Demo of the cursor grab

cursor_grab_demo.py

#!/usr/bin/python3

import base64
import io

# import the pygame module, so you can use it
import pygame

MARK_PNG = '''
iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAYAAABzenr0AAAAAXNSR0IArs4c6QAAAMJJREFUWIXt
lksOgDAIRMF48N4cN9VEpTDYX0w6S4Od1xFpiZaWJovBOmm8XugFEUnYYvyqc9f3CmBzB6joYwFU
mSsgqtfWxMFR3ojaR6UEmu3+ZqYk0TwBpRHteuVZcffMiWqTeaYQSqDHZxnShFMBvJ74TwLR7j7f
8foGBhBJIQjNvHoOIBDMKfS77hEABMKaIaTMnSGj2DqMup+GlrkHUA3hmSMARPkYjYIg5ijABYJA
ILegrwBE2OU0fDFdWpqqAzx5SqoAoleYAAAAAElFTkSuQmCC
'''

# define a main function
def main():

    # initialize the pygame module
    pygame.init()
    # load and set the logo
    logo = pygame.image.load(io.BytesIO(base64.b64decode(MARK_PNG)))
    pygame.display.set_icon(logo)
    pygame.display.set_caption("OHIMARK")

    # create a surface on screen that has the size of 240 x 180
    w = 240
    h = 180
    screen = pygame.display.set_mode((w, h))

    # define a variable to control the main loop
    running = True

    mark_x = 0
    mark_y = 0

    # main loop
    while running:
        # event handling, gets all event from the event queue
        for event in pygame.event.get():
            # only do something if the event is of type QUIT
            if event.type == pygame.QUIT:
                # change the value to False, to exit the main loop
                running = False
            elif event.type == pygame.MOUSEMOTION:
                print(event)
                mark_x += event.rel[0] / 10.0
                mark_y += event.rel[1] / 10.0
                #mark_x = event.pos[0]
                #mark_y = event.pos[1]

                mark_x = (w + (mark_x % w)) % w
                mark_y = (h + (mark_y % h)) % h
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE:
                    pygame.mouse.set_visible(True)
                    pygame.event.set_grab(False)
            elif event.type == pygame.MOUSEBUTTONDOWN:
                pygame.mouse.set_visible(False)
                pygame.event.set_grab(True)
            else:
                print(event)
        pygame.draw.rect(screen, (0, 0, 0), (0, 0, w, h))
        screen.blit(logo, (mark_x, mark_y))
        pygame.display.flip()


# run the main function only if this module is executed as the main script
# (if you import this as a module then nothing is executed)
if __name__=="__main__":
    # call the main function
    main()