Override this to intercept special key multiple events before they are processed by the application. If you return true, the application will not itself process the event. If you return false, the normal application processing will occur as if the IME had not seen the event at all.

The default implementation always returns false, except when in fullscreen mode, where it will consume DPAD movement events to move the cursor in the extracted text view, not allowing them to perform navigation in the underlying application.

[Android Documentation]