Python Pyglet mouse events don't call on_draw() nor make changes in window

Question

for some reason, any mouse event that happens with my program doesn't make the image in the window disappear nor reappear, although my on_key_press() function works.

I've tried state flags and declaring a new image resource, but it doesn't change anything in the window.

Is there a way to make this work? Should I revert to a previous pyglet version? If so, which version?

Here's my code of the program; it runs with the test image visible, and every time a key is pressed or the mouse is clicked, the image will disappear or reappear:

import pyglet

window = pyglet.window.Window()

image = pyglet.resource.image('test.png')
image.anchor_x = image.width // 2
image.anchor_y = image.height // 2

state = True


@window.event
def on_draw():
    print('on_draw() called')
    window.clear()
    if state:
        image.blit(window.width // 2, window.height // 2)


@window.event
def on_mouse_press(x, y, button, modifiers):
    global state, image
    if button == pyglet.window.mouse.LEFT:
        print('mouse press')
        if state:
            state = False
        else:
            state = True


@window.event
def on_key_press(symbol, modifiers):
    global state
    print('key press')
    if state:
        state = False
    else:
        state = True


pyglet.app.run()

Thanks!

Edit: My python version is 3.7.2 and my pyglet version is 1.4.7, and I use pycharm, if the fact seems to factor in...

Tested with Pyglet 1.4.2, 1.4.6 and 1.4.7 *(latest stable)*. No issues with this code. Either this code is not the actual code being used, or the problem described is not actually a problem. Have you printed `state` when printing `on_draw() called`. If you still believe this is a problem, please mention which Python and Pyglet version you're using. — Torxed, Nov 20 '19 at 13:11
Here's a video of it working, no changes to the code: https://youtu.be/u-JanvgjVXI (nVidia graphics card, Linux, latest drivers) — Torxed, Nov 20 '19 at 13:15
For debugging purposes, does this code work better: https://gist.github.com/Torxed/df5baafb6a61f6a067c54879859ecb40 or alternatively if that didn't work, does this solve the problem: https://gist.github.com/Torxed/2fd5f5c5ad155f722b97eb18f09741c1 (The last code uses sprites instead of raw images). If that doesn't work then there has to be some other kind of issue with how the state is handled or frame buffers being out of sync. Or again, this code isn't the actual code being used and the original image data being garbage collected or something sneaky. — Torxed, Nov 20 '19 at 13:38

score 3 · Accepted Answer · answered Nov 20 '19 at 13:47

It seems to be an issue with the decorator function.

As Torxed suggested, instead of decorating on_mouse_press, replace the window object's on_mouse_press function with your own declaration of that function:

import pyglet


image = pyglet.resource.image('test.png')
image.anchor_x = image.width // 2
image.anchor_y = image.height // 2

state = True


def on_draw():
    print('on_draw() called')
    window.clear()
    if state:
        image.blit(window.width // 2, window.height // 2)


def on_mouse_press(x, y, button, modifiers):
    global state
    print('mouse pressed')
    if state:
        state = False
    else:
        state = True


window = pyglet.window.Window()
window.on_draw = on_draw
window.on_mouse_press = on_mouse_press

pyglet.app.run()

Otherwise, create a subclass of the Window object and override the on_mouse_press function with your own declaration:

import pyglet

class Window(pyglet.window.Window):
    def __init__(self, *args, **kwargs):
        super().__init__(800, 600)
        self.image = pyglet.resource.image('test.png')

        self.image = pyglet.resource.image('test.png')
        self.image.anchor_x = self.image.width // 2
        self.image.anchor_y = self.image.height // 2

        self.state = True

    def on_draw(self):
        print('on_draw() called')
        window.clear()
        if self.state:
            self.image.blit(self.width // 2, self.height // 2)

    def on_mouse_press(self, x, y, button, modifiers):
        print('mouse pressed')
        if self.state:
            self.state = False
        else:
            self.state = True


window = Window()

pyglet.app.run()

Python Pyglet mouse events don't call on_draw() nor make changes in window

1 Answers1