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InputMethodEvent.CARET_POSITION_CHANGED

   <source lang="java">
 

/*

* @(#)CodePointInputMethod.java  1.6 05/11/17
* 
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
* 
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 
* -Redistribution of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
* 
* -Redistribution in binary form must reproduce the above copyright notice, 
*  this list of conditions and the following disclaimer in the documentation
*  and/or other materials provided with the distribution.
* 
* Neither the name of Sun Microsystems, Inc. or the names of contributors may 
* be used to endorse or promote products derived from this software without 
* specific prior written permission.
* 
* This software is provided "AS IS," without a warranty of any kind. ALL 
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST 
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, 
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY 
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, 
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
* 
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/

/*

* @(#)CodePointInputMethod.java  1.6 05/11/17
*/

//package com.sun.inputmethods.internal.codepointim; import java.awt.AWTEvent; import java.awt.Rectangle; import java.awt.Toolkit; import java.awt.event.InputMethodEvent; import java.awt.event.KeyEvent; import java.awt.font.TextAttribute; import java.awt.font.TextHitInfo; import java.awt.im.InputMethodHighlight; import java.awt.im.spi.InputMethod; import java.awt.im.spi.InputMethodContext; import java.io.IOException; import java.text.AttributedString; import java.util.Locale; /**

* The Code Point Input Method is a simple input method that allows Unicode
* characters to be entered using their code point or code unit values. See the
* accompanying file README.txt for more information.
*
* @author Brian Beck
*/

public class CodePointInputMethod implements InputMethod {

   private static final int UNSET           = 0;
   private static final int ESCAPE          = 1; // \u0000       - \uFFFF
   private static final int SPECIAL_ESCAPE  = 2; // \U000000     - \U10FFFF
   private static final int SURROGATE_PAIR  = 3; // \uD800\uDC00 - \uDBFF\uDFFF
   private InputMethodContext context;
   private Locale locale;
   private StringBuffer buffer;
   private int insertionPoint;
   private int format = UNSET;
   public CodePointInputMethod() throws IOException {
   }
   /**
    * This is the input method"s main routine.  The composed text is stored
    * in buffer.
    */
   public void dispatchEvent(AWTEvent event) {
       // This input method handles KeyEvent only.
       if (!(event instanceof KeyEvent)) {
           return;
       }
       KeyEvent e = (KeyEvent) event;
       int eventID = event.getID();
       boolean notInCompositionMode = buffer.length() == 0;
       if (eventID == KeyEvent.KEY_PRESSED) {
           // If we are not in composition mode, pass through
           if (notInCompositionMode)  {
               return;
           }
           switch (e.getKeyCode()) {
               case KeyEvent.VK_LEFT:
                   moveCaretLeft();
                   break;
               case KeyEvent.VK_RIGHT:
                   moveCaretRight();
                   break;
           }
       } else if (eventID == KeyEvent.KEY_TYPED) {
           char c = e.getKeyChar();
           // If we are not in composition mode, wait a back slash
           if (notInCompositionMode)  {
               // If the type character is not a back slash, pass through
               if (c != "\\") {
                   return;
               }
               startComposition(); // Enter to composition mode
           } else {
               switch (c) { 
               case " ": // Exit from composition mode
                   finishComposition();
                   break;
               case "\u007f":  // Delete
                   deleteCharacter();
                   break;
               case "\b":  // BackSpace
                   deletePreviousCharacter();
                   break;
               case "\u001b":  // Escape
                   cancelComposition();
                   break;
               case "\n":  // Return
               case "\t":  // Tab
                   sendCommittedText();
                   break;
               default:
                   composeUnicodeEscape(c);
                   break;
               }
           }
       } else {  // KeyEvent.KEY_RELEASED
           // If we are not in composition mode, pass through
           if (notInCompositionMode)  {
               return;
           }
       }
       e.consume();
   }
   private void composeUnicodeEscape(char c) {
       switch (buffer.length()) {
           case  1:  // \\
               waitEscapeCharacter(c);
               break;
           case 2:  // \\u or \\U
           case 3:  // \\ux or \\Ux
           case 4:  // \\uxx or \\Uxx
               waitDigit(c);
               break;
           case 5:  // \\uxxx or \\Uxxx
               if (format == SPECIAL_ESCAPE) {
                   waitDigit(c);
               } else {
                   waitDigit2(c);
               }
               break;
           case 6:  // \\uxxxx or \\Uxxxx
               if (format == SPECIAL_ESCAPE) {
                   waitDigit(c);
               } else if (format == SURROGATE_PAIR) {
                   waitBackSlashOrLowSurrogate(c);
               } else {
                   beep();
               }
               break;
           case 7:  // \\Uxxxxx
               // Only SPECIAL_ESCAPE format uses this state.
               // Since the second "\\u" of SURROGATE_PAIR format is inserted
               // automatically, users don"t have to type these keys.
               waitDigit(c);
               break;
           case 8:  // \\uxxxx\\u
           case 9:  // \\uxxxx\\ux
           case 10: // \\uxxxx\\uxx
           case 11: // \\uxxxx\\uxxx
               if (format == SURROGATE_PAIR) {
                   waitDigit(c);
               } else {
                   beep();
               }
               break;
           default:
               beep();
               break;
       }
   }
   private void waitEscapeCharacter(char c) {
       if (c == "u" || c == "U") {
           buffer.append(c);
           insertionPoint++;
           sendComposedText();
           format = (c == "u") ? ESCAPE : SPECIAL_ESCAPE;
       } else {
           if (c != "\\") {
               buffer.append(c);
               insertionPoint++;
           }
           sendCommittedText();
       }
   }
   private void waitDigit(char c) {
       if (Character.digit(c, 16) != -1) {
           buffer.insert(insertionPoint++, c);
           sendComposedText();
       } else {
           beep();
       }
   }
   private void waitDigit2(char c) {
       if (Character.digit(c, 16) != -1) {
           buffer.insert(insertionPoint++, c);
           char codePoint = (char)getCodePoint(buffer, 2, 5);
           if (Character.isHighSurrogate(codePoint)) {
               format = SURROGATE_PAIR;
               buffer.append("\\u");
               insertionPoint = 8;
           } else {
               format = ESCAPE;
           }
           sendComposedText();
       } else {
           beep();
       }
   }
   private void waitBackSlashOrLowSurrogate(char c) {
       if (insertionPoint == 6) {
           if (c == "\\") {
               buffer.append(c);
               buffer.append("u");
               insertionPoint = 8;
               sendComposedText();
           } else if (Character.digit(c, 16) != -1) {
               buffer.append("\\u");
               buffer.append(c);
               insertionPoint = 9;
               sendComposedText();
           } else {
               beep();
           }
       } else {
           beep();
       }
   }
   /**
    * Send the composed text to the client.
    */
   private void sendComposedText() {
       AttributedString as = new AttributedString(buffer.toString());
       as.addAttribute(TextAttribute.INPUT_METHOD_HIGHLIGHT,
                       InputMethodHighlight.SELECTED_RAW_TEXT_HIGHLIGHT);
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                 as.getIterator(), 0,
                                 TextHitInfo.leading(insertionPoint), null);
   }
   /**
    * Send the committed text to the client.
    */
   private void sendCommittedText() {
       AttributedString as = new AttributedString(buffer.toString());
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                 as.getIterator(), buffer.length(),
                                 TextHitInfo.leading(insertionPoint), null);
       buffer.setLength(0);
       insertionPoint = 0;
       format = UNSET;
   }
   /**
    * Move the insertion point one position to the left in the composed text.
    * Do not let the caret move to the left of the "\\u" or "\\U".
    */
   private void moveCaretLeft() {
       int len = buffer.length();
       if (--insertionPoint < 2) {
           insertionPoint++;
           beep();
       } else if (format == SURROGATE_PAIR && insertionPoint == 7) {
           insertionPoint = 8;
           beep();
       }
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.CARET_POSITION_CHANGED,
                                 null, 0,
                                 TextHitInfo.leading(insertionPoint), null);
   }
   /**
    * Move the insertion point one position to the right in the composed text.
    */
   private void moveCaretRight() {
       int len = buffer.length();
       if (++insertionPoint > len) {
           insertionPoint = len;
           beep();
       }
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.CARET_POSITION_CHANGED,
                                 null, 0,
                                 TextHitInfo.leading(insertionPoint), null);
   }
   /**
    * Delete the character preceding the insertion point in the composed text.
    * If the insertion point is not at the end of the composed text and the
    * preceding text is "\\u" or "\\U", ring the bell.
    */
   private void deletePreviousCharacter() {
       if (insertionPoint == 2) {
           if (buffer.length() == 2) {
               cancelComposition();
           } else {
               // Do not allow deletion of the leading "\\u" or "\\U" if there
               // are other digits in the composed text.
               beep();
           }
       } else if (insertionPoint == 8) {
           if (buffer.length() == 8) {
               if (format == SURROGATE_PAIR) {
                   buffer.deleteCharAt(--insertionPoint);
               }
               buffer.deleteCharAt(--insertionPoint);
               sendComposedText();
           } else {
               // Do not allow deletion of the second "\\u" if there are other
               // digits in the composed text.
               beep();
           }
       } else {
           buffer.deleteCharAt(--insertionPoint);
           if (buffer.length() == 0) {
               sendCommittedText();
           } else {
               sendComposedText();
           }
       }
   }
   /**
    * Delete the character following the insertion point in the composed text.
    * If the insertion point is at the end of the composed text, ring the bell.
    */
   private void deleteCharacter() {
       if (insertionPoint < buffer.length()) {
           buffer.deleteCharAt(insertionPoint);
           sendComposedText();
       } else {
           beep();
       }
   }
   private void startComposition() {
       buffer.append("\\");
       insertionPoint = 1;
       sendComposedText();
   }
   private void cancelComposition() {
       buffer.setLength(0);
       insertionPoint = 0;
       sendCommittedText();
   }
   private void finishComposition() {
       int len = buffer.length();
       if (len == 6 && format != SPECIAL_ESCAPE) {
           char codePoint = (char)getCodePoint(buffer, 2, 5);
           if (Character.isValidCodePoint(codePoint) && codePoint != 0xFFFF) {
               buffer.setLength(0);
               buffer.append(codePoint);
         sendCommittedText();
               return;
           }
       } else if (len == 8 && format == SPECIAL_ESCAPE) {
           int codePoint = getCodePoint(buffer, 2, 7);
           if (Character.isValidCodePoint(codePoint) && codePoint != 0xFFFF) {
               buffer.setLength(0);
               buffer.appendCodePoint(codePoint);
         sendCommittedText();
               return;
           }
       } else if (len == 12 && format == SURROGATE_PAIR) {
     char[] codePoint = {
               (char)getCodePoint(buffer, 2, 5),
         (char)getCodePoint(buffer, 8, 11)
           };
           if (Character.isHighSurrogate(codePoint[0]) &&
               Character.isLowSurrogate(codePoint[1])) {
         buffer.setLength(0);
         buffer.append(codePoint);
         sendCommittedText();
               return;
           }
       }
       beep();
   }
   private int getCodePoint(StringBuffer sb, int from, int to) {
       int value = 0;
       for (int i = from; i <= to; i++) {
           value = (value<<4) + Character.digit(sb.charAt(i), 16);
       }
       return value;
   }
   private static void beep() {
       Toolkit.getDefaultToolkit().beep();
   }
   public void activate() {
       if (buffer == null) {
           buffer = new StringBuffer(12);
           insertionPoint = 0;
       }
   }
   public void deactivate(boolean isTemporary) {
       if (!isTemporary) {
           buffer = null;
       }
   }
   public void dispose() {
   }
   public Object getControlObject() {
       return null;
   }
   public void endComposition() {
       sendCommittedText();
   }
   public Locale getLocale() {
       return locale;
   }
   public void hideWindows() {
   }
   public boolean isCompositionEnabled() {
       // always enabled
       return true;
   }
   public void notifyClientWindowChange(Rectangle location) {
   }
   public void reconvert() {
       // not supported yet
       throw new UnsupportedOperationException();
   }
   public void removeNotify() {
   }
   public void setCharacterSubsets(Character.Subset[] subsets) {
   }
   public void setCompositionEnabled(boolean enable) {
       // not supported yet
       throw new UnsupportedOperationException();
   }
   public void setInputMethodContext(InputMethodContext context) {
       this.context = context;
   }
   /*
    * The Code Point Input Method supports all locales.
    */
   public boolean setLocale(Locale locale) {
       this.locale = locale;
       return true;
   }

}


 </source>
   
  
 
  



InputMethodEvent.INPUT_METHOD_TEXT_CHANGED

   <source lang="java">
 

/*

* @(#)CodePointInputMethod.java  1.6 05/11/17
* 
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
* 
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 
* -Redistribution of source code must retain the above copyright notice, this
*  list of conditions and the following disclaimer.
* 
* -Redistribution in binary form must reproduce the above copyright notice, 
*  this list of conditions and the following disclaimer in the documentation
*  and/or other materials provided with the distribution.
* 
* Neither the name of Sun Microsystems, Inc. or the names of contributors may 
* be used to endorse or promote products derived from this software without 
* specific prior written permission.
* 
* This software is provided "AS IS," without a warranty of any kind. ALL 
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST 
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, 
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY 
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, 
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
* 
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/

/*

* @(#)CodePointInputMethod.java  1.6 05/11/17
*/

//package com.sun.inputmethods.internal.codepointim; import java.awt.AWTEvent; import java.awt.Rectangle; import java.awt.Toolkit; import java.awt.event.InputMethodEvent; import java.awt.event.KeyEvent; import java.awt.font.TextAttribute; import java.awt.font.TextHitInfo; import java.awt.im.InputMethodHighlight; import java.awt.im.spi.InputMethod; import java.awt.im.spi.InputMethodContext; import java.io.IOException; import java.text.AttributedString; import java.util.Locale; /**

* The Code Point Input Method is a simple input method that allows Unicode
* characters to be entered using their code point or code unit values. See the
* accompanying file README.txt for more information.
*
* @author Brian Beck
*/

public class CodePointInputMethod implements InputMethod {

   private static final int UNSET           = 0;
   private static final int ESCAPE          = 1; // \u0000       - \uFFFF
   private static final int SPECIAL_ESCAPE  = 2; // \U000000     - \U10FFFF
   private static final int SURROGATE_PAIR  = 3; // \uD800\uDC00 - \uDBFF\uDFFF
   private InputMethodContext context;
   private Locale locale;
   private StringBuffer buffer;
   private int insertionPoint;
   private int format = UNSET;
   public CodePointInputMethod() throws IOException {
   }
   /**
    * This is the input method"s main routine.  The composed text is stored
    * in buffer.
    */
   public void dispatchEvent(AWTEvent event) {
       // This input method handles KeyEvent only.
       if (!(event instanceof KeyEvent)) {
           return;
       }
       KeyEvent e = (KeyEvent) event;
       int eventID = event.getID();
       boolean notInCompositionMode = buffer.length() == 0;
       if (eventID == KeyEvent.KEY_PRESSED) {
           // If we are not in composition mode, pass through
           if (notInCompositionMode)  {
               return;
           }
           switch (e.getKeyCode()) {
               case KeyEvent.VK_LEFT:
                   moveCaretLeft();
                   break;
               case KeyEvent.VK_RIGHT:
                   moveCaretRight();
                   break;
           }
       } else if (eventID == KeyEvent.KEY_TYPED) {
           char c = e.getKeyChar();
           // If we are not in composition mode, wait a back slash
           if (notInCompositionMode)  {
               // If the type character is not a back slash, pass through
               if (c != "\\") {
                   return;
               }
               startComposition(); // Enter to composition mode
           } else {
               switch (c) { 
               case " ": // Exit from composition mode
                   finishComposition();
                   break;
               case "\u007f":  // Delete
                   deleteCharacter();
                   break;
               case "\b":  // BackSpace
                   deletePreviousCharacter();
                   break;
               case "\u001b":  // Escape
                   cancelComposition();
                   break;
               case "\n":  // Return
               case "\t":  // Tab
                   sendCommittedText();
                   break;
               default:
                   composeUnicodeEscape(c);
                   break;
               }
           }
       } else {  // KeyEvent.KEY_RELEASED
           // If we are not in composition mode, pass through
           if (notInCompositionMode)  {
               return;
           }
       }
       e.consume();
   }
   private void composeUnicodeEscape(char c) {
       switch (buffer.length()) {
           case  1:  // \\
               waitEscapeCharacter(c);
               break;
           case 2:  // \\u or \\U
           case 3:  // \\ux or \\Ux
           case 4:  // \\uxx or \\Uxx
               waitDigit(c);
               break;
           case 5:  // \\uxxx or \\Uxxx
               if (format == SPECIAL_ESCAPE) {
                   waitDigit(c);
               } else {
                   waitDigit2(c);
               }
               break;
           case 6:  // \\uxxxx or \\Uxxxx
               if (format == SPECIAL_ESCAPE) {
                   waitDigit(c);
               } else if (format == SURROGATE_PAIR) {
                   waitBackSlashOrLowSurrogate(c);
               } else {
                   beep();
               }
               break;
           case 7:  // \\Uxxxxx
               // Only SPECIAL_ESCAPE format uses this state.
               // Since the second "\\u" of SURROGATE_PAIR format is inserted
               // automatically, users don"t have to type these keys.
               waitDigit(c);
               break;
           case 8:  // \\uxxxx\\u
           case 9:  // \\uxxxx\\ux
           case 10: // \\uxxxx\\uxx
           case 11: // \\uxxxx\\uxxx
               if (format == SURROGATE_PAIR) {
                   waitDigit(c);
               } else {
                   beep();
               }
               break;
           default:
               beep();
               break;
       }
   }
   private void waitEscapeCharacter(char c) {
       if (c == "u" || c == "U") {
           buffer.append(c);
           insertionPoint++;
           sendComposedText();
           format = (c == "u") ? ESCAPE : SPECIAL_ESCAPE;
       } else {
           if (c != "\\") {
               buffer.append(c);
               insertionPoint++;
           }
           sendCommittedText();
       }
   }
   private void waitDigit(char c) {
       if (Character.digit(c, 16) != -1) {
           buffer.insert(insertionPoint++, c);
           sendComposedText();
       } else {
           beep();
       }
   }
   private void waitDigit2(char c) {
       if (Character.digit(c, 16) != -1) {
           buffer.insert(insertionPoint++, c);
           char codePoint = (char)getCodePoint(buffer, 2, 5);
           if (Character.isHighSurrogate(codePoint)) {
               format = SURROGATE_PAIR;
               buffer.append("\\u");
               insertionPoint = 8;
           } else {
               format = ESCAPE;
           }
           sendComposedText();
       } else {
           beep();
       }
   }
   private void waitBackSlashOrLowSurrogate(char c) {
       if (insertionPoint == 6) {
           if (c == "\\") {
               buffer.append(c);
               buffer.append("u");
               insertionPoint = 8;
               sendComposedText();
           } else if (Character.digit(c, 16) != -1) {
               buffer.append("\\u");
               buffer.append(c);
               insertionPoint = 9;
               sendComposedText();
           } else {
               beep();
           }
       } else {
           beep();
       }
   }
   /**
    * Send the composed text to the client.
    */
   private void sendComposedText() {
       AttributedString as = new AttributedString(buffer.toString());
       as.addAttribute(TextAttribute.INPUT_METHOD_HIGHLIGHT,
                       InputMethodHighlight.SELECTED_RAW_TEXT_HIGHLIGHT);
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                 as.getIterator(), 0,
                                 TextHitInfo.leading(insertionPoint), null);
   }
   /**
    * Send the committed text to the client.
    */
   private void sendCommittedText() {
       AttributedString as = new AttributedString(buffer.toString());
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.INPUT_METHOD_TEXT_CHANGED,
                                 as.getIterator(), buffer.length(),
                                 TextHitInfo.leading(insertionPoint), null);
       buffer.setLength(0);
       insertionPoint = 0;
       format = UNSET;
   }
   /**
    * Move the insertion point one position to the left in the composed text.
    * Do not let the caret move to the left of the "\\u" or "\\U".
    */
   private void moveCaretLeft() {
       int len = buffer.length();
       if (--insertionPoint < 2) {
           insertionPoint++;
           beep();
       } else if (format == SURROGATE_PAIR && insertionPoint == 7) {
           insertionPoint = 8;
           beep();
       }
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.CARET_POSITION_CHANGED,
                                 null, 0,
                                 TextHitInfo.leading(insertionPoint), null);
   }
   /**
    * Move the insertion point one position to the right in the composed text.
    */
   private void moveCaretRight() {
       int len = buffer.length();
       if (++insertionPoint > len) {
           insertionPoint = len;
           beep();
       }
       context.dispatchInputMethodEvent(
                                 InputMethodEvent.CARET_POSITION_CHANGED,
                                 null, 0,
                                 TextHitInfo.leading(insertionPoint), null);
   }
   /**
    * Delete the character preceding the insertion point in the composed text.
    * If the insertion point is not at the end of the composed text and the
    * preceding text is "\\u" or "\\U", ring the bell.
    */
   private void deletePreviousCharacter() {
       if (insertionPoint == 2) {
           if (buffer.length() == 2) {
               cancelComposition();
           } else {
               // Do not allow deletion of the leading "\\u" or "\\U" if there
               // are other digits in the composed text.
               beep();
           }
       } else if (insertionPoint == 8) {
           if (buffer.length() == 8) {
               if (format == SURROGATE_PAIR) {
                   buffer.deleteCharAt(--insertionPoint);
               }
               buffer.deleteCharAt(--insertionPoint);
               sendComposedText();
           } else {
               // Do not allow deletion of the second "\\u" if there are other
               // digits in the composed text.
               beep();
           }
       } else {
           buffer.deleteCharAt(--insertionPoint);
           if (buffer.length() == 0) {
               sendCommittedText();
           } else {
               sendComposedText();
           }
       }
   }
   /**
    * Delete the character following the insertion point in the composed text.
    * If the insertion point is at the end of the composed text, ring the bell.
    */
   private void deleteCharacter() {
       if (insertionPoint < buffer.length()) {
           buffer.deleteCharAt(insertionPoint);
           sendComposedText();
       } else {
           beep();
       }
   }
   private void startComposition() {
       buffer.append("\\");
       insertionPoint = 1;
       sendComposedText();
   }
   private void cancelComposition() {
       buffer.setLength(0);
       insertionPoint = 0;
       sendCommittedText();
   }
   private void finishComposition() {
       int len = buffer.length();
       if (len == 6 && format != SPECIAL_ESCAPE) {
           char codePoint = (char)getCodePoint(buffer, 2, 5);
           if (Character.isValidCodePoint(codePoint) && codePoint != 0xFFFF) {
               buffer.setLength(0);
               buffer.append(codePoint);
         sendCommittedText();
               return;
           }
       } else if (len == 8 && format == SPECIAL_ESCAPE) {
           int codePoint = getCodePoint(buffer, 2, 7);
           if (Character.isValidCodePoint(codePoint) && codePoint != 0xFFFF) {
               buffer.setLength(0);
               buffer.appendCodePoint(codePoint);
         sendCommittedText();
               return;
           }
       } else if (len == 12 && format == SURROGATE_PAIR) {
     char[] codePoint = {
               (char)getCodePoint(buffer, 2, 5),
         (char)getCodePoint(buffer, 8, 11)
           };
           if (Character.isHighSurrogate(codePoint[0]) &&
               Character.isLowSurrogate(codePoint[1])) {
         buffer.setLength(0);
         buffer.append(codePoint);
         sendCommittedText();
               return;
           }
       }
       beep();
   }
   private int getCodePoint(StringBuffer sb, int from, int to) {
       int value = 0;
       for (int i = from; i <= to; i++) {
           value = (value<<4) + Character.digit(sb.charAt(i), 16);
       }
       return value;
   }
   private static void beep() {
       Toolkit.getDefaultToolkit().beep();
   }
   public void activate() {
       if (buffer == null) {
           buffer = new StringBuffer(12);
           insertionPoint = 0;
       }
   }
   public void deactivate(boolean isTemporary) {
       if (!isTemporary) {
           buffer = null;
       }
   }
   public void dispose() {
   }
   public Object getControlObject() {
       return null;
   }
   public void endComposition() {
       sendCommittedText();
   }
   public Locale getLocale() {
       return locale;
   }
   public void hideWindows() {
   }
   public boolean isCompositionEnabled() {
       // always enabled
       return true;
   }
   public void notifyClientWindowChange(Rectangle location) {
   }
   public void reconvert() {
       // not supported yet
       throw new UnsupportedOperationException();
   }
   public void removeNotify() {
   }
   public void setCharacterSubsets(Character.Subset[] subsets) {
   }
   public void setCompositionEnabled(boolean enable) {
       // not supported yet
       throw new UnsupportedOperationException();
   }
   public void setInputMethodContext(InputMethodContext context) {
       this.context = context;
   }
   /*
    * The Code Point Input Method supports all locales.
    */
   public boolean setLocale(Locale locale) {
       this.locale = locale;
       return true;
   }

}


 </source>