| /******************************************************************************* |
| * Copyright (c) 2004, 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.internal.themes; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * @since 3.0 |
| */ |
| public class CascadingMap { |
| |
| private Map base, override; |
| |
| /** |
| * @param base the base (default) map |
| * @param override the override map |
| */ |
| public CascadingMap(Map base, Map override) { |
| this.base = base; |
| this.override = override; |
| } |
| |
| /** |
| * Return the union of the parent and child key sets. |
| * |
| * @return the union. This set is read only. |
| */ |
| public Set keySet() { |
| Set keySet = new HashSet(base.keySet()); |
| keySet.addAll(override.keySet()); |
| return Collections.unmodifiableSet(keySet); |
| } |
| |
| /** |
| * Get the value. Preference will be given to entries in the override map. |
| * |
| * @param key the key |
| * @return the value |
| */ |
| public Object get(Object key) { |
| if (override.containsKey(key)) { |
| return override.get(key); |
| } |
| return base.get(key); |
| } |
| } |