gov/nasa/worldwind/AVListImpl.java

   1 /*
   2 Copyright (C) 2001, 2006 United States Government
   3 as represented by the Administrator of the
   4 National Aeronautics and Space Administration.
   5 All Rights Reserved.
   6 */
   7 package gov.nasa.worldwind;
   8
   9 /**
  10  * An implementation class for the {@link AVList} interface. Classes implementing <code>AVList</code> can subclass or
  11  * aggreate this class to provide default <code>AVList</code> functionality. This class maintains a hash table of
  12  * attribute-value pairs.
  13  * <p/>
  14  * This class implements a notification mechanism for attribute-value changes. The mechanism provides a means for
  15  * objects to observe attribute changes or queries for certain keys without explicitly monitoring all keys. See {@link
  16  * java.beans.PropertyChangeSupport}.
  17  *
  18  * @author Tom Gaskins
  19  * @version $Id: AVListImpl.java 1742 2007-05-06 16:34:29Z tgaskins $
  20  */
  21 public class AVListImpl implements AVList, java.beans.PropertyChangeListener
  22 {
  23     // TODO: Make thread-safe
  24     /**
  25      * Available to sub-classes for further exposure of property-change functionality.
  26      */
  27     protected final java.beans.PropertyChangeSupport changeSupport = new java.beans.PropertyChangeSupport(this);
  28
  29     // To avoid unnecessary overhead, this object's hash map is created only if needed.
  30     private java.util.Map<String, Object> avList;
  31
  32     /**
  33      * Creates an empty attribute-value list.
  34      */
  35     public AVListImpl()
  36     {
  37     }
  38
  39     private boolean hasAvList()
  40     {
  41         return this.avList != null;
  42     }
  43
  44     private void createAvList()
  45     {
  46         if (!this.hasAvList())
  47         {
  48             this.avList = new java.util.HashMap<String, Object>();
  49         }
  50     }
  51
  52     private java.util.Map<String, Object> avList(boolean createIfNone)
  53     {
  54         if (createIfNone && !this.hasAvList())
  55             this.createAvList();
  56
  57         return this.avList;
  58     }
  59
  60     public final Object getValue(String key)
  61     {
  62         if (key == null)
  63         {
  64             String message = WorldWind.retrieveErrMsg("nullValue.AttributeKeyIsNull");
  65             WorldWind.logger().log(java.util.logging.Level.FINE, message);
  66             throw new IllegalArgumentException(message);
  67         }
  68
  69         if (this.hasAvList())
  70             return this.avList.get(key);
  71
  72         return null;
  73     }
  74
  75     public final String getStringValue(String key)
  76     {
  77         if (key == null)
  78         {
  79             String msg = WorldWind.retrieveErrMsg("nullValue.AttributeKeyIsNull");
  80             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
  81             throw new IllegalStateException(msg);
  82         }
  83         try
  84         {
  85             return (String) this.getValue(key);
  86         }
  87         catch (ClassCastException e)
  88         {
  89             String msg = WorldWind.retrieveErrMsg("AVAAccessibleImpl.AttributeValueForKeyIsNotAString") + key;
  90
  91             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
  92             throw new WWRuntimeException(msg, e);
  93         }
  94     }
  95
  96     public final void setValue(String key, Object value)
  97     {
  98         if (key == null)
  99         {
 100             String message = WorldWind.retrieveErrMsg("nullValue.AttributeKeyIsNull");
 101             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 102             throw new IllegalArgumentException(message);
 103         }
 104         // Capture the existing value if there is one, then set the new value.
 105         this.avList(true).put(key, value);
 106     }
 107
 108     public final boolean hasKey(String key)
 109     {
 110         if (key == null)
 111         {
 112             String message = WorldWind.retrieveErrMsg("nullValue.KeyIsNull");
 113             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 114             throw new IllegalArgumentException(message);
 115         }
 116
 117         return this.hasAvList() && this.avList.containsKey(key);
 118     }
 119
 120     public final void removeKey(String key)
 121     {
 122         if (key == null)
 123         {
 124             String message = WorldWind.retrieveErrMsg("nullValue.KeyIsNull");
 125             WorldWind.logger().log(java.util.logging.Level.FINE, message);
 126             throw new IllegalArgumentException(message);
 127         }
 128
 129         if (this.hasKey(key))
 130             this.avList.remove(key);
 131     }
 132
 133     public AVList copy()
 134     {
 135         AVListImpl clone = new AVListImpl();
 136
 137         clone.createAvList();
 138         clone.avList.putAll(this.avList);
 139
 140         return clone;
 141     }
 142
 143     public void addPropertyChangeListener(String propertyName, java.beans.PropertyChangeListener listener)
 144     {
 145         if (propertyName == null)
 146         {
 147             String msg = WorldWind.retrieveErrMsg("nullValue.PropertyNameIsNull");
 148             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 149             throw new IllegalArgumentException(msg);
 150         }
 151         if (listener == null)
 152         {
 153             String msg = WorldWind.retrieveErrMsg("nullValue.ListenerIsNull");
 154             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 155             throw new IllegalArgumentException(msg);
 156         }
 157         this.changeSupport.addPropertyChangeListener(propertyName, listener);
 158     }
 159
 160     public void removePropertyChangeListener(String propertyName, java.beans.PropertyChangeListener listener)
 161     {
 162         if (propertyName == null)
 163         {
 164             String msg = WorldWind.retrieveErrMsg("nullValue.PropertyNameIsNull");
 165             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 166             throw new IllegalArgumentException(msg);
 167         }
 168         if (listener == null)
 169         {
 170             String msg = WorldWind.retrieveErrMsg("nullValue.ListenerIsNull");
 171             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 172             throw new IllegalArgumentException(msg);
 173         }
 174         this.changeSupport.removePropertyChangeListener(propertyName, listener);
 175     }
 176
 177     public void addPropertyChangeListener(java.beans.PropertyChangeListener listener)
 178     {
 179         if (listener == null)
 180         {
 181             String msg = WorldWind.retrieveErrMsg("nullValue.ListenerIsNull");
 182             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 183             throw new IllegalArgumentException(msg);
 184         }
 185         this.changeSupport.addPropertyChangeListener(listener);
 186     }
 187
 188     public void removePropertyChangeListener(java.beans.PropertyChangeListener listener)
 189     {
 190         if (listener == null)
 191         {
 192             String msg = WorldWind.retrieveErrMsg("nullValue.ListenerIsNull");
 193             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 194             throw new IllegalArgumentException(msg);
 195         }
 196         this.changeSupport.removePropertyChangeListener(listener);
 197     }
 198
 199     public void firePropertyChange(java.beans.PropertyChangeEvent propertyChangeEvent)
 200     {
 201         if (propertyChangeEvent == null)
 202         {
 203             String msg = WorldWind.retrieveErrMsg("nullValue.PropertyChangeEventIsNull");
 204             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 205             throw new IllegalArgumentException(msg);
 206         }
 207         this.changeSupport.firePropertyChange(propertyChangeEvent);
 208     }
 209
 210     public void firePropertyChange(String propertyName, Object oldValue, Object newValue)
 211     {
 212         if (propertyName == null)
 213         {
 214             String msg = WorldWind.retrieveErrMsg("nullValue.PropertyNameIsNull");
 215             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 216             throw new IllegalArgumentException(msg);
 217         }
 218         this.changeSupport.firePropertyChange(propertyName, oldValue, newValue);
 219     }
 220
 221     /**
 222      * The property change listener for <em>this</em> instance.
 223      * Recieves property change notifications that this instance has registered with other proprty change notifiers.
 224      * @param propertyChangeEvent the event
 225      * @throws IllegalArgumentException if <code>propertyChangeEvent</code> is null
 226      */
 227     public void propertyChange(java.beans.PropertyChangeEvent propertyChangeEvent)
 228     {
 229         if (propertyChangeEvent == null)
 230         {
 231             String msg = WorldWind.retrieveErrMsg("nullValue.PropertyChangeEventIsNull");
 232             WorldWind.logger().log(java.util.logging.Level.FINE, msg);
 233             throw new IllegalArgumentException(msg);
 234         }
 235
 236         // Notify all *my* listeners of the change that I caught
 237         this.changeSupport.firePropertyChange(propertyChangeEvent);
 238     }
 239 }