Multiple viewports/windows

crates/eframe/src/epi/mod.rs

@@ -9,6 +9,7 @@
 #[cfg(not(target_arch = "wasm32"))]
 mod icon_data;
 
+use egui::ViewportRender;
 #[cfg(not(target_arch = "wasm32"))]
 pub use icon_data::IconData;
 
@@ -112,7 +113,7 @@ pub trait App {
     /// The [`egui::Context`] can be cloned and saved if you like.
     ///
     /// To force a repaint, call [`egui::Context::request_repaint`] at any time (e.g. from another thread).
-    fn update(&mut self, ctx: &egui::Context, frame: &mut Frame);
+    fn update(&mut self, ctx: &egui::Context, frame: &mut Frame, render: Option<&ViewportRender>);
 
     /// Get a handle to the app.
     ///
@@ -208,7 +209,7 @@ pub trait App {
         // NOTE: a bright gray makes the shadows of the windows look weird.
         // We use a bit of transparency so that if the user switches on the
         // `transparent()` option they get immediate results.
-        egui::Color32::from_rgba_unmultiplied(12, 12, 12, 180).to_normalized_gamma_f32()
+        egui::Color32::from_rgba_unmultiplied(12, 12, 12, 0).to_normalized_gamma_f32()
 
         // _visuals.window_fill() would also be a natural choice
     }
@@ -507,7 +508,7 @@ impl Default for NativeOptions {
             min_window_size: None,
             max_window_size: None,
             resizable: true,
-            transparent: false,
+            transparent: true,
             mouse_passthrough: false,
 
             active: true,
@@ -774,6 +775,9 @@ impl Frame {
         self.info.clone()
     }
 
+    /// If this is the main window will return true!
+    /// When is a single window mode will always return true!
+
     /// A place where you can store custom data in a way that persists when you restart the app.
     pub fn storage(&self) -> Option<&dyn Storage> {
         self.storage.as_deref()
@@ -809,7 +813,7 @@ impl Frame {
     /// struct MyApp;
     ///
     /// impl eframe::App for MyApp {
-    ///     fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
+    ///     fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame, _render: Option<&egui::ViewportRender>) {
     ///         // In real code the app would render something here
     ///         frame.request_screenshot();
     ///         // Things that are added to the frame after the call to

crates/eframe/src/lib.rs

@@ -32,7 +32,7 @@
 //! }
 //!
 //! impl eframe::App for MyEguiApp {
-//!    fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
+//!    fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame, _render: Option<&egui::ViewportRender>) {
 //!        egui::CentralPanel::default().show(ctx, |ui| {
 //!            ui.heading("Hello World!");
 //!        });
@@ -187,7 +187,7 @@ mod native;
 /// }
 ///
 /// impl eframe::App for MyEguiApp {
-///    fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
+///    fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame, _render: Option<&egui::ViewportRender>) {
 ///        egui::CentralPanel::default().show(ctx, |ui| {
 ///            ui.heading("Hello World!");
 ///        });
@@ -269,13 +269,24 @@ pub fn run_simple_native(
     native_options: NativeOptions,
     update_fun: impl FnMut(&egui::Context, &mut Frame) + 'static,
 ) -> Result<()> {
+    use egui::{ViewportId, ViewportRender};
+
     struct SimpleApp<U> {
         update_fun: U,
     }
 
     impl<U: FnMut(&egui::Context, &mut Frame)> App for SimpleApp<U> {
-        fn update(&mut self, ctx: &egui::Context, frame: &mut Frame) {
-            (self.update_fun)(ctx, frame);
+        fn update(
+            &mut self,
+            ctx: &egui::Context,
+            frame: &mut Frame,
+            render: Option<&ViewportRender>,
+        ) {
+            if ctx.get_viewport_id() == ViewportId::MAIN {
+                (self.update_fun)(ctx, frame);
+            } else if let Some(render_function) = render {
+                render_function(ctx);
+            }
         }
     }