Simple Implementation to address #1327 by adding a focused field to t…

…he window and related system (#1386)

* Simple Implementation to address #1327 by adding a focused field to the window and related system

* Changing Window update function from bevy_window to bevy_winit.

* Removing unused imports.

crates/bevy_window/src/window.rs

@@ -64,6 +64,7 @@ pub struct Window {
     cursor_visible: bool,
     cursor_locked: bool,
     cursor_position: Option<Vec2>,
+    focused: bool,
     mode: WindowMode,
     #[cfg(target_arch = "wasm32")]
     pub canvas: Option<String>,
@@ -152,6 +153,7 @@ impl Window {
             cursor_visible: window_descriptor.cursor_visible,
             cursor_locked: window_descriptor.cursor_locked,
             cursor_position: None,
+            focused: true,
             mode: window_descriptor.mode,
             #[cfg(target_arch = "wasm32")]
             canvas: window_descriptor.canvas.clone(),
@@ -395,6 +397,12 @@ impl Window {
             .push(WindowCommand::SetCursorPosition { position });
     }
 
+    #[allow(missing_docs)]
+    #[inline]
+    pub fn update_focused_status_from_backend(&mut self, focused: bool) {
+        self.focused = focused;
+    }
+
     #[allow(missing_docs)]
     #[inline]
     pub fn update_cursor_position_from_backend(&mut self, cursor_position: Option<Vec2>) {
@@ -418,6 +426,11 @@ impl Window {
     pub fn drain_commands(&mut self) -> impl Iterator<Item = WindowCommand> + '_ {
         self.command_queue.drain(..)
     }
+
+    #[inline]
+    pub fn is_focused(&self) -> bool {
+        self.focused
+    }
 }
 
 #[derive(Debug, Clone)]

crates/bevy_winit/src/lib.rs

@@ -407,6 +407,7 @@ pub fn winit_runner_with(mut app: App, mut event_loop: EventLoop<()>) {
                         );
                     }
                     WindowEvent::Focused(focused) => {
+                        window.update_focused_status_from_backend(focused);
                         let mut focused_events =
                             app.resources.get_mut::<Events<WindowFocused>>().unwrap();
                         focused_events.send(WindowFocused {