BUG 15/BUGCD1998_06.ISO/aplic/jbuilder/jsamples.z/HrefButtonArea.java

Java Source | 1997-07-30 | 4.8 KB | 149 lines

// $Header: z:/admin/metro_examples/java/demo/ImageMap/rcs/HrefButtonArea.java 1.1 1997/02/06 00:30:09 IPGIntel-2 Exp $
/*
 * @(#)HrefButtonArea.java    1.6 96/12/06
 *
 * Copyright (c) 1994-1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * 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 SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING 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.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

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     1.6, 12/06/96
 */
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;
    }
}