Marble: Navigational FloatItem: Keeping the arrows pressed should move the map continuously
completed by: Mohammed Nafees
mentors: Torsten Rahn, Dennis Nienhüser
Right now if you press the arrows in the ArrowDiscWidget of the Navigational Floatitem it will only move once. If the allow is pressed longer than pressThreshold = 300ms the map should continue to move a further step every 300ms until the mouse is released.Once released the map should stop moving.
This behaviour should be implemented for all four directions: Up, Down, Right and Left. While keeping the button pressed the styling of the buttons should reflect that state.