| /******************************************************************************* |
| * Copyright (c) 2005 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.core.commands.operations; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * <p> |
| * An undo context that can be used to represent any given object. Clients |
| * can add matching contexts to this context. This class may be instantiated |
| * by clients. |
| * </p> |
| * |
| * @since 3.1 |
| */ |
| public final class ObjectUndoContext extends UndoContext { |
| |
| private Object object; |
| |
| private String label; |
| |
| private List children = new ArrayList(); |
| |
| /** |
| * Construct an operation context that represents the given object. |
| * |
| * @param object |
| * the object to be represented. |
| */ |
| public ObjectUndoContext(Object object) { |
| this(object, null); |
| } |
| |
| /** |
| * Construct an operation context that represents the given object and has a |
| * specialized label. |
| * |
| * @param object |
| * the object to be represented. |
| * @param label |
| * the label for the context |
| */ |
| public ObjectUndoContext(Object object, String label) { |
| super(); |
| this.object = object; |
| this.label = label; |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.core.commands.operations.IUndoContext#getLabel() |
| */ |
| public String getLabel() { |
| if (label != null) |
| return label; |
| if (object != null) |
| return object.toString(); |
| return super.getLabel(); |
| } |
| |
| /** |
| * Return the object that is represented by this context. |
| * |
| * @return the object represented by this context. |
| */ |
| public Object getObject() { |
| return object; |
| } |
| |
| /** |
| * Add the specified context as a match of this context. Contexts added as |
| * matches of this context will be interpreted as a match of this context |
| * when the history is filtered for a particular context. Adding a match |
| * allows components to create their own contexts for implementing |
| * specialized behavior, yet have their operations appear in a more |
| * global context. |
| * |
| * @param context |
| * the context to be added as a match of this context |
| */ |
| public void addMatch(IUndoContext context) { |
| children.add(context); |
| } |
| |
| /** |
| * Remove the specified context as a match of this context. The context will |
| * no longer be interpreted as a match of this context when the history is |
| * filtered for a particular context. This method has no effect if the |
| * specified context was never previously added as a match. |
| * |
| * @param context |
| * the context to be removed from the list of matches for this |
| * context |
| */ |
| public void removeMatch(IUndoContext context) { |
| children.remove(context); |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.core.commands.operations.IUndoContext#matches(IUndoContext |
| * context) |
| */ |
| public boolean matches(IUndoContext context) { |
| // Check first for explicit matches that have been assigned. |
| if (children.contains(context)) |
| return true; |
| // Contexts for equal objects are considered matching |
| if (context instanceof ObjectUndoContext && getObject() != null) |
| return getObject().equals(((ObjectUndoContext)context).getObject()); |
| // Use the normal matching implementation |
| return super.matches(context); |
| } |
| |
| /** |
| * The string representation of this operation. Used for debugging purposes only. |
| * This string should not be shown to an end user. |
| * |
| * @return The string representation. |
| */ |
| public String toString() { |
| return getLabel(); |
| } |
| |
| |
| } |