/**
* Returns true if shift is down or MOD1 is down and the mouse is over the currently selected geometry
*/
private boolean keyboardModifierIndicatesAdd( EditToolHandler handler, MapMouseEvent event ) {
EditBlackboard editBlackboard = handler.getEditBlackboard(handler.getEditLayer());
boolean noIntersectingSelection = editBlackboard.getGeoms(event.x, event.y).isEmpty();
return event.isShiftDown()
|| (noIntersectingSelection && event
.isModifierDown(MapMouseEvent.MOD1_DOWN_MASK));
}