public static boolean isLeftMouseButton(MouseEvent anEvent){
  return ((anEvent.getModifiersEx() & InputEvent.BUTTON1_DOWN_MASK) != 0 || anEvent.getButton() == MouseEvent.BUTTON1);
}

public static boolean isLeftMouseButton ( MouseEvent anEvent ) { return ( ( anEvent . getModifiersEx ( ) & InputEvent . BUTTON1_DOWN_MASK ) != 0 || anEvent . getButton ( ) == MouseEvent . BUTTON1 ) ; }
returns true if the mouse event specifies the left mouse button .
