PyQt4 - timer.timeout.connect() - cannot find reference

Question

from PyQt4 import QtGui, QtCore
from code.pair import Pair
from code.breadth_first_search import breadth_first_search
import functools

class Ghosts(QtGui.QGraphicsPixmapItem):

    def __init__(self, name):
        super(Ghosts, self).__init__()

        self.set_image(name)

    def chase(self, goal):
        pos = Pair(self.x(), self.y())
        path = breadth_first_search(pos, goal)

        func = functools.partial(self.move_towards, path)
        timer = QtCore.QTimer()
        timer.timeout.connect(func)
        timer.start(700)

    def move_towards(self, path):
        print("in")
        if path.empty():
            return
        goal = path.get_nowait()
        self.setPos(goal.first(), goal.second())

When I type this it tells me timer.timeout.connect() - cannot find reference, this should resolve but doesn't and nothing happens when I run it. Then I try QtCore.QTimer.singleShot(700, func) instead of the timer above and it works perfecly but executes only once (as it should). Everything I tried to make a timer that executes many times fails. Please help.

Alexander Lutsenko · Accepted Answer · 2015-09-15 22:12:28Z

2

You made a very common mistake. Nothing holds a link to your timer, so it gets deleted after chaise function ends. Replace timer with self.timer.

edited Sep 15, 2015 at 22:12

answered Sep 3, 2015 at 12:07

Alexander Lutsenko

2,15810 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

findusl Over a year ago

If i have a function that generates the element that i want to connect to, how can i do that? I will only save it as an instance variable after the function returned it, as in the function i can't decide to which instance variable to assign it. See here: stackoverflow.com/questions/37534093/…

Collectives™ on Stack Overflow

PyQt4 - timer.timeout.connect() - cannot find reference

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related