/core/src/seco/notebook/html/BrowserLauncher.java

/*
 * This file is part of the Scriba source distribution. This is free, open-source 
 * software. For full licensing information, please see the LicensingInformation file
 * at the root level of the distribution.
 *
 * Copyright (c) 2006-2007 Kobrix Software, Inc.
 */
package seco.notebook.html;

//package edu.stanford.ejalbert;

//package net.sourceforge.processdash.ui.lib;

import java.io.File;

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 1999-2001 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. The author is not repsonsible for any loss of data or

 * functionality or any adverse or unexpected effects of using this software.

 * <p>

 * Credits: <br>

 * Steven Spencer, JavaWorld magazine (<a

 * href="http://www.javaworld.com/javaworld/javatips/jw-javatip66.html">Java Tip

 * 66</a>) <br>

 * Thanks also to Ron B. Yeh, Eric Shapiro, Ben Engber, Paul Teitlebaum, Andrea

 * Cantatore, Larry Barowski, Trevor Bedzek, Frank Miedrich, and Ron Rabakukk

 * 

 * @author Eric Albert (<a

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

 * @version 1.4b1 (Released June 20, 2001)

 */

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.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 getFileCreator method of com.apple.mrj.MRJFileUtils */

	private static Method getFileCreator;

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

	private static Method getFileType;

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

	private static Method openURL;

	/** 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;

	/** The linkage object required for JDirect 3 on Mac OS X. */

	private static Object linkage;

	/** The framework to reference on Mac OS X */

	private static final String JDirect_MacOSX = "/System/Library/Frameworks/Carbon.framework/Frameworks/HIToolbox.framework/HIToolbox";

	/** 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 Java on Mac OS X 10.0 (MRJ 3.0) */

	private static final int MRJ_3_0 = 3;

	/** JVM constant for MRJ 3.1 */

	private static final int MRJ_3_1 = 4;

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

	private static final int WINDOWS_NT = 5;

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

	private static final int WINDOWS_9x = 6;

	/** 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 third parameter for Runtime.exec() on Windows. This is a "title"

	 * parameter that the command line expects. Setting this parameter allows

	 * URLs containing spaces to work.

	 */

	private static final String THIRD_WINDOWS_PARAMETER = "\"\"";

	/**

	 * 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_REMOTE_PARAMETER = "-remote";

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

	private static final String NETSCAPE_OPEN_PARAMETER_END = ")'";

	/**

	 * The message from any exception thrown throughout the initialization

	 * process.

	 */

	private static String errorMessage;

	/**

	 * An initialization block that determines the operating system and loads

	 * the necessary runtime data.

	 */

	static

	{

		loadedWithoutErrors = true;

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

		if (osName.startsWith("Mac OS"))

		{

			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 && version < 3)

				{

					// Assume that all 2.x versions of MRJ work the same. MRJ

					// 2.1 actually

					// works via Runtime.exec() and 2.2 supports that but has an

					// openURL() method

					// as well that we currently ignore.

					jvm = MRJ_2_1;

				} else if (version == 3.0)

				{

					jvm = MRJ_3_0;

				} else if (version >= 3.1)

				{

					// Assume that all 3.1 and later versions of MRJ work the

					// same.

					jvm = MRJ_3_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

			{

				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");

				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 });

				getFileCreator = mrjFileUtilsClass.getDeclaredMethod(

						"getFileCreator", new Class[] { File.class });

				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;

		case MRJ_3_0:

			try

			{

				Class linker = Class.forName("com.apple.mrj.jdirect.Linker");

				Constructor constructor = linker

						.getConstructor(new Class[] { Class.class });

				linkage = constructor

						.newInstance(new Object[] { BrowserLauncher.class });

			}

			catch (ClassNotFoundException cnfe)

			{

				errorMessage = cnfe.getMessage();

				return false;

			}

			catch (NoSuchMethodException nsme)

			{

				errorMessage = nsme.getMessage();

				return false;

			}

			catch (InvocationTargetException ite)

			{

				errorMessage = ite.getMessage();

				return false;

			}

			catch (InstantiationException ie)

			{

				errorMessage = ie.getMessage();

				return false;

			}

			catch (IllegalAccessException iae)

			{

				errorMessage = iae.getMessage();

				return false;

			}

			break;

		case MRJ_3_1:

			try

			{

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

				openURL = mrjFileUtilsClass.getDeclaredMethod("openURL",

						new Class[] { String.class });

			}

			catch (ClassNotFoundException cnfe)

			{

				errorMessage = cnfe.getMessage();

				return false;

			}

			catch (NoSuchMethodException nsme)

			{

				errorMessage = nsme.getMessage();

				return false;

			}

			break;

		default:

			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;

					}

					// We're looking for a file with a creator code of 'MACS'

					// and

					// a type of 'FNDR'. Only requiring the type results in

					// non-Finder

					// applications being picked up on certain Mac OS 9 systems,

					// especially German ones, and sending a GURL event to those

					// applications results in a logout under Multiple Users.

					Object fileType = getFileType.invoke(null,

							new Object[] { file });

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

					{

						Object fileCreator = getFileCreator.invoke(null,

								new Object[] { file });

						if (FINDER_CREATOR.equals(fileCreator.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 MRJ_3_0:

		case MRJ_3_1:

			browser = ""; // Return something non-null

			break;

		case WINDOWS_NT:

			browser = "cmd.exe";

			break;

		case WINDOWS_9x:

			browser = "command.com";

			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 MRJ_3_0:

			int[] instance = new int[1];

			int result = ICStart(instance, 0);

			if (result == 0)

			{

				int[] selectionStart = new int[] { 0 };

				byte[] urlBytes = url.getBytes();

				int[] selectionEnd = new int[] { urlBytes.length };

				result = ICLaunchURL(instance[0], new byte[] { 0 }, urlBytes,

						urlBytes.length, selectionStart, selectionEnd);

				if (result == 0)

				{

					// Ignore the return value; the URL was launched

					// successfully

					// regardless of what happens here.

					ICStop(instance);

				} else

				{

					throw new IOException("Unable to launch URL: " + result);

				}

			} else

			{

				throw new IOException(

						"Unable to create an Internet Config instance: "

								+ result);

			}

			break;

		case MRJ_3_1:

			try

			{

				openURL.invoke(null, new Object[] { url });

			}

			catch (InvocationTargetException ite)

			{

				throw new IOException(

						"InvocationTargetException while calling openURL: "

								+ ite.getMessage());

			}

			catch (IllegalAccessException iae)

			{

				throw new IOException(

						"IllegalAccessException while calling openURL: "

								+ iae.getMessage());

			}

			break;

		case WINDOWS_NT:

		case WINDOWS_9x:

			// Add quotes around the URL to allow ampersands and other special

			// characters to work.

			Process process = Runtime.getRuntime().exec(

					new String[] { (String) browser, FIRST_WINDOWS_PARAMETER,

							SECOND_WINDOWS_PARAMETER, THIRD_WINDOWS_PARAMETER,

							'"' + url + '"' });

			// This avoids a memory leak on some versions of Java on Windows.

			// That's hinted at in

			// <http://developer.java.sun.com/developer/qow/archive/68/>.

			try

			{

				process.waitFor();

				process.exitValue();

			}

			catch (InterruptedException ie)

			{

				throw new IOException(

						"InterruptedException while launching browser: "

								+ ie.getMessage());

			}

			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 = Runtime.getRuntime().exec(

					new String[] {

							(String) browser,

							NETSCAPE_REMOTE_PARAMETER,

							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;

		}

	}



	/**

	 * Methods required for Mac OS X. The presence of native methods does not

	 * cause any problems on other platforms.

	 */

	private native static int ICStart(int[] instance, int signature);



	private native static int ICStop(int[] instance);



	private native static int ICLaunchURL(int instance, byte[] hint,

			byte[] data, int len, int[] selectionStart, int[] selectionEnd);

}