bundles/org.simantics.g2d/src/org/simantics/g2d/layers/SimpleLayers.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.g2d.layers;\r
  13 \r
  14 import java.util.Collections;\r
  15 import java.util.Comparator;\r
  16 import java.util.Set;\r
  17 import java.util.TreeSet;\r
  18 import java.util.concurrent.CopyOnWriteArrayList;\r
  19 \r
  20 /**\r
  21  * @author Antti Villberg\r
  22  */\r
  23 public class SimpleLayers implements ILayersEditor {\r
  24 \r
  25     private static final Comparator<ILayer> LAYER_COMPARATOR = new Comparator<ILayer>() {\r
  26         @Override\r
  27         public int compare(ILayer o1, ILayer o2) {\r
  28             return o1.getName().compareTo(o2.getName());\r
  29         }\r
  30     };\r
  31 \r
  32     private Set<ILayer>                                 all                      = new TreeSet<ILayer>(LAYER_COMPARATOR);\r
  33     private volatile Set<ILayer>                        allSnapshot;\r
  34 \r
  35     private Set<ILayer>                                 visible                  = new TreeSet<ILayer>(LAYER_COMPARATOR);\r
  36     private volatile Set<ILayer>                        visibleSnapshot;\r
  37 \r
  38     private CopyOnWriteArrayList<ILayersEditorListener> listeners                = new CopyOnWriteArrayList<ILayersEditorListener>();\r
  39 \r
  40     private boolean                                     ignoreFocusSettings      = false;\r
  41 \r
  42     private boolean                                     ignoreVisibilitySettings = false;\r
  43 \r
  44     public SimpleLayers() {\r
  45     }\r
  46 \r
  47     public SimpleLayers(String... content) {\r
  48         for (String s : content) {\r
  49             ILayer layer = new SimpleLayer(s);\r
  50             all.add(layer);\r
  51             visible.add(layer);\r
  52         }\r
  53         allSnapshot = null;\r
  54         visibleSnapshot = null;\r
  55     }\r
  56 \r
  57     @Override\r
  58     public Set<ILayer> getLayers() {\r
  59         // Double-checked locking idiom: http://en.wikipedia.org/wiki/Double-checked_locking\r
  60         // Works with acquire/release semantics for volatile\r
  61         // Broken under Java 1.4 and earlier semantics for volatile\r
  62         if (allSnapshot == null) {\r
  63             synchronized (this) {\r
  64                 if (allSnapshot == null) {\r
  65                     TreeSet<ILayer> ss = new TreeSet<ILayer>(LAYER_COMPARATOR);\r
  66                     ss.addAll(all);\r
  67                     allSnapshot = Collections.unmodifiableSet(ss);\r
  68                 }\r
  69             }\r
  70         }\r
  71         return allSnapshot;\r
  72     }\r
  73 \r
  74     @Override\r
  75     public Set<ILayer> getVisibleLayers() {\r
  76         // Double-checked locking idiom: http://en.wikipedia.org/wiki/Double-checked_locking\r
  77         // Works with acquire/release semantics for volatile\r
  78         // Broken under Java 1.4 and earlier semantics for volatile\r
  79         if (visibleSnapshot == null) {\r
  80             synchronized (this) {\r
  81                 if (visibleSnapshot == null) {\r
  82                     TreeSet<ILayer> ss = new TreeSet<ILayer>(LAYER_COMPARATOR);\r
  83                     ss.addAll(visible);\r
  84                     visibleSnapshot = Collections.unmodifiableSet(ss);\r
  85                 }\r
  86             }\r
  87         }\r
  88         return visibleSnapshot;\r
  89     }\r
  90 \r
  91     @Override\r
  92     public boolean isActive(ILayer layer) {\r
  93         synchronized (this) {\r
  94             return visible.contains(layer);\r
  95         }\r
  96     }\r
  97 \r
  98     @Override\r
  99     public void deactivate(ILayer layer) {\r
 100         boolean deactivated = false;\r
 101         synchronized (this) {\r
 102             deactivated = visible.remove(layer);\r
 103         }\r
 104         if (deactivated) {\r
 105             synchronized (this) {\r
 106                 visibleSnapshot = null;\r
 107             }\r
 108             for (ILayersEditorListener listener : listeners) {\r
 109                 listener.layerDeactivated(layer);\r
 110             }\r
 111         }\r
 112     }\r
 113 \r
 114     @Override\r
 115     public void activate(ILayer layer) {\r
 116         boolean activated = false;\r
 117         synchronized (this) {\r
 118             activated = visible.add(layer);\r
 119         }\r
 120         if (activated) {\r
 121             synchronized (this) {\r
 122                 visibleSnapshot = null;\r
 123             }\r
 124             for (ILayersEditorListener listener : listeners) {\r
 125                 listener.layerActivated(layer);\r
 126             }\r
 127         }\r
 128     }\r
 129 \r
 130     @Override\r
 131     public void addLayer(ILayer layer) {\r
 132         boolean added = false;\r
 133         synchronized (this) {\r
 134             added = all.add(layer);\r
 135         }\r
 136         if (added) {\r
 137             synchronized (this) {\r
 138                 allSnapshot = null;\r
 139             }\r
 140             for (ILayersEditorListener listener : listeners) {\r
 141                 listener.layerAdded(layer);\r
 142             }\r
 143         }\r
 144     }\r
 145 \r
 146     @Override\r
 147     public void removeLayer(ILayer layer) {\r
 148         boolean removed = false;\r
 149         synchronized (this) {\r
 150             removed = all.remove(layer);\r
 151             visible.remove(layer);\r
 152         }\r
 153         if (removed) {\r
 154             synchronized (this) {\r
 155                 allSnapshot = null;\r
 156                 visibleSnapshot = null;\r
 157             }\r
 158             for (ILayersEditorListener listener : listeners) {\r
 159                 listener.layerRemoved(layer);\r
 160             }\r
 161         }\r
 162     }\r
 163 \r
 164     @Override\r
 165     public void addListener(ILayersEditorListener listener) {\r
 166         listeners.add(listener);\r
 167     }\r
 168 \r
 169     @Override\r
 170     public void removeListener(ILayersEditorListener listener) {\r
 171         listeners.remove(listener);\r
 172     }\r
 173 \r
 174     @Override\r
 175     public boolean getIgnoreFocusSettings() {\r
 176         return ignoreFocusSettings;\r
 177     }\r
 178 \r
 179     @Override\r
 180     public void setIgnoreFocusSettings(boolean value) {\r
 181         boolean changed = ignoreFocusSettings != value;\r
 182         ignoreFocusSettings = value;\r
 183         if (changed) {\r
 184             for (ILayersEditorListener listener : listeners) {\r
 185                 listener.ignoreFocusChanged(value);\r
 186             }\r
 187         }\r
 188     }\r
 189 \r
 190     @Override\r
 191     public boolean getIgnoreVisibilitySettings() {\r
 192         return ignoreVisibilitySettings;\r
 193     }\r
 194 \r
 195     @Override\r
 196     public void setIgnoreVisibilitySettings(boolean value) {\r
 197         boolean changed = ignoreVisibilitySettings != value;\r
 198         ignoreVisibilitySettings = value;\r
 199         if (changed) {\r
 200             for (ILayersEditorListener listener : listeners) {\r
 201                 listener.ignoreVisibilityChanged(value);\r
 202             }\r
 203         }\r
 204     }\r
 205 \r
 206 }\r