/src/jade/gui/BrowserLauncher.java

package jade.gui;



//#MIDP_EXCLUDE_FILE



import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.lang.reflect.Constructor;

import java.lang.reflect.Field;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;



/**

 * BrowserLauncher is a class that provides one static method, openURL, which opens the default

 * web browser for the current user of the system to the given URL.  It may support other

 * protocols depending on the system -- mailto, ftp, etc. -- but that has not been rigorously

 * tested and is not guaranteed to work.

 * <p>

 * Yes, this is platform-specific code, and yes, it may rely on classes on certain platforms

 * that are not part of the standard JDK.  What we're trying to do, though, is to take something

 * that's frequently desirable but inherently platform-specific -- opening a default browser --

 * and allow programmers (you, for example) to do so without worrying about dropping into native

 * code or doing anything else similarly evil.

 * <p>

 * Anyway, this code is completely in Java and will run on all JDK 1.1-compliant systems without

 * modification or a need for additional libraries.  All classes that are required on certain

 * platforms to allow this to run are dynamically loaded at runtime via reflection and, if not

 * found, will not cause this to do anything other than returning an error when opening the

 * browser.

 * <p>

 * There are certain system requirements for this class, as it's running through Runtime.exec(),

 * which is Java's way of making a native system call.  Currently, this requires that a Macintosh

 * have a Finder which supports the GURL event, which is true for Mac OS 8.0 and 8.1 systems that

 * have the Internet Scripting AppleScript dictionary installed in the Scripting Additions folder

 * in the Extensions folder (which is installed by default as far as I know under Mac OS 8.0 and

 * 8.1), and for all Mac OS 8.5 and later systems.  On Windows, it only runs under Win32 systems

 * (Windows 95, 98, and NT 4.0, as well as later versions of all).  On other systems, this drops

 * back from the inherently platform-sensitive concept of a default browser and simply attempts

 * to launch Netscape via a shell command.

 * <p>

 * This code is Copyright 1999 by Eric Albert (ejalbert@cs.stanford.edu) and may be redistributed

 * or modified in any form without restrictions as long as the portion of this comment from this

 * paragraph through the end of the comment is not removed.  The author requests that he be

 * notified of any application, applet, or other binary that makes use of this code, but that's

 * more out of curiosity than anything and is not required.  This software includes no warranty.

 * <p>

 * Credits:

 * <br>Steven Spencer, JavaWorld magazine (<a href="http://www.javaworld.com/javaworld/javatips/jw-javatip66.html">Java Tip 66</a>)

 * <br>Ron B. Yeh, ZeroG

 * <br>Ben Engber, The New York Times

 * <br>Paul Teitlebaum and Andrea Cantatore, Datatech Software

 *

 * @author Eric Albert (<a href="mailto:ejalbert@cs.stanford.edu">ejalbert@cs.stanford.edu</a>)

 * @version 1.2 (Released July 28, 1999)

 */

public class BrowserLauncher {



	/**

	 * The Java virtual machine that we are running on.  Actually, in most cases we only care

	 * about the operating system, but some operating systems require us to switch on the VM. */

	private static int jvm;



	/** The browser for the system */

	private static Object browser;



	/**

	 * Caches whether any classes, methods, and fields that are not part of the JDK and need to

	 * be dynamically loaded at runtime loaded successfully.

	 * <p>

	 * Note that if this is <code>false</code>, <code>openURL()</code> will always return an

	 * IOException.

	 */

	private static boolean loadedWithoutErrors;



	/** The com.apple.mrj.MRJFileUtils class */

	private static Class mrjFileUtilsClass;



	/** The com.apple.mrj.MRJOSType class */

	private static Class mrjOSTypeClass;



	/** The com.apple.MacOS.MacOSError class */

	private static Class macOSErrorClass;

	

	/** The com.apple.MacOS.AEDesc class */

	private static Class aeDescClass;

	

	/** The <init>(int) method of com.apple.MacOS.AETarget */

	private static Constructor aeTargetConstructor;

	

	/** The <init>(int, int, int) method of com.apple.MacOS.AppleEvent */

	private static Constructor appleEventConstructor;

	

	/** The <init>(String) method of com.apple.MacOS.AEDesc */

	private static Constructor aeDescConstructor;

	

	/** The findFolder method of com.apple.mrj.MRJFileUtils */

	private static Method findFolder;



	/** The getFileType method of com.apple.mrj.MRJOSType */

	private static Method getFileType;

	

	/** The makeOSType method of com.apple.MacOS.OSUtils */

	private static Method makeOSType;

	

	/** The putParameter method of com.apple.MacOS.AppleEvent */

	private static Method putParameter;

	

	/** The sendNoReply method of com.apple.MacOS.AppleEvent */

	private static Method sendNoReply;

	

	/** Actually an MRJOSType pointing to the System Folder on a Macintosh */

	private static Object kSystemFolderType;



	/** The keyDirectObject AppleEvent parameter type */

	private static Integer keyDirectObject;



	/** The kAutoGenerateReturnID AppleEvent code */

	private static Integer kAutoGenerateReturnID;

	

	/** The kAnyTransactionID AppleEvent code */

	private static Integer kAnyTransactionID;



	/** JVM constant for MRJ 2.0 */

	private static final int MRJ_2_0 = 0;

	

	/** JVM constant for MRJ 2.1 or later */

	private static final int MRJ_2_1 = 1;



	/** JVM constant for any Windows NT JVM */

	private static final int WINDOWS_NT = 2;

	

	/** JVM constant for any Windows 9x JVM */

	private static final int WINDOWS_9x = 3;

	



	private static final int WINDOWS_2000 = 4;



	/** JVM constant for any other platform */

	private static final int OTHER = -1;



	/**

	 * The file type of the Finder on a Macintosh.  Hardcoding "Finder" would keep non-U.S. English

	 * systems from working properly.

	 */

	private static final String FINDER_TYPE = "FNDR";



	/**

	 * The creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the

	 * application.

	 */

	private static final String FINDER_CREATOR = "MACS";



	/** The name for the AppleEvent type corresponding to a GetURL event. */

	private static final String GURL_EVENT = "GURL";



	/**

	 * The first parameter that needs to be passed into Runtime.exec() to open the default web

	 * browser on Windows.

	 */

    private static final String FIRST_WINDOWS_PARAMETER = "/c";

    

    /** The second parameter for Runtime.exec() on Windows. */

    private static final String SECOND_WINDOWS_PARAMETER = "start";

	

	/**

	 * The shell parameters for Netscape that opens a given URL in an already-open copy of Netscape

	 * on many command-line systems.

	 */

	private static final String NETSCAPE_OPEN_PARAMETER_START = " -remote 'openURL(";

	private static final String NETSCAPE_OPEN_PARAMETER_END = ")'";

	

	/**

	 * The message from any exception thrown throughout the initialization process.

	 */

	private static String errorMessage;



    /**

       The URL for the official JADE Home Page.

    */

	public static String jadeURL ="http://jade.tilab.com/";

	/**

	 * An initialization block that determines the operating system and loads the necessary

	 * runtime data.

	 */

	static {

		loadedWithoutErrors = true;

		String osName = System.getProperty("os.name");

	

		if ("Mac OS".equals(osName)) {

			String mrjVersion = System.getProperty("mrj.version");

			String majorMRJVersion = mrjVersion.substring(0, 3);

			try {

				double version = Double.valueOf(majorMRJVersion).doubleValue();

				if (version == 2) {

					jvm = MRJ_2_0;

				} else if (version >= 2.1) {

					// For the time being, assume that all post-2.0 versions of MRJ work the same

					jvm = MRJ_2_1;

				} else {

					loadedWithoutErrors = false;

					errorMessage = "Unsupported MRJ version: " + version;

				}

			} catch (NumberFormatException nfe) {

				loadedWithoutErrors = false;

				errorMessage = "Invalid MRJ version: " + mrjVersion;

			}

		} else if (osName.startsWith("Windows")) {

			

			if (osName.indexOf("9") != -1) {

				jvm = WINDOWS_9x;

			}

			else 

			if(osName.indexOf("2") != -1){

				jvm = WINDOWS_2000;

			}

			else {

				jvm = WINDOWS_NT;

			}

		} 

		else {

			jvm = OTHER;

		}

	

		

		if (loadedWithoutErrors) {	// if we haven't hit any errors yet

			loadedWithoutErrors = loadClasses();

		}

	}



	/**

	 * This class should be never be instantiated; this just ensures so.

	 */

	private BrowserLauncher() { }

	

	/**

	 * Called by a static initializer to load any classes, fields, and methods required at runtime

	 * to locate the user's web browser.

	 * @return <code>true</code> if all intialization succeeded

	 *			<code>false</code> if any portion of the initialization failed

	 */

	private static boolean loadClasses() {

		switch (jvm) {

			case MRJ_2_0:

				try {

					Class aeTargetClass = Class.forName("com.apple.MacOS.AETarget");

					macOSErrorClass = Class.forName("com.apple.MacOS.MacOSError");

					Class osUtilsClass = Class.forName("com.apple.MacOS.OSUtils");

					Class appleEventClass = Class.forName("com.apple.MacOS.AppleEvent");

					Class aeClass = Class.forName("com.apple.MacOS.ae");

					aeDescClass = Class.forName("com.apple.MacOS.AEDesc");



					aeTargetConstructor = aeTargetClass.getDeclaredConstructor(new Class [] { int.class });

					appleEventConstructor = appleEventClass.getDeclaredConstructor(new Class[] { int.class, int.class, aeTargetClass, int.class, int.class });

					aeDescConstructor = aeDescClass.getDeclaredConstructor(new Class[] { String.class });



					makeOSType = osUtilsClass.getDeclaredMethod("makeOSType", new Class [] { String.class });

					putParameter = appleEventClass.getDeclaredMethod("putParameter", new Class[] { int.class, aeDescClass });

					sendNoReply = appleEventClass.getDeclaredMethod("sendNoReply", new Class[] { });



					Field keyDirectObjectField = aeClass.getDeclaredField("keyDirectObject");

					keyDirectObject = (Integer) keyDirectObjectField.get(null);

					Field autoGenerateReturnIDField = appleEventClass.getDeclaredField("kAutoGenerateReturnID");

					kAutoGenerateReturnID = (Integer) autoGenerateReturnIDField.get(null);

					Field anyTransactionIDField = appleEventClass.getDeclaredField("kAnyTransactionID");

					kAnyTransactionID = (Integer) anyTransactionIDField.get(null);

				} catch (ClassNotFoundException cnfe) {

					errorMessage = cnfe.getMessage();

					return false;

				} catch (NoSuchMethodException nsme) {

					errorMessage = nsme.getMessage();

					return false;

				} catch (NoSuchFieldException nsfe) {

					errorMessage = nsfe.getMessage();

					return false;

				} catch (IllegalAccessException iae) {

					errorMessage = iae.getMessage();

					return false;

				}

				break;

			case MRJ_2_1:

				try {

					mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");

					mrjOSTypeClass = Class.forName("com.apple.mrj.MRJOSType");

					Field systemFolderField = mrjFileUtilsClass.getDeclaredField("kSystemFolderType");

					kSystemFolderType = systemFolderField.get(null);

					findFolder = mrjFileUtilsClass.getDeclaredMethod("findFolder", new Class[] { mrjOSTypeClass });

					getFileType = mrjFileUtilsClass.getDeclaredMethod("getFileType", new Class[] { File.class });

				} catch (ClassNotFoundException cnfe) {

					errorMessage = cnfe.getMessage();

					return false;

				} catch (NoSuchFieldException nsfe) {

					errorMessage = nsfe.getMessage();

					return false;

				} catch (NoSuchMethodException nsme) {

					errorMessage = nsme.getMessage();

					return false;

				} catch (SecurityException se) {

					errorMessage = se.getMessage();

					return false;

				} catch (IllegalAccessException iae) {

					errorMessage = iae.getMessage();

					return false;

				}

				break;

		}

		return true;

	}



	/**

	 * Attempts to locate the default web browser on the local system.  Caches results so it

	 * only locates the browser once for each use of this class per JVM instance.

	 * @return The browser for the system.  Note that this may not be what you would consider

	 *			to be a standard web browser; instead, it's the application that gets called to

	 *			open the default web browser.  In some cases, this will be a non-String object

	 *			that provides the means of calling the default browser.

	 */

	private static Object locateBrowser() {

		if (browser != null) {

			return browser;

		}

		switch (jvm) {

			case MRJ_2_0:

				try {

					Integer finderCreatorCode = (Integer) makeOSType.invoke(null, new Object[] { FINDER_CREATOR });

					Object aeTarget = aeTargetConstructor.newInstance(new Object[] { finderCreatorCode });

					Integer gurlType = (Integer) makeOSType.invoke(null, new Object[] { GURL_EVENT });

					Object appleEvent = appleEventConstructor.newInstance(new Object[] { gurlType, gurlType, aeTarget, kAutoGenerateReturnID, kAnyTransactionID });

					// Don't set browser = appleEvent because then the next time we call

					// locateBrowser(), we'll get the same AppleEvent, to which we'll already have

					// added the relevant parameter. Instead, regenerate the AppleEvent every time.

					// There's probably a way to do this better; if any has any ideas, please let

					// me know.

					return appleEvent;

				} catch (IllegalAccessException iae) {

					browser = null;

					errorMessage = iae.getMessage();

					return browser;

				} catch (InstantiationException ie) {

					browser = null;

					errorMessage = ie.getMessage();

					return browser;

				} catch (InvocationTargetException ite) {

					browser = null;

					errorMessage = ite.getMessage();

					return browser;

				}

			case MRJ_2_1:

				File systemFolder;

				try {

					systemFolder = (File) findFolder.invoke(null, new Object[] { kSystemFolderType });

				} catch (IllegalArgumentException iare) {

					browser = null;

					errorMessage = iare.getMessage();

					return browser;

				} catch (IllegalAccessException iae) {

					browser = null;

					errorMessage = iae.getMessage();

					return browser;

				} catch (InvocationTargetException ite) {

					browser = null;

					errorMessage = ite.getTargetException().getClass() + ": " + ite.getTargetException().getMessage();

					return browser;

				}

				String[] systemFolderFiles = systemFolder.list();

				// Avoid a FilenameFilter because that can't be stopped mid-list

				for(int i = 0; i < systemFolderFiles.length; i++) {

					try {

						File file = new File(systemFolder, systemFolderFiles[i]);

						if (!file.isFile()) {

							continue;

						}

						Object fileType = getFileType.invoke(null, new Object[] { file });

						if (FINDER_TYPE.equals(fileType.toString())) {

							browser = file.toString();	// Actually the Finder, but that's OK

							return browser;

						}

					} catch (IllegalArgumentException iare) {

						browser = browser;

						errorMessage = iare.getMessage();

						return null;

					} catch (IllegalAccessException iae) {

						browser = null;

						errorMessage = iae.getMessage();

						return browser;

					} catch (InvocationTargetException ite) {

						browser = null;

						errorMessage = ite.getTargetException().getClass() + ": " + ite.getTargetException().getMessage();

						return browser;

					}

				}

				browser = null;

				break;

			case WINDOWS_NT:

				browser = "cmd.exe";

				break;

			case WINDOWS_9x:

				browser = "command.com";

				break;

			case WINDOWS_2000:

				browser ="";

				break;

			case OTHER:

			default:

				browser = "netscape";

				break;

		}

		

		

		return browser;

	}



	/**

	 * Attempts to open the default web browser to the given URL.

	 * @param url The URL to open

	 * @throws IOException If the web browser could not be located or does not run

	 */

	public static void openURL(String url) throws IOException {

		if (!loadedWithoutErrors) {

			throw new IOException("Exception in finding browser: " + errorMessage);

		}

		Object browser = locateBrowser();

		if (browser == null) {

			throw new IOException("Unable to locate browser: " + errorMessage);

		}

		switch (jvm) {

			case MRJ_2_0:

				Object aeDesc = null;

				try {

					aeDesc = aeDescConstructor.newInstance(new Object[] { url });

					putParameter.invoke(browser, new Object[] { keyDirectObject, aeDesc });

					sendNoReply.invoke(browser, new Object[] { });

				} catch (InvocationTargetException ite) {

					throw new IOException("InvocationTargetException while creating AEDesc: " + ite.getMessage());

				} catch (IllegalAccessException iae) {

					throw new IOException("IllegalAccessException while building AppleEvent: " + iae.getMessage());

				} catch (InstantiationException ie) {

					throw new IOException("InstantiationException while creating AEDesc: " + ie.getMessage());

				} finally {

					aeDesc = null;	// Encourage it to get disposed if it was created

					browser = null;	// Ditto

				}

				break;

			case MRJ_2_1:

				Runtime.getRuntime().exec(new String[] { (String) browser, url } );

				break;

		  case WINDOWS_NT:

		  case WINDOWS_9x:

				Runtime.getRuntime().exec(new String[] { (String)browser, FIRST_WINDOWS_PARAMETER,

																	SECOND_WINDOWS_PARAMETER, url });

		  

				break;

			case WINDOWS_2000:

				String cmd = "rundll32" + " " + "url.dll" + " " +  "FileProtocolHandler"+ " " + url; 

        Runtime.getRuntime().exec(cmd); 

				break;

			case OTHER:

				// Assume that we're on Unix and that Netscape is installed

				

				// First, attempt to open the URL in a currently running session of Netscape

				Process process = Runtime.getRuntime().exec((String) browser +

															NETSCAPE_OPEN_PARAMETER_START +	url +

															NETSCAPE_OPEN_PARAMETER_END);

				try {

					int exitCode = process.waitFor();

					if (exitCode != 0) {	// if Netscape was not open

						Runtime.getRuntime().exec(new String[] { (String) browser, url });

					}

				} catch (InterruptedException ie) {

					throw new IOException("InterruptedException while launching browser: " + ie.getMessage());

				}

				break;

			default:

				// This should never occur, but if it does, we'll try the simplest thing possible

				Runtime.getRuntime().exec(new String[] { (String) browser, url });

				break;

		}

	}

}