Allow the Entry input method to internally handle key press and release events.
If this function returns true, then no further processing should be done for this key event. See filter_keypress.
Note that you are expected to call this function from your handler when overriding key event handling. This is needed in the case when you need to insert your own key handling between the input method and the default key event handling of the Entry. See reset_im_context for an example of use.
the key event
true if the input method handled the key event.