bundles/org.simantics.utils.thread.swt/src/org/simantics/utils/threads/SWTThread.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 /*
  13  *
  14  * @author Toni Kalajainen
  15  */
  16 package org.simantics.utils.threads;
  17
  18 import java.util.concurrent.Executor;
  19
  20 import org.eclipse.swt.widgets.Display;
  21 import org.eclipse.swt.widgets.Widget;
  22
  23 public class SWTThread implements IThreadWorkQueue, Executor {
  24
  25         private final Display display;
  26         private final boolean executeAsync;
  27
  28         public static IThreadWorkQueue getThreadAccess(Display display, boolean executeAsync)
  29         {
  30                 return new SWTThread(display, executeAsync);
  31         }
  32
  33         public static IThreadWorkQueue getThreadAccess(Display display)
  34         {
  35                 return getThreadAccess(display, false);
  36         }
  37
  38         public static IThreadWorkQueue getThreadAccess(Widget widget)
  39         {
  40                 return new SWTThread(widget.getDisplay(), false);
  41         }
  42
  43         public static IThreadWorkQueue getThreadAccess() {
  44                 return new SWTThread(Display.getDefault(), false);
  45         }
  46
  47         SWTThread(Display display, boolean executeAsync)
  48         {
  49                 this.display = display;
  50                 this.executeAsync = executeAsync;
  51         }
  52
  53         @Override
  54         public Thread asyncExec(Runnable runnable) {
  55                 // Don't accept work if the SWT thread is disposed.
  56                 if (display.isDisposed())
  57                         return null;
  58                 display.asyncExec(runnable);
  59                 return display.getThread();
  60         }
  61
  62         @Override
  63         public boolean syncExec(Runnable runnable) {
  64                 // Don't accept work if the SWT thread is disposed.
  65                 if (display.isDisposed())
  66                         return false;
  67                 if (display.getThread() == Thread.currentThread ())
  68                         runnable.run();
  69                 else
  70                         display.syncExec(runnable);
  71                 return true;
  72         }
  73
  74         @Override
  75         public boolean currentThreadAccess() {
  76                 // A disposed SWT thread can never be the current thread access
  77                 if (display.isDisposed())
  78                         return false;
  79                 return display.getThread() == Thread.currentThread ();
  80         }
  81
  82         @Override
  83         public Thread getThread() {
  84                 // Use null to indicate disposed SWT thread.
  85                 if (display.isDisposed())
  86                         return null;
  87                 return display.getThread();
  88         }
  89
  90         @Override
  91         public String toString() {
  92                 return "SWT Thread";
  93         }
  94
  95         @Override
  96         public void execute(Runnable command) {
  97                 if (executeAsync) asyncExec(command);
  98                 else syncExec(command);
  99         }
 100 }