PyQt monkey patching QLineEdit.paste?

Question

I am trying to intercept paste() for a specific edit box. After much reading and head scratching I decided to try the big hammer and monkey patch. This didn\'t work for me

Answer 1

The reason you can't "monkey-patch" QLineEdit.paste() is because it's not a virtual function. The important thing about virtual functions is that when they are overridden, the reimplemented function will get called internally by Qt; whereas non-virtual overrides will only get called by Python code. So, since QLinedit.paste() isn't virtual, you will instead have to intercept all the events that would normally result in it being called internally by Qt.

That will mean reimplementing QLineEdit.keyPressEvent, so that you can trap the shortcuts for the default key bindings; and also QLineEdit.contextMenuEvent, so that you can modify the default context menu. And, depending on what you're trying to do, you might also need to override the default drag-and-drop handling. (If you prefer not to use a subclass, an event-filter can be used to monitor all the relevant events).

The QClipboard class provides access to the system clipboard, which will allow you to intercept the text before it is pasted. Every application has a single clipboard object, which can be accessed via QApplication.clipboard() or qApp.clipboard().