001 /* ActionMap.java -- 002 Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 package javax.swing; 039 040 import java.io.Serializable; 041 import java.util.Arrays; 042 import java.util.HashMap; 043 import java.util.HashSet; 044 import java.util.Map; 045 import 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 */ 060 public 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 }