Custom widget inheritance

[vpet98]

I have been trying to build me own widget that I want it to be mostly like Input widget, but without ability to modify text, so like a text with a cursor that can be moved in it.

To do so, I have a new class that inherits from Input class and I override some of the methods. While doing so, I noticed that some of the methods like _on_focus and _on_paste are not overriden as I expected. While I can verify that my methods are indeed executed, I also see the effects from the ones of the Input class to take place as if they are executed after my methods.

For example, if I change the _on_focus to have the cursor at start rather than end like this:

def _on_focus(self, _: Focus) -> None:
    self.cursor_position = 0  # modified line
    if self.cursor_blink:
        self._blink_timer.resume()
    self.app.cursor_position = self.cursor_screen_offset

I still see the cursor appear in the end of the text instead of it appearing over the first character as I would expect.

Is there any explanation of why this happens and how I can prevent it?

Thank you

[davep]

You probably want to have a read about default behaviours, and preventing them.