QRadioButton how add a selection check?

Question

On a selection check false i try to prevent the selection of that radiobutton. But it does get selected anyway, even with singleshot timer:

class MyQWidget(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        ...


        self.ui.buttonGroup.buttonPressed.connect(self.is_init)

    def is_init(self, button): 
        if True: #some check here to prevent selection of it
            print('no select')
            QTimer.singleShot(0, lambda: button.setChecked(False))

EDIT:
Assume a button group, i try to intercept the press call (not clicked) to not select that radio button if a custom test is false (if True: #some check), but i cannot prevent the button from being selected also i set it to False, how do abort the selection of the clicked/pressed radio button if a condition is not met?

I don't understand you, explain yourself better, also provide a [mre] — eyllanesc, Sep 21 '19 at 14:18
From what I understand you want that if a button is pressed and if certain conditions are met then you must change its status to False regardless of its current state, am I correct? — eyllanesc, Sep 21 '19 at 15:04
yes, anway the state, its false if a keypress happens + condition = not select readiobutton — droid192, Sep 21 '19 at 15:06

score 1 · Accepted Answer · answered Sep 21 '19 at 15:21

The problem is caused by:

A QButtonGroup is by default exclusive which implies that a button will always be selected causing the setChecked(False) not to work since it would imply having no button pressed, so there is to enable and disable that property in the change.
The change of state does not occur in the pressed but in the released so you must use the buttonReleased signal.

Considering the previous one in the next part I show a MWE:

from PySide2 import QtCore, QtWidgets


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.buttonGroup = QtWidgets.QButtonGroup(self)
        self.buttonGroup.buttonReleased.connect(self.on_buttonReleased)

        lay = QtWidgets.QHBoxLayout(self)

        for i in range(4):
            button = QtWidgets.QRadioButton(f"button-{i}")
            lay.addWidget(button)
            self.buttonGroup.addButton(button)

    @QtCore.Slot(QtWidgets.QAbstractButton)
    def on_buttonReleased(self, button):
        if True:
            self.buttonGroup.setExclusive(False)
            button.setChecked(False)
            self.buttonGroup.setExclusive(True)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.resize(640, 240)
    w.show()
    sys.exit(app.exec_())

thats exactly the point, since exclusive i use `keyPressed` to not change a buttongroup with 'exactlyone' selected unless its valid. in your example i would have none selected. But i try to keep the last valid radiobutton selected, thats why i intercept earlier before selecting another button (and manually keeping history is meh). — droid192, Sep 21 '19 at 18:11

QRadioButton how add a selection check?

1 Answers1