Allow windows to maximized. (#1004)

Adds a new `set_maximized` method to allow users to maximize windows.

crates/bevy_window/src/window.rs

@@ -82,6 +82,9 @@ pub enum WindowCommand {
     SetCursorPosition {
         position: Vec2,
     },
+    SetMaximized {
+        maximized: bool,
+    },
 }
 
 /// Defines the way a window is displayed
@@ -140,6 +143,12 @@ impl Window {
         self.height
     }
 
+    #[inline]
+    pub fn set_maximized(&mut self, maximized: bool) {
+        self.command_queue
+            .push(WindowCommand::SetMaximized { maximized });
+    }
+
     pub fn set_resolution(&mut self, width: u32, height: u32) {
         self.width = width;
         self.height = height;

crates/bevy_winit/src/lib.rs

@@ -104,6 +104,10 @@ fn change_window(_: &mut World, resources: &mut Resources) {
                         ))
                         .unwrap_or_else(|e| error!("Unable to set cursor position: {}", e));
                 }
+                bevy_window::WindowCommand::SetMaximized { maximized } => {
+                    let window = winit_windows.get_window(id).unwrap();
+                    window.set_maximized(maximized)
+                }
             }
         }
     }