Replace Arc<Context> with struct CtxRef

CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Changed 🔧
 
+* `Arc<Context>` has been replaced with `CtxRef` everywhere.
 * Slight tweak of the default `Style` and font sizes.
 * `SidePanel::left` and `TopPanel::top` now takes `impl Hash` as first argument.
 * A `Window` may now cover an existing `CentralPanel`.

egui/benches/benchmark.rs

@@ -4,7 +4,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
     let raw_input = egui::RawInput::default();
 
     {
-        let mut ctx = egui::Context::new();
+        let mut ctx = egui::CtxRef::default();
         let mut demo_windows = egui::demos::DemoWindows::default();
 
         c.bench_function("demo_windows_minimal", |b| {
@@ -17,7 +17,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
     }
 
     {
-        let mut ctx = egui::Context::new();
+        let mut ctx = egui::CtxRef::default();
         ctx.memory().all_collpasing_are_open = true; // expand the demo window with everything
         let mut demo_windows = egui::demos::DemoWindows::default();
 
@@ -31,7 +31,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
     }
 
     {
-        let mut ctx = egui::Context::new();
+        let mut ctx = egui::CtxRef::default();
         ctx.memory().all_collpasing_are_open = true; // expand the demo window with everything
         let mut demo_windows = egui::demos::DemoWindows::default();
         ctx.begin_frame(raw_input.clone());
@@ -44,7 +44,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
     }
 
     {
-        let mut ctx = egui::Context::new();
+        let mut ctx = egui::CtxRef::default();
         ctx.begin_frame(raw_input);
         egui::CentralPanel::default().show(&ctx, |ui| {
             c.bench_function("label", |b| {

egui/src/app.rs

@@ -7,8 +7,6 @@
 
 // TODO: move egui/src/app.rs to own crate, e.g. egui_framework ?
 
-use crate::Context;
-
 /// Implement this trait to write apps that can be compiled both natively using the [`egui_glium`](https://crates.io/crates/egui_glium) crate,
 /// and deployed as a web site using the [`egui_web`](https://crates.io/crates/egui_web) crate.
 pub trait App {
@@ -24,15 +22,11 @@ pub trait App {
     /// Called once before the first frame.
     /// Allows you to do setup code and to call `ctx.set_fonts()`.
     /// Optional.
-    fn setup(&mut self, _ctx: &std::sync::Arc<Context>) {}
+    fn setup(&mut self, _ctx: &crate::CtxRef) {}
 
     /// Called each time the UI needs repainting, which may be many times per second.
     /// Put your widgets into a `SidePanel`, `TopPanel`, `CentralPanel`, `Window` or `Area`.
-    fn ui(
-        &mut self,
-        ctx: &std::sync::Arc<Context>,
-        integration_context: &mut IntegrationContext<'_>,
-    );
+    fn ui(&mut self, ctx: &crate::CtxRef, integration_context: &mut IntegrationContext<'_>);
 
     /// Called once on shutdown. Allows you to save state.
     fn on_exit(&mut self, _storage: &mut dyn Storage) {}

egui/src/containers/area.rs

@@ -2,7 +2,7 @@
 //! It has no frame or own size. It is potentially movable.
 //! It is the foundation for windows and popups.
 
-use std::{fmt::Debug, hash::Hash, sync::Arc};
+use std::{fmt::Debug, hash::Hash};
 
 use crate::*;
 
@@ -103,7 +103,7 @@ pub(crate) struct Prepared {
 }
 
 impl Area {
-    pub(crate) fn begin(self, ctx: &Arc<Context>) -> Prepared {
+    pub(crate) fn begin(self, ctx: &CtxRef) -> Prepared {
         let Area {
             id,
             movable,
@@ -131,7 +131,7 @@ impl Area {
         }
     }
 
-    pub fn show(self, ctx: &Arc<Context>, add_contents: impl FnOnce(&mut Ui)) -> Response {
+    pub fn show(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui)) -> Response {
         let prepared = self.begin(ctx);
         let mut content_ui = prepared.content_ui(ctx);
         add_contents(&mut content_ui);
@@ -148,7 +148,7 @@ impl Prepared {
         &mut self.state
     }
 
-    pub(crate) fn content_ui(&self, ctx: &Arc<Context>) -> Ui {
+    pub(crate) fn content_ui(&self, ctx: &CtxRef) -> Ui {
         let max_rect = Rect::from_min_size(self.state.pos, Vec2::infinity());
         let clip_rect = max_rect
             .expand(ctx.style().visuals.clip_rect_margin)
@@ -163,7 +163,7 @@ impl Prepared {
     }
 
     #[allow(clippy::needless_pass_by_value)] // intentional to swallow up `content_ui`.
-    pub(crate) fn end(self, ctx: &Arc<Context>, content_ui: Ui) -> Response {
+    pub(crate) fn end(self, ctx: &CtxRef, content_ui: Ui) -> Response {
         let Prepared {
             layer_id,
             mut state,

egui/src/containers/panel.rs

@@ -3,7 +3,6 @@
 //! the only places where you can put you widgets.
 
 use crate::*;
-use std::sync::Arc;
 
 // ----------------------------------------------------------------------------
 
@@ -27,11 +26,7 @@ impl SidePanel {
 }
 
 impl SidePanel {
-    pub fn show<R>(
-        self,
-        ctx: &Arc<Context>,
-        add_contents: impl FnOnce(&mut Ui) -> R,
-    ) -> (R, Response) {
+    pub fn show<R>(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Response) {
         let Self { id, max_width } = self;
 
         let mut panel_rect = ctx.available_rect();
@@ -80,11 +75,7 @@ impl TopPanel {
 }
 
 impl TopPanel {
-    pub fn show<R>(
-        self,
-        ctx: &Arc<Context>,
-        add_contents: impl FnOnce(&mut Ui) -> R,
-    ) -> (R, Response) {
+    pub fn show<R>(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Response) {
         let Self { id, max_height } = self;
         let max_height = max_height.unwrap_or_else(|| ctx.style().spacing.interact_size.y);
 
@@ -122,11 +113,7 @@ impl TopPanel {
 pub struct CentralPanel {}
 
 impl CentralPanel {
-    pub fn show<R>(
-        self,
-        ctx: &Arc<Context>,
-        add_contents: impl FnOnce(&mut Ui) -> R,
-    ) -> (R, Response) {
+    pub fn show<R>(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Response) {
         let Self {} = self;
 
         let panel_rect = ctx.available_rect();

egui/src/containers/popup.rs

@@ -1,9 +1,7 @@
-use std::sync::Arc;
-
 use crate::*;
 
 /// Show a tooltip at the current mouse position (if any).
-pub fn show_tooltip(ctx: &Arc<Context>, add_contents: impl FnOnce(&mut Ui)) {
+pub fn show_tooltip(ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui)) {
     let tooltip_rect = ctx.memory().tooltip_rect;
 
     let window_pos = if let Some(tooltip_rect) = tooltip_rect {
@@ -23,15 +21,15 @@ pub fn show_tooltip(ctx: &Arc<Context>, add_contents: impl FnOnce(&mut Ui)) {
 }
 
 /// Show a tooltip at the current mouse position (if any).
-pub fn show_tooltip_text(ctx: &Arc<Context>, text: impl Into<String>) {
+pub fn show_tooltip_text(ctx: &CtxRef, text: impl Into<String>) {
     show_tooltip(ctx, |ui| {
         ui.add(crate::widgets::Label::new(text));
     })
 }
 
 /// Show a pop-over window.
 fn show_popup(
-    ctx: &Arc<Context>,
+    ctx: &CtxRef,
     id: Id,
     window_pos: Pos2,
     add_contents: impl FnOnce(&mut Ui),

egui/src/containers/window.rs

@@ -1,7 +1,5 @@
 // WARNING: the code in here is horrible. It is a behemoth that needs breaking up into simpler parts.
 
-use std::sync::Arc;
-
 use crate::{paint::*, widgets::*, *};
 
 use super::*;
@@ -183,13 +181,13 @@ impl<'open> Window<'open> {
 }
 
 impl<'open> Window<'open> {
-    pub fn show(self, ctx: &Arc<Context>, add_contents: impl FnOnce(&mut Ui)) -> Option<Response> {
+    pub fn show(self, ctx: &CtxRef, add_contents: impl FnOnce(&mut Ui)) -> Option<Response> {
         self.show_impl(ctx, Box::new(add_contents))
     }
 
     fn show_impl<'c>(
         self,
-        ctx: &Arc<Context>,
+        ctx: &CtxRef,
         add_contents: Box<dyn FnOnce(&mut Ui) + 'c>,
     ) -> Option<Response> {
         let Window {