What do you mean by “identify click event”?
Note that there is no real click event in Qt in the sense of QEvents. There are mouse down and up events, and there is a double click event, but no click event. A click is simply a mouse down, followed by a mouse up in the same region of your widget.

If understand you correctly, then you just need to override

and when the event occurs, this event handler will be automatically called.

Hi Lyuts,
I am already doing that.But I need to identify a customised Opengl Widget,based on which area it is clicked.
So how do I identify this click area or bounding rectangle of my customised Opengl Widget?

Well, because you do the rendering of that custom widget, it’s up to you to identify what part of the widget was clicked. Qt can’t help you with that.

on mouse click event you can get cursor position using

overriding the mouse event functions should work as said earlier. Do you need to identify an object in an opengl view, a 3d object you added to the scene ?