Source for javax.swing.undo.UndoableEdit

   1: /* UndoableEdit.java --
   2:    Copyright (C) 2002, 2006, 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 javax.swing.undo;
  39: 
  40: /**
  41:  * An editing operation that supports undo/redoability.
  42:  * 
  43:  * @author Andrew Selkirk
  44:  */
  45: public interface UndoableEdit 
  46: {
  47: 
  48:   /**
  49:    * Incorporates another editing action into this one, thus forming a
  50:    * combined action.
  51:    *
  52:    * @param edit the editing action to be incorporated.
  53:    * 
  54:    * @return <code>true</code> if the edit was combined successfully, and 
  55:    *         <code>false</code> if it could not be combined.
  56:    */
  57:   boolean addEdit(UndoableEdit edit);
  58: 
  59:   /**
  60:    * Determines whether it would be possible to redo this editing
  61:    * action.
  62:    *
  63:    * @return <code>true</code> to indicate that this action can be
  64:    * redone, <code>false</code> otherwise.
  65:    *
  66:    * @see #redo()
  67:    * @see #canUndo()
  68:    */
  69:   boolean canRedo();
  70: 
  71:   /**
  72:    * Determines whether it would be possible to undo this editing
  73:    * action.
  74:    *
  75:    * @return <code>true</code> to indicate that this action can be
  76:    * undone, <code>false</code> otherwise.
  77:    *
  78:    * @see #undo()
  79:    * @see #canRedo()
  80:    */
  81:   boolean canUndo();
  82: 
  83:   /**
  84:    * Informs this edit action that it will no longer be used. Some
  85:    * actions might use this information to release resources, for
  86:    * example open files.  Called by {@link UndoManager} before this
  87:    * action is removed from the edit queue.
  88:    */
  89:   void die();
  90: 
  91:   /**
  92:    * Returns a human-readable, localized name that describes this
  93:    * editing action and can be displayed to the user.
  94:    *
  95:    * @return The presentation name.
  96:    */
  97:   String getPresentationName();
  98: 
  99:   /**
 100:    * Returns the redo presentation name.
 101:    * 
 102:    * @return The redo presentation name.
 103:    */
 104:   String getRedoPresentationName();
 105: 
 106:   /**
 107:    * Returns the undo presentation name.
 108:    * 
 109:    * @return The undo presentation name.
 110:    */
 111:   String getUndoPresentationName();
 112: 
 113:   /**
 114:    * Determines whether this editing action is significant enough for
 115:    * being seperately undoable by the user. A typical significant
 116:    * action would be the resizing of an object. However, changing the
 117:    * selection in a text document would usually not be considered
 118:    * significant.
 119:    *
 120:    * @return <code>true</code> to indicate that the action is
 121:    * significant enough for being separately undoable, or
 122:    * <code>false</code> otherwise.
 123:    */
 124:   boolean isSignificant();
 125: 
 126:   /**
 127:    * Redoes this editing action.
 128:    *
 129:    * @throws CannotRedoException if the edit cannot be undone.
 130:    *
 131:    * @see #canRedo()
 132:    * @see #undo()
 133:    */
 134:   void redo() throws CannotRedoException;
 135: 
 136:   /**
 137:    * Incorporates another editing action into this one, thus forming a
 138:    * combined action that replaces the argument action.
 139:    *
 140:    * @param edit the editing action to be replaced.
 141:    * 
 142:    * @return <code>true</code> if the edit is successfully replaced, and 
 143:    *         <code>false</code> otherwise.
 144:    */
 145:   boolean replaceEdit(UndoableEdit edit);
 146: 
 147:   /**
 148:    * Undoes this editing action.
 149:    *
 150:    * @throws CannotUndoException if the edit cannot be undone.
 151:    *
 152:    * @see #canUndo()
 153:    * @see #redo()
 154:    */
 155:   void undo() throws CannotUndoException;
 156: 
 157: }