License text 

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER 
 * Copyright  2008, 2010 Oracle and/or its affiliates.  All rights reserved. 
 * Use is subject to license terms.
 * 
 * This file is available and licensed under the following license:
 * 
 * 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 Oracle Corporation 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 draganddrop;

import javafx.scene.*;
import javafx.scene.input.*;

public class DragBehavior {
    public var target: Node;
    public var targetWidth: Number;
    public var targetHeight: Number;
    public var maxX = 200.0;
    public var maxY = 200.0;
    var startX = 0.0;
    var startY = 0.0;
    
    init {
        target.onMousePressed = function(e:MouseEvent):Void {
            startX = e.sceneX-target.translateX;
            startY = e.sceneY-target.translateY;
        }
        target.onMouseDragged = function(e:MouseEvent):Void {
            var tx = e.sceneX-startX;
            if(tx < 0) { tx = 0; }
            if(tx > maxX - targetWidth) { tx = maxX - targetWidth; }
            target.translateX = tx;

            var ty = e.sceneY-startY;
            if(ty < 0) { ty = 0; }
            if(ty > maxY - targetHeight) { ty = maxY - targetHeight; }
            target.translateY = ty;
        }
    }
}
JavaFX Sample
License text 

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER 
 * Copyright  2008, 2010 Oracle and/or its affiliates.  All rights reserved. 
 * Use is subject to license terms.
 * 
 * This file is available and licensed under the following license:
 * 
 * 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 Oracle Corporation 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 draganddrop;

import javafx.scene.*;
import javafx.scene.input.*;

public class DragBehavior {
    public var target: Node;
    public var targetWidth: Number;
    public var targetHeight: Number;
    public var maxX = 200.0;
    public var maxY = 200.0;
    var startX = 0.0;
    var startY = 0.0;
    
    init {
        target.onMousePressed = function(e:MouseEvent):Void {
            startX = e.sceneX-target.translateX;
            startY = e.sceneY-target.translateY;
        }
        target.onMouseDragged = function(e:MouseEvent):Void {
            var tx = e.sceneX-startX;
            if(tx < 0) { tx = 0; }
            if(tx > maxX - targetWidth) { tx = maxX - targetWidth; }
            target.translateX = tx;

            var ty = e.sceneY-startY;
            if(ty < 0) { ty = 0; }
            if(ty > maxY - targetHeight) { ty = maxY - targetHeight; }
            target.translateY = ty;
        }
    }
}