+    fn detect_files_being_dropped(&mut self, ctx: &egui::Context) {
         use egui::*;
 
         // Preview hovering files:

eframe/examples/hello_world.rs

@@ -21,7 +21,7 @@ impl epi::App for MyApp {
         "My egui App"
     }
 
-    fn update(&mut self, ctx: &egui::CtxRef, frame: &epi::Frame) {
+    fn update(&mut self, ctx: &egui::Context, frame: &epi::Frame) {
         let Self { name, age } = self;
 
         egui::CentralPanel::default().show(ctx, |ui| {

eframe/examples/image.rs

@@ -12,7 +12,7 @@ impl epi::App for MyApp {
         "Show an image with eframe/egui"
     }
 
-    fn update(&mut self, ctx: &egui::CtxRef, frame: &epi::Frame) {
+    fn update(&mut self, ctx: &egui::Context, frame: &epi::Frame) {
         if self.texture.is_none() {
             // Load the image:
             let image_data = include_bytes!("rust-logo-256x256.png");

eframe/src/lib.rs

@@ -26,7 +26,7 @@
 //!        "My egui App"
 //!    }
 //!
-//!    fn update(&mut self, ctx: &egui::CtxRef, frame: &epi::Frame) {
+//!    fn update(&mut self, ctx: &egui::Context, frame: &epi::Frame) {
 //!        egui::CentralPanel::default().show(ctx, |ui| {
 //!            ui.heading("Hello World!");
 //!        });
@@ -129,7 +129,7 @@ pub fn start_web(canvas_id: &str, app: Box<dyn epi::App>) -> Result<(), wasm_bin
 ///        "My egui App"
 ///    }
 ///
-///    fn update(&mut self, ctx: &egui::CtxRef, frame: &epi::Frame) {
+///    fn update(&mut self, ctx: &egui::Context, frame: &epi::Frame) {
 ///        egui::CentralPanel::default().show(ctx, |ui| {
 ///            ui.heading("Hello World!");
 ///        });
@@ -160,7 +160,7 @@ pub fn run_native(app: Box<dyn epi::App>, native_options: epi::NativeOptions) ->
 ///        "My egui App"
 ///    }
 ///
-///    fn update(&mut self, ctx: &egui::CtxRef, frame: &epi::Frame) {
+///    fn update(&mut self, ctx: &egui::Context, frame: &epi::Frame) {
 ///        egui::CentralPanel::default().show(ctx, |ui| {
 ///            ui.heading("Hello World!");
 ///        });

egui-winit/src/epi.rs

@@ -191,7 +191,7 @@ impl Persistence {
 pub struct EpiIntegration {
     frame: epi::Frame,
     persistence: crate::epi::Persistence,
-    pub egui_ctx: egui::CtxRef,
+    pub egui_ctx: egui::Context,
     egui_winit: crate::State,
     pub app: Box<dyn epi::App>,
     /// When set, it is time to quit
@@ -206,7 +206,7 @@ impl EpiIntegration {
         persistence: crate::epi::Persistence,
         app: Box<dyn epi::App>,
     ) -> Self {
-        let egui_ctx = egui::CtxRef::default();
+        let egui_ctx = egui::Context::default();
 
         *egui_ctx.memory() = persistence.load_memory().unwrap_or_default();
 
@@ -250,7 +250,7 @@ impl EpiIntegration {
     }
 
     fn warm_up(&mut self, window: &winit::window::Window) {
-        let saved_memory = self.egui_ctx.memory().clone();
+        let saved_memory: egui::Memory = self.egui_ctx.memory().clone();
         self.egui_ctx.memory().set_everything_is_visible(true);
         let (_, tex_alloc_data, _) = self.update(window);
         self.frame.lock().output.tex_allocation_data = tex_alloc_data; // handle it next frame

egui/src/containers/area.rs

@@ -176,7 +176,7 @@ pub(crate) struct Prepared {
 impl Area {
     pub fn show<R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
         let prepared = self.begin(ctx);
@@ -186,7 +186,7 @@ impl Area {
         InnerResponse { inner, response }
     }
 
-    pub(crate) fn begin(self, ctx: &CtxRef) -> Prepared {
+    pub(crate) fn begin(self, ctx: &Context) -> Prepared {
         let Area {
             id,
             movable,
@@ -234,7 +234,7 @@ impl Area {
         }
     }
 
-    pub fn show_open_close_animation(&self, ctx: &CtxRef, frame: &Frame, is_open: bool) {
+    pub fn show_open_close_animation(&self, ctx: &Context, frame: &Frame, is_open: bool) {
         // must be called first so animation managers know the latest state
         let visibility_factor = ctx.animate_bool(self.id.with("close_animation"), is_open);
 
@@ -276,7 +276,7 @@ impl Prepared {
         self.drag_bounds
     }
 
-    pub(crate) fn content_ui(&self, ctx: &CtxRef) -> Ui {
+    pub(crate) fn content_ui(&self, ctx: &Context) -> Ui {
         let screen_rect = ctx.input().screen_rect();
 
         let bounds = if let Some(bounds) = self.drag_bounds {
@@ -317,7 +317,7 @@ impl Prepared {
     }
 
     #[allow(clippy::needless_pass_by_value)] // intentional to swallow up `content_ui`.
-    pub(crate) fn end(self, ctx: &CtxRef, content_ui: Ui) -> Response {
+    pub(crate) fn end(self, ctx: &Context, content_ui: Ui) -> Response {
         let Prepared {
             layer_id,
             mut state,
@@ -370,8 +370,9 @@ impl Prepared {
 }
 
 fn pointer_pressed_on_area(ctx: &Context, layer_id: LayerId) -> bool {
-    if let Some(pointer_pos) = ctx.input().pointer.interact_pos() {
-        ctx.input().pointer.any_pressed() && ctx.layer_id_at(pointer_pos) == Some(layer_id)
+    if let Some(pointer_pos) = ctx.pointer_interact_pos() {
+        let any_pressed = ctx.input().pointer.any_pressed();
+        any_pressed && ctx.layer_id_at(pointer_pos) == Some(layer_id)
     } else {
         false
     }

egui/src/containers/panel.rs

@@ -199,7 +199,7 @@ impl SidePanel {
         let mut is_resizing = false;
         if resizable {
             let resize_id = id.with("__resize");
-            if let Some(pointer) = ui.input().pointer.latest_pos() {
+            if let Some(pointer) = ui.ctx().latest_pointer_pos() {
                 let we_are_on_top = ui
                     .ctx()
                     .layer_id_at(pointer)
@@ -284,7 +284,7 @@ impl SidePanel {
     /// Show the panel at the top level.
     pub fn show<R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
         self.show_dyn(ctx, Box::new(add_contents))
@@ -293,7 +293,7 @@ impl SidePanel {
     /// Show the panel at the top level.
     fn show_dyn<'c, R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let layer_id = LayerId::background();
@@ -485,7 +485,8 @@ impl TopBottomPanel {
         let mut is_resizing = false;
         if resizable {
             let resize_id = id.with("__resize");
-            if let Some(pointer) = ui.input().pointer.latest_pos() {
+            let latest_pos = ui.input().pointer.latest_pos();
+            if let Some(pointer) = latest_pos {
                 let we_are_on_top = ui
                     .ctx()
                     .layer_id_at(pointer)
@@ -570,7 +571,7 @@ impl TopBottomPanel {
     /// Show the panel at the top level.
     pub fn show<R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
         self.show_dyn(ctx, Box::new(add_contents))
@@ -579,7 +580,7 @@ impl TopBottomPanel {
     /// Show the panel at the top level.
     fn show_dyn<'c, R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let layer_id = LayerId::background();
@@ -670,7 +671,7 @@ impl CentralPanel {
     /// Show the panel at the top level.
     pub fn show<R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
         self.show_dyn(ctx, Box::new(add_contents))
@@ -679,7 +680,7 @@ impl CentralPanel {
     /// Show the panel at the top level.
     fn show_dyn<'c, R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> InnerResponse<R> {
         let available_rect = ctx.available_rect();

egui/src/containers/popup.rs

@@ -66,7 +66,11 @@ impl MonoState {
 /// }
 /// # });
 /// ```
-pub fn show_tooltip<R>(ctx: &CtxRef, id: Id, add_contents: impl FnOnce(&mut Ui) -> R) -> Option<R> {
+pub fn show_tooltip<R>(
+    ctx: &Context,
+    id: Id,
+    add_contents: impl FnOnce(&mut Ui) -> R,
+) -> Option<R> {
     show_tooltip_at_pointer(ctx, id, add_contents)
 }
 
@@ -88,7 +92,7 @@ pub fn show_tooltip<R>(ctx: &CtxRef, id: Id, add_contents: impl FnOnce(&mut Ui)
 /// # });
 /// ```
 pub fn show_tooltip_at_pointer<R>(
-    ctx: &CtxRef,
+    ctx: &Context,
     id: Id,
     add_contents: impl FnOnce(&mut Ui) -> R,
 ) -> Option<R> {
@@ -104,7 +108,7 @@ pub fn show_tooltip_at_pointer<R>(
 ///
 /// If the tooltip does not fit under the area, it tries to place it above it instead.
 pub fn show_tooltip_for<R>(
-    ctx: &CtxRef,
+    ctx: &Context,
     id: Id,
     rect: &Rect,
     add_contents: impl FnOnce(&mut Ui) -> R,
@@ -129,7 +133,7 @@ pub fn show_tooltip_for<R>(
 ///
 /// Returns `None` if the tooltip could not be placed.
 pub fn show_tooltip_at<R>(
-    ctx: &CtxRef,
+    ctx: &Context,
     id: Id,
     suggested_position: Option<Pos2>,
     add_contents: impl FnOnce(&mut Ui) -> R,
@@ -146,7 +150,7 @@ pub fn show_tooltip_at<R>(
 }
 
 fn show_tooltip_at_avoid_dyn<'c, R>(
-    ctx: &CtxRef,
+    ctx: &Context,
     mut id: Id,
     suggested_position: Option<Pos2>,
     above: bool,
@@ -229,15 +233,15 @@ fn show_tooltip_at_avoid_dyn<'c, R>(
 /// }
 /// # });
 /// ```
-pub fn show_tooltip_text(ctx: &CtxRef, id: Id, text: impl Into<WidgetText>) -> Option<()> {
+pub fn show_tooltip_text(ctx: &Context, id: Id, text: impl Into<WidgetText>) -> Option<()> {
     show_tooltip(ctx, id, |ui| {
         crate::widgets::Label::new(text).ui(ui);
     })
 }
 
 /// Show a pop-over window.
 fn show_tooltip_area_dyn<'c, R>(
-    ctx: &CtxRef,
+    ctx: &Context,
     id: Id,
     window_pos: Pos2,
     add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,

egui/src/containers/scroll_area.rs

@@ -523,12 +523,11 @@ impl Prepared {
             };
             let content_response = ui.interact(inner_rect, id.with("area"), sense);
 
-            let input = ui.input();
             if content_response.dragged() {
                 for d in 0..2 {
                     if has_bar[d] {
-                        state.offset[d] -= input.pointer.delta()[d];
-                        state.vel[d] = input.pointer.velocity()[d];
+                        state.offset[d] -= ui.input().pointer.delta()[d];
+                        state.vel[d] = ui.input().pointer.velocity()[d];
                         state.scroll_stuck_to_end[d] = false;
                     } else {
                         state.vel[d] = 0.0;
@@ -537,7 +536,7 @@ impl Prepared {
             } else {
                 let stop_speed = 20.0; // Pixels per second.
                 let friction_coeff = 1000.0; // Pixels per second squared.
-                let dt = input.unstable_dt;
+                let dt = ui.input().unstable_dt;
 
                 let friction = friction_coeff * dt;
                 if friction > state.vel.length() || state.vel.length() < stop_speed {

egui/src/containers/window.rs

@@ -235,15 +235,15 @@ impl<'open> Window<'open> {
     #[inline]
     pub fn show<R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> Option<InnerResponse<Option<R>>> {
         self.show_dyn(ctx, Box::new(add_contents))
     }
 
     fn show_dyn<'c, R>(
         self,
-        ctx: &CtxRef,
+        ctx: &Context,
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> Option<InnerResponse<Option<R>>> {
         let Window {
@@ -296,7 +296,7 @@ impl<'open> Window<'open> {
             .and_then(|window_interaction| {
                 // Calculate roughly how much larger the window size is compared to the inner rect
                 let title_bar_height = if with_title_bar {
-                    title.font_height(ctx.fonts(), &ctx.style()) + title_content_spacing
+                    title.font_height(ctx) + title_content_spacing
                 } else {
                     0.0
                 };
@@ -757,7 +757,7 @@ fn show_title_bar(
 ) -> TitleBar {
     let inner_response = ui.horizontal(|ui| {
         let height = title
-            .font_height(ui.fonts(), ui.style())
+            .font_height(ui.ctx())
             .max(ui.spacing().interact_size.y);
         ui.set_min_height(height);