Split drawing and processing events into different functions

src/main.go

@@ -40,6 +40,7 @@ func main() {
 
 	for window.screen != nil {
 		window.Draw()
+		window.ProcessEvents()
 	}
 
 }

src/window.go

@@ -126,7 +126,9 @@ func (window *Window) Draw() {
 
 	// Update screen
 	window.screen.Show()
+}
 
+func (window *Window) ProcessEvents() {
 	// Poll event
 	ev := window.screen.PollEvent()