Programming Languages Suite/JBuilder8.iso/Solaris/resource/jre/demo/plugin/applets/ImageMap/HrefButtonArea.java

Java Source | 2002-09-06 | 4.8 KB | 157 lines

/*
 * Copyright (c) 2002 Sun Microsystems, Inc. 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.
 *
 * -Redistribution in binary form must reproduct 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 Sun Microsystems, Inc. or the names of contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT
 * BE LIABLE FOR ANY DAMAGES OR LIABILITIES SUFFERED BY LICENSEE AS A RESULT
 * OF OR RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE SOFTWARE, EVEN
 * IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that Software is not designed, licensed or intended for
 * use in the design, construction, operation or maintenance of any nuclear
 * facility.
 */

/*
 * @(#)HrefButtonArea.java    1.11 02/06/13
 */

import java.awt.Graphics;
import java.awt.Image;
import java.net.URL;
import java.net.MalformedURLException;

/**
 * An improved "Fetch a URL" ImageArea class.
 * This class extends the basic ImageArea Class to fetch a URL when
 * the user clicks in the area.  In addition, special custom highlights
 * are used to make the area look and feel like a 3-D button.
 *
 * @author     Jim Graham
 * @version     1.11, 06/13/02
 */
class HrefButtonArea extends ImageMapArea {
    /** The URL to be fetched when the user clicks on this area. */
    URL anchor;
    /** The highlight image for when the button is "UP". */
    Image upImage;
    /** The highlight image for when the button is "DOWN". */
    Image downImage;
    /** This flag indicates if the "button" is currently pressed. */
    boolean pressed = false;
    /** The border size for the 3-D effect. */
    int border = 5;

    /**
     * The argument string is the URL to be fetched.
     * This method also constructs the various highlight images needed
     * to achieve the 3-D effect.
     */
    public void handleArg(String arg) {
    try {
        anchor = new URL(parent.getDocumentBase(), arg);
    } catch (MalformedURLException e) {
        anchor = null;
    }
    if (border * 2 > W || border * 2 > H) {
        border = Math.min(W, H) / 2;
    }
    }

    public void makeImages() {
    upImage = parent.getHighlight(X, Y, W, H,
                      new ButtonFilter(false,
                               parent.hlpercent,
                               border, W, H));
    downImage = parent.getHighlight(X, Y, W, H,
                    new ButtonFilter(true,
                             parent.hlpercent,
                             border, W, H));
    }

    public boolean imageUpdate(Image img, int infoflags,
                   int x, int y, int width, int height) {
    if (img == (pressed ? downImage : upImage)) {
        return parent.imageUpdate(img, infoflags, x + X, y + Y,
                      width, height);
    } else {
        return (img == downImage || img == upImage);
    }
    }

    /**
     * The isTerminal method indicates whether events should propagate
     * to the areas underlying this one.
     */
    public boolean isTerminal() {
    return true;
    }

    /**
     * The status message area is updated to show the destination URL.
     * The graphical highlight is achieved using the ButtonFilter.
     */
    public void highlight(Graphics g) {
    if (entered) {
        g.drawImage(pressed ? downImage : upImage, X, Y, this);
    }
    }

    public void enter() {
    showStatus((anchor != null)
           ? "Go To " + anchor.toExternalForm()
           : null);
    repaint();
    }

    public void exit() {
    showStatus(null);
    repaint();
    }

    /**
     * Since the highlight changes when the button is pressed, we need
     * to record the "pressed" state and induce a repaint.
     */
    public boolean press() {
    pressed = true;
    repaint();
    return true;
    }

    /**
     * The new URL is fetched when the user releases the mouse button
     * only if they are still in the area.
     */
    public boolean lift(int x, int y) {
    pressed = false;
    repaint();
    if (inside(x, y) && anchor != null) {
        showDocument(anchor);
    }
    return true;
    }
}