001    /* InputMethodEvent.java -- events from a text input method
002       Copyright (C) 1999, 2002, 2005  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.awt.event;
040    
041    import gnu.java.lang.CPStringBuilder;
042    
043    import java.awt.AWTEvent;
044    import java.awt.Component;
045    import java.awt.EventQueue;
046    import java.awt.font.TextHitInfo;
047    import java.io.IOException;
048    import java.io.ObjectInputStream;
049    import java.text.AttributedCharacterIterator;
050    
051    /**
052     * This class is for event generated by change in a text input method.
053     *
054     * @author Aaron M. Renn (arenn@urbanophile.com)
055     * @see InputMethodListener
056     * @since 1.2
057     * @status updated to 1.4
058     */
059    public class InputMethodEvent extends AWTEvent
060    {
061      /**
062       * Compatible with JDK 1.2+.
063       */
064      private static final long serialVersionUID = 4727190874778922661L;
065    
066      /** This is the first id in the range of event ids used by this class. */
067      public static final int INPUT_METHOD_FIRST = 1100;
068    
069      /** This event id indicates that the text in the input method has changed. */
070      public static final int INPUT_METHOD_TEXT_CHANGED = 1100;
071    
072      /** This event id indicates that the input method curor point has changed. */
073      public static final int CARET_POSITION_CHANGED = 1101;
074    
075      /** This is the last id in the range of event ids used by this class. */
076      public static final int INPUT_METHOD_LAST = 1101;
077    
078      /**
079       * The timestamp when this event was created.
080       *
081       * @serial the timestamp
082       * @since 1.4
083       */
084      private long when;
085    
086      /** The input method text. */
087      private final transient AttributedCharacterIterator text;
088    
089      /** The number of committed characters in the text. */
090      private final transient int committedCharacterCount;
091    
092      /** The caret. */
093      private final transient TextHitInfo caret;
094    
095      /** The most important position to be visible. */
096      private final transient TextHitInfo visiblePosition;
097    
098      /**
099       * Initializes a new instance of <code>InputMethodEvent</code> with the
100       * specified source, id, timestamp, text, char count, caret, and visible
101       * position.
102       *
103       * @param source the source that generated the event
104       * @param id the event id
105       * @param when the timestamp of the event
106       * @param text the input text
107       * @param committedCharacterCount the number of committed characters
108       * @param caret the caret position
109       * @param visiblePosition the position most important to make visible
110       * @throws IllegalArgumentException if source is null, id is invalid, id is
111       *         CARET_POSITION_CHANGED and text is non-null, or if
112       *         committedCharacterCount is out of range
113       * @since 1.4
114       */
115      public InputMethodEvent(Component source, int id, long when,
116                              AttributedCharacterIterator text,
117                              int committedCharacterCount, TextHitInfo caret,
118                              TextHitInfo visiblePosition)
119      {
120        super(source, id);
121        this.when = when;
122        this.text = text;
123        this.committedCharacterCount = committedCharacterCount;
124        this.caret = caret;
125        this.visiblePosition = visiblePosition;
126        if (id < INPUT_METHOD_FIRST || id > INPUT_METHOD_LAST
127            || (id == CARET_POSITION_CHANGED && text != null)
128            || committedCharacterCount < 0
129            || (committedCharacterCount
130                > (text == null ? 0 : text.getEndIndex() - text.getBeginIndex())))
131          throw new IllegalArgumentException();
132      }
133    
134      /**
135       * Initializes a new instance of <code>InputMethodEvent</code> with the
136       * specified source, id, text, char count, caret, and visible position.
137       *
138       * @param source the source that generated the event
139       * @param id the event id
140       * @param text the input text
141       * @param committedCharacterCount the number of committed characters
142       * @param caret the caret position
143       * @param visiblePosition the position most important to make visible
144       * @throws IllegalArgumentException if source is null, id is invalid, id is
145       *         CARET_POSITION_CHANGED and text is non-null, or if
146       *         committedCharacterCount is out of range
147       * @since 1.4
148       */
149      public InputMethodEvent(Component source, int id,
150                              AttributedCharacterIterator text,
151                              int committedCharacterCount, TextHitInfo caret,
152                              TextHitInfo visiblePosition)
153      {
154        this(source, id, EventQueue.getMostRecentEventTime(), text,
155             committedCharacterCount, caret, visiblePosition);
156      }
157    
158      /**
159       * Initializes a new instance of <code>InputMethodEvent</code> with the
160       * specified source, id, caret, and visible position, and with a null
161       * text and char count.
162       *
163       * @param source the source that generated the event
164       * @param id the event id
165       * @param caret the caret position
166       * @param visiblePosition the position most important to make visible
167       * @throws IllegalArgumentException if source is null or id is invalid
168       * @since 1.4
169       */
170      public InputMethodEvent(Component source, int id, TextHitInfo caret,
171                              TextHitInfo visiblePosition)
172      {
173        this(source, id, EventQueue.getMostRecentEventTime(), null, 0, caret,
174             visiblePosition);
175      }
176    
177      /**
178       * This method returns the input method text. This can be <code>null</code>,
179       * and will always be null for <code>CARET_POSITION_CHANGED</code> events.
180       * Characters from 0 to <code>getCommittedCharacterCount()-1</code> have
181       * been committed, the remaining characters are composed text.
182       *
183       * @return the input method text, or null
184       */
185      public AttributedCharacterIterator getText()
186      {
187        return text;
188      }
189    
190      /**
191       * Returns the number of committed characters in the input method text.
192       *
193       * @return the number of committed characters in the input method text
194       */
195      public int getCommittedCharacterCount()
196      {
197        return committedCharacterCount;
198      }
199    
200      /**
201       * Returns the caret position. The caret offset is relative to the composed
202       * text of the most recent <code>INPUT_METHOD_TEXT_CHANGED</code> event.
203       *
204       * @return the caret position, or null
205       */
206      public TextHitInfo getCaret()
207      {
208        return caret;
209      }
210    
211      /**
212       * Returns the position that is most important to be visible, or null if
213       * such a hint is not necessary. The caret offset is relative to the composed
214       * text of the most recent <code>INPUT_METHOD_TEXT_CHANGED</code> event.
215       *
216       * @return the position that is most important to be visible
217       */
218      public TextHitInfo getVisiblePosition()
219      {
220        return visiblePosition;
221      }
222    
223      /**
224       * This method consumes the event.  A consumed event is not processed
225       * in the default manner by the component that generated it.
226       */
227      public void consume()
228      {
229        consumed = true;
230      }
231    
232      /**
233       * This method tests whether or not this event has been consumed.
234       *
235       * @return true if the event has been consumed
236       */
237      public boolean isConsumed()
238      {
239        return consumed;
240      }
241    
242      /**
243       * Return the timestamp of this event.
244       *
245       * @return the timestamp
246       * @since 1.4
247       */
248      public long getWhen()
249      {
250        return when;
251      }
252    
253      /**
254       * This method returns a string identifying the event. This contains the
255       * event ID, the committed and composed characters separated by '+', the
256       * number of committed characters, the caret, and the visible position.
257       *
258       * @return a string identifying the event
259       */
260      public String paramString()
261      {
262        CPStringBuilder s
263          = new CPStringBuilder(80 + (text == null ? 0
264                                   : text.getEndIndex() - text.getBeginIndex()));
265        s.append(id == INPUT_METHOD_TEXT_CHANGED ? "INPUT_METHOD_TEXT_CHANGED, "
266                 : "CARET_POSITION_CHANGED, ");
267        if (text == null)
268          s.append("no text, 0 characters committed, caret: ");
269        else
270          {
271            s.append('"');
272            int i = text.getBeginIndex();
273            int j = committedCharacterCount;
274            while (--j >= 0)
275              s.append(text.setIndex(i++));
276            s.append("\" + \"");
277            j = text.getEndIndex() - i;
278            while (--j >= 0)
279              s.append(text.setIndex(i++));
280            s.append("\", ").append(committedCharacterCount)
281              .append(" characters committed, caret: ");          
282          }
283        s.append(caret == null ? (Object) "no caret" : caret).append(", ")
284          .append(visiblePosition == null ? (Object) "no visible position"
285                  : visiblePosition);
286        return s.toString();
287      }
288    
289      /**
290       * Reads in the object from a serial stream, updating when to
291       * {@link EventQueue#getMostRecentEventTime()} if necessary.
292       *
293       * @param s the stream to read from
294       * @throws IOException if deserialization fails
295       * @throws ClassNotFoundException if deserialization fails
296       * @serialData default, except for updating when
297       */
298      private void readObject(ObjectInputStream s)
299        throws IOException, ClassNotFoundException
300      {
301        s.defaultReadObject();
302        if (when == 0)
303          when = EventQueue.getMostRecentEventTime();
304      }
305    } // class InputMethodEvent