QPushButton reacts to press when disabled.

martinmaeland

Hi,

Problem
I have a simple gui with a push button. When the button is pressed a function is called. I have noticed that the button can be pressed multiple times and that the callback function is ran multiple times. As if the callbacks are queued up.

To sort this I have tried to use setEnable(False), which do disable the button (it is greyed out). However, the button still register presses, and when the callback function is completed, it starts again. Pressing the button enough times causes the application to crash.

What i want
I want to do something like this.

self.btn = QPushButton('Refresh', self)
self.btn.clicked.connect(self.refresh)

def refresh(self):
    self.btn.setEnabled(False)
    # do something that takes a couple of seconds
    self.btn.setEnabled(True)

I have tried

Using a QTimer to handle the setEnable() method, and then call the function if the button is pressed and disabled.
Using a QThread to basically do the same as above.
Using a dummy-button. Identical to the original button, but without any callback-functions.
Showing/hiding the button.

mranger90

This simple test works with pyside6

import sys
from PySide6.QtWidgets import QApplication, QWidget, QPushButton
from PySide6.QtCore import QTimer


class Widget(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        self.btn = QPushButton('Refresh', self)
        self.btn.clicked.connect(self.refresh)
        self.btnTimer = QTimer(self)
        self.btnTimer.setInterval(2000)
        self.btnTimer.setSingleShot(True)
        self.btnTimer.timeout.connect(self.timerTimeout)

    def refresh(self):
        self.btn.setEnabled(False)
        self.btnTimer.start()
        print('Button was pressed, starting timer')

    def timerTimeout(self):
        self.btn.setEnabled(True)
        print('In Timer TimeOut')



if __name__ == "__main__":
    app = QApplication([])
    window = Widget()
    window.show()
    sys.exit(app.exec())

JonB

@martinmaeland
Hello and welcome.

You should not be having so much trouble. For example, the code you showed should work (AFAIK), it should not generate new clicked signal while disabled. Do you do anything which could affect this in your # do something that takes a couple of seconds?

martinmaeland

Hello @JonB,

Thank you for the response.

I have the same issue if i do it like this:

def refresh(self):
    self.btn.setEnabled(False)
    sleep(2)
    self.btn.setEnabled(True)

JonB

@martinmaeland
When you use this code, do you visually see the button disabled before the 2 second sleep?

mranger90

This simple test works with pyside6

import sys
from PySide6.QtWidgets import QApplication, QWidget, QPushButton
from PySide6.QtCore import QTimer


class Widget(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        self.btn = QPushButton('Refresh', self)
        self.btn.clicked.connect(self.refresh)
        self.btnTimer = QTimer(self)
        self.btnTimer.setInterval(2000)
        self.btnTimer.setSingleShot(True)
        self.btnTimer.timeout.connect(self.timerTimeout)

    def refresh(self):
        self.btn.setEnabled(False)
        self.btnTimer.start()
        print('Button was pressed, starting timer')

    def timerTimeout(self):
        self.btn.setEnabled(True)
        print('In Timer TimeOut')



if __name__ == "__main__":
    app = QApplication([])
    window = Widget()
    window.show()
    sys.exit(app.exec())

martinmaeland

@JonB

Yes, the button does visually disable for 2 seconds.

martinmaeland

@mranger90

I actually tried this myself after I posted this, and it worked! As long as the timer interval is long enough. Found that 100 ms is enough for it to be pretty responsive and not queue up the callbacks.

Thank you :)