bundles/org.simantics.modeling.ui/src/org/simantics/modeling/ui/diagramEditor/DisposingPolicy.java

   1 package org.simantics.modeling.ui.diagramEditor;\r
   2 \r
   3 import gnu.trove.map.hash.TObjectLongHashMap;\r
   4 \r
   5 import java.util.ArrayDeque;\r
   6 \r
   7 import org.eclipse.swt.widgets.Display;\r
   8 \r
   9 \r
  10 public class DisposingPolicy {\r
  11     \r
  12     public static final boolean DEBUG = false;\r
  13     \r
  14     public static final int MAX_QUEUE_LENGTH = 8;\r
  15     public static final long DISPOSE_TIME = 30000L; // ms\r
  16     public static final long MIN_DELAY = 200L; // ms\r
  17     \r
  18     private ArrayDeque<Runnable> disposerQueue = new ArrayDeque<Runnable>(MAX_QUEUE_LENGTH);\r
  19     private TObjectLongHashMap<Runnable> disposeTime =\r
  20             new TObjectLongHashMap<Runnable>(MAX_QUEUE_LENGTH);\r
  21     private Runnable currentlyScheduled = null;\r
  22     \r
  23     private Runnable disposeOne = new Runnable() {\r
  24         @Override\r
  25         public void run() {\r
  26             if(!disposerQueue.isEmpty()) {\r
  27                 Runnable runnable = disposerQueue.removeFirst();\r
  28                 disposeTime.remove(runnable);\r
  29                 currentlyScheduled = null;\r
  30                 runnable.run();\r
  31                 if(DEBUG)\r
  32                     System.out.println("Executed disposer " + runnable);\r
  33                 if(!disposerQueue.isEmpty())\r
  34                     scheduleDispose();\r
  35             }\r
  36         }\r
  37     };\r
  38     \r
  39     private void scheduleDispose() {\r
  40         currentlyScheduled = disposerQueue.peekFirst();\r
  41         long delay = Math.max(\r
  42                 disposeTime.get(currentlyScheduled) - System.currentTimeMillis(),\r
  43                 MIN_DELAY);\r
  44         Display.getCurrent().timerExec((int)delay, disposeOne);\r
  45         if(DEBUG)\r
  46             System.out.println("Scheduled disposer " + currentlyScheduled + " in " + delay + " ms");\r
  47     }\r
  48     \r
  49     /**\r
  50      * Runs the disposer either after DISPOSE_TIME or when there are\r
  51      * more than MAX_QUEUE_LENGTH disposers active and this is first\r
  52      * of them (by activation order). This method must be called from\r
  53      * UI thread.\r
  54      */\r
  55     public void addDisposer(Runnable disposer) {\r
  56         if(DEBUG)\r
  57             System.out.println("Added disposer " + disposer);\r
  58         if(disposeTime.contains(disposer))\r
  59             return;\r
  60         if(disposerQueue.size() >= MAX_QUEUE_LENGTH)\r
  61             disposeOne.run();\r
  62         disposerQueue.addLast(disposer);\r
  63         disposeTime.put(disposer, System.currentTimeMillis()+DISPOSE_TIME);\r
  64         if(disposerQueue.size() == 1)\r
  65             scheduleDispose();\r
  66     }\r
  67     \r
  68     /**\r
  69      * Cancels a disposer added before. This method must be called from\r
  70      * UI thread.\r
  71      */\r
  72     public void removeDisposer(Runnable disposer) {\r
  73         if(DEBUG)\r
  74             System.out.println("Removed disposer " + disposer);\r
  75         disposerQueue.remove(disposer);\r
  76         disposeTime.remove(disposer);\r
  77         if(disposer == currentlyScheduled) {\r
  78             currentlyScheduled = null;\r
  79             if(!disposerQueue.isEmpty())\r
  80                 scheduleDispose();\r
  81         }\r
  82     }\r
  83     \r
  84 }\r