001/* ActionMap.java -- 002 Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package javax.swing; 039 040import java.io.Serializable; 041import java.util.Arrays; 042import java.util.HashMap; 043import java.util.HashSet; 044import java.util.Map; 045import java.util.Set; 046 047 048/** 049 * Maps arbitrary keys (usually Strings) to {@link Action} instances. This 050 * is used in combination with {@link InputMap}s. 051 * 052 * If a component receives an input event, this is looked up in 053 * the component's <code>InputMap</code>. The result is an object which 054 * serves as a key to the components <code>ActionMap</code>. Finally 055 * the <code>Action</code> that is stored is executed. 056 * 057 * @author Andrew Selkirk 058 * @author Michael Koch 059 */ 060public class ActionMap 061 implements Serializable 062{ 063 private static final long serialVersionUID = -6277518704513986346L; 064 065 /** 066 * actionMap 067 */ 068 private Map actionMap = new HashMap(); 069 070 /** 071 * parent 072 */ 073 private ActionMap parent; 074 075 /** 076 * Creates a new <code>ActionMap</code> instance. 077 */ 078 public ActionMap() 079 { 080 // Nothing to do here. 081 } 082 083 /** 084 * Returns an action associated with an object. 085 * 086 * @param key the key of the enty 087 * 088 * @return the action associated with key, may be null 089 */ 090 public Action get(Object key) 091 { 092 Object result = actionMap.get(key); 093 094 if (result == null && parent != null) 095 result = parent.get(key); 096 097 return (Action) result; 098 } 099 100 /** 101 * Puts a new <code>Action</code> into the <code>ActionMap</code>. 102 * If action is null an existing entry will be removed. 103 * 104 * @param key the key for the entry 105 * @param action the action. 106 */ 107 public void put(Object key, Action action) 108 { 109 if (action == null) 110 actionMap.remove(key); 111 else 112 actionMap.put(key, action); 113 } 114 115 /** 116 * Remove an entry from the <code>ActionMap</code>. 117 * 118 * @param key the key of the entry to remove 119 */ 120 public void remove(Object key) 121 { 122 actionMap.remove(key); 123 } 124 125 /** 126 * Returns the parent of this <code>ActionMap</code>. 127 * 128 * @return the parent, may be null. 129 */ 130 public ActionMap getParent() 131 { 132 return parent; 133 } 134 135 /** 136 * Sets a parent for this <code>ActionMap</code>. 137 * 138 * @param parentMap the new parent 139 */ 140 public void setParent(ActionMap parentMap) 141 { 142 if (parentMap != this) 143 parent = parentMap; 144 } 145 146 /** 147 * Returns the number of entries in this <code>ActionMap</code>. 148 * 149 * @return the number of entries 150 */ 151 public int size() 152 { 153 return actionMap.size(); 154 } 155 156 /** 157 * Clears the <code>ActionMap</code>. 158 */ 159 public void clear() 160 { 161 actionMap.clear(); 162 } 163 164 /** 165 * Returns all keys of entries in this <code>ActionMap</code>. 166 * 167 * @return an array of keys 168 */ 169 public Object[] keys() 170 { 171 if (size() != 0) 172 return actionMap.keySet().toArray(); 173 return null; 174 } 175 176 /** 177 * Returns all keys of entries in this <code>ActionMap</code> 178 * and all its parents. 179 * 180 * @return an array of keys 181 */ 182 public Object[] allKeys() 183 { 184 Set set = new HashSet(); 185 186 if (parent != null) 187 set.addAll(Arrays.asList(parent.allKeys())); 188 189 set.addAll(actionMap.keySet()); 190 if (set.size() != 0) 191 return set.toArray(); 192 return null; 193 } 194 195}