Qt Python - in a list of buttons change color of all buttons up until the one that was clicked

Question

I have a list of Qt buttons like this: self.buttons = [button1, button2, button3] When one is clicked, I want all the buttons that come before the one that was clicked in the list to change their colors.

I made a for loop to loop through the buttons and connect each one to a function that I defined, but when I click a button and the connected function runs, it does not know the order of the button in the buttons list, therefore I cannot make the other buttons change colors. I was thinking that I need to somehow pass the button's id or something to the function but couldn't figure out how to do it as I cannot pass arguments to the connected function: self.button1.clicked.connect(self.change_color)

One argument is automatically passed to the connected function by Qt itself but it is the main window and it does not help my situation:

def change_color(i):  
    print(i)

Output when clicked:

<__main__.Main_Window(0x6000019e0000, name="MainWindow") at 0x11df5ccc0>

The first argument of instance methods is always the instance itself (what's normally called `self`, which is probably your window in this case). Read [What is the purpose of the word 'self'?](https://stackoverflow.com/q/2709821) and do some research about classes, instances and methods. — musicamante, Jan 19 '22 at 20:01

score 4 · Accepted Answer · answered Jan 19 '22 at 20:18

Add all the buttons to a QButtonGroup (using their index as id) and then connect to the group's idClicked signal. This will automatically send the index of the clicked button. Below is a simple demo that shows how to do it:

import sys, random
from PySide2 import QtCore, QtWidgets

class Window(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()
        layout = QtWidgets.QVBoxLayout(self)
        self.buttons = QtWidgets.QButtonGroup(self)
        for index in range(1, 11):
            button = QtWidgets.QPushButton(f'Button {index}')
            self.buttons.addButton(button, index)
            layout.addWidget(button)
        self.buttons.idClicked.connect(self.handleButtons)

    def handleButtons(self, index):
        color = f'#{random.randint(0, 0xFFFFFF):06x}'
        for index in range(1, index):
            self.buttons.button(index).setStyleSheet(f'background: {color}')

if __name__ == '__main__':

    app = QtWidgets.QApplication(sys.argv)
    window = Window()
    window.setWindowTitle('Test')
    window.show()
    sys.exit(app.exec_())

Qt Python - in a list of buttons change color of all buttons up until the one that was clicked

1 Answers1