bundles/org.simantics.diagram/src/org/simantics/diagram/ui/WorkbenchSelectionProvider.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.diagram.ui;\r
  13 \r
  14 import java.util.ArrayList;\r
  15 import java.util.Collections;\r
  16 import java.util.concurrent.CopyOnWriteArrayList;\r
  17 import java.util.concurrent.TimeUnit;\r
  18 \r
  19 import org.eclipse.jface.viewers.IPostSelectionProvider;\r
  20 import org.eclipse.jface.viewers.ISelection;\r
  21 import org.eclipse.jface.viewers.ISelectionChangedListener;\r
  22 import org.eclipse.jface.viewers.SelectionChangedEvent;\r
  23 import org.eclipse.jface.viewers.StructuredSelection;\r
  24 import org.eclipse.ui.IWorkbenchPartSite;\r
  25 import org.simantics.diagram.elements.AdaptableImmutableProxyElement;\r
  26 import org.simantics.g2d.canvas.ICanvasContext;\r
  27 import org.simantics.g2d.canvas.impl.AbstractCanvasParticipant;\r
  28 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;\r
  29 import org.simantics.g2d.canvas.impl.HintReflection.HintListener;\r
  30 import org.simantics.g2d.diagram.participant.Selection;\r
  31 import org.simantics.g2d.element.ElementHints;\r
  32 import org.simantics.g2d.element.IElement;\r
  33 import org.simantics.utils.datastructures.hints.IHintObservable;\r
  34 import org.simantics.utils.datastructures.hints.IHintContext.Key;\r
  35 import org.simantics.utils.threads.IThreadWorkQueue;\r
  36 import org.simantics.utils.threads.ThreadUtils;\r
  37 \r
  38 /**\r
  39  * A canvas participant that listens to the #0 mouse selection and provides it\r
  40  * forward through the {@link IPostSelectionProvider} interface.\r
  41  * \r
  42  * @author Tuukka Lehtonen\r
  43  */\r
  44 public class WorkbenchSelectionProvider extends AbstractCanvasParticipant implements IPostSelectionProvider {\r
  45 \r
  46     private static final long                                 POST_SELECTION_DELAY = 300;\r
  47 \r
  48     @Dependency protected Selection selection;\r
  49 \r
  50     protected IThreadWorkQueue                                swt;\r
  51     protected IWorkbenchPartSite                              site;\r
  52     protected ISelection                                      currentSelection = StructuredSelection.EMPTY;\r
  53     protected CopyOnWriteArrayList<ISelectionChangedListener> listeners        = new CopyOnWriteArrayList<ISelectionChangedListener>();\r
  54     protected CopyOnWriteArrayList<ISelectionChangedListener> postListeners    = new CopyOnWriteArrayList<ISelectionChangedListener>();\r
  55 \r
  56     public WorkbenchSelectionProvider(IThreadWorkQueue swt) {\r
  57         this(swt, null);\r
  58     }\r
  59 \r
  60     public WorkbenchSelectionProvider(IThreadWorkQueue swt, IWorkbenchPartSite site) {\r
  61         this.swt = swt;\r
  62         this.site = site;\r
  63         if (site != null)\r
  64             site.setSelectionProvider(this);\r
  65     }\r
  66 \r
  67     @Override\r
  68     public void addedToContext(ICanvasContext ctx) {\r
  69         super.addedToContext(ctx);\r
  70         if (site != null && site.getSelectionProvider() != this) {\r
  71             swt.asyncExec(new Runnable() {\r
  72                 @Override\r
  73                 public void run() {\r
  74                     if (site.getSelectionProvider() != WorkbenchSelectionProvider.this)\r
  75                         site.setSelectionProvider(WorkbenchSelectionProvider.this);\r
  76                 }\r
  77             });\r
  78         }\r
  79     }\r
  80 \r
  81     @Override\r
  82     public void removedFromContext(ICanvasContext ctx) {\r
  83         if (site != null && site.getSelectionProvider() == this) {\r
  84             swt.asyncExec(new Runnable() {\r
  85                 @Override\r
  86                 public void run() {\r
  87                     if (site.getSelectionProvider() == WorkbenchSelectionProvider.this)\r
  88                         site.setSelectionProvider(null);\r
  89                 }\r
  90             });\r
  91         }\r
  92         super.removedFromContext(ctx);\r
  93     }\r
  94 \r
  95     @HintListener(Class = Selection.class, Field = "SELECTION0")\r
  96     public void hintChanged(IHintObservable sender, Key key, Object oldValue, Object newValue) {\r
  97         Iterable<?> selection = (Iterable<?>) newValue;\r
  98         final ISelection s = constructAdaptableSelection(selection);\r
  99         swt.asyncExec(new Runnable() {\r
 100             @Override\r
 101             public void run() {\r
 102                 currentSelection = s;\r
 103                 fireSelectionChanged(s);\r
 104                 schedulePostSelectionChanged(s);\r
 105             }\r
 106         });\r
 107     }\r
 108 \r
 109     @HintListener(Class = Selection.class, Field = "SELECTION0")\r
 110     public void hintRemoved(IHintObservable sender, Key key, Object oldValue) {\r
 111         //System.out.println("selection removed: " + oldValue);\r
 112         final ISelection s = constructAdaptableSelection(Collections.emptyList());\r
 113         swt.asyncExec(new Runnable() {\r
 114             @Override\r
 115             public void run() {\r
 116                 currentSelection = s;\r
 117                 fireSelectionChanged(s);\r
 118                 schedulePostSelectionChanged(s);\r
 119             }\r
 120         });\r
 121     }\r
 122 \r
 123     // Post selection changed scheduling helper.\r
 124     private int modCount = 0;\r
 125 \r
 126     protected void schedulePostSelectionChanged(final ISelection s) {\r
 127         final int count = ++modCount;\r
 128         ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {\r
 129             @Override\r
 130             public void run() {\r
 131                 int newCount = modCount;\r
 132                 if (count != newCount)\r
 133                     return;\r
 134                 if (isRemoved())\r
 135                     return;\r
 136                 swt.asyncExec(new Runnable() {\r
 137                     @Override\r
 138                     public void run() {\r
 139                         if (isRemoved())\r
 140                             return;\r
 141                         firePostSelectionChanged(s);\r
 142                     }\r
 143                 });\r
 144             }\r
 145         }, POST_SELECTION_DELAY, TimeUnit.MILLISECONDS);\r
 146     }\r
 147 \r
 148     protected ISelection constructAdaptableSelection(Iterable<?> selection) {\r
 149         ArrayList<Object> objects = new ArrayList<Object>();\r
 150         for (Object o : selection) {\r
 151             if (o instanceof IElement) {\r
 152                 IElement e = (IElement) o;\r
 153                 Object object = e.getHint(ElementHints.KEY_OBJECT);\r
 154                 if (object != null) {\r
 155                     objects.add(new AdaptableImmutableProxyElement(e));\r
 156                 } else {\r
 157                     System.out.println("  discarding element from selection, null object for " + e);\r
 158                 }\r
 159             } else {\r
 160                 System.out.println("  unrecognized selection: " + o.getClass() + ": " + o);\r
 161             }\r
 162         }\r
 163         return new StructuredSelection(objects);\r
 164     }\r
 165 \r
 166     void fireSelectionChanged(ISelection selection) {\r
 167         SelectionChangedEvent e = new SelectionChangedEvent(this, selection);\r
 168         for (ISelectionChangedListener l : listeners)\r
 169             l.selectionChanged(e);\r
 170     }\r
 171 \r
 172     void firePostSelectionChanged(ISelection selection) {\r
 173         SelectionChangedEvent e = new SelectionChangedEvent(this, selection);\r
 174         for (ISelectionChangedListener l : postListeners)\r
 175             l.selectionChanged(e);\r
 176     }\r
 177 \r
 178     @Override\r
 179     public void addPostSelectionChangedListener(ISelectionChangedListener listener) {\r
 180         postListeners.add(listener);\r
 181     }\r
 182 \r
 183     @Override\r
 184     public void removePostSelectionChangedListener(ISelectionChangedListener listener) {\r
 185         postListeners.remove(listener);\r
 186     }\r
 187 \r
 188     @Override\r
 189     public void addSelectionChangedListener(ISelectionChangedListener listener) {\r
 190         listeners.add(listener);\r
 191     }\r
 192 \r
 193     @Override\r
 194     public void removeSelectionChangedListener(ISelectionChangedListener listener) {\r
 195         listeners.remove(listener);\r
 196     }\r
 197 \r
 198     @Override\r
 199     public ISelection getSelection() {\r
 200         return currentSelection;\r
 201     }\r
 202 \r
 203     @Override\r
 204     public void setSelection(ISelection selection) {\r
 205         System.out.println("WorkbenchSelectionProvider: TODO: set selection: " + selection);\r
 206     }\r
 207 \r
 208 }\r