Add `Frame::set_window_title()` (#828)

* Add `Frame::set_window_title()`

* Changelog and fmt for `Frame::set_window_title()`

Co-authored-by: Caleb Smith <caleb@myrvmail.com>

eframe/CHANGELOG.md

@@ -5,6 +5,7 @@ NOTE: [`egui_web`](egui_web/CHANGELOG.md), [`egui-winit`](egui-winit/CHANGELOG.m
 
 
 ## Unreleased
+* `Frame` now provides `set_window_title` to set window title dynamically
 * `Frame` now provides `set_decorations` to set whether to show window decorations.
 * Remove "http" feature (use https://github.com/emilk/ehttp instead!).
 * Increase native scroll speed.

egui-winit/src/epi.rs

@@ -59,6 +59,7 @@ pub fn handle_app_output(
     let epi::backend::AppOutput {
         quit: _,
         window_size,
+        window_title,
         decorated,
         drag_window,
     } = app_output;
@@ -77,6 +78,10 @@ pub fn handle_app_output(
         );
     }
 
+    if let Some(window_title) = window_title {
+        window.set_title(&window_title);
+    }
+
     if drag_window {
         let _ = window.drag_window();
     }

egui_glium/src/epi_backend.rs

@@ -166,7 +166,7 @@ pub fn run(mut app: Box<dyn epi::App>, native_options: &epi::NativeOptions) -> !
                 egui_winit::epi::handle_app_output(
                     display.gl_window().window(),
                     egui.ctx().pixels_per_point(),
-                    app_output,
+                    app_output.clone(),
                 );
 
                 *control_flow = if app_output.quit {

egui_glow/src/epi_backend.rs

@@ -183,7 +183,7 @@ pub fn run(mut app: Box<dyn epi::App>, native_options: &epi::NativeOptions) -> !
                 egui_winit::epi::handle_app_output(
                     gl_window.window(),
                     egui.ctx().pixels_per_point(),
-                    app_output,
+                    app_output.clone(),
                 );
 
                 *control_flow = if app_output.quit {

egui_web/src/backend.rs

@@ -260,6 +260,7 @@ impl AppRunner {
             let epi::backend::AppOutput {
                 quit: _,        // Can't quit a web page
                 window_size: _, // Can't resize a web page
+                window_title: _,
                 decorated: _,   // Can't show decorations
                 drag_window: _, // Can't be dragged
             } = app_output;

epi/src/lib.rs

@@ -279,6 +279,11 @@ impl<'a> Frame<'a> {
         self.0.output.window_size = Some(size);
     }
 
+    /// Set the desired title of the window.
+    pub fn set_window_title(&mut self, title: &str) {
+        self.0.output.window_title = Some(title.to_owned());
+    }
+
     /// Set whether to show window decorations (i.e. a frame around you app).
     /// If false it will be difficult to move and resize the app.
     pub fn set_decorations(&mut self, decorated: bool) {
@@ -439,7 +444,7 @@ pub mod backend {
     }
 
     /// Action that can be taken by the user app.
-    #[derive(Clone, Copy, Debug, Default, PartialEq)]
+    #[derive(Clone, Debug, Default, PartialEq)]
     pub struct AppOutput {
         /// Set to `true` to stop the app.
         /// This does nothing for web apps.
@@ -448,6 +453,9 @@ pub mod backend {
         /// Set to some size to resize the outer window (e.g. glium window) to this size.
         pub window_size: Option<egui::Vec2>,
 
+        /// Set to some string to rename the outer window (e.g. glium window) to this title.
+        pub window_title: Option<String>,
+
         /// Set to some bool to change window decorations
         pub decorated: Option<bool>,