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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</code>
 * defines a <code>DragGestureRecognizer</code>
 * 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</code>
     * given the <code>DragSource</code> for the
     * <code>Component</code> c, the <code>Component</code>
     * to observe, the action(s)
     * permitted for this drag operation, and
     * the <code>DragGestureListener</code> to
     * notify when a drag gesture is detected.
     * <P>
     * @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</code>
     * given the <code>DragSource</code> for
     * the <code>Component</code> c,
     * the <code>Component</code> to observe, and the action(s)
     * permitted for this drag operation.
     * <P>
     * @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</code>
     * given the <code>DragSource</code> for the
     * <code>Component</code> c, and the
     * <code>Component</code> to observe.
     * <P>
     * @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</code>
     * given the <code>DragSource</code> for the <code>Component</code>.
     * <P>
     * @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.
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    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</code>.
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    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.
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    public void mouseReleased(MouseEvent e) { }

    
Invoked when the mouse enters a component.



Params:
  • e – the MouseEvent
/**
     * Invoked when the mouse enters a component.
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    public void mouseEntered(MouseEvent e) { }

    
Invoked when the mouse exits a component.



Params:
  • e – the MouseEvent
/**
     * Invoked when the mouse exits a component.
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    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.
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    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).
     * <P>
     * @param e the <code>MouseEvent</code>
     */

    public void mouseMoved(MouseEvent e) { }
}