How do I prevent a Right mouse press event from cancelling item selection in QGraphicsScene?

enjoysmath

Currently, this code has no effect:

    def mousePressEvent(self, event):
        if self._place is None:
            if event.button() != Qt.RightButton:   # reserved for context menu so it doesn't disturb current selection
                super().mousePressEvent(event)
        else:
            if event.button() == Qt.LeftButton:
                self._place = None
            elif event.button() == Qt.RightButton:
                if self.rightClickOnPlaceHandler is not None:
                    self.rightClickOnPlaceHandler(self._place, event)

in terms of fixing my problem. The problem is that the selected items become no longer selected upon any press of the scene, except of course the focused item remains selected when you press on it. I need the items to remain selected upon right mouse clicking so that the context menu can operate on selected items ("Lock", "Unlock", "Copy", "Delete" [selected]).

enjoysmath

Solved it. Put this in itemChange handler of your GraphicsItem base class (you need to have made one):

        elif change == self.ItemSelectedChange and self.scene():
            if self.scene().rightMousePressed():
                return self.isSelected()
            return value
        else:

And in graphics_scene.py:

    def mousePressEvent(self, event):
        if self._place is None:
            if event.button() != Qt.RightButton:   # reserved for context menu so it doesn't disturb current selection
                super().mousePressEvent(event)
            else:
                self._rightPress = True  
#          ....
                    
    def mouseReleaseEvent(self, event):
        self._rightPress = False
        super().mouseReleaseEvent(event)

This works for my app.