Checkbox keeps initial state even after it has been changed

SIG_KILL

This widget I created is just a vBox of 16 checkboxes. The problem I am stuck on is the checkbox always returns the initial state it was assigned. I have attached the full code of the widget and a screenshot before/after checking it.

Windows: 10
Python: 3.10.5
PySide6: 6.3.0

from typing import Dict

from PySide6.QtCore import Qt, Signal
from PySide6.QtWidgets import (
    QWidget,
    QCheckBox,
    QVBoxLayout,
)


class SwarmTable(QWidget):

    def __init__(self, parent=None):
        super().__init__(parent)
        self.parent = parent

        self.layout = QVBoxLayout()
        self.layout.setContentsMargins(10, 10, 10, 10)
        self.layout.setSpacing(1)

        self.add_rows()
        self.setLayout(self.layout)
        self.layout.addStretch(1)

    def add_rows(self):
        for port in range(1, 17):
            cb = QCheckBox(self)
            cb.setText(f"Port {port}")
            cb.setCheckState(Qt.Unchecked)
            cb.setEnabled(port < 15)
            self.layout.addWidget(cb, 0, Qt.AlignLeft | Qt.AlignVCenter)

    def get_active_ports(self) -> Dict[int, bool]:
        for c in self.children():
            if isinstance(c, QCheckBox):
                print(f"{c.text()} is {c.checkState()}")

Initializes as expected SwarmTable.get_active_ports() returns:

Port 1 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 2 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 3 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 4 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 5 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 6 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 7 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 8 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 9 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 10 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 11 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 12 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 13 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 14 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 15 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 16 is PySide6.QtCore.Qt.CheckState.Unchecked

However when I click a port, it shows visually correct but SwarmTable.get_active_ports() still returns the same incorrect information.

Port 1 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 2 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 3 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 4 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 5 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 6 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 7 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 8 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 9 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 10 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 11 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 12 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 13 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 14 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 15 is PySide6.QtCore.Qt.CheckState.Unchecked
Port 16 is PySide6.QtCore.Qt.CheckState.Unchecked

Any ideas or suggestions would be appreciated. Been stuck on this for a few hours. Thanks!

SGaist

Hi,

Where and how are you calling get_active_ports ?

SIG_KILL

@SGaist
I have an object that holds all my external process communication. When I click the purple "play" button in the toolbar, it calls the slot ProcManager.start_process seen in the following.

class ProcManager(QObject):
    status_fwd = Signal(str)
    result_fwd = Signal(dict)

    uut_pt_fwd = Signal(dict)
    ref_pt_fwd = Signal(np.float64)

    active_uut_fwd = Signal(dict)

    active_step_fwd = Signal(dict)
    all_steps_fwd = Signal(dict)

    def __init__(self, parent):
        super().__init__(parent)
        self.parent = parent

        self.passive_cal = QProcess()
        self.passive_cal.setProcessChannelMode(QProcess.MergedChannels)
        self.passive_cal.setProgram("cal_passive_ion")

        self._timer = QTimer()
        self._timer.setInterval(100)
        self._timer.timeout.connect(self.read_stdout)

    def __init__(self, parent):
        super().__init__(parent)
        self.parent = parent
        self.pool = QThreadPool.globalInstance()

        self.passive_cal = QProcess()
        self.passive_cal.setProcessChannelMode(QProcess.MergedChannels)
        self.passive_cal.setProgram("cal_passive_ion")

        self._timer = QTimer()
        self._timer.setInterval(100)
        self._timer.timeout.connect(self.read_stdout)

    @Slot()
    def start_process(self):
        # get_active_ports() returns Dict[int, bool] 
        #   where int is the port number and bool is whether it is active
        # Don't need to go past here to observer issue.
        _a = json.dumps(self.parent.main_activity.tabs.ports_view.get_active_ports())

        self.passive_cal.setArguments([f"--active-ports={_a}"])
        self.passive_cal.start()
        self._timer.start()

    @Slot()
    def stop_process(self):
        self.passive_cal.terminate()

and for reference heres my Mainwindow and MainActivity


class MainActivity(QWidget):
    def __init__(self, parent=None):
        super().__init__()
        self.parent = parent
        layout = QHBoxLayout()
        layout.addWidget(self.tabs, 2)
        layout.addWidget(self.chart, 8)
        self.setLayout(layout)

    @cached_property
    def tabs(self):
        return DetailsTabs(self)

    @cached_property
    def chart(self):
        return PressurePlot(self)


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.session = Session(self)
        self.settings = Settings(self)
        self.proc_man = ProcManager(self)
        self.toolbar.start_calibration.connect(self.proc_man.start_process)
        self.toolbar.stop_calibration.connect(self.proc_man.stop_process)
        self.addToolBar(self.toolbar)
        self.setCentralWidget(self.main_activity)

    @cached_property
    def toolbar(self):
        return Toolbar(self)

    @cached_property
    def main_activity(self):
        return MainActivity(self)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setStyle("Fusion")

    window = MainWindow()
    window.resize(QSize(1400, 947))
    window.show()

    sys.exit(app.exec())

SGaist

One issue I can see is that your widget explicitly grabs data from an unrelated widget through the parent which is a bad sign.

It should rather be the other way around, the widget should be configured externally or through signals and slots.

SIG_KILL

@SGaist I am not sure what you mean by "your widget explicitly grabs data from an unrelated widget through the parent" but I removed any use of self.parent... made get_active_ports into a slot that emits a signal. I then observed the same issue.

So just out of curiosity I wanted to remove the cached_property decorator to see if that was part of the issue, and I noticed the table widget was a property, not a cached_property. So now my main widget looks like this:

class MainActivity(QWidget):
    def __init__(self, parent=None):
        super().__init__()
        self.parent = parent
        layout = QHBoxLayout()
        layout.addWidget(self.tabs, 2)
        layout.addWidget(self.chart, 8)
        self.setLayout(layout)

    @cached_property  # <-- was @property
    def tabs(self):
        return DetailsTabs(self)

    @cached_property
    def chart(self):
        return PressurePlot(self)

That was a typo on my part. Everything works fine now. Better, actually, because I think the change to signal/slot is more consistent.

Thanks for you help help @SGaist , wouldn't have seen my if I didn't go to change that method call to a signal/slot. :)