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Diffstat (limited to 'libjava/classpath/javax/swing/undo/StateEdit.java')
| -rw-r--r-- | libjava/classpath/javax/swing/undo/StateEdit.java | 265 |
1 files changed, 0 insertions, 265 deletions
diff --git a/libjava/classpath/javax/swing/undo/StateEdit.java b/libjava/classpath/javax/swing/undo/StateEdit.java deleted file mode 100644 index 819d052..0000000 --- a/libjava/classpath/javax/swing/undo/StateEdit.java +++ /dev/null @@ -1,265 +0,0 @@ -/* StateEdit.java -- UndoableEdit for StateEditable implementations. - Copyright (C) 2002, 2003 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath 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 2, or (at your option) -any later version. - -GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package javax.swing.undo; - -import java.util.Hashtable; -import java.util.Iterator; - -/** - * A helper class, making it easy to support undo and redo. - * - * <p>The following example shows how to use this class.</p> - * - * <pre> - * Foo foo; // class Foo implements {@link StateEditable} - * StateEdit edit; - * - * edit = new StateEdit(foo, "Name Change"); - * foo.setName("Jane Doe"); - * edit.end(); - * undoManager.addEdit(edit); - * </pre> - * - * <p>If <code>Foo</code>’s implementation of {@link - * StateEditable} considers the name as part of the editable state, - * the user can now choose “Undo Name Change” or - * “Redo Name Change” from the respective menu. No - * further undo support is needed from the application.</p> - * - * <p>The following explains what happens in the example.</p> - * - * <ol> - * <li>When a <code>StateEdit</code> is created, the associated - * {@link StateEditable} gets asked to store its state into a hash - * table, {@link #preState}.</li> - * <li>The application will now perform some changes to the edited - * object. This typically happens by invoking methods on the edited - * object.</li> - * <li>The editing phase is terminated by invoking the {@link #end()} - * method of the <code>StateEdit</code>. The <code>end()</code> method - * does two things. - * - * <ul> - * <li>The edited object receives a second request for storing - * its state. This time, it will use a different hash table, {@link - * #postState}.</li> - * <li>To increase efficiency, the <code>StateEdit</code> now removes - * any entries from {@link #preState} and {@link #postState} that have - * the same key, and whose values are equal. Equality is determined - * by invoking the <code>equals</code> method inherited from - * {@link java.lang.Object}.</li> - * </ul></li> - * <li>When the user later chooses to undo the <code>StateEdit</code>, - * the edited object is asked to {@linkplain StateEditable#restoreState - * restore its state} from the {@link #preState} table. Similarly, - * when the user chooses to <i>redo</i> the <code>StateEdit</code>, - * the edited object gets asked to restore its state from the {@link - * #postState}.</li> - * </ol> - * - * @author Andrew Selkirk (aselkirk@sympatico.ca) - * @author Sascha Brawer (brawer@dandelis.ch) - */ -public class StateEdit - extends AbstractUndoableEdit -{ - /** - * The ID of the Java source file in Sun’s Revision Control - * System (RCS). This certainly should not be part of the API - * specification. But in order to be API-compatible with - * Sun’s reference implementation, GNU Classpath also has to - * provide this field and match its value. The value used here has - * been in every JDK release at least from 1.2 to 1.5. - */ - protected static final String RCSID = "$" + - "Id: StateEdit.java,v 1.6 1997/10/01 20:05:51 sandipc Exp $"; - - - /** - * The object which is being edited by this <code>StateEdit</code>. - */ - protected StateEditable object; - - - /** - * The state of <code>object</code> at the time of constructing - * this <code>StateEdit</code>. - */ - protected Hashtable<Object, Object> preState; - - - /** - * The state of <code>object</code> at the time when {@link #end()} - * was called. - */ - protected Hashtable<Object, Object> postState; - - - /** - * A human-readable name for this edit action. - */ - protected String undoRedoName; - - - /** - * Constructs a <code>StateEdit</code>, specifying the object whose - * state is being edited. - * - * @param obj the object whose state is being edited by this - * <code>StateEdit</code>. - */ - public StateEdit(StateEditable obj) - { - init(obj, null); - } - - - /** - * Constructs a <code>StateEdit</code>, specifying the object whose - * state is being edited. - * - * @param obj the object whose state is being edited by this - * <code>StateEdit</code>. - * - * @param name the human-readable name of the editing action. - */ - public StateEdit(StateEditable obj, String name) - { - init(obj, name); - } - - - /** - * Initializes this <code>StateEdit</code>. The edited object will - * be asked to store its current state into {@link #preState}. - * - * @param obj the object being edited. - * - * @param name the human-readable name of the editing action. - */ - protected void init(StateEditable obj, String name) - { - object = obj; - undoRedoName = name; - preState = new Hashtable<Object,Object>(); - postState = new Hashtable<Object,Object>(); - obj.storeState(preState); - } - - - /** - * Informs this <code>StateEdit</code> that all edits are finished. - * The edited object will be asked to store its state into {@link - * #postState}, and any redundant entries will get removed from - * {@link #preState} and {@link #postState}. - */ - public void end() - { - object.storeState(postState); - removeRedundantState(); - } - - - /** - * Undoes this edit operation. The edited object will be asked to - * {@linkplain StateEditable#restoreState restore its state} from - * {@link #preState}. - * - * @throws CannotUndoException if {@link #canUndo()} returns - * <code>false</code>, for example because this action has already - * been undone. - */ - public void undo() - { - super.undo(); - object.restoreState(preState); - } - - - /** - * Redoes this edit operation. The edited object will be asked to - * {@linkplain StateEditable#restoreState restore its state} from - * {@link #postState}. - * - * @throws CannotRedoException if {@link #canRedo()} returns - * <code>false</code>, for example because this action has not yet - * been undone. - */ - public void redo() - { - super.redo(); - object.restoreState(postState); - } - - - /** - * Returns a human-readable, localized name that describes this - * editing action and can be displayed to the user. - * - * @return the name, or <code>null</code> if no presentation - * name is available. - */ - public String getPresentationName() - { - return undoRedoName; - } - - - /** - * Removes all redundant entries from the pre- and post-edit state - * hash tables. An entry is considered redundant if it is present - * both before and after the edit, and if the two values are equal. - */ - protected void removeRedundantState() - { - Iterator<Object> i = preState.keySet().iterator(); - while (i.hasNext()) - { - Object key = i.next(); - if (postState.containsKey(key)) - { - if (preState.get(key).equals(postState.get(key))) - { - i.remove(); - postState.remove(key); - } - } - } - } -} |