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.Optional;\r
  17 import java.util.concurrent.CopyOnWriteArrayList;\r
  18 import java.util.concurrent.TimeUnit;\r
  19 \r
  20 import org.eclipse.jface.viewers.IPostSelectionProvider;\r
  21 import org.eclipse.jface.viewers.ISelection;\r
  22 import org.eclipse.jface.viewers.ISelectionChangedListener;\r
  23 import org.eclipse.jface.viewers.SelectionChangedEvent;\r
  24 import org.eclipse.jface.viewers.StructuredSelection;\r
  25 import org.eclipse.ui.IWorkbenchPartSite;\r
  26 import org.simantics.Logger;\r
  27 import org.simantics.db.exception.DatabaseException;\r
  28 import org.simantics.diagram.elements.AdaptableImmutableProxyElement;\r
  29 import org.simantics.g2d.canvas.ICanvasContext;\r
  30 import org.simantics.g2d.canvas.impl.AbstractCanvasParticipant;\r
  31 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;\r
  32 import org.simantics.g2d.canvas.impl.HintReflection.HintListener;\r
  33 import org.simantics.g2d.diagram.participant.ElementJSON;\r
  34 import org.simantics.g2d.diagram.participant.Selection;\r
  35 import org.simantics.g2d.element.ElementHints;\r
  36 import org.simantics.g2d.element.IElement;\r
  37 import org.simantics.ui.selection.WorkbenchSelectionUtils;\r
  38 import org.simantics.utils.datastructures.hints.IHintObservable;\r
  39 import org.simantics.utils.datastructures.hints.IHintContext.Key;\r
  40 import org.simantics.utils.threads.IThreadWorkQueue;\r
  41 import org.simantics.utils.threads.ThreadUtils;\r
  42 \r
  43 /**\r
  44  * A canvas participant that listens to the #0 mouse selection and provides it\r
  45  * forward through the {@link IPostSelectionProvider} interface.\r
  46  * \r
  47  * @author Tuukka Lehtonen\r
  48  */\r
  49 public class WorkbenchSelectionProvider extends AbstractCanvasParticipant implements IPostSelectionProvider, ElementJSON {\r
  50 \r
  51     private static final long                                 POST_SELECTION_DELAY = 300;\r
  52 \r
  53     @Dependency protected Selection selection;\r
  54 \r
  55     protected IThreadWorkQueue                                swt;\r
  56     protected IWorkbenchPartSite                              site;\r
  57     protected ISelection                                      currentSelection = StructuredSelection.EMPTY;\r
  58     protected CopyOnWriteArrayList<ISelectionChangedListener> listeners        = new CopyOnWriteArrayList<ISelectionChangedListener>();\r
  59     protected CopyOnWriteArrayList<ISelectionChangedListener> postListeners    = new CopyOnWriteArrayList<ISelectionChangedListener>();\r
  60 \r
  61     public WorkbenchSelectionProvider(IThreadWorkQueue swt) {\r
  62         this(swt, null);\r
  63     }\r
  64 \r
  65     public WorkbenchSelectionProvider(IThreadWorkQueue swt, IWorkbenchPartSite site) {\r
  66         this.swt = swt;\r
  67         this.site = site;\r
  68         if (site != null)\r
  69             site.setSelectionProvider(this);\r
  70     }\r
  71 \r
  72     @Override\r
  73     public void addedToContext(ICanvasContext ctx) {\r
  74         super.addedToContext(ctx);\r
  75         if (site != null && site.getSelectionProvider() != this) {\r
  76             swt.asyncExec(new Runnable() {\r
  77                 @Override\r
  78                 public void run() {\r
  79                     if (site.getSelectionProvider() != WorkbenchSelectionProvider.this)\r
  80                         site.setSelectionProvider(WorkbenchSelectionProvider.this);\r
  81                 }\r
  82             });\r
  83         }\r
  84     }\r
  85 \r
  86     @Override\r
  87     public void removedFromContext(ICanvasContext ctx) {\r
  88         if (site != null && site.getSelectionProvider() == this) {\r
  89             swt.asyncExec(new Runnable() {\r
  90                 @Override\r
  91                 public void run() {\r
  92                     if (site.getSelectionProvider() == WorkbenchSelectionProvider.this)\r
  93                         site.setSelectionProvider(null);\r
  94                 }\r
  95             });\r
  96         }\r
  97         super.removedFromContext(ctx);\r
  98     }\r
  99 \r
 100     @HintListener(Class = Selection.class, Field = "SELECTION0")\r
 101     public void hintChanged(IHintObservable sender, Key key, Object oldValue, Object newValue) {\r
 102         Iterable<?> selection = (Iterable<?>) newValue;\r
 103         final ISelection s = constructAdaptableSelection(selection);\r
 104         swt.asyncExec(new Runnable() {\r
 105             @Override\r
 106             public void run() {\r
 107                 currentSelection = s;\r
 108                 fireSelectionChanged(s);\r
 109                 schedulePostSelectionChanged(s);\r
 110             }\r
 111         });\r
 112     }\r
 113 \r
 114     @HintListener(Class = Selection.class, Field = "SELECTION0")\r
 115     public void hintRemoved(IHintObservable sender, Key key, Object oldValue) {\r
 116         //System.out.println("selection removed: " + oldValue);\r
 117         final ISelection s = constructAdaptableSelection(Collections.emptyList());\r
 118         swt.asyncExec(new Runnable() {\r
 119             @Override\r
 120             public void run() {\r
 121                 currentSelection = s;\r
 122                 fireSelectionChanged(s);\r
 123                 schedulePostSelectionChanged(s);\r
 124             }\r
 125         });\r
 126     }\r
 127 \r
 128     // Post selection changed scheduling helper.\r
 129     private int modCount = 0;\r
 130 \r
 131     protected void schedulePostSelectionChanged(final ISelection s) {\r
 132         final int count = ++modCount;\r
 133         ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {\r
 134             @Override\r
 135             public void run() {\r
 136                 int newCount = modCount;\r
 137                 if (count != newCount)\r
 138                     return;\r
 139                 if (isRemoved())\r
 140                     return;\r
 141                 swt.asyncExec(new Runnable() {\r
 142                     @Override\r
 143                     public void run() {\r
 144                         if (isRemoved())\r
 145                             return;\r
 146                         firePostSelectionChanged(s);\r
 147                     }\r
 148                 });\r
 149             }\r
 150         }, POST_SELECTION_DELAY, TimeUnit.MILLISECONDS);\r
 151     }\r
 152 \r
 153     protected ISelection constructAdaptableSelection(Iterable<?> selection) {\r
 154         ArrayList<Object> objects = new ArrayList<Object>();\r
 155         for (Object o : selection) {\r
 156             if (o instanceof IElement) {\r
 157                 IElement e = (IElement) o;\r
 158                 Object object = e.getHint(ElementHints.KEY_OBJECT);\r
 159                 if (object != null) {\r
 160                     objects.add(new AdaptableImmutableProxyElement(e));\r
 161                 } else {\r
 162                     System.out.println("  discarding element from selection, null object for " + e);\r
 163                 }\r
 164             } else {\r
 165                 System.out.println("  unrecognized selection: " + o.getClass() + ": " + o);\r
 166             }\r
 167         }\r
 168         return new StructuredSelection(objects);\r
 169     }\r
 170 \r
 171     void fireSelectionChanged(ISelection selection) {\r
 172         SelectionChangedEvent e = new SelectionChangedEvent(this, selection);\r
 173         for (ISelectionChangedListener l : listeners)\r
 174             l.selectionChanged(e);\r
 175     }\r
 176 \r
 177     void firePostSelectionChanged(ISelection selection) {\r
 178         SelectionChangedEvent e = new SelectionChangedEvent(this, selection);\r
 179         for (ISelectionChangedListener l : postListeners)\r
 180             l.selectionChanged(e);\r
 181     }\r
 182 \r
 183     @Override\r
 184     public void addPostSelectionChangedListener(ISelectionChangedListener listener) {\r
 185         postListeners.add(listener);\r
 186     }\r
 187 \r
 188     @Override\r
 189     public void removePostSelectionChangedListener(ISelectionChangedListener listener) {\r
 190         postListeners.remove(listener);\r
 191     }\r
 192 \r
 193     @Override\r
 194     public void addSelectionChangedListener(ISelectionChangedListener listener) {\r
 195         listeners.add(listener);\r
 196     }\r
 197 \r
 198     @Override\r
 199     public void removeSelectionChangedListener(ISelectionChangedListener listener) {\r
 200         listeners.remove(listener);\r
 201     }\r
 202 \r
 203     @Override\r
 204     public ISelection getSelection() {\r
 205         return currentSelection;\r
 206     }\r
 207 \r
 208     @Override\r
 209     public void setSelection(ISelection selection) {\r
 210         System.out.println("WorkbenchSelectionProvider: TODO: set selection: " + selection);\r
 211     }\r
 212 \r
 213     @Override\r
 214     public Optional<String> getJSON(IElement element) {\r
 215         ISelection sel = constructAdaptableSelection(Collections.singleton(element));\r
 216         try {\r
 217             return Optional.ofNullable( WorkbenchSelectionUtils.getPossibleJSON(sel) );\r
 218         } catch (DatabaseException e) {\r
 219             Logger.defaultLogError(e);\r
 220             return Optional.empty();\r
 221         }\r
 222     }\r
 223 \r
 224 }\r