Source for java.awt.im.spi.InputMethod

   1: /* InputMethod.java -- defines an interface for complex text input
   2:    Copyright (C) 2002, 2005  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package java.awt.im.spi;
  39: 
  40: import java.awt.AWTEvent;
  41: import java.awt.Rectangle;
  42: import java.util.Locale;
  43: 
  44: /**
  45:  * This interface supports complex text input, often for situations where
  46:  * the text is more complex than a keyboard will accomodate. For example,
  47:  * this can be used for Chinese, Japanese, and Korean, where multiple
  48:  * keystrokes are necessary to compose text. This could also support things
  49:  * like phonetic English, or reordering Thai.
  50:  *
  51:  * <p>These contexts can be loaded by the input method framework, using
  52:  * {@link InputContext#selectInputMethod(Locale)}.
  53:  *
  54:  * @author Eric Blake (ebb9@email.byu.edu)
  55:  * @since 1.3
  56:  * @status updated to 1.4
  57:  */
  58: public interface InputMethod
  59: {
  60:   /**
  61:    * Set the input method context, which ties the input method to a client
  62:    * component. This is called once automatically when creating the input
  63:    * method.
  64:    *
  65:    * @param context the context for this input method
  66:    * @throws NullPointerException if context is null
  67:    */
  68:   void setInputMethodContext(InputMethodContext context);
  69: 
  70:   /**
  71:    * Sets the input locale. If the input method supports that locale, it
  72:    * changes its behavior to be consistent with the locale and returns true.
  73:    * Otherwise, it returns false. This is called by
  74:    * {@link InputContext#selectInputMethod(Locale)} when the user specifies
  75:    * a locale, or when the previously selected input method had a locale.
  76:    *
  77:    * @param locale the locale to use for input
  78:    * @return true if the change is successful
  79:    * @throws NullPointerException if locale is null
  80:    */
  81:   boolean setLocale(Locale locale);
  82: 
  83:   /**
  84:    * Returns the current input locale, or null if none is defined. This is
  85:    * called by {@link InputContext#getLocale()}, or before switching input
  86:    * methods.
  87:    *
  88:    * @return the current input locale, or null
  89:    */
  90:   Locale getLocale();
  91: 
  92:   /**
  93:    * Sets the allowed Unicode subsets that this input method can use. Null
  94:    * indicates that all characters are allowed. This is called after creation,
  95:    * or when switching to this input method, by
  96:    * {@link InputContext#setCharacterSubsets(Character.Subset[])}.
  97:    *
  98:    * @param subsets the accepted subsets for this input method, or null for all
  99:    */
 100:   void setCharacterSubsets(Character.Subset[] subsets);
 101: 
 102:   /**
 103:    * Changes the enabled status of this input method. An enabled input method
 104:    * accepts incoming events for composition and control purposes, while a
 105:    * disabled input method ignores events (except for control purposes). This
 106:    * is called by {@link InputContext#setCompositionEnabled(boolean)} or when
 107:    * switching from an input method if the previous input method returned
 108:    * without exception on {@link #isCompositionEnabled()}.
 109:    *
 110:    * @param enable whether to enable this input method
 111:    * @throws UnsupportedOperationException if enabling/disabling is unsupported
 112:    * @see #isCompositionEnabled()
 113:    */
 114:   void setCompositionEnabled(boolean enable);
 115: 
 116:   /**
 117:    * Find out if this input method is enabled. This is called by
 118:    * {@link InputContext#isCompositionEnabled()}, or when switching input
 119:    * methods via {@link InputContext#selectInputMethod(Locale)}.
 120:    *
 121:    * @return true if this input method is enabled
 122:    * @throws UnsupportedOperationException if enabling/disabling is unsupported
 123:    * @see #setCompositionEnabled(boolean)
 124:    */
 125:   boolean isCompositionEnabled();
 126: 
 127:   /**
 128:    * Starts a reconversion operation. The input method gets its text from the
 129:    * client, using {@link InputMethodRequests#getSelectedText(Attribute[])}.
 130:    * Then the composed and committed text produced by the operation is sent
 131:    * back to the client using a sequence of InputMethodEvents. This is called
 132:    * by {@link InputContext#reconvert()}.
 133:    *
 134:    * @throws UnsupportedOperationException if reconversion is unsupported
 135:    */
 136:   void reconvert();
 137: 
 138:   /**
 139:    * Dispatch an event to the input method. If input method support is enabled,
 140:    * certain events are dispatched to the input method before the client
 141:    * component or event listeners. The input method must either consume the
 142:    * event or pass it on to the component. Instances of InputEvent, including
 143:    * KeyEvent and MouseEvent, are given to this input method. This method is
 144:    * called by {@link InputContext#dispatchEvent(AWTEvent)}.
 145:    *
 146:    * @param event the event to dispatch
 147:    * @throws NullPointerException if event is null
 148:    */
 149:   void dispatchEvent(AWTEvent event);
 150: 
 151:   /**
 152:    * Notify this input method of changes in the client window. This is called
 153:    * when notifications are enabled (see {@link
 154:    * InputMethodContext#enableClientWindowNotification(InputMethod, boolean)},
 155:    * if {@link #removeNotify(Component)} has not been called. The following
 156:    * situations trigger a notification:<ul>
 157:    * <li>The client window changes in location, size, visibility,
 158:    * iconification, or is closed.</li>
 159:    * <li>When enabling client notification (or on the first activation after
 160:    * enabling if no client existed at the time).</li>
 161:    * <li>When activating a new client after <code>removeNotify</code> was
 162:    * called on a previous client.</li>
 163:    * </ul>
 164:    *
 165:    * @param bounds the client window's current bounds, or null
 166:    */
 167:   void notifyClientWindowChange(Rectangle bounds);
 168: 
 169:   /**
 170:    * Activate this input method for input processing. If the input method
 171:    * provides its own windows, it should make them open and visible at this
 172:    * time. This method is called when a client component receives a
 173:    * FOCUS_GAINED event, or when switching to this input method from another
 174:    * one. It is only called when the input method is inactive, assuming that
 175:    * new instances begin in an inactive state.
 176:    */
 177:   void activate();
 178: 
 179:   /**
 180:    * Deactivate this input method, either temporarily or permanently for the
 181:    * given client. If the input method provides its own windows, it should
 182:    * only close those related to the current composition (such as a lookup
 183:    * choice panel), while leaving more persistant windows (like a control
 184:    * panel) open to avoid screen flicker. Before control is given to another
 185:    * input method, {@link #hideWindows()} will be called on this instance.
 186:    * This method is called when a client component receives a
 187:    * FOCUS_LOST event, when switching to another input method, or before
 188:    * {@link #removeNotify()} when the client is removed.
 189:    *
 190:    * @param isTemporary true if the focus change is temporary
 191:    */
 192:   void deactivate(boolean isTemporary);
 193: 
 194:   /**
 195:    * Close or hide all windows opened by this input method. This is called
 196:    * before activating a different input method, and before calling
 197:    * {@link #dispose()} on this instance. It is only called when the input
 198:    * method is inactive.
 199:    */
 200:   void hideWindows();
 201: 
 202:   /**
 203:    * Notify the input method that a client component has been removed from its
 204:    * hierarchy, or that input method support has been disabled. This is
 205:    * called by {@link InputContext#removeNotify()}, and only when the input
 206:    * method is inactive.
 207:    */
 208:   void removeNotify();
 209: 
 210:   /**
 211:    * End any input composition currently taking place. Depending on the
 212:    * platform and user preferences, this may commit or delete uncommitted text,
 213:    * using input method events. This may be called for a variety of reasons,
 214:    * such as when the user moves the insertion point in the client text outside
 215:    * the range of the composed text, or when text is saved to file. This is
 216:    * called by {@link InputContext#endComposition()}, when switching to a
 217:    * new input method, or by {@link InputContext#selectInputMethod(Locale)}.
 218:    */
 219:   void endComposition();
 220: 
 221:   /**
 222:    * Disposes the input method and release any resources it is using. In
 223:    * particular, the input method should dispose windows and close files. This
 224:    * is called by {@link InputContext#dispose()}, when the input method is
 225:    * inactive; and nothing will be called on this instance afterwards.
 226:    */
 227:   void dispose();
 228: 
 229:   /**
 230:    * Returns a control object from this input method, or null. A control object
 231:    * provides method to control the behavior of this input method, as well as
 232:    * query information about it. The object is implementation dependent, so
 233:    * clients must compare the result against known input method control
 234:    * object types. This is called by
 235:    * {@link InputContext#getInputMethodControlObject()}.
 236:    *
 237:    * @return the control object, or null
 238:    */
 239:   Object getControlObject();
 240: } // interface InputMethod