I am trying to implement tri-state checkboxes into a QMenu. My menu hierarchy will be something like:
menuA
|-- a101
|-- a102
menuB
|-- b101
Where the first tier (menuA, menuB) are of tri-state checkboxes while its sub items are normal checkboxes, implemented using QAction.
And so, with the use of QWidgetAction and QCheckBox, seemingly I am able to get the tristate working on the first tier level.
However as soon as I tried to use setMenu that contains the sub items into the first tier items, the options are no longer checkable even though it is able to display the sub items accordingly.
Initially I am using only QAction widgets but as I am iterating the sub items, the first tier item is always shown as a full check in which I would like to rectify it if possible and hence I am trying to make use of the tri-state.
Eg. If a101 is checked, menuA will be set with a partial state. If both a101 and a102 are checked, menuA will then be set with (full) check state.
class CustomCheckBox(QtGui.QCheckBox):
def __init__(self, text="", parent=None):
super(CustomCheckBox, self).__init__(text, parent=parent)
self.setText(text)
self.setTristate(True)
class QSubAction(QtGui.QAction):
def __init__(self, text="", parent=None):
super(QSubAction, self).__init__(text, parent)
self.setCheckable(True)
self.toggled.connect(self.checkbox_toggle)
def checkbox_toggle(self, value):
print value
class QCustomMenu(QtGui.QMenu):
"""Customized QMenu."""
def __init__(self, title, parent=None):
super(QCustomMenu, self).__init__(title=str(title), parent=parent)
self.setup_menu()
def mousePressEvent(self,event):
action = self.activeAction()
if not isinstance(action,QSubAction) and action is not None:
action.trigger()
return
elif isinstance(action,QSubAction):
action.toggle()
return
return QtGui.QMenu.mousePressEvent(self,event)
def setup_menu(self):
self.setContextMenuPolicy(QtCore.Qt.DefaultContextMenu)
def contextMenuEvent(self, event):
no_right_click = [QAddAction]
if any([isinstance(self.actionAt(event.pos()), instance) for instance in no_right_click]):
return
pos = event.pos()
def addAction(self, action):
super(QCustomMenu, self).addAction(action)
class MainApp(QtGui.QWidget):
def __init__(self, parent=None):
super(MainApp, self).__init__(parent)
self.test_dict = {
"testA" :{
"menuA": ["a101", "a102"],
},
"testBC": {
"menuC": ["c101", "c102", "c103"],
"menuB": ["b101"]
},
}
v_layout = QtGui.QVBoxLayout()
self.btn1 = QtGui.QPushButton("TEST BTN1")
v_layout.addWidget(self.btn1)
self.setLayout(v_layout)
self.setup_connections()
def setup_connections(self):
self.btn1.clicked.connect(self.button1_test)
def button1_test(self):
self.qmenu = QCustomMenu(title='', parent=self)
for pk, pv in self.test_dict.items():
base_qmenu = QCustomMenu(title=pk, parent=self)
base_checkbox = CustomCheckBox(pk, base_qmenu)
base_action = QtGui.QWidgetAction(base_checkbox)
base_action.setMenu(base_qmenu) # This is causing the option un-checkable
base_action.setDefaultWidget(base_checkbox)
self.qmenu.addAction(base_action)
for v in pv:
action = QSubAction(v, self)
base_qmenu.addAction(action)
self.qmenu.exec_(QtGui.QCursor.pos())
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
w = MainApp()
w.show()
sys.exit(app.exec_())
The reason for which you can't set the state of a sub menu is that QMenu automatically uses the click on a sub menu to open it, "consuming" the click event.
To get that you'll have to ensure where the user is clicking and, if it's one of your QWidgetActions trigger it, ensuring that the event is not being propagated furthermore.
Also, the tri state logic is added to the children state, using the toggled signal that checks all menu actions to decide the actual state.
Note that contextMenuEvent (along with the menu policy setting) has been removed.
Finally, consider that using a checkbox that does not trigger an action in a menu item is not suggested, as it's counterintuitive since it goes against the expected behavior of a menu item.
class CustomCheckBox(QtGui.QCheckBox):
def __init__(self, text="", parent=None):
super(CustomCheckBox, self).__init__(text, parent=parent)
self.setText(text)
self.setTristate(True)
def mousePressEvent(self, event):
# only react to left click buttons and toggle, do not cycle
# through the three states (which wouldn't make much sense)
if event.button() == QtCore.Qt.LeftButton:
self.toggle()
def toggle(self):
super(CustomCheckBox, self).toggle()
newState = self.isChecked()
for action in self.actions():
# block the signal to avoid recursion
oldState = action.isChecked()
action.blockSignals(True)
action.setChecked(newState)
action.blockSignals(False)
if oldState != newState:
# if you *really* need to trigger the action, do it
# only if the action wasn't already checked
action.triggered.emit(newState)
class QSubAction(QtGui.QAction):
def __init__(self, text="", parent=None):
super(QSubAction, self).__init__(text, parent)
self.setCheckable(True)
class QCustomMenu(QtGui.QMenu):
"""Customized QMenu."""
def __init__(self, title, parent=None):
super(QCustomMenu, self).__init__(title=str(title), parent=parent)
def mousePressEvent(self,event):
actionAt = self.actionAt(event.pos())
if isinstance(actionAt, QtGui.QWidgetAction):
# the first mousePressEvent is sent from the parent menu, so the
# QWidgetAction found is one of the sub menu actions
actionAt.defaultWidget().toggle()
return
action = self.activeAction()
if not isinstance(action,QSubAction) and action is not None:
action.trigger()
return
elif isinstance(action,QSubAction):
action.toggle()
return
QtGui.QMenu.mousePressEvent(self,event)
def addAction(self, action):
super(QCustomMenu, self).addAction(action)
if isinstance(self.menuAction(), QtGui.QWidgetAction):
# since this is a QWidgetAction menu, add the action
# to the widget and connect the action toggled signal
action.toggled.connect(self.checkChildrenState)
self.menuAction().defaultWidget().addAction(action)
def checkChildrenState(self):
actionStates = [a.isChecked() for a in self.actions()]
if all(actionStates):
state = QtCore.Qt.Checked
elif any(actionStates):
state = QtCore.Qt.PartiallyChecked
else:
state = QtCore.Qt.Unchecked
self.menuAction().defaultWidget().setCheckState(state)