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.db.exception.DatabaseException;\r
  27 import org.simantics.diagram.elements.AdaptableImmutableProxyElement;\r
  28 import org.simantics.g2d.canvas.ICanvasContext;\r
  29 import org.simantics.g2d.canvas.impl.AbstractCanvasParticipant;\r
  30 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;\r
  31 import org.simantics.g2d.canvas.impl.HintReflection.HintListener;\r
  32 import org.simantics.g2d.diagram.participant.ElementJSON;\r
  33 import org.simantics.g2d.diagram.participant.Selection;\r
  34 import org.simantics.g2d.element.ElementHints;\r
  35 import org.simantics.g2d.element.IElement;\r
  36 import org.simantics.ui.selection.WorkbenchSelectionUtils;\r
  37 import org.simantics.utils.datastructures.hints.IHintContext.Key;\r
  38 import org.simantics.utils.datastructures.hints.IHintObservable;\r
  39 import org.simantics.utils.threads.IThreadWorkQueue;\r
  40 import org.simantics.utils.threads.ThreadUtils;\r
  41 import org.slf4j.Logger;\r
  42 import org.slf4j.LoggerFactory;\r
  43 \r
  44 /**\r
  45  * A canvas participant that listens to the #0 mouse selection and provides it\r
  46  * forward through the {@link IPostSelectionProvider} interface.\r
  47  * \r
  48  * @author Tuukka Lehtonen\r
  49  */\r
  50 public class WorkbenchSelectionProvider extends AbstractCanvasParticipant implements IPostSelectionProvider, ElementJSON {\r
  51 \r
  52     private static final Logger LOGGER = LoggerFactory.getLogger(WorkbenchSelectionProvider.class);\r
  53 \r
  54     private static final long                                 POST_SELECTION_DELAY = 300;\r
  55 \r
  56     @Dependency protected Selection selection;\r
  57 \r
  58     protected IThreadWorkQueue                                swt;\r
  59     protected IWorkbenchPartSite                              site;\r
  60     protected ISelection                                      currentSelection = StructuredSelection.EMPTY;\r
  61     protected CopyOnWriteArrayList<ISelectionChangedListener> listeners        = new CopyOnWriteArrayList<ISelectionChangedListener>();\r
  62     protected CopyOnWriteArrayList<ISelectionChangedListener> postListeners    = new CopyOnWriteArrayList<ISelectionChangedListener>();\r
  63 \r
  64     public WorkbenchSelectionProvider(IThreadWorkQueue swt) {\r
  65         this(swt, null);\r
  66     }\r
  67 \r
  68     public WorkbenchSelectionProvider(IThreadWorkQueue swt, IWorkbenchPartSite site) {\r
  69         this.swt = swt;\r
  70         this.site = site;\r
  71         if (site != null)\r
  72             site.setSelectionProvider(this);\r
  73     }\r
  74 \r
  75     @Override\r
  76     public void addedToContext(ICanvasContext ctx) {\r
  77         super.addedToContext(ctx);\r
  78         if (site != null && site.getSelectionProvider() != this) {\r
  79             swt.asyncExec(new Runnable() {\r
  80                 @Override\r
  81                 public void run() {\r
  82                     if (site.getSelectionProvider() != WorkbenchSelectionProvider.this)\r
  83                         site.setSelectionProvider(WorkbenchSelectionProvider.this);\r
  84                 }\r
  85             });\r
  86         }\r
  87     }\r
  88 \r
  89     @Override\r
  90     public void removedFromContext(ICanvasContext ctx) {\r
  91         if (site != null && site.getSelectionProvider() == this) {\r
  92             swt.asyncExec(new Runnable() {\r
  93                 @Override\r
  94                 public void run() {\r
  95                     if (site.getSelectionProvider() == WorkbenchSelectionProvider.this)\r
  96                         site.setSelectionProvider(null);\r
  97                 }\r
  98             });\r
  99         }\r
 100         super.removedFromContext(ctx);\r
 101     }\r
 102 \r
 103     @HintListener(Class = Selection.class, Field = "SELECTION0")\r
 104     public void hintChanged(IHintObservable sender, Key key, Object oldValue, Object newValue) {\r
 105         Iterable<?> selection = (Iterable<?>) newValue;\r
 106         final ISelection s = constructAdaptableSelection(selection);\r
 107         swt.asyncExec(new Runnable() {\r
 108             @Override\r
 109             public void run() {\r
 110                 currentSelection = s;\r
 111                 fireSelectionChanged(s);\r
 112                 schedulePostSelectionChanged(s);\r
 113             }\r
 114         });\r
 115     }\r
 116 \r
 117     @HintListener(Class = Selection.class, Field = "SELECTION0")\r
 118     public void hintRemoved(IHintObservable sender, Key key, Object oldValue) {\r
 119         //System.out.println("selection removed: " + oldValue);\r
 120         final ISelection s = constructAdaptableSelection(Collections.emptyList());\r
 121         swt.asyncExec(new Runnable() {\r
 122             @Override\r
 123             public void run() {\r
 124                 currentSelection = s;\r
 125                 fireSelectionChanged(s);\r
 126                 schedulePostSelectionChanged(s);\r
 127             }\r
 128         });\r
 129     }\r
 130 \r
 131     // Post selection changed scheduling helper.\r
 132     private int modCount = 0;\r
 133 \r
 134     protected void schedulePostSelectionChanged(final ISelection s) {\r
 135         final int count = ++modCount;\r
 136         ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {\r
 137             @Override\r
 138             public void run() {\r
 139                 int newCount = modCount;\r
 140                 if (count != newCount)\r
 141                     return;\r
 142                 if (isRemoved())\r
 143                     return;\r
 144                 swt.asyncExec(new Runnable() {\r
 145                     @Override\r
 146                     public void run() {\r
 147                         if (isRemoved())\r
 148                             return;\r
 149                         firePostSelectionChanged(s);\r
 150                     }\r
 151                 });\r
 152             }\r
 153         }, POST_SELECTION_DELAY, TimeUnit.MILLISECONDS);\r
 154     }\r
 155 \r
 156     protected ISelection constructAdaptableSelection(Iterable<?> selection) {\r
 157         ArrayList<Object> objects = new ArrayList<Object>();\r
 158         for (Object o : selection) {\r
 159             if (o instanceof IElement) {\r
 160                 IElement e = (IElement) o;\r
 161                 Object object = e.getHint(ElementHints.KEY_OBJECT);\r
 162                 if (object != null) {\r
 163                     objects.add(new AdaptableImmutableProxyElement(e));\r
 164                 } else {\r
 165                     System.out.println("  discarding element from selection, null object for " + e);\r
 166                 }\r
 167             } else {\r
 168                 System.out.println("  unrecognized selection: " + o.getClass() + ": " + o);\r
 169             }\r
 170         }\r
 171         return new StructuredSelection(objects);\r
 172     }\r
 173 \r
 174     void fireSelectionChanged(ISelection selection) {\r
 175         SelectionChangedEvent e = new SelectionChangedEvent(this, selection);\r
 176         for (ISelectionChangedListener l : listeners)\r
 177             l.selectionChanged(e);\r
 178     }\r
 179 \r
 180     void firePostSelectionChanged(ISelection selection) {\r
 181         SelectionChangedEvent e = new SelectionChangedEvent(this, selection);\r
 182         for (ISelectionChangedListener l : postListeners)\r
 183             l.selectionChanged(e);\r
 184     }\r
 185 \r
 186     @Override\r
 187     public void addPostSelectionChangedListener(ISelectionChangedListener listener) {\r
 188         postListeners.add(listener);\r
 189     }\r
 190 \r
 191     @Override\r
 192     public void removePostSelectionChangedListener(ISelectionChangedListener listener) {\r
 193         postListeners.remove(listener);\r
 194     }\r
 195 \r
 196     @Override\r
 197     public void addSelectionChangedListener(ISelectionChangedListener listener) {\r
 198         listeners.add(listener);\r
 199     }\r
 200 \r
 201     @Override\r
 202     public void removeSelectionChangedListener(ISelectionChangedListener listener) {\r
 203         listeners.remove(listener);\r
 204     }\r
 205 \r
 206     @Override\r
 207     public ISelection getSelection() {\r
 208         return currentSelection;\r
 209     }\r
 210 \r
 211     @Override\r
 212     public void setSelection(ISelection selection) {\r
 213         System.out.println("WorkbenchSelectionProvider: TODO: set selection: " + selection);\r
 214     }\r
 215 \r
 216     @Override\r
 217     public Optional<String> getJSON(IElement element) {\r
 218         ISelection sel = constructAdaptableSelection(Collections.singleton(element));\r
 219         try {\r
 220             return Optional.ofNullable( WorkbenchSelectionUtils.getPossibleJSON(sel) );\r
 221         } catch (DatabaseException e) {\r
 222             LOGGER.error("Unexpected failure while constructing JSON from element " + element, e);\r
 223             return Optional.empty();\r
 224         }\r
 225     }\r
 226 \r
 227 }\r