test explicit drop

Author: gzp

examples/multiwindow.rs

@@ -6,8 +6,14 @@ fn main() {
     let window1 = winit::Window::new(&events_loop).unwrap();
     let window2 = winit::Window::new(&events_loop).unwrap();
     let window3 = winit::Window::new(&events_loop).unwrap();
+    let window4 = winit::Window::new(&events_loop).unwrap();
 
-    let mut num_windows = 3;
+    let window4_id = window4.id();
+    let mut window4_opt = Some(window4);
+
+    let mut num_windows = 4;
+
+    println!("Press any key on any window to drop the 4th window explicitly. (Testing impl Drop for Window)");
 
     if cfg!(target_os = "linux") {
         println!("Running this example under wayland may not display a window at all.\n\
@@ -24,6 +30,8 @@ fn main() {
                     println!("Window 2 has been closed")
                 } else if window_id == window3.id() {
                     println!("Window 3 has been closed");
+                } else if window_id == window4_id {
+                    println!("Window 4 has been closed");
                 } else {
                     unreachable!()
                 }
@@ -33,6 +41,12 @@ fn main() {
                     return winit::ControlFlow::Break;
                 }
             },
+
+            winit::Event::WindowEvent { event: winit::WindowEvent::KeyboardInput{..}, .. } => {
+                println!("Dropping window 4 explicitly");
+                window4_opt = None;
+            },
+
             _ => (),
         }
         winit::ControlFlow::Continue