Made Application.Draw() thread-safe (for real this time). Fixes #136

application.go

@@ -227,13 +227,14 @@ func (a *Application) Suspend(f func()) bool {
 // Draw refreshes the screen. It calls the Draw() function of the application's
 // root primitive and then syncs the screen buffer.
 func (a *Application) Draw() *Application {
-	a.RLock()
+	a.Lock()
+	defer a.Unlock()
+
 	screen := a.screen
 	root := a.root
 	fullscreen := a.rootFullscreen
 	before := a.beforeDraw
 	after := a.afterDraw
-	a.RUnlock()
 
 	// Maybe we're not ready yet or not anymore.
 	if screen == nil || root == nil {