src/java.desktop/share/classes/java/awt/event/MouseAdapter.java

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package java.awt.event;

/**
 * An abstract adapter class for receiving mouse events.
 * The methods in this class are empty. This class exists as
 * convenience for creating listener objects.
 * <P>
 * Mouse events let you track when a mouse is pressed, released, clicked,
 * moved, dragged, when it enters a component, when it exits and
 * when a mouse wheel is moved.
 * <P>
 * Extend this class to create a {@code MouseEvent}
 * (including drag and motion events) or/and {@code MouseWheelEvent}
 * listener and override the methods for the events of interest. (If you implement the
 * {@code MouseListener},
 * {@code MouseMotionListener}
 * interface, you have to define all of
 * the methods in it. This abstract class defines null methods for them
 * all, so you can only have to define methods for events you care about.)
 * <P>
 * Create a listener object using the extended class and then register it with
 * a component using the component's {@code addMouseListener}
 * {@code addMouseMotionListener}, {@code addMouseWheelListener}
 * methods.
 * The relevant method in the listener object is invoked  and the {@code MouseEvent}
 * or {@code MouseWheelEvent}  is passed to it in following cases:
 * <ul>
 * <li>when a mouse button is pressed, released, or clicked (pressed and  released)
 * <li>when the mouse cursor enters or exits the component
 * <li>when the mouse wheel rotated, or mouse moved or dragged
 * </ul>
 *
 * @author Carl Quinn
 * @author Andrei Dmitriev
 *
 * @see MouseEvent
 * @see MouseWheelEvent
 * @see MouseListener
 * @see MouseMotionListener
 * @see MouseWheelListener
 * @see <a href="https://docs.oracle.com/javase/tutorial/uiswing/events/mouselistener.html">Tutorial: Writing a Mouse Listener</a>
 *
 * @since 1.1
 */
public abstract class MouseAdapter implements MouseListener, MouseWheelListener, MouseMotionListener {

    /**
     * Constructs a {@code MouseAdapter}.
     */
    protected MouseAdapter() {}

    /**
     * {@inheritDoc}
     */
    public void mouseClicked(MouseEvent e) {}

    /**
     * {@inheritDoc}
     */
    public void mousePressed(MouseEvent e) {}

    /**
     * {@inheritDoc}
     */
    public void mouseReleased(MouseEvent e) {}

    /**
     * {@inheritDoc}
     */
    public void mouseEntered(MouseEvent e) {}

    /**
     * {@inheritDoc}
     */
    public void mouseExited(MouseEvent e) {}

    /**
     * {@inheritDoc}
     * @since 1.6
     */
    public void mouseWheelMoved(MouseWheelEvent e){}

    /**
     * {@inheritDoc}
     * @since 1.6
     */
    public void mouseDragged(MouseEvent e){}

    /**
     * {@inheritDoc}
     * @since 1.6
     */
    public void mouseMoved(MouseEvent e){}
}