epi/eframe: move options out of `trait App` into new `NativeOptions`

eframe/CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to the `eframe` crate.
 
 
 ## Unreleased
+* Moved options out of `trait App` into new `NativeOptions`.
 
 
 ## 0.11.0 - 2021-04-05

eframe/examples/hello_world.rs

@@ -41,5 +41,6 @@ impl epi::App for MyApp {
 }
 
 fn main() {
-    eframe::run_native(Box::new(MyApp::default()));
+    let options = eframe::NativeOptions::default();
+    eframe::run_native(Box::new(MyApp::default()), options);
 }

eframe/src/lib.rs

@@ -20,6 +20,9 @@
 
 pub use {egui, epi};
 
+#[cfg(not(target_arch = "wasm32"))]
+pub use epi::NativeOptions;
+
 // ----------------------------------------------------------------------------
 // When compiling for web
 
@@ -56,6 +59,6 @@ pub fn start_web(canvas_id: &str, app: Box<dyn epi::App>) -> Result<(), wasm_bin
 
 /// Call from `fn main` like this: `eframe::run_native(Box::new(MyEguiApp::default()))`
 #[cfg(not(target_arch = "wasm32"))]
-pub fn run_native(app: Box<dyn epi::App>) -> ! {
-    egui_glium::run(app)
+pub fn run_native(app: Box<dyn epi::App>, native_options: epi::NativeOptions) -> ! {
+    egui_glium::run(app, native_options)
 }

egui_demo_app/src/main.rs

@@ -8,5 +8,10 @@
 // When compiling natively:
 fn main() {
     let app = egui_demo_lib::WrapApp::default();
-    eframe::run_native(Box::new(app));
+    let options = eframe::NativeOptions {
+        // Let's show off that we support transparent windows
+        transparent: true,
+        ..Default::default()
+    };
+    eframe::run_native(Box::new(app), options);
 }

egui_demo_lib/src/wrap_app.rs

@@ -54,10 +54,6 @@ impl epi::App for WrapApp {
         self.backend_panel.max_size_points_active
     }
 
-    // Let's show off that we support transparent windows (on native):
-    fn transparent(&self) -> bool {
-        true
-    }
     fn clear_color(&self) -> egui::Rgba {
         egui::Rgba::TRANSPARENT // we set a `CentralPanel` fill color in `demo_windows.rs`
     }

egui_glium/src/backend.rs

@@ -76,20 +76,22 @@ fn window_builder_drag_and_drop(
 
 fn create_display(
     app: &dyn epi::App,
+    native_options: &epi::NativeOptions,
     window_settings: Option<WindowSettings>,
     window_icon: Option<glutin::window::Icon>,
     event_loop: &glutin::event_loop::EventLoop<RequestRepaintEvent>,
 ) -> glium::Display {
     let mut window_builder = glutin::window::WindowBuilder::new()
-        .with_decorations(app.decorated())
-        .with_resizable(app.is_resizable())
+        .with_decorations(native_options.decorated)
+        .with_resizable(native_options.resizable)
         .with_title(app.name())
         .with_window_icon(window_icon)
-        .with_transparent(app.transparent());
+        .with_transparent(native_options.transparent);
 
-    window_builder = window_builder_drag_and_drop(window_builder, app.drag_and_drop_support());
+    window_builder =
+        window_builder_drag_and_drop(window_builder, native_options.drag_and_drop_support);
 
-    let initial_size_points = app.initial_window_size();
+    let initial_size_points = native_options.initial_window_size;
 
     if let Some(window_settings) = &window_settings {
         window_builder = window_settings.initialize_size(window_builder);
@@ -154,13 +156,14 @@ fn integration_info(
     }
 }
 
-fn load_icon(icon_data: Option<epi::IconData>) -> Option<glutin::window::Icon> {
-    let icon_data = icon_data?;
+fn load_icon(icon_data: epi::IconData) -> Option<glutin::window::Icon> {
     glutin::window::Icon::from_rgba(icon_data.rgba, icon_data.width, icon_data.height).ok()
 }
 
+// ----------------------------------------------------------------------------
+
 /// Run an egui app
-pub fn run(mut app: Box<dyn epi::App>) -> ! {
+pub fn run(mut app: Box<dyn epi::App>, nativve_options: epi::NativeOptions) -> ! {
     let mut storage = create_storage(app.name());
 
     if let Some(storage) = &mut storage {
@@ -169,8 +172,8 @@ pub fn run(mut app: Box<dyn epi::App>) -> ! {
 
     let window_settings = deserialize_window_settings(&storage);
     let event_loop = glutin::event_loop::EventLoop::with_user_event();
-    let icon = load_icon(app.icon_data());
-    let display = create_display(&*app, window_settings, icon, &event_loop);
+    let icon = nativve_options.icon_data.clone().and_then(load_icon);
+    let display = create_display(&*app, &nativve_options, window_settings, icon, &event_loop);
 
     let repaint_signal = std::sync::Arc::new(GliumRepaintSignal(std::sync::Mutex::new(
         event_loop.create_proxy(),

egui_glium/src/lib.rs

@@ -25,6 +25,8 @@ pub mod window_settings;
 pub use backend::*;
 pub use painter::Painter;
 
+pub use epi::NativeOptions;
+
 use {
     copypasta::ClipboardProvider,
     egui::*,

epi/src/lib.rs

@@ -108,21 +108,11 @@ pub trait App {
     /// The name of your App.
     fn name(&self) -> &str;
 
-    /// The initial size of the native window in points (logical pixels).
-    fn initial_window_size(&self) -> Option<egui::Vec2> {
-        None
-    }
-
     /// Time between automatic calls to `save()`
     fn auto_save_interval(&self) -> std::time::Duration {
         std::time::Duration::from_secs(30)
     }
 
-    /// Returns true if this app window should be resizable.
-    fn is_resizable(&self) -> bool {
-        true
-    }
-
     /// The size limit of the web app canvas
     fn max_size_points(&self) -> egui::Vec2 {
         // Some browsers get slow with huge WebGL canvases, so we limit the size:
@@ -137,33 +127,49 @@ pub trait App {
         // `transparent()` option they get immediate results.
         egui::Color32::from_rgba_unmultiplied(12, 12, 12, 180).into()
     }
+}
 
+/// Options controlling the behavior of a native window
+#[derive(Clone)]
+pub struct NativeOptions {
     /// The application icon, e.g. in the Windows task bar etc.
-    fn icon_data(&self) -> Option<IconData> {
-        None
-    }
+    pub icon_data: Option<IconData>,
+
+    /// The initial size of the native window in points (logical pixels).
+    pub initial_window_size: Option<egui::Vec2>,
+
+    /// Should the app window be resizable?
+    pub resizable: bool,
 
     /// On desktop: add window decorations (i.e. a frame around your app)?
     /// If false it will be difficult to move and resize the app.
-    fn decorated(&self) -> bool {
-        true
-    }
+    pub decorated: bool,
 
     /// On desktop: make the window transparent.
-    /// You control the transparency with [`Self::clear_color()`].
+    /// You control the transparency with [`App::clear_color()`].
     /// You should avoid having a [`egui::CentralPanel`], or make sure its frame is also transparent.
-    fn transparent(&self) -> bool {
-        false
-    }
+    pub transparent: bool,
 
     /// On Windows: enable drag and drop support.
     /// Set to false to avoid issues with crates such as cpal which uses that use multi-threaded COM API <https://github.com/rust-windowing/winit/pull/1524>
-    fn drag_and_drop_support(&self) -> bool {
-        true
+    pub drag_and_drop_support: bool,
+}
+
+impl Default for NativeOptions {
+    fn default() -> Self {
+        Self {
+            icon_data: None,
+            initial_window_size: None,
+            resizable: true,
+            decorated: true,
+            transparent: false,
+            drag_and_drop_support: true,
+        }
     }
 }
 
 /// Image data for the icon.
+#[derive(Clone)]
 pub struct IconData {
     /// RGBA pixels.
     pub rgba: Vec<u8>,