python - How does PySide/PyQt QMainWindow close a QDockWidget? -

i need know how qdockwidget closed. have serial port/thread attached qdockwidget, , need make sure thread , serial port close properly.

class serialdock(qdockwidget):     ...      def close(self):         print("close")         self.serialport.close()         self.thread.close()      def closeevent(self, event):         print("closeevent")         self.serialport.close()         self.thread.close() 

the close , closeevents not called when click qmainwindow x button. have call close method qmainwindow close? way know solve use qapplication.abouttoquit signal, , don't want have remember set 1 specific widget. how qdockwidget destroyed or closed?

you can use destroyed signal in qdockwidget:

import pyqt4.qtgui ui import pyqt4.qtcore core  app = ui.qapplication([])  mw = ui.qmainwindow() mw.setcentralwidget(ui.qtextedit())  dw = ui.qdockwidget("test",mw) dw.setwidget(ui.qlabel("content"))  mw.adddockwidget(core.qt.rightdockwidgetarea, dw)  def ondestroy(w):     print("do stuff here")     print(w)  dw.destroyed.connect(ondestroy)  mw.show() app.exec_()