fix the sticky key down

Author: InnocentusLime

src/lib.rs

@@ -792,8 +792,19 @@ impl EventHandler for Stage {
     }
 
     fn window_minimized_event(&mut self) {
+        let context = get_context();
+
         #[cfg(target_os = "android")]
-        get_context().audio_context.pause();
+        context.audio_context.pause();
+
+        // Clear held down keys and button and announce them as released
+        context.mouse_released.extend(context.mouse_down.drain());
+        context.keys_released.extend(context.keys_down.drain());
+
+        // Announce all touches as released
+        for (_, touch) in context.touches.iter_mut() {
+            touch.phase = input::TouchPhase::Ended;
+        }
     }
 
     fn quit_requested_event(&mut self) {