URLButton.java Source code

Introduction

Here is the source code for URLButton.java

Source

/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 * 
 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
 * 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */

import java.applet.Applet;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Label;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.net.URL;

/**
 * URLButton -- a Button-like object that jumps to a URL. MUST have an Applet
 * parent since we use Applet methods.
 */
public class URLButton extends Label implements MouseListener {
    /** Applet parent, for showStatus() and showDocument(). */
    Applet parent;

    /** Text to display in label() */
    String t;

    /** URL to jump to mouseReleased mouseEnter() */
    URL u;

    /** Construct a URLButton given a URL */
    URLButton(Applet parent, String t, URL u) {
        super(t);
        this.parent = parent;
        this.t = t;
        this.u = u;
        addMouseListener(this);
    }

    /** paint() method just draws a box around us */
    public void paint(Graphics g) {
        // super.paint(graphics g);
        Dimension d = getSize();
        g.drawRect(0, 0, d.width - 1, d.height - 1);
    }

    /** When mouse enters, showStatus of URL */
    public void mouseEntered(MouseEvent e) {
        parent.showStatus(u.toExternalForm());
    }

    /** When mouse enters, clear showStatus */
    public void mouseExited(MouseEvent e) {
        parent.showStatus("");
    }

    /** When the button is pressed, go for it! */
    public void mousePressed(MouseEvent e) {
        parent.showStatus("Showing document at URL " + u);

        parent.getAppletContext().showDocument(u);
        // No error checking on showDocument() -- the
        // browser will honk at the user if the link
        // is invalid. We should open "u" ourselves,
        // check the open, and close it. Or not...
    }

    /** NotUsed */
    public void mouseClicked(MouseEvent e) {
        parent.showStatus("in mouseClicked");
    }

    /** NotUsed */
    public void mouseReleased(MouseEvent e) {
        parent.showStatus("in mouseReleased");
    }
}