Mouse Listeners and Mouse Motion Listeners

Generally you respond to mouse events directed at your component, by registering a MouseListener object with the component.

public interface MouseListener extends EventListener

For reasons of efficiency, the MouseListener interface only declares five methods:

 public abstract void mouseClicked(MouseEvent evt)
 public abstract void mousePressed(MouseEvent evt)
 public abstract void mouseReleased(MouseEvent evt)
 public abstract void mouseEntered(MouseEvent evt)
 public abstract void mouseExited(MouseEvent evt)

A mouse listener does not respond to mouse dragged or mouse moved events because these are too common. Responding to each of them, even with a noop method, would result in many unnecessary method calls. Instead, mouse moved and mouse dragged events are responded to by the MouseMotionListener interface.

public interface MouseMotionListener extends EventListener

The MouseMotionListener interface declares these two methods that are missing from MouseListener:

  public abstract void mouseDragged(MouseEvent evt)
  public abstract void mouseMoved(MouseEvent evt)

If you don't care about mouse dragged and mouse moved events, then you simply don't register a MouseMotionListener on the component; and the component won't bother to report such events.

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Copyright 1998, 2006 Elliotte Rusty Harold
Last Modified April 26, 2006