/*
 * Jalview - A Sequence Alignment Editor and Viewer (Version 2.6)
 * Copyright (C) 2010 J Procter, AM Waterhouse, G Barton, M Clamp, S Searle
 * 
 * This file is part of Jalview.
 * 
 * Jalview 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 3 of the License, or (at your option) any later version.
 * 
 * Jalview 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 Jalview.  If not, see <http://www.gnu.org/licenses/>.
 */
package jalview.util;

import java.io.*;
import java.lang.reflect.*;

/**
 * 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 &lt;init&gt;(int) method of com.apple.MacOS.AETarget */
  private static Constructor aeTargetConstructor;

  /** The &lt;init&gt;(int, int, int) method of com.apple.MacOS.AppleEvent */
  private static Constructor appleEventConstructor;

  /** The &lt;init&gt;(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_NEW_WINDOW = ", new-window";

  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. s 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)
        {
          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 = jalview.bin.Cache.getDefault("DEFAULT_BROWSER", "firefox");

      break;
    }

    return browser;
  }

  /**
   * used to ensure that browser is up-to-date after a configuration change
   * (Unix DEFAULT_BROWSER property change).
   */
  public static void resetBrowser()
  {
    browser = null;
  }

  /**
   * 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 (actually Firefox) is
      // installed
      // First, attempt to open the URL in a currently running session of
      // Netscape
      // JBPNote log debug

      /*
       * System.out.println("Executing : "+browser+" "+
       * NETSCAPE_REMOTE_PARAMETER+" "+ NETSCAPE_OPEN_PARAMETER_START + url +
       * NETSCAPE_OPEN_NEW_WINDOW + NETSCAPE_OPEN_PARAMETER_END);
       */
      process = Runtime.getRuntime().exec(
              new String[]
              {
                  (String) browser,
                  NETSCAPE_REMOTE_PARAMETER,

                  NETSCAPE_OPEN_PARAMETER_START + url
                          + NETSCAPE_OPEN_NEW_WINDOW
                          + 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);
}