content: /*
   *    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., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  /*
   * BrowserHelper.java
   * Copyright (C) 2006 University of Waikato, Hamilton, New Zealand
   */
  
  package weka.gui;
  
  import java.awt.Color;
  import java.awt.Component;
  import java.awt.event.MouseAdapter;
  import java.awt.event.MouseEvent;
  import java.lang.reflect.Method;
  
  import javax.swing.JLabel;
  import javax.swing.JOptionPane;
  
  
  /**
   * A little helper class for browser related stuff. <p/>
   * 
   * The <code>openURL</code> method is based on 
   * <a href="http://www.centerkey.com/java/browser/" target="_blank">Bare Bones Browser Launch</a>,
   * which is placed in the public domain.
   * 
   * @author  fracpete (fracpete at waikato dot ac dot nz)
   * @version $Revision: 6314 $
   */
  public class BrowserHelper {
  
    /** Linux/Unix binaries to look for */
    public final static String[] LINUX_BROWSERS = 
      {"firefox", "google-chrome", "opera", "konqueror", "epiphany", "mozilla", "netscape"};
    
    /**
     * opens the URL in a browser.
     * 
     * @param url		the URL to open
     */
    public static void openURL(String url) {
      openURL(null, url);
    }
  
    /**
     * opens the URL in a browser.
     * 
     * @param parent	the parent component
     * @param url		the URL to open
     */
    public static void openURL(Component parent, String url) {
      openURL(parent, url, true);
    }
  
    /**
     * opens the URL in a browser.
     * 
     * @param parent	the parent component
     * @param url		the URL to open
     * @param showDialog	whether to display a dialog in case of an error or
     * 			just print the error to the console
     */
    public static void openURL(Component parent, String url, boolean showDialog) {
      String osName = System.getProperty("os.name"); 
      try { 
        // Mac OS
        if (osName.startsWith("Mac OS")) { 
  	Class fileMgr = Class.forName("com.apple.eio.FileManager"); 
  	Method openURL = fileMgr.getDeclaredMethod("openURL", new Class[] {String.class}); 
  	openURL.invoke(null, new Object[] {url}); 
        } 
        // Windows
        else if (osName.startsWith("Windows")) {
  	Runtime.getRuntime().exec("rundll32 url.dll,FileProtocolHandler " + url); 
        }
        // assume Unix or Linux
        else {  
  	String browser = null; 
  	for (int count = 0; count < LINUX_BROWSERS.length && browser == null; count++) {
  	  // look for binaries and take first that's available
  	  if (Runtime.getRuntime().exec(new String[] {"which", LINUX_BROWSERS[count]}).waitFor() == 0) {
  	    browser = LINUX_BROWSERS[count];
  	    break;
  	  }
  	}
  	if (browser == null) 
  	  throw new Exception("Could not find web browser");
  	else
  	  Runtime.getRuntime().exec(new String[] {browser, url});
        }
      }
      catch (Exception e) {
        String errMsg = "Error attempting to launch web browser:\n" + e.getMessage();
        
        if (showDialog)
  	JOptionPane.showMessageDialog(
  	    parent, errMsg);
        else
  	System.err.println(errMsg);
      }
    } 
    
    /**
     * Generates a label with a clickable link.
     * 
     * @param url		the url of the link
     * @param text	the text to display instead of URL. if null or of 
     * 			length 0 then the URL is used
     * @return		the generated label
     */
    public static JLabel createLink(String url, String text) {
      final String urlF = url;
      final JLabel result = new JLabel();
      result.setText((text == null) || (text.length() == 0) ? url : text);
      result.setToolTipText("Click to open link in browser");
      result.setForeground(Color.BLUE);
      result.addMouseListener(new MouseAdapter() {
        public void mouseClicked(MouseEvent e) {
  	if (e.getButton() == MouseEvent.BUTTON1) {
  	  BrowserHelper.openURL(urlF);
  	}
  	else {
  	  super.mouseClicked(e);
  	}
        }
        public void mouseEntered(MouseEvent e) {
  	result.setForeground(Color.RED);
        }
        public void mouseExited(MouseEvent e) {
  	result.setForeground(Color.BLUE);
        }
      });
      
      return result;
    }
  }
  