如何在 QEvent 中捕获 NonClientAreaMouseMove 事件

Question

I try to find a way to catch event when user move Qdialog from titleBar. My goal is to attach a drag event to dock my custom qdialog inside my mainWindow. (on Linux)

In other terms, do what dockwidgets do (I can use dockwidget) I have to do the same with Custom Qdialog (or widget with Qt.Window flags)

I see in c++ Qt source code than for QDockWidget, They use this kind of stuff:

bool QDockWidget::event(QEvent *event)
{   [...]
  case QEvent::NonClientAreaMouseMove:
  case QEvent::NonClientAreaMouseButtonPress:
  case QEvent::NonClientAreaMouseButtonRelease:
  case QEvent::NonClientAreaMouseButtonDblClick:
      d->nonClientAreaMouseEvent(static_cast<QMouseEvent*>(event));

But when I try to catch this kind of event on pyside, I recieve nothin:

    def event(self, e):
      print('event %s' % e.type())
      return super(myDyalig,self).event(e)

event PySide2.QtCore.QEvent.Type.ActivationChange
event PySide2.QtCore.QEvent.Type.UpdateRequest
event PySide2.QtCore.QEvent.Type.Paint
# I recieve only this move event when user stop moving (when he 
#  release  the button)
event PySide2.QtCore.QEvent.Type.Move 
event PySide2.QtCore.QEvent.Type.WindowActivate
event PySide2.QtCore.QEvent.Type.ActivationChange
event PySide2.QtCore.QEvent.Type.UpdateRequest
event PySide2.QtCore.QEvent.Type.Paint

Any idea how to do this ? (or another idea how to realize a drag event with qdialog)

Edit:

a minimal example:

 from PySide2.QtCore import *
from PySide2.QtGui import *
from PySide2.QtWidgets import *

class CustomDialog(QDialog):

    def __init__(self, parent=None):
        super(CustomDialog,self).__init__(parent)
        self.setFixedSize(QSize(200,200))

    def event(self, e):
        print('event %s' % e.type())
        return super(CustomDialog,self).event(e)

def main():
    import sys
    app = QApplication(sys.argv)
    dial = CustomDialog()
    dial.show()

    sys.exit(app.exec_())
if __name__ == '__main__':
    main()

Answer 1

You need to install an event filter:

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

    #...

    self.installEventFilter(self)

def eventFilter(self, obj, event):
    if event.type() in (QEvent.NonClientAreaMouseButtonPress, QEvent.NonClientAreaMouseButtonPress, QEvent.Move):
        print(event)
    return super().eventFilter(obj, event)

See also: https://doc.qt.io/qt-5/eventsandfilters.html