/*  * CVS identifier: *  * $Id: ImgMouseListener.java,v 1.1.1.1 2002/07/22 09:26:45 grosbois Exp $ *  * Class:                   ImgMouseListener *  * Description:             Handles the mouse events for scrolling an image *                          displayed in an ImgScrollPane. *  *  *  * COPYRIGHT: *  * This software module was originally developed by Rapha雔 Grosbois and * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel * Askel鰂 (Ericsson Radio Systems AB); and Bertrand Berthelot, David * Bouchard, F閘ix Henry, Gerard Mozelle and Patrice Onno (Canon Research * Centre France S.A) in the course of development of the JPEG2000 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This * software module is an implementation of a part of the JPEG 2000 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio * Systems AB and Canon Research Centre France S.A (collectively JJ2000 * Partners) agree not to assert against ISO/IEC and users of the JPEG * 2000 Standard (Users) any of their rights under the copyright, not * including other intellectual property rights, for this software module * with respect to the usage by ISO/IEC and Users of this software module * or modifications thereof for use in hardware or software products * claiming conformance to the JPEG 2000 Standard. Those intending to use * this software module in hardware or software products are advised that * their use may infringe existing patents. The original developers of * this software module, JJ2000 Partners and ISO/IEC assume no liability * for use of this software module or modifications thereof. No license * or right to this software module is granted for non JPEG 2000 Standard * conforming products. JJ2000 Partners have full right to use this * software module for his/her own purpose, assign or donate this * software module to any third party and to inhibit third parties from * using this software module for non JPEG 2000 Standard conforming * products. This copyright notice must be included in all copies or * derivative works of this software module. *  * Copyright (c) 1999/2000 JJ2000 Partners. *  *  *  */package jj2000.disp;import jj2000.j2k.decoder.*;import java.awt.event.*;import java.awt.*;/** * This class handles the dragging of an image displayed in an * ImgScrollPane. When the mouse is dragged the image scrolls accordingly. * * <P>Objects of this class must be registerd as both mouse listener and mouse  * motion listener. * * <P>While the dragging is taking place the cursor is changed to the * MOVE_CURSOR type. The original cursor is restored when the mouse is * released after the drag. * * */public class ImgMouseListener extends MouseAdapter     implements MouseMotionListener {    /** The component where the image is displayed */    ImgScrollPane isp;    /** The horizontal coordinate where the drag starts */    int startMouseX;    /** The vertical coordinate where the drag starts */    int startMouseY;    /** The horizontal scroll position when the drag started */    int startScrollX;    /** The vertical scroll position when the drag started */    int startScrollY;    Cursor prevCursor;    /**     * Instantiate a new ImgMouseListener that will work on the specified     * ImgScrollPane.     *     * @param isp The image scroll pane on which the actions should operate.     * */    public ImgMouseListener(ImgScrollPane isp) {        this.isp = isp;    }    public void mousePressed(MouseEvent e) {        // Get the possibly start drag position        startMouseX = e.getX();        startMouseY = e.getY();        // Get the start scroll position        startScrollX = isp.getHAdjustable().getValue();        startScrollY = isp.getVAdjustable().getValue();    }    public void mouseReleased(MouseEvent e) {        // Restore the last cursor, if any        if (prevCursor != null) {            isp.setCursor(prevCursor);            prevCursor = null;        }    }    public void mouseDragged(MouseEvent evt) {        int scrollX,scrollY;        // Set the drag cursor        if (prevCursor == null) {            prevCursor = isp.getCursor();            isp.setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));        }        // Calculate new scroll position and set it        scrollX = startScrollX + startMouseX - evt.getX();        scrollY = startScrollY + startMouseY - evt.getY();        isp.setScrollPosition(scrollX,scrollY);    }    public void mouseMoved(MouseEvent evt) {    }}