Can't access event.state or event.gain of ACTIVEEVENT

Question

I was writing a paused screen for my game, the paused screen will be activated whenever the pygame window loses focus, here is my code:

import pygame
from sys import exit

pygame.init()

screen = pygame.display.set_mode((500, 500))
clock = pygame.time.Clock()
FPS = 60

while True:
    screen.fill('Black')
    clock.tick(FPS)

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()

        if event.type == pygame.ACTIVEEVENT:
            if event.state == 0:
                # paused screen goes here

    pygame.display.update()

from the documentation I read, the event I should check for is pygame.ACTIVEEVENT and that event has 2 attributes: event.gain and event.state. However, when I tried to access one of them, it prompts an error:

pygame 2.1.2 (SDL 2.0.18, Python 3.10.5)
Hello from the pygame community. https://www.pygame.org/contribute.html
Traceback (most recent call last):
  File "D:\WorkDir\Dinosaur	est.py", line 20, in 
    if event.state == 0:
AttributeError: 'Event' object has no attribute 'state'

I searched up answers online but I couldn't find any. I found a question that is somewhat related to this:
In pygame for event.type == ACTIVEEVENT, where is the documentation on what the different event.state and event.gain parameters mean?

I tried the code from the accepted answer but the bug was still there:

Traceback (most recent call last):
 File "D:\WorkDir\Dinosaur	est.py", line 28, in 
   main()
 File "D:\WorkDir\Dinosaur	est.py", line 18, in main
   if e.state & APPMOUSEFOCUS == APPMOUSEFOCUS:
AttributeError: 'Event' object has no attribute 'state'

user_2280890 · Answer

If you print the ACTIVEEVENT events, e.g. print(f"Active Event {event}") you're trying to handle, you'll see that the first one doesn't have gain or state. You can probably skip this event, using something like

elif event.type == pygame.ACTIVEEVENT:
    print(f"Active Event {event}")
    try:
        print(f"Event state: {event.state}")
    except AttributeError:
        pass

You should see something like:

pygame 2.1.2 (SDL 2.0.18, Python 3.9.13)
Hello from the pygame community. https://www.pygame.org/contribute.html
Active Event 
Active Event 
Active Event 
Active Event 
Active Event 
Active Event

However, you're using the latest PyGame so you can use the more specific events like WINDOWFOCUSGAINED and WINDOWFOCUSLOST to toggle your paused state. Here's a minimal example:

import pygame
 
screen = pygame.display.set_mode((480, 320))
pygame.init()

counter = 0
paused = False
run = True
clock = pygame.time.Clock()
while run:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
        elif event.type == pygame.WINDOWFOCUSGAINED:
            print(f"Gain Focus {event}")
            paused = False
        elif event.type == pygame.WINDOWFOCUSLOST:
            print(f"Lost Focus {event}")
            paused = True

    screen.fill(pygame.Color("grey"))
    pygame.display.update()
    clock.tick(60)  # limit to 60 FPS
    pygame.display.set_caption(f"Paused: {paused}, Counter {counter:,}")
    if not paused:
        counter += 1

pygame.quit()

The window will look like this when runninn:

You'll see console output like this:

pygame 2.1.2 (SDL 2.0.18, Python 3.9.13)
Hello from the pygame community. https://www.pygame.org/contribute.html
Gain Focus 
Lost Focus 
Gain Focus 
Lost Focus 
Gain Focus

Can't access event.state or event.gain of ACTIVEEVENT

1 Answers