odk/examples/DevelopersGuide/OfficeDev/DesktopEnvironment/ViewContainer.java

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   3  *  $RCSfile: ViewContainer.java,v $
   4  *
   5  *  $Revision: 1.4 $
   6  *
   7  *  last change: $Author: rt $ $Date: 2005-01-31 16:40:33 $
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  40
  41 // __________ Imports __________
  42
  43 import com.sun.star.uno.UnoRuntime;
  44
  45 import java.lang.*;
  46 import java.util.*;
  47
  48 // __________ Implementation __________
  49
  50 /**
  51  * It's implement a static container which hold
  52  * all opened documents and her views alive.
  53  * It's possible to register/deregister such views,
  54  * to get information about these and it provides
  55  * some global functionality - like termination of
  56  * this demo application.
  57  *
  58  * @author     Andreas Schl&uuml;ns
  59  * @created    01.03.2002 08:42
  60  */
  61 public class ViewContainer extends Thread
  62 {
  63     // ____________________
  64
  65     /**
  66      * provides a singleton view container
  67      * Neccessary for terminate(9 functionality to be able
  68      * to call Runtime.runFinilization().
  69      *
  70      * @return a reference to the singleton ViewContainer instance
  71      */
  72     public static synchronized ViewContainer getGlobalContainer()
  73     {
  74         if (maSingleton==null)
  75             maSingleton=new ViewContainer();
  76         return maSingleton;
  77     }
  78
  79     // ____________________
  80
  81     /**
  82      * ctor
  83      * It's private - because nobody should create any instance
  84      * expect the only global one, which wil be created by ourself!
  85      */
  86     private ViewContainer()
  87     {
  88         mlViews          = new Vector();
  89         mlListener       = new Vector();
  90         mbShutdownActive = false       ;
  91         Runtime.getRuntime().addShutdownHook(this);
  92     }
  93
  94     // ____________________
  95
  96     /**
  97      * This register a new view inside this global container
  98      * (if it doesnt already exist).
  99      *
 100      * @param   aView       view which whish to be registered inside this container
 101      */
 102     public void addView(Object aView)
 103     {
 104         synchronized(mlViews)
 105         {
 106             if(mlViews.contains(aView)==false)
 107                 mlViews.add(aView);
 108         }
 109     }
 110
 111     // ____________________
 112
 113     /**
 114      * This deregister a view from this global container.
 115      * Normaly it should be the last reference to the view
 116      * and her finalize() method should be called.
 117      * If last view will be closed here - we terminate these
 118      * java application too. Because there is no further
 119      * visible frame anymore.
 120      *
 121      * @param aView
 122      *          view object which wish to be deregistered
 123      */
 124     public void removeView(Object aView)
 125     {
 126         int nViewCount = 0;
 127         synchronized(mlViews)
 128         {
 129             if(mlViews.contains(aView)==true)
 130                 mlViews.remove(aView);
 131
 132             nViewCount = mlViews.size();
 133
 134             if (nViewCount<1)
 135                 mlViews = null;
 136         }
 137         // If this view is a registered shutdown listener on this view container
 138         // too, we must call his interface and forget him as possible listener.
 139         // It's neccessary to guarantee his dead ...
 140         boolean bShutdownView = false;
 141         synchronized(mlListener)
 142         {
 143             bShutdownView = mlListener.contains(aView);
 144             if (bShutdownView==true)
 145                 mlListener.remove(aView);
 146         }
 147         if (bShutdownView==true)
 148             ((IShutdownListener)aView).shutdown();
 149
 150         // We use a system.exit() to finish the whole application.
 151         // And further we have registered THIS instance as a possible shutdown
 152         // hook at the runtime class. So our run() method will be called.
 153         // Teh our view container should be empty - but
 154         // our listener container can include some references.
 155         // These objects wich to be informed then and release e.g. some
 156         // remote references.
 157         if (nViewCount<1)
 158         {
 159             boolean bNeccessary = false;
 160             synchronized(this)
 161             {
 162                 bNeccessary = ! mbShutdownActive;
 163             }
 164             if (bNeccessary==true)
 165             {
 166                 System.out.println("call exit(0)!");
 167                 System.exit(0);
 168             }
 169         }
 170     }
 171
 172     // ____________________
 173
 174     /**
 175      * add/remove listener for possibe shutdown events
 176      */
 177     public void addListener( IShutdownListener rListener )
 178     {
 179         synchronized(mlListener)
 180         {
 181             if ( ! mlListener.contains(rListener) )
 182                 mlListener.add(rListener);
 183         }
 184     }
 185
 186     // ____________________
 187
 188     public void removeListener( IShutdownListener rListener )
 189     {
 190         synchronized(mlListener)
 191         {
 192             if ( mlListener.contains(rListener) )
 193                 mlListener.remove(rListener);
 194         }
 195     }
 196
 197     // ____________________
 198
 199     /**
 200      * Is called from current runtime system of the java machine
 201      * on shutdown. We inform all current registered listener and
 202      * views. They should deinitialize her internal things then.
 203      */
 204     public void run()
 205     {
 206         synchronized(this)
 207         {
 208             if (mbShutdownActive)
 209                 return;
 210             mbShutdownActive=true;
 211         }
 212
 213         while( true )
 214         {
 215             IShutdownListener aListener = null;
 216             synchronized(mlListener)
 217             {
 218                 try{
 219                     aListener = (IShutdownListener)mlListener.firstElement();
 220                 } catch(java.util.NoSuchElementException exEmpty) {}
 221             }
 222             if (aListener==null)
 223                 break;
 224
 225             aListener.shutdown();
 226             // May this listener has dergeistered himself.
 227             // But if not we must do it for him. Our own
 228             // method "removeListener()" ignore requests for
 229             // already gone listener objects.
 230             removeListener(aListener);
 231         }
 232
 233         if (mlViews!=null)
 234         {
 235             synchronized(mlViews)
 236             {
 237                 mlViews.clear();
 238                 mlViews = null;
 239             }
 240         }
 241
 242         if (mlListener!=null)
 243         {
 244             synchronized(mlListener)
 245             {
 246                 mlListener.clear();
 247                 mlListener = null;
 248             }
 249         }
 250     }
 251
 252     // ____________________
 253
 254     /**
 255      * @const   BASICNAME   it's used to create uinque names for all regieterd views
 256      */
 257     private static final String BASICNAME = "Document View ";
 258
 259     // ____________________
 260
 261     /**
 262      * @member  mbInplace           indicates using of inplace office frames instead of outplace ones
 263      * @member  maSingleton         singleton instance of this view container
 264      * @member  mlViews             list of all currently registered document views
 265      * @member  mlListener          list of all currently registered shutdown listener
 266      * @member  mbShutdownActive    if this shutdown hook already was started it's not a good idea to
 267      *                              call System.exit() again for other conditions.
 268      *                              We supress it by using this variable!
 269      */
 270     public  static boolean       mbInplace   = false ;
 271     private static ViewContainer maSingleton = null  ;
 272     private        Vector        mlViews             ;
 273     private        Vector        mlListener          ;
 274     private        boolean       mbShutdownActive    ;
 275 }