jmemousedraggesturerecognizer.java

java 3d game jme 工程开发源代码

/*
 * Copyright (c) 2003-2009 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.jmex.awt.swingui.dnd;

import java.awt.Component;
import java.awt.dnd.DnDConstants;
import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.SwingUtilities;

/**
 * @author Galun
 */
public class JMEMouseDragGestureRecognizer implements MouseListener, MouseMotionListener {

    private MouseEvent firstEvent = null;
    private int motionThreshold = 5;
    //    private Logger log = logger;
    private JMEDragGestureListener dragGestureListener;
    private Component component;
    private JMEDragAndDrop dnd;

    /**
     * create a new gesture recognizer that will send an event if it detects a drag gesture
     *
     * @param dragAndDropSupport JMEDragAndDrop this recognizer should use
     * @param c   the component to monitor
     * @param act the allowed action (TODO: not yet used - probably remove?) 
     * @param dgl the drag gesture listener
     */
    public JMEMouseDragGestureRecognizer( JMEDragAndDrop dragAndDropSupport, Component c, int act, JMEDragGestureListener dgl ) {
        dragGestureListener = dgl;
        this.component = c;
        c.addMouseListener( this );
        c.addMouseMotionListener( this );
        dnd = dragAndDropSupport;
    }

    protected int mapDragOperationFromModifiers( MouseEvent e ) {
        int mods = e.getModifiersEx();

        if ( ( mods & InputEvent.BUTTON1_DOWN_MASK ) != InputEvent.BUTTON1_DOWN_MASK ) {
            return DnDConstants.ACTION_NONE;
        }

        return DnDConstants.ACTION_MOVE;
    }

    /**
     * Invoked when the mouse has been pressed on a component.
     * <p/>
     *
     * @param e the <code>MouseEvent</code>
     */

    public void mousePressed( MouseEvent e ) {
//        TestJMEDragAndDrop.addText("mousePressed on " + ((JComponent)e.getSource()).getName());
        if ( mapDragOperationFromModifiers( e ) != DnDConstants.ACTION_NONE ) {
            firstEvent = e;
            e.consume();
        }
    }

    public void mouseReleased( MouseEvent e ) {
        if ( dnd.isDragging() ) {
            dnd.doDrop( e );
        }
        firstEvent = null;
    }

    public void mouseDragged( MouseEvent e ) {
        //log.info("mouseDragged: " + e.getSource());
//        TestJMEDragAndDrop.addText("mouseDragged: " + ((JComponent)e.getSource()).getName() +
//                " " + e.getWhen() + " firstEvent" + (firstEvent == null ? "==" : "!=") + "null");
        if ( firstEvent != null ) {
            e.consume();

            int action = mapDragOperationFromModifiers( e );
            if ( action == DnDConstants.ACTION_NONE ) {
                return;
            }

            int dx = Math.abs( e.getX() - firstEvent.getX() );
            int dy = Math.abs( e.getY() - firstEvent.getY() );
            if ( ( dx > getMotionThreshold() ) || ( dy > getMotionThreshold() ) ) {
                SwingUtilities.convertMouseEvent( firstEvent.getComponent(), firstEvent, component );
                final JMEDragGestureEvent dge = new JMEDragGestureEvent( this, action,
                        firstEvent.getPoint(), firstEvent );
                dispatchDragGestureEvent( dge );
                firstEvent = null;
            }
        } else {
            if ( dnd.isDragging() ) {
                dnd.doDrag( e );
                e.consume();
            }
        }
    }

    protected void dispatchDragGestureEvent( final JMEDragGestureEvent event ) {
        SwingUtilities.invokeLater( new Runnable() {
            public void run() {
                dragGestureListener.dragGestureRecognized( event );
            }
        } );
    }

    /**
     * get the minimum width in pixel (horiz. and vertical) that one has to drag before the event is fired
     *
     * @return the current threshold
     */
    public int getMotionThreshold() {
        return motionThreshold;
    }

    /**
     * set the minimum width in pixel (horiz. and vertical) that one has to drag before the event is fired
     *
     * @param newThreshold the width in pixel
     */
    public void setMotionThreshold( int newThreshold ) {
        if ( newThreshold < 1 ) {
            throw new IllegalArgumentException( "motion threshold must be at least 1" );
        }
        motionThreshold = newThreshold;
    }

    public void mouseClicked( MouseEvent e ) {
        firstEvent = null;
    }

    public void mouseEntered( MouseEvent e ) {
        if ( dnd.isDragging() ) {
            dnd.mouseEntered( e );
        }
    }

    public void mouseExited( MouseEvent e ) {
        if ( dnd.isDragging() ) {
            dnd.mouseExited( e );
        }
    }

    public void mouseMoved(MouseEvent e) {
    }
}