feat(startscreen): add reaction on button events

src/startscreen.py

@@ -10,7 +10,6 @@ class Startscreen:
         self.button_color = (0, 255, 0)
         self.button_hover_color = (200, 255, 0)
 
-        # todo buttons must be initialized here
         self.button_start = Button("[ENTER] Immatrikulieren",
                                    500,
                                    70,
@@ -36,11 +35,15 @@ class Startscreen:
         self.screen.blit(title, (10, 10))
         message = self.font_label.render("Welcome to FH - Study with purpose", True, (0, 255, 255))
 
-        # todo buttons must be drawn here
+        # draw buttons and get click state
         button_start_pressed = self.button_start.draw(self.screen)
-        button_start_pressed = self.button_quit.draw(self.screen)
+        button_quit_pressed = self.button_quit.draw(self.screen)
 
-        # todo check button events/click
+        # react on button clicks
+        if button_start_pressed:
+            return "game"
+        if button_quit_pressed:
+            return "quit"
 
         # check key down events - exit/quit
         for event in pygame.event.get():
@@ -48,7 +51,9 @@ class Startscreen:
                 return "quit"
 
             if event.type == pygame.KEYDOWN:
+                if event.key == pygame.K_RETURN:
+                    return "game"
                 if event.key == pygame.K_ESCAPE:
                     return "quit"
 
-        return "startscreen"
+        return "start"