/release/installer/mac/console/src/main/java/org/geoserver/console/Browser.java

    /*
     * This code is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public 
     * License as published by the Free Software Foundation; either 
     * version 2.1 of the License, or (at your option) any later version.
     *
     * This code 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 Lesser General Public License for more details.
     *
     * You should have received a copy of the GNU Lesser 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 org.geoserver.console;


    



import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;



    /**
     * Browser 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)
     *
     * @author <a href="mailto:jacob.dreyer@geosoft.no">Jacob Dreyer</a>
     * Added methods to the API and adjusted the linux version slightly.
     */
    public class Browser {

      /**
       * 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 Browser() {}
            
      /**
       * 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[] { Browser.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;
            }

            // Avoid a FilenameFilter because that can't be stopped mid-list
            String[] systemFolderFiles = systemFolder.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())) {
                    // Actually the Finder, but that's OK
                    browser = file.toString();      
                    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;
      }



      /**
       * Open the specified file in the client web browser.
       * 
       * @param file  File to open
       * @throws     IOException If there is brwoser problem.
       * 
       */
      public static void openUrl (File file)
        throws IOException
      {
        openUrl ("file://" + file.getPath());
      }


      
      /**
       * Open the specified URL in the client web browser.
       * 
       * @param url  URL to open.
       * @throws     IOException If there is brwoser problem.   
       */
      public static void openUrl (URL url)
        throws IOException
      {
        openUrl (url.toString());
      }
      

      
      /**
       * Open the specified URL in the client web browser.
       * 
       * @param url  URL to open.
       * @throws     IOException If there is brwoser problem.   
       */
      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
            String command = browser.toString() + " -raise " +
                             NETSCAPE_REMOTE_PARAMETER + " " +
                             NETSCAPE_OPEN_PARAMETER_START + 
                             url + NETSCAPE_OPEN_PARAMETER_END;

            process = Runtime.getRuntime().exec (command);
            
            try {
              int exitCode = process.waitFor();
              if (exitCode != 0) {    // if Netscape was not open
                Runtime.getRuntime().exec(new String[] { (String) browser, url });
              }
            } 
            catch (InterruptedException exception) {
              exception.printStackTrace();
              throw new IOException("InterruptedException while launching browser: " + exception.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);
    }