/*
 * UI-package
 * Copyright (c) 1998 Mats Bovin. All rights reserved.
 *
 * File: HyperLink.java
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

package embe.ui;

import java.awt.Dimension;
import java.awt.Event;
import java.awt.FontMetrics;
import java.net.URL;
import java.applet.AppletContext;


/**
 * This class implements a clickable hyperlink. It works like an
 * ordinary link in an HTML-document. It displays an underlined
 * string or short text and when clicked upon loads a specfied URL
 * in the browser. Since this class needs an AppletContext to work
 * it will only make sense using it in applets.
 * <P>
 * The class needs an URL to the document that is to be shown.
 * It also needs two strings. One is the text to be shown in
 * the link itself. The other is a string that is shown, using
 * the <TT>showStatus()</TT>-method, every time the mouse is moved over
 * the link.
 * <P>
 * When the mouse is clicked somewhere over the link the specified
 * URL is loaded. The target of the new document can be specified
 * in the constructor. The target-string is passed on to <TT>showDocument()</TT>
 * and should therefore be one of the strings supported by that
 * method. Possible strings are:
 *  "_self" = show in current frame,
 *  "_parent" = show in parent frame,
 *  "_top" = show in top-most frame,
 *  "_blank" = show in new unnamed top-level window,
 *  name = show in new top-level window named <I>name</I>.
 * If no target is given in the constructor the default is "_blank".
 *
 * @see java.net.URL
 * @see java.applet.AppletContext
 *
 * @version 1.00 jan-98
 * @author Mats Bovin
 */
public class HyperLink extends java.awt.Canvas {

 /** The URL to load */
  protected URL url_ = null;

 /** The clickable text (the link itself) */
  protected String text_;

 /** The string to show (showStatus()) when the mouse is over the link */
  protected String mouseOver_;

 /** Where shall we view the page */
  protected String target_;

 /** We need an AppletContext to be able to surf */
  protected AppletContext appletContext_ = null;


  /**
   * Constructs a new HyperLink. URL.toString() will
   * be used for the clickable text and the text
   * shown when the mouse is over the link. The URL
   * will be displayed in a new blank window.
   * @param url the URL to load
   * @param ac an AppletContext
   */
  public HyperLink(URL url, AppletContext ac) {
    this(url, ac, url.toString(), url.toString(), "_blank"); }

  /**
   * Constructs a new HyperLink. URL.toString() will
   * be used for the text shown when the mouse is
   * over the link. The URL will be displayed in a
   * new blank window.
   * @param url the URL to load
   * @param ac an AppletContext
   * @param text the clickable text
   */
  public HyperLink(URL url, AppletContext ac, String text) {
    this(url, ac, text, url.toString(), "_blank"); }

  /**
   * Constructs a new HyperLink. The new document
   * will be displayed in a new blank window.
   * @param url the URL to load
   * @param ac an AppletContext
   * @param text the clickable text
   * @param mouseOver the string to show when the mouse is over the link
   */
  public HyperLink(URL url, AppletContext ac, String text, String mouseOver) {
    this(url, ac, text, mouseOver, "_blank"); }

  /**
   * Constructs a new HyperLink.
   * @param url the URL to load
   * @param ac an AppletContext
   * @param text the clickable text
   * @param mouseOver the string to show when the mouse is over the link
   * @param target a String indicating where to display the page.
   * Possible strings are:
   *  "_self" = show in current frame,
   *  "_parent" = show in parent frame,
   *  "_top" = show in top-most frame,
   *  "_blank" = show in new unnamed top-level window,
   *  name = show in new top-level window named name
   */
  public HyperLink(URL url, AppletContext ac, String text, String mouseOver, String target) {
    url_ = url;
    appletContext_ = ac;
    text_ = text;
    mouseOver_ = mouseOver;
    target_ = target;
    setForeground(java.awt.Color.blue);
  }


   /** Prints and underlines the text. */
   public void paint(java.awt.Graphics g) {
     Dimension d = size();
     g.drawString(text_, 0, d.height - 4);
     g.drawLine(0, d.height - 3, d.width, d.height - 3);
   }


   /** Shows a text when the mouse is over the link. */
   public boolean mouseEnter(Event evt, int x, int y) {
     if(appletContext_ != null)
       appletContext_.showStatus(mouseOver_);
     return true;
   }


   /** Clears the text when the mouse leaves the link. */
   public boolean mouseExit(Event evt, int x, int y) {
     if(appletContext_ != null)
       appletContext_.showStatus("");
     return true;
   }


   /** Loads the URL in the specified target. */
   public boolean mouseUp(Event evt, int x, int y) {
     if(appletContext_ != null)
       appletContext_.showDocument(url_, target_);
     return true;
   }


  /* Returns size of component */
  public java.awt.Rectangle bounds() {
    FontMetrics fm = getFontMetrics(getFont());
    Dimension d = new Dimension(fm.stringWidth(text_), fm.getHeight()); //14
    return new java.awt.Rectangle(d);
  }

  public Dimension minimumSize() {
    FontMetrics fm = getFontMetrics(getFont());
    return new Dimension(fm.stringWidth(text_), fm.getHeight()); //14
  }

  public Dimension preferredSize() {
    FontMetrics fm = getFontMetrics(getFont());
    return new Dimension(fm.stringWidth(text_), fm.getHeight()); //14
  }


}