Pygame "pop up" text - How to show an image only for a period of time?

Question

Im learning pygame at the moment and was wondering, how can i make a "pop up" text that say "+1 coin" (or basiclly anything) on the screen for a few seconds, without having to use pygame.time.delay() or time.sleep() since those stop the game, but i want the player to be able to keep playing, while the text is displaying on the screen.

Answer 1

If you want to control something over time in Pygame you have two options:

1. Use pygame.time.get_ticks() to measure time and implement logic that controls the visibility of the text depending on the time. pygame.time.get_ticks() returns the number of milliseconds since pygame.init(). Get the current time the text pops up and calculate the time the text must disappear:

   draw_text = true
   hide_text_time = pygame.time.get_ticks() + 1000 # 1 second
   

   if draw_text and pygame.time.get_ticks() > hide_text_time:
       draw_text = false 
   

2. Use the timer event. Use pygame.time.set_timer() to repeatedly create a USEREVENT in the event queue. The time has to be set in milliseconds. Start a timer event when the text pops up and hide the text when the event occurs:

   draw_text = true
   hide_text_event = pygame.USEREVENT + 1
   pygame.time.set_timer(hide_text_event, 1000, 1) # 1 second, one time
   

   # applicaition loop
   while True:
   
       # event loop
       for event in pygame.event.get():
           if event.type == hide_text_event:
               draw_text = False
   

For some complete examples, see the answers to the questions:

• Adding a particle effect to my clicker game
• Spawning multiple instances of the same object concurrently in python.

---

Minimal example (the pop up time can be controlled with the variable pop_up_seconds):

PYGBAG demo

import pygame

pygame.init()
window = pygame.display.set_mode((400, 200))
font = pygame.font.SysFont(None, 40)
clock = pygame.time.Clock()

text = font.render("+1", True, (0, 255, 0))
text_pos_and_time = []
pop_up_seconds = 1

player = pygame.Rect(0, 80, 40, 40)
coins = [pygame.Rect(i*100+100, 80, 40, 40) for i in range(3)]

run = True
while run:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    keys = pygame.key.get_pressed()
    player.x = (player.x + (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * 3) % 300    

    current_time = pygame.time.get_ticks()
    for coin in coins[:]:
        if player.colliderect(coin):
            text_pos_and_time.append((coin.center, current_time + pop_up_seconds * 1000))
            coins.remove(coin)

    window.fill(0)    
    pygame.draw.rect(window, "red", player)
    for coin in coins:
        pygame.draw.circle(window, "yellow", coin.center, 20)
    for pos_time in text_pos_and_time[:]:
        if pos_time[1] > current_time:
            window.blit(text, text.get_rect(center = pos_time[0]))
        else:
            text_pos_and_time.remove(pos_time)    
    pygame.display.flip()

pygame.quit()
exit()