Refactor viewport ids in eframe (#3607)

Simplifies some things

crates/eframe/src/native/epi_integration.rs

@@ -309,16 +309,6 @@ impl EpiIntegration {
         }
     }
 
-    pub fn handle_platform_output(
-        &mut self,
-        window: &winit::window::Window,
-        viewport_id: ViewportId,
-        platform_output: egui::PlatformOutput,
-        egui_winit: &mut egui_winit::State,
-    ) {
-        egui_winit.handle_platform_output(window, viewport_id, &self.egui_ctx, platform_output);
-    }
-
     // ------------------------------------------------------------------------
     // Persistence stuff:
 

crates/eframe/src/native/glow_integration.rs

@@ -506,7 +506,7 @@ impl GlowWinitRunning {
             let window = viewport.window.as_ref().unwrap();
 
             let egui_winit = viewport.egui_winit.as_mut().unwrap();
-            let mut raw_input = egui_winit.take_egui_input(window, viewport.ids);
+            let mut raw_input = egui_winit.take_egui_input(window);
             let viewport_ui_cb = viewport.viewport_ui_cb.clone();
 
             self.integration.pre_update();
@@ -562,7 +562,7 @@ impl GlowWinitRunning {
         let egui_winit = viewport.egui_winit.as_mut().unwrap();
 
         integration.post_update();
-        integration.handle_platform_output(window, viewport_id, platform_output, egui_winit);
+        egui_winit.handle_platform_output(window, &integration.egui_ctx, platform_output);
 
         let clipped_primitives = integration.egui_ctx.tessellate(shapes, pixels_per_point);
 
@@ -1018,6 +1018,7 @@ impl GlutinWindowContext {
 
             viewport.egui_winit.get_or_insert_with(|| {
                 egui_winit::State::new(
+                    viewport_id,
                     event_loop,
                     Some(window.scale_factor() as f32),
                     self.max_texture_side,
@@ -1276,7 +1277,7 @@ fn render_immediate_viewport(
             return;
         };
 
-        let mut raw_input = winit_state.take_egui_input(window, ids);
+        let mut raw_input = winit_state.take_egui_input(window);
         raw_input.viewports = glutin
             .viewports
             .iter()
@@ -1360,7 +1361,7 @@ fn render_immediate_viewport(
         }
     }
 
-    winit_state.handle_platform_output(window, ids.this, egui_ctx, platform_output);
+    winit_state.handle_platform_output(window, egui_ctx, platform_output);
 
     glutin.handle_viewport_output(viewport_output);
 }

crates/eframe/src/native/wgpu_integration.rs

@@ -196,6 +196,7 @@ impl WgpuWinitApp {
         }
 
         let mut egui_winit = egui_winit::State::new(
+            ViewportId::ROOT,
             event_loop,
             Some(window.scale_factor() as f32),
             painter.max_texture_side(),
@@ -504,7 +505,6 @@ impl WgpuWinitRunning {
             viewport.update_viewport_info();
 
             let Viewport {
-                ids,
                 viewport_ui_cb,
                 window,
                 egui_winit,
@@ -525,10 +525,7 @@ impl WgpuWinitRunning {
                 }
             }
 
-            let mut raw_input = egui_winit.as_mut().unwrap().take_egui_input(
-                window,
-                ViewportIdPair::from_self_and_parent(viewport_id, ids.parent),
-            );
+            let mut raw_input = egui_winit.as_mut().unwrap().take_egui_input(window);
 
             integration.pre_update();
 
@@ -581,7 +578,7 @@ impl WgpuWinitRunning {
             viewport_output,
         } = full_output;
 
-        integration.handle_platform_output(window, viewport_id, platform_output, egui_winit);
+        egui_winit.handle_platform_output(window, &integration.egui_ctx, platform_output);
 
         {
             let clipped_primitives = integration.egui_ctx.tessellate(shapes, pixels_per_point);
@@ -778,6 +775,7 @@ impl Viewport {
                 }
 
                 self.egui_winit = Some(egui_winit::State::new(
+                    viewport_id,
                     event_loop,
                     Some(window.scale_factor() as f32),
                     painter.max_texture_side(),
@@ -866,7 +864,7 @@ fn render_immediate_viewport(
             return;
         };
 
-        let mut input = winit_state.take_egui_input(window, ids);
+        let mut input = winit_state.take_egui_input(window);
         input.viewports = viewports
             .iter()
             .map(|(id, viewport)| (*id, viewport.info.clone()))
@@ -926,7 +924,7 @@ fn render_immediate_viewport(
         false,
     );
 
-    winit_state.handle_platform_output(window, ids.this, egui_ctx, platform_output);
+    winit_state.handle_platform_output(window, egui_ctx, platform_output);
 
     handle_viewport_output(viewport_output, viewports, *focused_viewport);
 }

crates/egui-winit/src/lib.rs

@@ -14,9 +14,7 @@ pub use accesskit_winit;
 pub use egui;
 #[cfg(feature = "accesskit")]
 use egui::accesskit;
-use egui::{
-    Pos2, Rect, Vec2, ViewportBuilder, ViewportCommand, ViewportId, ViewportIdPair, ViewportInfo,
-};
+use egui::{Pos2, Rect, Vec2, ViewportBuilder, ViewportCommand, ViewportId, ViewportInfo};
 pub use winit;
 
 pub mod clipboard;
@@ -59,6 +57,7 @@ pub struct EventResponse {
 ///
 /// Instantiate one of these per viewport/window.
 pub struct State {
+    viewport_id: ViewportId,
     start_time: web_time::Instant,
     egui_input: egui::RawInput,
     pointer_pos_in_points: Option<egui::Pos2>,
@@ -93,6 +92,7 @@ pub struct State {
 impl State {
     /// Construct a new instance
     pub fn new(
+        viewport_id: ViewportId,
         display_target: &dyn HasRawDisplayHandle,
         native_pixels_per_point: Option<f32>,
         max_texture_side: Option<usize>,
@@ -105,6 +105,7 @@ impl State {
         };
 
         let mut slf = Self {
+            viewport_id,
             start_time: web_time::Instant::now(),
             egui_input,
             pointer_pos_in_points: None,
@@ -202,7 +203,7 @@ impl State {
     /// You need to set [`egui::RawInput::viewports`] yourself though.
     /// Use [`Self::update_viewport_info`] to update the info for each
     /// viewport.
-    pub fn take_egui_input(&mut self, window: &Window, ids: ViewportIdPair) -> egui::RawInput {
+    pub fn take_egui_input(&mut self, window: &Window) -> egui::RawInput {
         crate::profile_function!();
 
         let pixels_per_point = self.pixels_per_point();
@@ -226,7 +227,7 @@ impl State {
             .then(|| Rect::from_min_size(Pos2::ZERO, screen_size_in_points));
 
         // Tell egui which viewport is now active:
-        self.egui_input.viewport_ids = ids;
+        self.egui_input.viewport_id = self.viewport_id;
         self.egui_input.native_pixels_per_point = Some(native_pixels_per_point(window));
         self.egui_input.take()
     }
@@ -692,7 +693,6 @@ impl State {
     pub fn handle_platform_output(
         &mut self,
         window: &Window,
-        viewport_id: ViewportId,
         egui_ctx: &egui::Context,
         platform_output: egui::PlatformOutput,
     ) {
@@ -709,7 +709,8 @@ impl State {
             accesskit_update,
         } = platform_output;
 
-        self.current_pixels_per_point = egui_ctx.input_for(viewport_id, |i| i.pixels_per_point); // someone can have changed it to scale the UI
+        self.current_pixels_per_point =
+            egui_ctx.input_for(self.viewport_id, |i| i.pixels_per_point); // someone can have changed it to scale the UI
 
         self.set_cursor_icon(window, cursor_icon);
 

crates/egui/src/context.rs

@@ -227,8 +227,13 @@ struct ContextImpl {
 
 impl ContextImpl {
     fn begin_frame_mut(&mut self, mut new_raw_input: RawInput) {
-        let ids = new_raw_input.viewport_ids;
-        let viewport_id = ids.this;
+        let viewport_id = new_raw_input.viewport_id;
+        let parent_id = new_raw_input
+            .viewports
+            .get(&viewport_id)
+            .and_then(|v| v.parent)
+            .unwrap_or_default();
+        let ids = ViewportIdPair::from_self_and_parent(viewport_id, parent_id);
         self.viewport_stack.push(ids);
         let viewport = self.viewports.entry(viewport_id).or_default();
 

crates/egui/src/data/input.rs

@@ -2,7 +2,7 @@
 
 use epaint::ColorImage;
 
-use crate::{emath::*, ViewportIdMap, ViewportIdPair};
+use crate::{emath::*, ViewportId, ViewportIdMap};
 
 /// What the integrations provides to egui at the start of each frame.
 ///
@@ -15,8 +15,8 @@ use crate::{emath::*, ViewportIdMap, ViewportIdPair};
 #[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct RawInput {
-    /// The id of the active viewport, and out parent.
-    pub viewport_ids: ViewportIdPair,
+    /// The id of the active viewport.
+    pub viewport_id: ViewportId,
 
     /// Information about all egui viewports.
     pub viewports: ViewportIdMap<ViewportInfo>,
@@ -89,7 +89,7 @@ pub struct RawInput {
 impl Default for RawInput {
     fn default() -> Self {
         Self {
-            viewport_ids: Default::default(),
+            viewport_id: Default::default(),
             viewports: Default::default(),
             screen_rect: None,
             pixels_per_point: None,
@@ -107,13 +107,19 @@ impl Default for RawInput {
 }
 
 impl RawInput {
+    /// Info about the active viewport
+    #[inline]
+    pub fn viewport(&self) -> &ViewportInfo {
+        self.viewports.get(&self.viewport_id).expect("Failed to find current viewport in egui RawInput. This is the fault of the egui backend")
+    }
+
     /// Helper: move volatile (deltas and events), clone the rest.
     ///
     /// * [`Self::hovered_files`] is cloned.
     /// * [`Self::dropped_files`] is moved.
     pub fn take(&mut self) -> RawInput {
         RawInput {
-            viewport_ids: self.viewport_ids,
+            viewport_id: self.viewport_id,
             viewports: self.viewports.clone(),
             screen_rect: self.screen_rect.take(),
             pixels_per_point: self.pixels_per_point.take(), // take the diff
@@ -132,7 +138,7 @@ impl RawInput {
     /// Add on new input.
     pub fn append(&mut self, newer: Self) {
         let Self {
-            viewport_ids,
+            viewport_id: viewport_ids,
             viewports,
             screen_rect,
             pixels_per_point,
@@ -147,7 +153,7 @@ impl RawInput {
             focused,
         } = newer;
 
-        self.viewport_ids = viewport_ids;
+        self.viewport_id = viewport_ids;
         self.viewports = viewports;
         self.screen_rect = screen_rect.or(self.screen_rect);
         self.pixels_per_point = pixels_per_point.or(self.pixels_per_point);
@@ -1106,7 +1112,7 @@ fn format_kb_shortcut() {
 impl RawInput {
     pub fn ui(&self, ui: &mut crate::Ui) {
         let Self {
-            viewport_ids,
+            viewport_id,
             viewports,
             screen_rect,
             pixels_per_point,
@@ -1121,10 +1127,7 @@ impl RawInput {
             focused,
         } = self;
 
-        ui.label(format!(
-            "Active viwport: {:?}, parent: {:?}",
-            viewport_ids.this, viewport_ids.parent,
-        ));
+        ui.label(format!("Active viwport: {viewport_id:?}"));
         for (id, viewport) in viewports {
             ui.group(|ui| {
                 ui.label(format!("Viewport {id:?}"));

crates/egui/src/input_state.rs

@@ -232,8 +232,9 @@ impl InputState {
     }
 
     /// Info about the active viewport
+    #[inline]
     pub fn viewport(&self) -> &ViewportInfo {
-        self.raw.viewports.get(&self.raw.viewport_ids.this).expect("Failed to find current viewport in egui RawInput. This is the fault of the egui backend")
+        self.raw.viewport()
     }
 
     #[inline(always)]

crates/egui/src/memory.rs

@@ -559,7 +559,7 @@ impl Memory {
         self.window_interactions
             .retain(|id, _| viewports.contains(id));
 
-        self.viewport_id = new_input.viewport_ids.this;
+        self.viewport_id = new_input.viewport_id;
         self.interactions
             .entry(self.viewport_id)
             .or_default()

crates/egui_glow/src/winit.rs

@@ -1,7 +1,7 @@
 pub use egui_winit;
 pub use egui_winit::EventResponse;
 
-use egui::{ViewportId, ViewportIdPair, ViewportOutput};
+use egui::{ViewportId, ViewportOutput};
 use egui_winit::winit;
 
 use crate::shader_version::ShaderVersion;
@@ -35,6 +35,7 @@ impl EguiGlow {
             .unwrap();
 
         let egui_winit = egui_winit::State::new(
+            ViewportId::ROOT,
             event_loop,
             native_pixels_per_point,
             Some(painter.max_texture_side()),
@@ -58,9 +59,7 @@ impl EguiGlow {
 
     /// Call [`Self::paint`] later to paint.
     pub fn run(&mut self, window: &winit::window::Window, run_ui: impl FnMut(&egui::Context)) {
-        let raw_input = self
-            .egui_winit
-            .take_egui_input(window, ViewportIdPair::ROOT);
+        let raw_input = self.egui_winit.take_egui_input(window);
 
         let egui::FullOutput {
             platform_output,
@@ -87,12 +86,8 @@ impl EguiGlow {
             }
         }
 
-        self.egui_winit.handle_platform_output(
-            window,
-            ViewportId::ROOT,
-            &self.egui_ctx,
-            platform_output,
-        );
+        self.egui_winit
+            .handle_platform_output(window, &self.egui_ctx, platform_output);
 
         self.shapes = shapes;
         self.pixels_per_point = pixels_per_point;