python - Pygame mouse clicking detection

Question

I was wondering how to write code that would detect the mouse clicking on a sprite. For example:

if #Function that checks for mouse clicked on Sprite:
    print ("You have opened a chest!")

question from:https://stackoverflow.com/questions/66054694/pygame-falling-digit-block-game-and-using-mouse-to-click-on-digits-in-order-to-a

Answer 1

I assume your game has a main loop, and all your sprites are in a list called sprites.

In your main loop, get all events, and check for the MOUSEBUTTONDOWN or MOUSEBUTTONUP event.

while ... # your main loop
  # get all events
  ev = pygame.event.get()

  # proceed events
  for event in ev:

    # handle MOUSEBUTTONUP
    if event.type == pygame.MOUSEBUTTONUP:
      pos = pygame.mouse.get_pos()

      # get a list of all sprites that are under the mouse cursor
      clicked_sprites = [s for s in sprites if s.rect.collidepoint(pos)]
      # do something with the clicked sprites...

So basically you have to check for a click on a sprite yourself every iteration of the mainloop. You'll want to use mouse.get_pos() and rect.collidepoint().

Pygame does not offer event driven programming, as e.g. cocos2d does.

Another way would be to check the position of the mouse cursor and the state of the pressed buttons, but this approach has some issues.

if pygame.mouse.get_pressed()[0] and mysprite.rect.collidepoint(pygame.mouse.get_pos()):
  print ("You have opened a chest!")

You'll have to introduce some kind of flag if you handled this case, since otherwise this code will print "You have opened a chest!" every iteration of the main loop.

handled = False

while ... // your loop

  if pygame.mouse.get_pressed()[0] and mysprite.rect.collidepoint(pygame.mouse.get_pos()) and not handled:
    print ("You have opened a chest!")
    handled = pygame.mouse.get_pressed()[0]

Of course you can subclass Sprite and add a method called is_clicked like this:

class MySprite(Sprite):
  ...

  def is_clicked(self):
    return pygame.mouse.get_pressed()[0] and self.rect.collidepoint(pygame.mouse.get_pos())

So, it's better to use the first approach IMHO.