ViewportModel viewport = getInputController().getViewportModel();
switch (key) {
case KeyCodeMap.ARROW_LEFT:
case KeyCodeMap.ARROW_RIGHT:
viewport.shiftHorizontally(key == KeyCodeMap.ARROW_RIGHT);
return true;
case KeyCodeMap.ARROW_UP:
case KeyCodeMap.ARROW_DOWN:
viewport.shiftVertically(key == KeyCodeMap.ARROW_DOWN, false);