| /******************************************************************************* |
| * Copyright (c) 2003, 2006 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.ui.commands; |
| |
| import java.util.Map; |
| |
| import org.eclipse.ui.internal.util.Util; |
| |
| /** |
| * An instance of this class describes changes to an instance of |
| * <code>IHandler</code>. |
| * <p> |
| * This class is not intended to be extended by clients. |
| * </p> |
| * |
| * @since 3.0 |
| * @see IHandlerListener#handlerChanged(HandlerEvent) |
| * @deprecated Please use the "org.eclipse.core.commands" plug-in instead. |
| */ |
| public final class HandlerEvent { |
| |
| /** |
| * Whether the attributes of the handler changed. |
| */ |
| private final boolean attributeValuesByNameChanged; |
| |
| /** |
| * The handler that changed; this value is never <code>null</code>. |
| */ |
| private final IHandler handler; |
| |
| /** |
| * This is the cached result of getPreviousAttributeValuesByName. It is |
| * computed the first time getPreviousAttributeValuesByName is called. |
| */ |
| private Map previousAttributeValuesByName; |
| |
| /** |
| * The map of previous attributes, if they changed. If they did not change, |
| * then this value is <code>null</code>. The map's keys are the attribute |
| * names (strings), and its value are any object. |
| * |
| * This is the original map passed into the constructor. This object always |
| * returns a copy of this map, not the original. However the constructor of |
| * this object is called very frequently and the map is rarely requested, |
| * so we only copy the map the first time it is requested. |
| * |
| * @since 3.1 |
| */ |
| private final Map originalPreviousAttributeValuesByName; |
| |
| /** |
| * Creates a new instance of this class. |
| * |
| * @param handler |
| * the instance of the interface that changed. |
| * @param attributeValuesByNameChanged |
| * true, iff the attributeValuesByName property changed. |
| * @param previousAttributeValuesByName |
| * the map of previous attribute values by name. This map may be |
| * empty. If this map is not empty, it's collection of keys must |
| * only contain instances of <code>String</code>. This map |
| * must be <code>null</code> if attributeValuesByNameChanged is |
| * <code>false</code> and must not be null if |
| * attributeValuesByNameChanged is <code>true</code>. |
| */ |
| public HandlerEvent(IHandler handler, boolean attributeValuesByNameChanged, |
| Map previousAttributeValuesByName) { |
| if (handler == null) { |
| throw new NullPointerException(); |
| } |
| |
| if (!attributeValuesByNameChanged |
| && previousAttributeValuesByName != null) { |
| throw new IllegalArgumentException(); |
| } |
| |
| if (attributeValuesByNameChanged) { |
| this.originalPreviousAttributeValuesByName = previousAttributeValuesByName; |
| } else { |
| this.originalPreviousAttributeValuesByName = null; |
| } |
| |
| this.handler = handler; |
| this.attributeValuesByNameChanged = attributeValuesByNameChanged; |
| } |
| |
| /** |
| * Returns the instance of the interface that changed. |
| * |
| * @return the instance of the interface that changed. Guaranteed not to be |
| * <code>null</code>. |
| */ |
| public IHandler getHandler() { |
| return handler; |
| } |
| |
| /** |
| * Returns the map of previous attribute values by name. |
| * |
| * @return the map of previous attribute values by name. This map may be |
| * empty. If this map is not empty, it's collection of keys is |
| * guaranteed to only contain instances of <code>String</code>. |
| * This map is guaranteed to be <code>null</code> if |
| * haveAttributeValuesByNameChanged() is <code>false</code> and is |
| * guaranteed to not be null if haveAttributeValuesByNameChanged() |
| * is <code>true</code>. |
| */ |
| public Map getPreviousAttributeValuesByName() { |
| if (originalPreviousAttributeValuesByName == null) { |
| return null; |
| } |
| |
| if (previousAttributeValuesByName == null) { |
| previousAttributeValuesByName = Util.safeCopy( |
| originalPreviousAttributeValuesByName, String.class, Object.class, |
| false, true); |
| } |
| |
| return previousAttributeValuesByName; |
| } |
| |
| /** |
| * Returns whether or not the attributeValuesByName property changed. |
| * |
| * @return true, iff the attributeValuesByName property changed. |
| */ |
| public boolean haveAttributeValuesByNameChanged() { |
| return attributeValuesByNameChanged; |
| } |
| } |