QDialog: how to use question mark (?) button?

Question

By default, QDialog windows have a question mark pushbutton in the upper-right corner. When I press it, the mouse cursor is changed to the \'Forbidden\' cursor,

Answer 1

Based on Chernobyl's answer, this is how I did it in Python (PySide):

def event(self, event): 
    if event.type() == QtCore.QEvent.EnterWhatsThisMode:
        print "click"
        return True
    return QtGui.QDialog.event(self, event)

That is, you reimplement event when app enters 'WhatsThisMode'. Otherwise, pass along control back to the base class.

It almost works. The only wrinkle is that the mouse cursor is still turned into the 'Forbidden' shape. Based on another post, I got rid of that by adding:

QtGui.QWhatsThis.leaveWhatsThisMode()

As the line right before the print command in the previous.