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package java.awt.dnd;

import java.awt.Component;

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;


This abstract subclass of DragGestureRecognizer defines a DragGestureRecognizer for mouse-based gestures. Each platform implements its own concrete subclass of this class, available via the Toolkit.createDragGestureRecognizer() method, to encapsulate the recognition of the platform dependent mouse gesture(s) that initiate a Drag and Drop operation. 
 Mouse drag gesture recognizers should honor the drag gesture motion threshold, available through DragSource.getDragThreshold. A drag gesture should be recognized only when the distance in either the horizontal or vertical direction between the location of the latest mouse dragged event and the location of the corresponding mouse button pressed event is greater than the drag gesture motion threshold. 
 Drag gesture recognizers created with DragSource.createDefaultDragGestureRecognizer follow this convention. 
Author:Laurence P. G. Cable
See Also:
/**
 * This abstract subclass of {@code DragGestureRecognizer}
 * defines a {@code DragGestureRecognizer}
 * for mouse-based gestures.
 *
 * Each platform implements its own concrete subclass of this class,
 * available via the Toolkit.createDragGestureRecognizer() method,
 * to encapsulate
 * the recognition of the platform dependent mouse gesture(s) that initiate
 * a Drag and Drop operation.
 * <p>
 * Mouse drag gesture recognizers should honor the
 * drag gesture motion threshold, available through
 * {@link DragSource#getDragThreshold}.
 * A drag gesture should be recognized only when the distance
 * in either the horizontal or vertical direction between
 * the location of the latest mouse dragged event and the
 * location of the corresponding mouse button pressed event
 * is greater than the drag gesture motion threshold.
 * <p>
 * Drag gesture recognizers created with
 * {@link DragSource#createDefaultDragGestureRecognizer}
 * follow this convention.
 *
 * @author Laurence P. G. Cable
 *
 * @see java.awt.dnd.DragGestureListener
 * @see java.awt.dnd.DragGestureEvent
 * @see java.awt.dnd.DragSource
 */

public abstract class MouseDragGestureRecognizer extends DragGestureRecognizer implements MouseListener, MouseMotionListener {

    private static final long serialVersionUID = 6220099344182281120L;

    
Construct a new MouseDragGestureRecognizer given the DragSource for the Component c, the Component to observe, the action(s) permitted for this drag operation, and the DragGestureListener to notify when a drag gesture is detected. 
Params:
  • ds –  The DragSource for the Component c
  • c –   The Component to observe
  • act – The actions permitted for this Drag
  • dgl – The DragGestureListener to notify when a gesture is detected
/**
     * Construct a new {@code MouseDragGestureRecognizer}
     * given the {@code DragSource} for the
     * {@code Component} c, the {@code Component}
     * to observe, the action(s)
     * permitted for this drag operation, and
     * the {@code DragGestureListener} to
     * notify when a drag gesture is detected.
     *
     * @param ds  The DragSource for the Component c
     * @param c   The Component to observe
     * @param act The actions permitted for this Drag
     * @param dgl The DragGestureListener to notify when a gesture is detected
     *
     */

    protected MouseDragGestureRecognizer(DragSource ds, Component c, int act, DragGestureListener dgl) {
        super(ds, c, act, dgl);
    }

    
Construct a new MouseDragGestureRecognizer given the DragSource for the Component c, the Component to observe, and the action(s) permitted for this drag operation. 
Params:
  • ds –  The DragSource for the Component c
  • c –   The Component to observe
  • act – The actions permitted for this drag
/**
     * Construct a new {@code MouseDragGestureRecognizer}
     * given the {@code DragSource} for
     * the {@code Component} c,
     * the {@code Component} to observe, and the action(s)
     * permitted for this drag operation.
     *
     * @param ds  The DragSource for the Component c
     * @param c   The Component to observe
     * @param act The actions permitted for this drag
     */

    protected MouseDragGestureRecognizer(DragSource ds, Component c, int act) {
        this(ds, c, act, null);
    }

    
Construct a new MouseDragGestureRecognizer given the DragSource for the Component c, and the Component to observe. 
Params:
  • ds –  The DragSource for the Component c
  • c –   The Component to observe
/**
     * Construct a new {@code MouseDragGestureRecognizer}
     * given the {@code DragSource} for the
     * {@code Component} c, and the
     * {@code Component} to observe.
     *
     * @param ds  The DragSource for the Component c
     * @param c   The Component to observe
     */

    protected MouseDragGestureRecognizer(DragSource ds, Component c) {
        this(ds, c, DnDConstants.ACTION_NONE);
    }

    
Construct a new MouseDragGestureRecognizer given the DragSource for the Component. 
Params:
  • ds –  The DragSource for the Component
/**
     * Construct a new {@code MouseDragGestureRecognizer}
     * given the {@code DragSource} for the {@code Component}.
     *
     * @param ds  The DragSource for the Component
     */

    protected MouseDragGestureRecognizer(DragSource ds) {
        this(ds, null);
    }

    
register this DragGestureRecognizer's Listeners with the Component

/**
     * register this DragGestureRecognizer's Listeners with the Component
     */

    protected void registerListeners() {
        component.addMouseListener(this);
        component.addMouseMotionListener(this);
    }

    
unregister this DragGestureRecognizer's Listeners with the Component
subclasses must override this method

/**
     * unregister this DragGestureRecognizer's Listeners with the Component
     *
     * subclasses must override this method
     */


    protected void unregisterListeners() {
        component.removeMouseListener(this);
        component.removeMouseMotionListener(this);
    }

    
Invoked when the mouse has been clicked on a component.

Params:
  • e – the MouseEvent
/**
     * Invoked when the mouse has been clicked on a component.
     *
     * @param e the {@code MouseEvent}
     */

    public void mouseClicked(MouseEvent e) { }

    
Invoked when a mouse button has been pressed on a Component. 
Params:
  • e – the MouseEvent
/**
     * Invoked when a mouse button has been
     * pressed on a {@code Component}.
     *
     * @param e the {@code MouseEvent}
     */

    public void mousePressed(MouseEvent e) { }

    
Invoked when a mouse button has been released on a component.

Params:
  • e – the MouseEvent
/**
     * Invoked when a mouse button has been released on a component.
     *
     * @param e the {@code MouseEvent}
     */

    public void mouseReleased(MouseEvent e) { }

    
Invoked when the mouse enters a component.

Params:
  • e – the MouseEvent
/**
     * Invoked when the mouse enters a component.
     *
     * @param e the {@code MouseEvent}
     */

    public void mouseEntered(MouseEvent e) { }

    
Invoked when the mouse exits a component.

Params:
  • e – the MouseEvent
/**
     * Invoked when the mouse exits a component.
     *
     * @param e the {@code MouseEvent}
     */

    public void mouseExited(MouseEvent e) { }

    
Invoked when a mouse button is pressed on a component.

Params:
  • e – the MouseEvent
/**
     * Invoked when a mouse button is pressed on a component.
     *
     * @param e the {@code MouseEvent}
     */

    public void mouseDragged(MouseEvent e) { }

    
Invoked when the mouse button has been moved on a component
(with no buttons no down).

Params:
  • e – the MouseEvent
/**
     * Invoked when the mouse button has been moved on a component
     * (with no buttons no down).
     *
     * @param e the {@code MouseEvent}
     */

    public void mouseMoved(MouseEvent e) { }
}