toolkit/test/accessibility/EventQueue.java

   1 import com.sun.star.accessibility.*;
   2 import com.sun.star.lang.EventObject;
   3
   4 import java.util.LinkedList;
   5
   6 /** The event queue singleton dispatches events received from OpenOffice.org
   7     applications in a thread separate from the AWB main thread.
   8
   9     The queue of event objects, LinkedList<Runnable> The queue object will
  10     also serve as lock for the consumer/producer type syncronization.
  11 */
  12 class EventQueue
  13     implements Runnable
  14 {
  15     public boolean mbVerbose = false;
  16     public boolean mbHandleDisposingEventsSynchronous = true;
  17
  18     public synchronized static EventQueue Instance ()
  19     {
  20         if (maInstance == null)
  21             maInstance = new EventQueue ();
  22         return maInstance;
  23     }
  24
  25     public void addEvent (Runnable aEvent)
  26     {
  27         synchronized (maMonitor)
  28         {
  29             if (mbVerbose)
  30                 System.out.println ("queing regular event " + aEvent);
  31             maRegularQueue.addLast (aEvent);
  32             maMonitor.notify ();
  33         }
  34     }
  35
  36
  37     public void addDisposingEvent (Runnable aEvent)
  38     {
  39         if (mbHandleDisposingEventsSynchronous)
  40             aEvent.run ();
  41         else
  42             synchronized (maMonitor)
  43             {
  44                 if (mbVerbose)
  45                     System.out.println ("queing disposing event " + aEvent);
  46                 maDisposingQueue.addLast (aEvent);
  47                 maMonitor.notify ();
  48             }
  49     }
  50
  51
  52     private EventQueue ()
  53     {
  54         maMonitor = new Boolean (true);
  55         maRegularQueue = new LinkedList();
  56         maDisposingQueue = new LinkedList();
  57         new Thread(this, "AWB.EventQueue").start();
  58     }
  59
  60
  61     /// This thread's main method: deliver all events
  62     public void run()
  63     {
  64         // in an infinite loop, check for events to deliver, then
  65         // wait on lock (which will be notified when new events arrive)
  66         while( true )
  67         {
  68             Runnable aEvent = null;
  69             do
  70             {
  71                 synchronized (maMonitor)
  72                 {
  73                     if (maDisposingQueue.size() > 0)
  74                     {
  75                         aEvent = (Runnable)maDisposingQueue.removeFirst();
  76                         if (mbVerbose)
  77                             System.out.println ("delivering disposing event " + aEvent);
  78                     }
  79                     else if (maRegularQueue.size() > 0)
  80                     {
  81                         aEvent = (Runnable)maRegularQueue.removeFirst();
  82                         if (mbVerbose)
  83                             System.out.println ("delivering regular event " + aEvent);
  84                     }
  85                     else
  86                         aEvent = null;
  87                 }
  88                 if (aEvent != null)
  89                 {
  90                     try
  91                     {
  92                         aEvent.run();
  93                     }
  94                     catch( Throwable e )
  95                     {
  96                         System.out.println(
  97                             "caught exception during event delivery: " + e );
  98                         e.printStackTrace();
  99                     }
 100                 }
 101             }
 102             while( aEvent != null );
 103
 104             try
 105             {
 106                 synchronized (maMonitor)
 107                 {
 108                     maMonitor.wait();
 109                 }
 110             }
 111             catch (Exception e)
 112             {
 113                 // can't wait? odd!
 114                 System.err.println("Can't wait!");
 115                 e.printStackTrace();
 116             }
 117         }
 118     }
 119
 120     private static EventQueue maInstance = null;
 121     private Object maMonitor;
 122     private LinkedList maRegularQueue;
 123     private LinkedList maDisposingQueue;
 124 }
 125
 126