Add an optional app_id field to eframe's NativeOptions (emilk#1600).

This is used in the window builder to set the application ID, which is e.g. important for a proper configuration in `.desktop` files under Wayland.
When no application ID is explicitly set, it defaults to the title of the window.

Author: thomaskrause

crates/eframe/CHANGELOG.md

@@ -8,6 +8,7 @@ NOTE: [`egui-winit`](../egui-winit/CHANGELOG.md), [`egui_glium`](../egui_glium/C
 #### Desktop/Native:
 * Add `Frame::request_screenshot` and `Frame::screenshot` to communicate to the backend that a screenshot of the current frame should be exposed by `Frame` during `App::post_rendering` ([#2676](https://github.com/emilk/egui/pull/2676)).
 * Add `eframe::run_simple_native` - a simple API for simple apps ([#2453](https://github.com/emilk/egui/pull/2453)).
+* Add `NativeOptions::app_id` which allows to set the Wayland application ID ([#1600](https://github.com/emilk/egui/issues/1600)).
 * Fix bug where the eframe window is never destroyed on Linux when using `run_and_return` ([#2892](https://github.com/emilk/egui/issues/2892))
 
 #### Web:

crates/eframe/src/epi/mod.rs

@@ -383,6 +383,21 @@ pub struct NativeOptions {
     /// Configures wgpu instance/device/adapter/surface creation and renderloop.
     #[cfg(feature = "wgpu")]
     pub wgpu_options: egui_wgpu::WgpuConfiguration,
+
+    /// On Wayland: Application ID for the window.
+    ///
+    /// The application ID is used in several places of the compositor, e.g. for
+    /// grouping windows of the same application. It is also important for
+    /// connecting the configuration of a `.desktop` file with the window, by
+    /// using the application ID as file name. This allows e.g. a proper icon
+    /// handling under Wayland.
+    ///
+    /// See [Waylands XDG shell documentation][xdg-shell] for more information
+    /// on this Wayland-specific option.
+    ///
+    /// [xdg-shell]: https://wayland.app/protocols/xdg-shell#xdg_toplevel:request:set_app_id
+    #[cfg(feature = "wayland")]
+    pub app_id: Option<String>,
 }
 
 #[cfg(not(target_arch = "wasm32"))]
@@ -397,6 +412,9 @@ impl Clone for NativeOptions {
             #[cfg(feature = "wgpu")]
             wgpu_options: self.wgpu_options.clone(),
 
+            #[cfg(feature = "wayland")]
+            app_id: self.app_id.clone(),
+
             ..*self
         }
     }
@@ -453,6 +471,9 @@ impl Default for NativeOptions {
 
             #[cfg(feature = "wgpu")]
             wgpu_options: egui_wgpu::WgpuConfiguration::default(),
+
+            #[cfg(feature = "wayland")]
+            app_id: None,
         }
     }
 }

crates/eframe/src/native/epi_integration.rs

@@ -3,6 +3,9 @@ use winit::event_loop::EventLoopWindowTarget;
 #[cfg(target_os = "macos")]
 use winit::platform::macos::WindowBuilderExtMacOS as _;
 
+#[cfg(feature = "wayland")]
+use winit::platform::wayland::WindowBuilderExtWayland as _;
+
 #[cfg(feature = "accesskit")]
 use egui::accesskit;
 use egui::NumExt as _;
@@ -118,6 +121,12 @@ pub fn window_builder<E>(
             .with_fullsize_content_view(true);
     }
 
+    #[cfg(feature = "wayland")]
+    {
+        window_builder =
+            window_builder.with_name(native_options.app_id.as_deref().unwrap_or(title), "");
+    }
+
     if let Some(min_size) = *min_window_size {
         window_builder = window_builder.with_min_inner_size(points_to_size(min_size));
     }