bundles/org.simantics.browsing.ui.swt/src/org/simantics/browsing/ui/swt/GraphExplorerImpl.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2012 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 package org.simantics.browsing.ui.swt;
  13
  14 import java.util.ArrayList;
  15 import java.util.Arrays;
  16 import java.util.Collection;
  17 import java.util.Collections;
  18 import java.util.Deque;
  19 import java.util.HashMap;
  20 import java.util.HashSet;
  21 import java.util.Iterator;
  22 import java.util.LinkedList;
  23 import java.util.List;
  24 import java.util.Map;
  25 import java.util.Set;
  26 import java.util.WeakHashMap;
  27 import java.util.concurrent.CopyOnWriteArrayList;
  28 import java.util.concurrent.ExecutorService;
  29 import java.util.concurrent.Future;
  30 import java.util.concurrent.ScheduledExecutorService;
  31 import java.util.concurrent.TimeUnit;
  32 import java.util.concurrent.atomic.AtomicBoolean;
  33 import java.util.concurrent.atomic.AtomicReference;
  34 import java.util.function.BiFunction;
  35 import java.util.function.Consumer;
  36
  37 import org.eclipse.core.runtime.Assert;
  38 import org.eclipse.core.runtime.AssertionFailedException;
  39 import org.eclipse.core.runtime.IProgressMonitor;
  40 import org.eclipse.core.runtime.IStatus;
  41 import org.eclipse.core.runtime.MultiStatus;
  42 import org.eclipse.core.runtime.Status;
  43 import org.eclipse.core.runtime.jobs.Job;
  44 import org.eclipse.jface.action.IStatusLineManager;
  45 import org.eclipse.jface.resource.ColorDescriptor;
  46 import org.eclipse.jface.resource.DeviceResourceException;
  47 import org.eclipse.jface.resource.DeviceResourceManager;
  48 import org.eclipse.jface.resource.FontDescriptor;
  49 import org.eclipse.jface.resource.ImageDescriptor;
  50 import org.eclipse.jface.resource.JFaceResources;
  51 import org.eclipse.jface.resource.LocalResourceManager;
  52 import org.eclipse.jface.resource.ResourceManager;
  53 import org.eclipse.jface.viewers.IPostSelectionProvider;
  54 import org.eclipse.jface.viewers.ISelection;
  55 import org.eclipse.jface.viewers.ISelectionChangedListener;
  56 import org.eclipse.jface.viewers.ISelectionProvider;
  57 import org.eclipse.jface.viewers.IStructuredSelection;
  58 import org.eclipse.jface.viewers.SelectionChangedEvent;
  59 import org.eclipse.jface.viewers.StructuredSelection;
  60 import org.eclipse.jface.viewers.TreeSelection;
  61 import org.eclipse.swt.SWT;
  62 import org.eclipse.swt.SWTException;
  63 import org.eclipse.swt.custom.CCombo;
  64 import org.eclipse.swt.custom.TreeEditor;
  65 import org.eclipse.swt.events.FocusEvent;
  66 import org.eclipse.swt.events.FocusListener;
  67 import org.eclipse.swt.events.KeyEvent;
  68 import org.eclipse.swt.events.KeyListener;
  69 import org.eclipse.swt.events.MouseEvent;
  70 import org.eclipse.swt.events.MouseListener;
  71 import org.eclipse.swt.events.SelectionEvent;
  72 import org.eclipse.swt.events.SelectionListener;
  73 import org.eclipse.swt.graphics.Color;
  74 import org.eclipse.swt.graphics.Font;
  75 import org.eclipse.swt.graphics.GC;
  76 import org.eclipse.swt.graphics.Image;
  77 import org.eclipse.swt.graphics.Point;
  78 import org.eclipse.swt.graphics.RGB;
  79 import org.eclipse.swt.graphics.Rectangle;
  80 import org.eclipse.swt.widgets.Composite;
  81 import org.eclipse.swt.widgets.Control;
  82 import org.eclipse.swt.widgets.Display;
  83 import org.eclipse.swt.widgets.Event;
  84 import org.eclipse.swt.widgets.Listener;
  85 import org.eclipse.swt.widgets.ScrollBar;
  86 import org.eclipse.swt.widgets.Shell;
  87 import org.eclipse.swt.widgets.Text;
  88 import org.eclipse.swt.widgets.Tree;
  89 import org.eclipse.swt.widgets.TreeColumn;
  90 import org.eclipse.swt.widgets.TreeItem;
  91 import org.eclipse.ui.IWorkbenchPart;
  92 import org.eclipse.ui.IWorkbenchSite;
  93 import org.eclipse.ui.PlatformUI;
  94 import org.eclipse.ui.contexts.IContextActivation;
  95 import org.eclipse.ui.contexts.IContextService;
  96 import org.eclipse.ui.services.IServiceLocator;
  97 import org.eclipse.ui.swt.IFocusService;
  98 import org.simantics.browsing.ui.BuiltinKeys;
  99 import org.simantics.browsing.ui.CheckedState;
 100 import org.simantics.browsing.ui.Column;
 101 import org.simantics.browsing.ui.Column.Align;
 102 import org.simantics.browsing.ui.DataSource;
 103 import org.simantics.browsing.ui.ExplorerState;
 104 import org.simantics.browsing.ui.GraphExplorer;
 105 import org.simantics.browsing.ui.NodeContext;
 106 import org.simantics.browsing.ui.NodeContext.CacheKey;
 107 import org.simantics.browsing.ui.NodeContext.PrimitiveQueryKey;
 108 import org.simantics.browsing.ui.NodeContext.QueryKey;
 109 import org.simantics.browsing.ui.NodeContextPath;
 110 import org.simantics.browsing.ui.NodeQueryManager;
 111 import org.simantics.browsing.ui.NodeQueryProcessor;
 112 import org.simantics.browsing.ui.PrimitiveQueryProcessor;
 113 import org.simantics.browsing.ui.SelectionDataResolver;
 114 import org.simantics.browsing.ui.SelectionFilter;
 115 import org.simantics.browsing.ui.StatePersistor;
 116 import org.simantics.browsing.ui.common.AdaptableHintContext;
 117 import org.simantics.browsing.ui.common.ColumnKeys;
 118 import org.simantics.browsing.ui.common.ErrorLogger;
 119 import org.simantics.browsing.ui.common.NodeContextBuilder;
 120 import org.simantics.browsing.ui.common.NodeContextUtil;
 121 import org.simantics.browsing.ui.common.internal.GECache;
 122 import org.simantics.browsing.ui.common.internal.GENodeQueryManager;
 123 import org.simantics.browsing.ui.common.internal.IGECache;
 124 import org.simantics.browsing.ui.common.internal.IGraphExplorerContext;
 125 import org.simantics.browsing.ui.common.internal.UIElementReference;
 126 import org.simantics.browsing.ui.common.processors.DefaultCheckedStateProcessor;
 127 import org.simantics.browsing.ui.common.processors.DefaultComparableChildrenProcessor;
 128 import org.simantics.browsing.ui.common.processors.DefaultFinalChildrenProcessor;
 129 import org.simantics.browsing.ui.common.processors.DefaultImageDecoratorProcessor;
 130 import org.simantics.browsing.ui.common.processors.DefaultImagerFactoriesProcessor;
 131 import org.simantics.browsing.ui.common.processors.DefaultImagerProcessor;
 132 import org.simantics.browsing.ui.common.processors.DefaultLabelDecoratorProcessor;
 133 import org.simantics.browsing.ui.common.processors.DefaultLabelerFactoriesProcessor;
 134 import org.simantics.browsing.ui.common.processors.DefaultLabelerProcessor;
 135 import org.simantics.browsing.ui.common.processors.DefaultPrunedChildrenProcessor;
 136 import org.simantics.browsing.ui.common.processors.DefaultSelectedImageDecoratorFactoriesProcessor;
 137 import org.simantics.browsing.ui.common.processors.DefaultSelectedLabelDecoratorFactoriesProcessor;
 138 import org.simantics.browsing.ui.common.processors.DefaultSelectedLabelerProcessor;
 139 import org.simantics.browsing.ui.common.processors.DefaultSelectedViewpointFactoryProcessor;
 140 import org.simantics.browsing.ui.common.processors.DefaultSelectedViewpointProcessor;
 141 import org.simantics.browsing.ui.common.processors.DefaultViewpointContributionProcessor;
 142 import org.simantics.browsing.ui.common.processors.DefaultViewpointContributionsProcessor;
 143 import org.simantics.browsing.ui.common.processors.DefaultViewpointProcessor;
 144 import org.simantics.browsing.ui.common.processors.IsExpandedProcessor;
 145 import org.simantics.browsing.ui.common.processors.NoSelectionRequestProcessor;
 146 import org.simantics.browsing.ui.common.processors.ProcessorLifecycle;
 147 import org.simantics.browsing.ui.common.state.ExplorerStates;
 148 import org.simantics.browsing.ui.content.ImageDecorator;
 149 import org.simantics.browsing.ui.content.Imager;
 150 import org.simantics.browsing.ui.content.LabelDecorator;
 151 import org.simantics.browsing.ui.content.Labeler;
 152 import org.simantics.browsing.ui.content.Labeler.CustomModifier;
 153 import org.simantics.browsing.ui.content.Labeler.DeniedModifier;
 154 import org.simantics.browsing.ui.content.Labeler.DialogModifier;
 155 import org.simantics.browsing.ui.content.Labeler.EnumerationModifier;
 156 import org.simantics.browsing.ui.content.Labeler.FilteringModifier;
 157 import org.simantics.browsing.ui.content.Labeler.LabelerListener;
 158 import org.simantics.browsing.ui.content.Labeler.Modifier;
 159 import org.simantics.browsing.ui.content.PrunedChildrenResult;
 160 import org.simantics.browsing.ui.model.nodetypes.EntityNodeType;
 161 import org.simantics.browsing.ui.model.nodetypes.NodeType;
 162 import org.simantics.browsing.ui.swt.internal.Threads;
 163 import org.simantics.db.layer0.SelectionHints;
 164 import org.simantics.utils.ObjectUtils;
 165 import org.simantics.utils.datastructures.BijectionMap;
 166 import org.simantics.utils.datastructures.disposable.AbstractDisposable;
 167 import org.simantics.utils.datastructures.hints.IHintContext;
 168 import org.simantics.utils.threads.IThreadWorkQueue;
 169 import org.simantics.utils.threads.SWTThread;
 170 import org.simantics.utils.threads.ThreadUtils;
 171 import org.simantics.utils.ui.ISelectionUtils;
 172 import org.simantics.utils.ui.SWTUtils;
 173 import org.simantics.utils.ui.jface.BasePostSelectionProvider;
 174 import org.simantics.utils.ui.widgets.VetoingEventHandler;
 175 import org.simantics.utils.ui.workbench.WorkbenchUtils;
 176
 177 import gnu.trove.map.hash.THashMap;
 178 import gnu.trove.procedure.TObjectProcedure;
 179 import gnu.trove.set.hash.THashSet;
 180
 181 /**
 182  * @see #getMaxChildren()
 183  * @see #setMaxChildren(int)
 184  * @see #getMaxChildren(NodeQueryManager, NodeContext)
 185  */
 186 class GraphExplorerImpl extends GraphExplorerImplBase implements Listener, GraphExplorer /*, IPostSelectionProvider*/ {
 187
 188         private static class GraphExplorerPostSelectionProvider implements IPostSelectionProvider {
 189
 190                 private GraphExplorerImpl ge;
 191
 192                 GraphExplorerPostSelectionProvider(GraphExplorerImpl ge) {
 193                         this.ge = ge;
 194                 }
 195
 196                 void dispose() {
 197                         ge = null;
 198                 }
 199
 200             @Override
 201             public void setSelection(final ISelection selection) {
 202                 if(ge == null) return;
 203                 ge.setSelection(selection, false);
 204             }
 205
 206
 207             @Override
 208             public void removeSelectionChangedListener(ISelectionChangedListener listener) {
 209                 if(ge == null) return;
 210                 if(ge.isDisposed()) {
 211                     if (DEBUG_SELECTION_LISTENERS)
 212                         System.out.println("GraphExplorerImpl is disposed in removeSelectionChangedListener: " + listener);
 213                     return;
 214                 }
 215                 //assertNotDisposed();
 216                 //System.out.println("Remove selection changed listener: " + listener);
 217                 ge.selectionProvider.removeSelectionChangedListener(listener);
 218             }
 219
 220             @Override
 221             public void addPostSelectionChangedListener(ISelectionChangedListener listener) {
 222                 if(ge == null) return;
 223                 if (!ge.thread.currentThreadAccess())
 224                     throw new AssertionError(getClass().getSimpleName() + ".addPostSelectionChangedListener called from non SWT-thread: " + Thread.currentThread());
 225                 if(ge.isDisposed()) {
 226                     System.out.println("Client BUG: GraphExplorerImpl is disposed in addPostSelectionChangedListener: " + listener);
 227                     return;
 228                 }
 229                 //System.out.println("Add POST selection changed listener: " + listener);
 230                 ge.selectionProvider.addPostSelectionChangedListener(listener);
 231             }
 232
 233             @Override
 234             public void removePostSelectionChangedListener(ISelectionChangedListener listener) {
 235                 if(ge == null) return;
 236                 if(ge.isDisposed()) {
 237                     if (DEBUG_SELECTION_LISTENERS)
 238                         System.out.println("GraphExplorerImpl is disposed in removePostSelectionChangedListener: " + listener);
 239                     return;
 240                 }
 241 //              assertNotDisposed();
 242                 //System.out.println("Remove POST selection changed listener: " + listener);
 243                 ge.selectionProvider.removePostSelectionChangedListener(listener);
 244             }
 245
 246
 247             @Override
 248             public void addSelectionChangedListener(ISelectionChangedListener listener) {
 249                 if(ge == null) return;
 250                 if (!ge.thread.currentThreadAccess())
 251                     throw new AssertionError(getClass().getSimpleName() + ".addSelectionChangedListener called from non SWT-thread: " + Thread.currentThread());
 252                 //System.out.println("Add selection changed listener: " + listener);
 253                 if (ge.tree.isDisposed() || ge.selectionProvider == null) {
 254                     System.out.println("Client BUG: GraphExplorerImpl is disposed in addSelectionChangedListener: " + listener);
 255                     return;
 256                 }
 257
 258                 ge.selectionProvider.addSelectionChangedListener(listener);
 259             }
 260
 261
 262             @Override
 263             public ISelection getSelection() {
 264                 if(ge == null) return StructuredSelection.EMPTY;
 265                 if (!ge.thread.currentThreadAccess())
 266                     throw new AssertionError(getClass().getSimpleName() + ".getSelection called from non SWT-thread: " + Thread.currentThread());
 267                 if (ge.tree.isDisposed() || ge.selectionProvider == null)
 268                     return StructuredSelection.EMPTY;
 269                 return ge.selectionProvider.getSelection();
 270             }
 271
 272         }
 273
 274     /**
 275      * If this explorer is running with an Eclipse workbench open, this
 276      * Workbench UI context will be activated whenever inline editing is started
 277      * through {@link #startEditing(TreeItem, int)} and deactivated when inline
 278      * editing finishes.
 279      *
 280      * This context information can be used to for UI handler activity testing.
 281      */
 282     private static final String INLINE_EDITING_UI_CONTEXT = "org.simantics.browsing.ui.inlineEditing";
 283
 284     private static final String KEY_DRAG_COLUMN = "dragColumn";
 285
 286     private static final boolean                   DEBUG_SELECTION_LISTENERS = false;
 287
 288     private static final int                       DEFAULT_CONSECUTIVE_LABEL_REFRESH_DELAY = 200;
 289
 290     public static final int                        DEFAULT_MAX_CHILDREN                    = 1000;
 291
 292     private static final long                      POST_SELECTION_DELAY                    = 300;
 293
 294     /**
 295      * The time in milliseconds that must elapse between consecutive
 296      * {@link Tree} {@link SelectionListener#widgetSelected(SelectionEvent)}
 297      * invocations in order for this class to construct a new selection.
 298      *
 299      * <p>
 300      * This is done because selection construction can be very expensive as the
 301      * selected set grows larger when the user is pressing shift+arrow keys.
 302      * GraphExplorerImpl will naturally listen to all changes in the tree
 303      * selection, but as an optimization will not construct new
 304      * StructuredSelection instances for every selection change event. A new
 305      * selection will be constructed and set only if the selection hasn't
 306      * changed for the amount of milliseconds specified by this constant.
 307      */
 308     private static final long                      SELECTION_CHANGE_QUIET_TIME             = 150;
 309
 310     private final IThreadWorkQueue                 thread;
 311
 312     /**
 313      * Local method for checking from whether resources are loaded in
 314      * JFaceResources.
 315      */
 316     private final LocalResourceManager             localResourceManager;
 317
 318     /**
 319      * Local device resource manager that is safe to use in
 320      * {@link ImageLoaderJob} for creating images in a non-UI thread.
 321      */
 322     private final ResourceManager                  resourceManager;
 323
 324     /*
 325      * Package visibility.
 326      * TODO: Get rid of these.
 327      */
 328     Tree                                           tree;
 329
 330     @SuppressWarnings({ "rawtypes" })
 331     final HashMap<CacheKey<?>, NodeQueryProcessor> processors            = new HashMap<CacheKey<?>, NodeQueryProcessor>();
 332     @SuppressWarnings({ "rawtypes" })
 333     final HashMap<Object, PrimitiveQueryProcessor> primitiveProcessors   = new HashMap<Object, PrimitiveQueryProcessor>();
 334     @SuppressWarnings({ "rawtypes" })
 335     final HashMap<Class, DataSource>               dataSources           = new HashMap<Class, DataSource>();
 336
 337     class GraphExplorerContext extends AbstractDisposable implements IGraphExplorerContext {
 338         // This is for query debugging only.
 339         int                  queryIndent   = 0;
 340
 341         GECache              cache         = new GECache();
 342         AtomicBoolean        propagating   = new AtomicBoolean(false);
 343         Object               propagateList = new Object();
 344         Object               propagate     = new Object();
 345         List<Runnable>       scheduleList  = new ArrayList<Runnable>();
 346         final Deque<Integer> activity      = new LinkedList<Integer>();
 347         int                  activityInt   = 0;
 348
 349         /**
 350          * Stores the currently running query update runnable. If
 351          * <code>null</code> there's nothing scheduled yet in which case
 352          * scheduling can commence. Otherwise the update should be skipped.
 353          */
 354         AtomicReference<Runnable> currentQueryUpdater = new AtomicReference<Runnable>();
 355
 356         /**
 357          * Keeps track of nodes that have already been auto-expanded. After
 358          * being inserted into this set, nodes will not be forced to stay in an
 359          * expanded state after that. This makes it possible for the user to
 360          * close auto-expanded nodes.
 361          */
 362         Map<NodeContext, Boolean>     autoExpanded  = new WeakHashMap<NodeContext, Boolean>();
 363
 364
 365         @Override
 366         protected void doDispose() {
 367                 saveState();
 368             autoExpanded.clear();
 369         }
 370
 371         @Override
 372         public IGECache getCache() {
 373             return cache;
 374         }
 375
 376         @Override
 377         public int queryIndent() {
 378             return queryIndent;
 379         }
 380
 381         @Override
 382         public int queryIndent(int offset) {
 383             queryIndent += offset;
 384             return queryIndent;
 385         }
 386
 387         @Override
 388         @SuppressWarnings("unchecked")
 389         public <T> NodeQueryProcessor<T> getProcessor(Object o) {
 390             return processors.get(o);
 391         }
 392
 393         @Override
 394         @SuppressWarnings("unchecked")
 395         public <T> PrimitiveQueryProcessor<T> getPrimitiveProcessor(Object o) {
 396             return primitiveProcessors.get(o);
 397         }
 398
 399         @SuppressWarnings("unchecked")
 400         @Override
 401         public <T> DataSource<T> getDataSource(Class<T> clazz) {
 402             return dataSources.get(clazz);
 403         }
 404
 405         @Override
 406         public void update(UIElementReference ref) {
 407             //System.out.println("GE.update " + ref);
 408             TreeItemReference tiref = (TreeItemReference) ref;
 409             TreeItem item = tiref.getItem();
 410             // NOTE: must be called regardless of the the item value.
 411             // A null item is currently used to indicate a tree root update.
 412             GraphExplorerImpl.this.update(item);
 413         }
 414
 415         @Override
 416         public Object getPropagateLock() {
 417             return propagate;
 418         }
 419
 420         @Override
 421         public Object getPropagateListLock() {
 422             return propagateList;
 423         }
 424
 425         @Override
 426         public boolean isPropagating() {
 427             return propagating.get();
 428         }
 429
 430         @Override
 431         public void setPropagating(boolean b) {
 432             this.propagating.set(b);
 433         }
 434
 435         @Override
 436         public List<Runnable> getScheduleList() {
 437             return scheduleList;
 438         }
 439
 440         @Override
 441         public void setScheduleList(List<Runnable> list) {
 442             this.scheduleList = list;
 443         }
 444
 445         @Override
 446         public Deque<Integer> getActivity() {
 447             return activity;
 448         }
 449
 450         @Override
 451         public void setActivityInt(int i) {
 452             this.activityInt = i;
 453         }
 454
 455         @Override
 456         public int getActivityInt() {
 457             return activityInt;
 458         }
 459
 460         @Override
 461         public void scheduleQueryUpdate(Runnable r) {
 462             if (GraphExplorerImpl.this.isDisposed() || queryUpdateScheduler.isShutdown())
 463                 return;
 464             //System.out.println("Scheduling query update for runnable " + r);
 465             if (currentQueryUpdater.compareAndSet(null, r)) {
 466                 //System.out.println("Scheduling query update for runnable " + r);
 467                 queryUpdateScheduler.execute(QUERY_UPDATE_SCHEDULER);
 468             }
 469         }
 470
 471         Runnable QUERY_UPDATE_SCHEDULER = new Runnable() {
 472             @Override
 473             public void run() {
 474                 Runnable r = currentQueryUpdater.getAndSet(null);
 475                 if (r != null) {
 476                     //System.out.println("Running query update runnable " + r);
 477                     r.run();
 478                 }
 479             }
 480         };
 481     }
 482
 483     GraphExplorerContext                         explorerContext     = new GraphExplorerContext();
 484
 485     HashSet<TreeItem>                            pendingItems        = new HashSet<TreeItem>();
 486     boolean                                      updating            = false;
 487     boolean                                      pendingRoot         = false;
 488
 489     @SuppressWarnings("deprecation")
 490     ModificationContext                          modificationContext = null;
 491
 492     NodeContext                                  rootContext;
 493
 494     StatePersistor                               persistor           = null;
 495
 496     boolean                                      editable            = true;
 497
 498     /**
 499      * This is a reverse mapping from {@link NodeContext} tree objects back to
 500      * their owner TreeItems.
 501      *
 502      * <p>
 503      * Access this map only in the SWT thread to keep it thread-safe.
 504      * </p>
 505      */
 506     BijectionMap<NodeContext, TreeItem>         contextToItem     = new BijectionMap<NodeContext, TreeItem>();
 507
 508     /**
 509      * Columns of the UI viewer. Use {@link #setColumns(Column[])} to
 510      * initialize.
 511      */
 512     Column[]                                     columns           = new Column[0];
 513     Map<String, Integer>                         columnKeyToIndex  = new HashMap<String, Integer>();
 514     boolean                                      refreshingColumnSizes = false;
 515     boolean                                      columnsAreVisible = true;
 516
 517     /**
 518      * An array reused for invoking {@link TreeItem#setImage(Image[])} instead
 519      * of constantly allocating new arrays for setting each TreeItems images.
 520      * This works because {@link TreeItem#setImage(Image[])} does not take hold
 521      * of the array itself, only the contents of the array.
 522      *
 523      * @see #setImage(NodeContext, TreeItem, Imager, Collection, int)
 524      */
 525     Image[]                                      columnImageArray = { null };
 526
 527     /**
 528      * Used for collecting Image or ImageDescriptor instances for a single
 529      * TreeItem when initially setting images for a TreeItem.
 530      *
 531      * @see #setImage(NodeContext, TreeItem, Imager, Collection, int)
 532      */
 533     Object[]                                     columnDescOrImageArray = { null };
 534
 535     final ExecutorService                        queryUpdateScheduler = Threads.getExecutor();
 536     final ScheduledExecutorService               uiUpdateScheduler    = ThreadUtils.getNonBlockingWorkExecutor();
 537
 538     /** Set to true when the Tree widget is disposed. */
 539     private boolean                              disposed                 = false;
 540     private final CopyOnWriteArrayList<FocusListener>  focusListeners           = new CopyOnWriteArrayList<FocusListener>();
 541     private final CopyOnWriteArrayList<MouseListener>  mouseListeners           = new CopyOnWriteArrayList<MouseListener>();
 542     private final CopyOnWriteArrayList<KeyListener>    keyListeners             = new CopyOnWriteArrayList<KeyListener>();
 543
 544     /** Selection provider */
 545     private   GraphExplorerPostSelectionProvider postSelectionProvider = new GraphExplorerPostSelectionProvider(this);
 546     protected BasePostSelectionProvider          selectionProvider        = new BasePostSelectionProvider();
 547     protected SelectionDataResolver              selectionDataResolver;
 548     protected SelectionFilter                    selectionFilter;
 549     protected BiFunction<GraphExplorer, Object[], Object[]> selectionTransformation = new BiFunction<GraphExplorer, Object[], Object[]>() {
 550
 551         @Override
 552         public Object[] apply(GraphExplorer explorer, Object[] objects) {
 553             Object[] result = new Object[objects.length];
 554             for (int i = 0; i < objects.length; i++) {
 555                 IHintContext context = new AdaptableHintContext(SelectionHints.KEY_MAIN);
 556                 context.setHint(SelectionHints.KEY_MAIN, objects[i]);
 557                 result[i] = context;
 558             }
 559             return result;
 560         }
 561
 562     };
 563     protected FontDescriptor                     originalFont;
 564     protected ColorDescriptor                    originalForeground;
 565     protected ColorDescriptor                    originalBackground;
 566
 567     /**
 568      * The set of currently selected TreeItem instances. This set is needed
 569      * because we need to know in {@link #setData(Event)} whether the updated
 570      * item was a part of the current selection in which case the selection must
 571      * be updated.
 572      */
 573     private final Map<TreeItem, NodeContext>     selectedItems            = new HashMap<TreeItem, NodeContext>();
 574
 575     /**
 576      * TODO: specify what this is for
 577      */
 578     private final Set<NodeContext>               selectionRefreshContexts = new HashSet<NodeContext>();
 579
 580     /**
 581      * If this field is non-null, it means that if {@link #setData(Event)}
 582      * encounters a NodeContext equal to this one, it must make the TreeItem
 583      * assigned to that NodeContext the topmost item of the tree using
 584      * {@link Tree#setTopItem(TreeItem)}. After this the field value is
 585      * nullified.
 586      *
 587      * <p>
 588      * This is related to {@link #initializeState()}, i.e. explorer state
 589      * restoration.
 590      */
 591 //    private NodeContext[] topNodePath = NodeContext.NONE;
 592 //    private int[] topNodePath = {};
 593 //    private int currentTopNodePathIndex = -1;
 594
 595     /**
 596      * See {@link #setAutoExpandLevel(int)}
 597      */
 598     private int autoExpandLevel = 0;
 599
 600     /**
 601      * <code>null</code> if not explicitly set through
 602      * {@link #setServiceLocator(IServiceLocator)}.
 603      */
 604     private IServiceLocator serviceLocator;
 605
 606     /**
 607      * The global workbench context service, if the workbench is available.
 608      * Retrieved in the constructor.
 609      */
 610     private IContextService contextService = null;
 611
 612     /**
 613      * The global workbench IFocusService, if the workbench is available.
 614      * Retrieved in the constructor.
 615      */
 616     private IFocusService focusService = null;
 617
 618     /**
 619      * A Workbench UI context activation that is activated when starting inline
 620      * editing through {@link #startEditing(TreeItem, int)}.
 621      *
 622      * @see #activateEditingContext()
 623      * @see #deactivateEditingContext()
 624      */
 625     private IContextActivation editingContext = null;
 626
 627     static class ImageTask {
 628         NodeContext node;
 629         TreeItem item;
 630         Object[] descsOrImages;
 631         public ImageTask(NodeContext node, TreeItem item, Object[] descsOrImages) {
 632             this.node = node;
 633             this.item = item;
 634             this.descsOrImages = descsOrImages;
 635         }
 636     }
 637
 638     /**
 639      * The job that is used for off-loading image loading tasks (see
 640      * {@link ImageTask} to a worker thread from the main UI thread.
 641      *
 642      * @see #setPendingImages(IProgressMonitor)
 643      */
 644     ImageLoaderJob           imageLoaderJob;
 645
 646     /**
 647      * The set of currently gathered up image loading tasks for
 648      * {@link #imageLoaderJob} to execute.
 649      *
 650      * @see #setPendingImages(IProgressMonitor)
 651      */
 652     Map<TreeItem, ImageTask> imageTasks     = new THashMap<TreeItem, ImageTask>();
 653
 654     /**
 655      * A state flag indicating whether the vertical scroll bar was visible for
 656      * {@link #tree} the last time it was checked. Since there is no listener
 657      * that can provide this information, we check it in {@link #setData(Event)}
 658      * every time any data for a TreeItem is updated. If the visibility changes,
 659      * we will force re-layouting of the tree's parent composite.
 660      *
 661      * @see #setData(Event)
 662      */
 663     private boolean verticalBarVisible = false;
 664
 665     static class TransientStateImpl implements TransientExplorerState {
 666
 667         private Integer activeColumn = null;
 668
 669                 @Override
 670                 public synchronized Integer getActiveColumn() {
 671                         return activeColumn;
 672                 }
 673
 674                 public synchronized void setActiveColumn(Integer column) {
 675                         activeColumn = column;
 676                 }
 677
 678     }
 679
 680     private TransientStateImpl transientState = new TransientStateImpl();
 681
 682     boolean scheduleUpdater() {
 683
 684         if (tree.isDisposed())
 685             return false;
 686
 687         if (pendingRoot == true || !pendingItems.isEmpty()) {
 688             assert(!tree.isDisposed());
 689
 690             int activity = explorerContext.activityInt;
 691             long delay = 30;
 692             if (activity < 100) {
 693 //                System.out.println("Scheduling update immediately.");
 694             } else if (activity < 1000) {
 695 //                System.out.println("Scheduling update after 500ms.");
 696                 delay = 500;
 697             } else {
 698 //                System.out.println("Scheduling update after 3000ms.");
 699                 delay = 3000;
 700             }
 701
 702             updateCounter = 0;
 703
 704             //System.out.println("Scheduling UI update after " + delay + " ms.");
 705             uiUpdateScheduler.schedule(new Runnable() {
 706                 @Override
 707                 public void run() {
 708
 709                     if (tree.isDisposed())
 710                         return;
 711
 712                     if (updateCounter > 0) {
 713                         updateCounter = 0;
 714                         uiUpdateScheduler.schedule(this, 50, TimeUnit.MILLISECONDS);
 715                     } else {
 716                         tree.getDisplay().asyncExec(new UpdateRunner(GraphExplorerImpl.this, GraphExplorerImpl.this.explorerContext));
 717                     }
 718
 719                 }
 720             }, delay, TimeUnit.MILLISECONDS);
 721
 722             updating = true;
 723             return true;
 724         }
 725
 726         return false;
 727     }
 728
 729     int updateCounter = 0;
 730
 731     void update(TreeItem item) {
 732
 733         synchronized(pendingItems) {
 734
 735 //              System.out.println("update " + item);
 736
 737                 updateCounter++;
 738
 739             if(item == null) pendingRoot = true;
 740             else pendingItems.add(item);
 741
 742             if(updating == true) return;
 743
 744             scheduleUpdater();
 745
 746         }
 747
 748     }
 749
 750     private int maxChildren = DEFAULT_MAX_CHILDREN;
 751
 752     @Override
 753     public int getMaxChildren() {
 754         return maxChildren;
 755     }
 756
 757     @Override
 758     public int getMaxChildren(NodeQueryManager manager, NodeContext context) {
 759         Integer result = manager.query(context, BuiltinKeys.SHOW_MAX_CHILDREN);
 760         //System.out.println("getMaxChildren(" + manager + ", " + context + "): " + result);
 761         if (result != null) {
 762             if (result < 0)
 763                 throw new AssertionError("BuiltinKeys.SHOW_MAX_CHILDREN query must never return < 0, got " + result);
 764             return result;
 765         }
 766         return maxChildren;
 767     }
 768
 769     @Override
 770     public void setMaxChildren(int maxChildren) {
 771         this.maxChildren = maxChildren;
 772     }
 773
 774     @Override
 775     public void setModificationContext(@SuppressWarnings("deprecation") ModificationContext modificationContext) {
 776         this.modificationContext = modificationContext;
 777     }
 778
 779     /**
 780      * @param parent the parent SWT composite
 781      */
 782     public GraphExplorerImpl(Composite parent) {
 783         this(parent, SWT.BORDER | SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
 784     }
 785
 786     /**
 787      * Stores the node context and the modifier that is currently being
 788      * modified. These are used internally to prevent duplicate edits from being
 789      * initiated which should always be a sensible thing to do.
 790      */
 791     private Set<NodeContext> currentlyModifiedNodes   = new THashSet<NodeContext>();
 792
 793     private final TreeEditor editor;
 794     private Color            invalidModificationColor = null;
 795
 796     /**
 797      * @param item the TreeItem to start editing
 798      * @param columnIndex the index of the column to edit, starts counting from
 799      *        0
 800      * @return <code>true</code> if the editing was initiated successfully or
 801      *         <code>false</code> if editing could not be started due to lack of
 802      *         {@link Modifier} for the labeler in question.
 803      */
 804     private String startEditing(final TreeItem item, final int columnIndex, String columnKey) {
 805         if (!editable)
 806             return "Rename not supported for selection";
 807
 808         GENodeQueryManager manager = new GENodeQueryManager(this.explorerContext, null, null, TreeItemReference.create(item.getParentItem()));
 809         final NodeContext context = (NodeContext) item.getData();
 810         Labeler labeler = manager.query(context, BuiltinKeys.SELECTED_LABELER);
 811         if (labeler == null)
 812             return "Rename not supported for selection";
 813
 814         if(columnKey == null) columnKey = columns[columnIndex].getKey();
 815
 816         // columnKey might be prefixed with '#' to indicate
 817         // textual editing is preferred. Try to get modifier
 818         // for that first and only if it fails, try without
 819         // the '#' prefix.
 820         Modifier modifier = labeler.getModifier(modificationContext, columnKey);
 821         if (modifier == null) {
 822             if(columnKey.startsWith("#"))
 823                 modifier = labeler.getModifier(modificationContext, columnKey.substring(1));
 824             if (modifier == null)
 825                 return "Rename not supported for selection";
 826         }
 827         if (modifier instanceof DeniedModifier) {
 828                 DeniedModifier dm = (DeniedModifier)modifier;
 829                 return dm.getMessage();
 830         }
 831
 832         // Prevent editing of a single node context multiple times.
 833         if (currentlyModifiedNodes.contains(context)) {
 834             //System.out.println("discarding duplicate edit for context " + context);
 835             return "Rename not supported for selection";
 836         }
 837
 838         // Clean up any previous editor control
 839         Control oldEditor = editor.getEditor();
 840         if (oldEditor != null)
 841             oldEditor.dispose();
 842
 843         if (modifier instanceof DialogModifier) {
 844             performDialogEditing(item, columnIndex, context, (DialogModifier) modifier);
 845         } else if (modifier instanceof CustomModifier) {
 846             startCustomEditing(item, columnIndex, context, (CustomModifier) modifier);
 847         } else if (modifier instanceof EnumerationModifier) {
 848             startEnumerationEditing(item, columnIndex, context, (EnumerationModifier) modifier);
 849         } else {
 850             startTextEditing(item, columnIndex, context, modifier);
 851         }
 852
 853         return null;
 854     }
 855
 856     /**
 857      * @param item
 858      * @param columnIndex
 859      * @param context
 860      * @param modifier
 861      */
 862     void performDialogEditing(final TreeItem item, final int columnIndex, final NodeContext context,
 863             final DialogModifier modifier) {
 864         final AtomicBoolean disposed = new AtomicBoolean(false);
 865         Consumer<String> callback = result -> {
 866             if (disposed.get())
 867                 return;
 868             String error = modifier.isValid(result);
 869             if (error == null) {
 870                 modifier.modify(result);
 871                 // Item may be disposed if the tree gets reset after a previous editing.
 872                 if (!item.isDisposed()) {
 873                     item.setText(columnIndex, result);
 874                     queueSelectionRefresh(context);
 875                 }
 876             }
 877         };
 878
 879         currentlyModifiedNodes.add(context);
 880         try {
 881             String status = modifier.query(tree, item, columnIndex, context, callback);
 882             if (status != null)
 883                 ErrorLogger.defaultLog( new Status(IStatus.INFO, Activator.PLUGIN_ID, status) );
 884         } finally {
 885             currentlyModifiedNodes.remove(context);
 886             disposed.set(true);
 887         }
 888     }
 889
 890     private void reconfigureTreeEditor(TreeItem item, int columnIndex, Control control, int widthHint, int heightHint, int insetX, int insetY) {
 891         Point size = control.computeSize(widthHint, heightHint);
 892         editor.horizontalAlignment = SWT.LEFT;
 893         Rectangle itemRect = item.getBounds(columnIndex),
 894                   rect = tree.getClientArea();
 895         editor.minimumWidth = Math.max(size.x, itemRect.width) + insetX * 2;
 896         int left = itemRect.x,
 897             right = rect.x + rect.width;
 898         editor.minimumWidth = Math.min(editor.minimumWidth, right - left);
 899         editor.minimumHeight = size.y + insetY * 2;
 900         editor.layout();
 901     }
 902
 903     void reconfigureTreeEditorForText(TreeItem item, int columnIndex, Control control, String text, int heightHint, int insetX, int insetY) {
 904         GC gc = new GC(control);
 905         Point size = gc.textExtent(text);
 906         gc.dispose();
 907         reconfigureTreeEditor(item, columnIndex, control, size.x, SWT.DEFAULT, insetX, insetY);
 908     }
 909
 910     /**
 911      * @param item
 912      * @param columnIndex
 913      * @param context
 914      * @param modifier
 915      */
 916     void startCustomEditing(final TreeItem item, final int columnIndex, final NodeContext context,
 917             final CustomModifier modifier) {
 918         final Object obj = modifier.createControl(tree, item, columnIndex, context);
 919         if (!(obj instanceof Control))
 920             throw new UnsupportedOperationException("SWT control required, got " + obj + " from CustomModifier.createControl(Object)");
 921         final Control control = (Control) obj;
 922
 923 //        final int insetX = 0;
 924 //        final int insetY = 0;
 925 //        control.addListener(SWT.Resize, new Listener() {
 926 //            @Override
 927 //            public void handleEvent(Event e) {
 928 //                Rectangle rect = control.getBounds();
 929 //                control.setBounds(rect.x + insetX, rect.y + insetY, rect.width - insetX * 2, rect.height - insetY * 2);
 930 //            }
 931 //        });
 932         control.addListener(SWT.Dispose, new Listener() {
 933             @Override
 934             public void handleEvent(Event event) {
 935                 currentlyModifiedNodes.remove(context);
 936                 queueSelectionRefresh(context);
 937                 deactivateEditingContext();
 938             }
 939         });
 940
 941         if (!(control instanceof Shell)) {
 942             editor.setEditor(control, item, columnIndex);
 943         }
 944
 945
 946         control.setFocus();
 947
 948         GraphExplorerImpl.this.reconfigureTreeEditor(item, columnIndex, control, SWT.DEFAULT, SWT.DEFAULT, 0, 0);
 949
 950         activateEditingContext(control);
 951
 952         // Removed in disposeListener above
 953         currentlyModifiedNodes.add(context);
 954         //System.out.println("START CUSTOM EDITING: " + item);
 955     }
 956
 957     /**
 958      * @param item
 959      * @param columnIndex
 960      * @param context
 961      * @param modifier
 962      */
 963     void startEnumerationEditing(final TreeItem item, final int columnIndex, final NodeContext context, final EnumerationModifier modifier) {
 964         String initialText = modifier.getValue();
 965         if (initialText == null)
 966             throw new AssertionError("Labeler.Modifier.getValue() returned null");
 967
 968         List<String> values = modifier.getValues();
 969         String selectedValue = modifier.getValue();
 970         int selectedIndex = values.indexOf(selectedValue);
 971         if (selectedIndex == -1)
 972             throw new AssertionFailedException(modifier + " EnumerationModifier.getValue returned '" + selectedValue + "' which is not among the possible values returned by EnumerationModifier.getValues(): " + values);
 973
 974         final CCombo combo = new CCombo(tree, SWT.FLAT | SWT.BORDER | SWT.READ_ONLY | SWT.DROP_DOWN);
 975         combo.setVisibleItemCount(10);
 976         //combo.setEditable(false);
 977
 978         for (String value : values) {
 979             combo.add(value);
 980         }
 981         combo.select(selectedIndex);
 982
 983         Listener comboListener = new Listener() {
 984             boolean arrowTraverseUsed = false;
 985             @Override
 986             public void handleEvent(final Event e) {
 987                 //System.out.println("FOO: " + e);
 988                 switch (e.type) {
 989                     case SWT.KeyDown:
 990                         if (e.character == SWT.CR) {
 991                             // Commit edit directly on ENTER press.
 992                             String text = combo.getText();
 993                             modifier.modify(text);
 994                             // Item may be disposed if the tree gets reset after a previous editing.
 995                             if (!item.isDisposed()) {
 996                                 item.setText(columnIndex, text);
 997                                 queueSelectionRefresh(context);
 998                             }
 999                             combo.dispose();
1000                             e.doit = false;
1001                         } else if (e.keyCode == SWT.ESC) {
1002                             // Cancel editing immediately
1003                             combo.dispose();
1004                             e.doit = false;
1005                         }
1006                         break;
1007                     case SWT.Selection:
1008                     {
1009                         if (arrowTraverseUsed) {
1010                             arrowTraverseUsed = false;
1011                             return;
1012                         }
1013
1014                         String text = combo.getText();
1015                         modifier.modify(text);
1016
1017                         // Item may be disposed if the tree gets reset after a previous editing.
1018                         if (!item.isDisposed()) {
1019                             item.setText(columnIndex, text);
1020                             queueSelectionRefresh(context);
1021                         }
1022                         combo.dispose();
1023                         break;
1024                     }
1025                     case SWT.FocusOut: {
1026                         String text = combo.getText();
1027                         modifier.modify(text);
1028
1029                         // Item may be disposed if the tree gets reset after a previous editing.
1030                         if (!item.isDisposed()) {
1031                             item.setText(columnIndex, text);
1032                             queueSelectionRefresh(context);
1033                         }
1034                         combo.dispose();
1035                         break;
1036                     }
1037                     case SWT.Traverse: {
1038                         switch (e.detail) {
1039                             case SWT.TRAVERSE_RETURN:
1040                                 String text = combo.getText();
1041                                 modifier.modify(text);
1042                                 if (!item.isDisposed()) {
1043                                     item.setText(columnIndex, text);
1044                                     queueSelectionRefresh(context);
1045                                 }
1046                                 arrowTraverseUsed = false;
1047                                 // FALL THROUGH
1048                             case SWT.TRAVERSE_ESCAPE:
1049                                 combo.dispose();
1050                                 e.doit = false;
1051                                 break;
1052                             case SWT.TRAVERSE_ARROW_NEXT:
1053                             case SWT.TRAVERSE_ARROW_PREVIOUS:
1054                                 arrowTraverseUsed = true;
1055                                 break;
1056                             default:
1057                                 //System.out.println("unhandled traversal: " + e.detail);
1058                                 break;
1059                         }
1060                         break;
1061                     }
1062                     case SWT.Dispose:
1063                         currentlyModifiedNodes.remove(context);
1064                         deactivateEditingContext();
1065                         break;
1066                 }
1067             }
1068         };
1069         combo.addListener(SWT.MouseWheel, VetoingEventHandler.INSTANCE);
1070         combo.addListener(SWT.KeyDown, comboListener);
1071         combo.addListener(SWT.FocusOut, comboListener);
1072         combo.addListener(SWT.Traverse, comboListener);
1073         combo.addListener(SWT.Selection, comboListener);
1074         combo.addListener(SWT.Dispose, comboListener);
1075
1076         editor.setEditor(combo, item, columnIndex);
1077
1078         combo.setFocus();
1079         combo.setListVisible(true);
1080
1081         GraphExplorerImpl.this.reconfigureTreeEditorForText(item, columnIndex, combo, combo.getText(), SWT.DEFAULT, 0, 0);
1082
1083         activateEditingContext(combo);
1084
1085         // Removed in comboListener
1086         currentlyModifiedNodes.add(context);
1087
1088         //System.out.println("START ENUMERATION EDITING: " + item);
1089     }
1090
1091     /**
1092      * @param item
1093      * @param columnIndex
1094      * @param context
1095      * @param modifier
1096      */
1097     void startTextEditing(final TreeItem item, final int columnIndex, final NodeContext context, final Modifier modifier) {
1098         String initialText = modifier.getValue();
1099         if (initialText == null)
1100             throw new AssertionError("Labeler.Modifier.getValue() returned null, modifier=" + modifier);
1101
1102         final Composite composite = new Composite(tree, SWT.NONE);
1103         //composite.setBackground(composite.getDisplay().getSystemColor(SWT.COLOR_RED));
1104         final Text text = new Text(composite, SWT.BORDER);
1105         final int insetX = 0;
1106         final int insetY = 0;
1107         composite.addListener(SWT.Resize, new Listener() {
1108             @Override
1109             public void handleEvent(Event e) {
1110                 Rectangle rect = composite.getClientArea();
1111                 text.setBounds(rect.x + insetX, rect.y + insetY, rect.width - insetX * 2, rect.height
1112                         - insetY * 2);
1113             }
1114         });
1115         final FilteringModifier filter = modifier instanceof FilteringModifier ? (FilteringModifier) modifier : null;
1116         Listener textListener = new Listener() {
1117
1118                 boolean modified = false;
1119
1120             @Override
1121             public void handleEvent(final Event e) {
1122                 String error;
1123                 String newText;
1124                 switch (e.type) {
1125                     case SWT.FocusOut:
1126                         if(modified) {
1127                                 //System.out.println("FOCUS OUT " + item);
1128                                 newText = text.getText();
1129                                 error = modifier.isValid(newText);
1130                                 if (error == null) {
1131                                         modifier.modify(newText);
1132
1133                                         // Item may be disposed if the tree gets reset after a previous editing.
1134                                         if (!item.isDisposed()) {
1135                                                 item.setText(columnIndex, newText);
1136                                                 queueSelectionRefresh(context);
1137                                         }
1138                                 } else {
1139                                         //                                System.out.println("validation error: " + error);
1140                                 }
1141                         }
1142                         composite.dispose();
1143                         break;
1144                     case SWT.Modify:
1145                         newText = text.getText();
1146                         error = modifier.isValid(newText);
1147                         if (error != null) {
1148                             text.setBackground(invalidModificationColor);
1149                             errorStatus(error);
1150                             //System.out.println("validation error: " + error);
1151                         } else {
1152                             text.setBackground(null);
1153                             errorStatus(null);
1154                         }
1155                         modified = true;
1156                         break;
1157                     case SWT.Verify:
1158
1159                         // Safety check since it seems that this may happen with
1160                         // virtual trees.
1161                         if (item.isDisposed())
1162                             return;
1163
1164                         // Filter input if necessary
1165                         e.text = filter != null ? filter.filter(e.text) : e.text;
1166
1167                         newText = text.getText();
1168                         String leftText = newText.substring(0, e.start);
1169                         String rightText = newText.substring(e.end, newText.length());
1170                         GraphExplorerImpl.this.reconfigureTreeEditorForText(
1171                                 item, columnIndex, text, leftText + e.text + rightText,
1172                                 SWT.DEFAULT, insetX, insetY);
1173                         break;
1174                     case SWT.Traverse:
1175                         switch (e.detail) {
1176                             case SWT.TRAVERSE_RETURN:
1177                                 if(modified) {
1178                                         newText = text.getText();
1179                                         error = modifier.isValid(newText);
1180                                         if (error == null) {
1181                                                 modifier.modify(newText);
1182                                                 if (!item.isDisposed()) {
1183                                                         item.setText(columnIndex, newText);
1184                                                         queueSelectionRefresh(context);
1185                                                 }
1186                                         }
1187                                 }
1188                                 // FALL THROUGH
1189                             case SWT.TRAVERSE_ESCAPE:
1190                                 composite.dispose();
1191                                 e.doit = false;
1192                                 break;
1193                             default:
1194                                 //System.out.println("unhandled traversal: " + e.detail);
1195                                 break;
1196                         }
1197                         break;
1198
1199                     case SWT.Dispose:
1200                         currentlyModifiedNodes.remove(context);
1201                         deactivateEditingContext();
1202                         errorStatus(null);
1203                         break;
1204                 }
1205             }
1206         };
1207         // Set the initial text before registering a listener. We do not want immediate modification!
1208         text.setText(initialText);
1209         text.addListener(SWT.FocusOut, textListener);
1210         text.addListener(SWT.Traverse, textListener);
1211         text.addListener(SWT.Verify, textListener);
1212         text.addListener(SWT.Modify, textListener);
1213         text.addListener(SWT.Dispose, textListener);
1214         editor.setEditor(composite, item, columnIndex);
1215         text.selectAll();
1216         text.setFocus();
1217
1218         // Initialize TreeEditor properly.
1219         GraphExplorerImpl.this.reconfigureTreeEditorForText(
1220                 item, columnIndex, text, initialText,
1221                 SWT.DEFAULT, insetX, insetY);
1222
1223         // Removed in textListener
1224         currentlyModifiedNodes.add(context);
1225
1226         activateEditingContext(text);
1227
1228         //System.out.println("START TEXT EDITING: " + item);
1229     }
1230
1231     protected void errorStatus(String error) {
1232         IStatusLineManager status = getStatusLineManager();
1233         if (status != null) {
1234             status.setErrorMessage(error);
1235         }
1236     }
1237
1238     protected IStatusLineManager getStatusLineManager() {
1239         if (serviceLocator instanceof IWorkbenchPart) {
1240             return WorkbenchUtils.getStatusLine((IWorkbenchPart) serviceLocator);
1241         } else if (serviceLocator instanceof IWorkbenchSite) {
1242             return WorkbenchUtils.getStatusLine((IWorkbenchSite) serviceLocator);
1243         }
1244         return null;
1245     }
1246
1247     protected void activateEditingContext(Control control) {
1248         if (contextService != null) {
1249             editingContext = contextService.activateContext(INLINE_EDITING_UI_CONTEXT);
1250         }
1251         if (control != null && focusService != null) {
1252             focusService.addFocusTracker(control, INLINE_EDITING_UI_CONTEXT);
1253             // No need to remove the control, it will be
1254             // removed automatically when it is disposed.
1255         }
1256     }
1257
1258     protected void deactivateEditingContext() {
1259         IContextActivation a = editingContext;
1260         if (a != null) {
1261             editingContext = null;
1262             contextService.deactivateContext(a);
1263         }
1264     }
1265
1266     /**
1267      * @param forContext
1268      */
1269     void queueSelectionRefresh(NodeContext forContext) {
1270         selectionRefreshContexts.add(forContext);
1271     }
1272
1273     @Override
1274     public String startEditing(NodeContext context, String columnKey_) {
1275         assertNotDisposed();
1276         if (!thread.currentThreadAccess())
1277             throw new IllegalStateException("not in SWT display thread " + thread.getThread());
1278
1279         String columnKey = columnKey_;
1280         if(columnKey.startsWith("#")) {
1281                 columnKey = columnKey.substring(1);
1282         }
1283
1284         Integer columnIndex = columnKeyToIndex.get(columnKey);
1285         if (columnIndex == null)
1286             return "Rename not supported for selection";
1287
1288         TreeItem item = contextToItem.getRight(context);
1289         if (item == null)
1290             return "Rename not supported for selection";
1291
1292         return startEditing(item, columnIndex, columnKey_);
1293
1294     }
1295
1296     @Override
1297     public String startEditing(String columnKey) {
1298
1299         ISelection selection = postSelectionProvider.getSelection();
1300         if(selection == null) return "Rename not supported for selection";
1301         NodeContext context = ISelectionUtils.filterSingleSelection(selection, NodeContext.class);
1302         if(context == null) return "Rename not supported for selection";
1303
1304         return startEditing(context, columnKey);
1305
1306     }
1307
1308     /**
1309      * @param site <code>null</code> if the explorer is detached from the workbench
1310      * @param parent the parent SWT composite
1311      * @param style the tree style to use, check the see tags for the available flags
1312      *
1313      * @see SWT#SINGLE
1314      * @see SWT#MULTI
1315      * @see SWT#CHECK
1316      * @see SWT#FULL_SELECTION
1317      * @see SWT#NO_SCROLL
1318      * @see SWT#H_SCROLL
1319      * @see SWT#V_SCROLL
1320      */
1321     public GraphExplorerImpl(Composite parent, int style) {
1322
1323         setServiceLocator(null);
1324
1325         this.localResourceManager = new LocalResourceManager(JFaceResources.getResources());
1326         this.resourceManager = new DeviceResourceManager(parent.getDisplay());
1327
1328         this.imageLoaderJob = new ImageLoaderJob(this);
1329         this.imageLoaderJob.setPriority(Job.DECORATE);
1330
1331         invalidModificationColor = (Color) localResourceManager.get( ColorDescriptor.createFrom( new RGB(255, 128, 128) ) );
1332
1333         this.thread = SWTThread.getThreadAccess(parent);
1334
1335         for(int i=0;i<10;i++) explorerContext.activity.push(0);
1336
1337         tree = new Tree(parent, style);
1338         tree.addListener(SWT.SetData, this);
1339         tree.addListener(SWT.Expand, this);
1340         tree.addListener(SWT.Dispose, this);
1341         tree.addListener(SWT.Activate, this);
1342
1343         tree.setData(KEY_GRAPH_EXPLORER, this);
1344
1345         // These are both required for performing column resizing without flicker.
1346         // See SWT.Resize event handling in #handleEvent() for more explanations.
1347         parent.addListener(SWT.Resize, this);
1348         tree.addListener(SWT.Resize, this);
1349
1350         originalFont = JFaceResources.getDefaultFontDescriptor();
1351 //        originalBackground = JFaceResources.getColorRegistry().get(symbolicName);
1352 //        originalForeground = tree.getForeground();
1353
1354         tree.setFont((Font) localResourceManager.get(originalFont));
1355
1356         columns = new Column[] { new Column(ColumnKeys.SINGLE) };
1357         columnKeyToIndex = Collections.singletonMap(ColumnKeys.SINGLE, 0);
1358
1359         editor = new TreeEditor(tree);
1360         editor.horizontalAlignment = SWT.LEFT;
1361         editor.grabHorizontal = true;
1362         editor.minimumWidth = 50;
1363
1364         setBasicListeners();
1365         setDefaultProcessors();
1366
1367         this.toolTip = new GraphExplorerToolTip(explorerContext, tree);
1368     }
1369
1370     @Override
1371     public IThreadWorkQueue getThread() {
1372         return thread;
1373     }
1374
1375     TreeItem previousSingleSelection = null;
1376     long focusGainedAt = Long.MIN_VALUE;
1377
1378     protected GraphExplorerToolTip toolTip;
1379
1380     protected void setBasicListeners() {
1381         // Keep track of the previous single selection to help
1382         // decide whether to start editing a tree node on mouse
1383         // downs or not.
1384         tree.addListener(SWT.Selection, new Listener() {
1385             @Override
1386             public void handleEvent(Event event) {
1387                 TreeItem[] selection = tree.getSelection();
1388                 if (selection.length == 1) {
1389                     //for (TreeItem item : selection)
1390                     //    System.out.println("selection: " + item);
1391                     previousSingleSelection = selection[0];
1392                 } else {
1393                     previousSingleSelection = null;
1394                 }
1395             }
1396         });
1397
1398         // Try to start editing of tree column when clicked for the second time.
1399         Listener mouseEditListener = new Listener() {
1400
1401             Future<?> startEdit = null;
1402
1403             @Override
1404             public void handleEvent(Event event) {
1405                 if (event.type == SWT.DragDetect) {
1406                     // Needed to prevent editing from being started when in fact
1407                     // the user starts dragging an item.
1408                     //System.out.println("DRAG DETECT: " + event);
1409                     cancelEdit();
1410                     return;
1411                 }
1412                 //System.out.println("mouse down: " + event);
1413                 if (event.button == 1) {
1414                     // Always ignore the first mouse button press that focuses
1415                     // the control. Do not let it start in-line editing since
1416                     // that is very annoying to users and not how the UI's that
1417                     // people are used to behave.
1418                     long eventTime = ((long) event.time) & 0xFFFFFFFFL;
1419                     if ((eventTime - focusGainedAt) < 250L) {
1420                         //System.out.println("ignore mouse down " + focusGainedAt + ", " + eventTime + " = " + (eventTime-focusGainedAt));
1421                         return;
1422                     }
1423                     //System.out.println("testing whether to start editing");
1424
1425                     final Point point = new Point(event.x, event.y);
1426                     final TreeItem item = tree.getItem(point);
1427                     if (item == null)
1428                         return;
1429                     //System.out.println("mouse down @ " + point + ": " + item + ", previous item: " + previousSingleSelection);
1430
1431                     // Only start editing if the item was already selected.
1432                     if (!item.equals(previousSingleSelection)) {
1433                         cancelEdit();
1434                         return;
1435                     }
1436
1437                     if (tree.getColumnCount() > 1) {
1438                         // TODO: reconsider this logic, might not be good in general.
1439                         for (int i = 0; i < tree.getColumnCount(); i++) {
1440                             if (item.getBounds(i).contains(point)) {
1441                                 tryScheduleEdit(event, item, point, 100, i);
1442                                 return;
1443                             }
1444                         }
1445                     } else {
1446                         //System.out.println("clicks: " + event.count);
1447                         if (item.getBounds().contains(point)) {
1448                             if (event.count == 1) {
1449                                 tryScheduleEdit(event, item, point, 500, 0);
1450                             } else {
1451                                 cancelEdit();
1452                             }
1453                         }
1454                     }
1455                 }
1456             }
1457
1458             void tryScheduleEdit(Event event, final TreeItem item, Point point, long delayMs, final int column) {
1459                 //System.out.println("\tCONTAINS: " + item);
1460                 if (!cancelEdit())
1461                     return;
1462
1463                 //System.out.println("\tScheduling edit: " + item);
1464                 startEdit = ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {
1465                     @Override
1466                     public void run() {
1467                         ThreadUtils.asyncExec(thread, new Runnable() {
1468                             @Override
1469                             public void run() {
1470                                 if (item.isDisposed())
1471                                     return;
1472                                 startEditing(item, column, null);
1473                             }
1474                         });
1475                     }
1476                 }, delayMs, TimeUnit.MILLISECONDS);
1477             }
1478
1479             boolean cancelEdit() {
1480                 Future<?> f = startEdit;
1481                 if (f != null) {
1482                     // Try to cancel the start edit task if it's not running yet.
1483                     startEdit = null;
1484                     if (!f.isDone()) {
1485                         boolean ret = f.cancel(false);
1486                         //System.out.println("\tCancelled edit: " + ret);
1487                         return ret;
1488                     }
1489                 }
1490                 //System.out.println("\tNo edit in progress to cancel");
1491                 return true;
1492             }
1493         };
1494         tree.addListener(SWT.MouseDown, mouseEditListener);
1495         tree.addListener(SWT.DragDetect, mouseEditListener);
1496         tree.addListener(SWT.DragDetect, new Listener() {
1497             @Override
1498             public void handleEvent(Event event) {
1499                 Point test = new Point(event.x, event.y);
1500                 TreeItem item = tree.getItem(test);
1501                 if(item != null) {
1502                     for(int i=0;i<tree.getColumnCount();i++) {
1503                         Rectangle rect = item.getBounds(i);
1504                         if(rect.contains(test)) {
1505                             tree.setData(KEY_DRAG_COLUMN, i);
1506                             return;
1507                         }
1508                     }
1509                 }
1510                 tree.setData(KEY_DRAG_COLUMN, -1);
1511             }
1512         });
1513         tree.addListener(SWT.MouseMove, new Listener() {
1514             @Override
1515             public void handleEvent(Event event) {
1516                 Point test = new Point(event.x, event.y);
1517                 TreeItem item = tree.getItem(test);
1518                 if(item != null) {
1519                     for(int i=0;i<tree.getColumnCount();i++) {
1520                         Rectangle rect = item.getBounds(i);
1521                         if(rect.contains(test)) {
1522                                 transientState.setActiveColumn(i);
1523                             return;
1524                         }
1525                     }
1526                 }
1527                 transientState.setActiveColumn(null);
1528             }
1529         });
1530
1531         // Add focus/mouse/key listeners for supporting the respective
1532         // add/remove listener methods in IGraphExplorer.
1533         tree.addFocusListener(new FocusListener() {
1534             @Override
1535             public void focusGained(FocusEvent e) {
1536                 focusGainedAt = ((long) e.time) & 0xFFFFFFFFL;
1537                 for (FocusListener listener : focusListeners)
1538                     listener.focusGained(e);
1539             }
1540             @Override
1541             public void focusLost(FocusEvent e) {
1542                 for (FocusListener listener : focusListeners)
1543                     listener.focusLost(e);
1544             }
1545         });
1546         tree.addMouseListener(new MouseListener() {
1547             @Override
1548             public void mouseDoubleClick(MouseEvent e) {
1549                 for (MouseListener listener : mouseListeners) {
1550                     listener.mouseDoubleClick(e);
1551                 }
1552             }
1553             @Override
1554             public void mouseDown(MouseEvent e) {
1555                 for (MouseListener listener : mouseListeners) {
1556                     listener.mouseDown(e);
1557                 }
1558             }
1559             @Override
1560             public void mouseUp(MouseEvent e) {
1561                 for (MouseListener listener : mouseListeners) {
1562                     listener.mouseUp(e);
1563                 }
1564             }
1565         });
1566         tree.addKeyListener(new KeyListener() {
1567             @Override
1568             public void keyPressed(KeyEvent e) {
1569                 for (KeyListener listener : keyListeners) {
1570                     listener.keyPressed(e);
1571                 }
1572             }
1573             @Override
1574             public void keyReleased(KeyEvent e) {
1575                 for (KeyListener listener : keyListeners) {
1576                     listener.keyReleased(e);
1577                 }
1578             }
1579         });
1580
1581                 // Add a tree selection listener for keeping the selection of
1582                 // GraphExplorer's ISelectionProvider up-to-date.
1583         tree.addSelectionListener(new SelectionListener() {
1584             @Override
1585             public void widgetDefaultSelected(SelectionEvent e) {
1586                 widgetSelected(e);
1587             }
1588             @Override
1589             public void widgetSelected(SelectionEvent e) {
1590                 widgetSelectionChanged(false);
1591             }
1592         });
1593
1594         // This listener takes care of updating the set of currently selected
1595         // TreeItem instances. This set is needed because we need to know in
1596         // #setData(Event) whether the updated item was a part of the current
1597         // selection in which case the selection must be updated.
1598         selectionProvider.addSelectionChangedListener(new ISelectionChangedListener() {
1599             @Override
1600             public void selectionChanged(SelectionChangedEvent event) {
1601                 //System.out.println("selection changed: " + event.getSelection());
1602                 Set<NodeContext> set = ISelectionUtils.filterSetSelection(event.getSelection(), NodeContext.class);
1603                 selectedItems.clear();
1604                 for (NodeContext nc : set) {
1605                     TreeItem item = contextToItem.getRight(nc);
1606                     if (item != null)
1607                         selectedItems.put(item, nc);
1608                 }
1609                 //System.out.println("newly selected items: " + selectedItems);
1610             }
1611         });
1612     }
1613
1614     /**
1615      * Mod count for delaying post selection changed events.
1616      */
1617     int postSelectionModCount = 0;
1618
1619     /**
1620      * Last tree selection modification time for implementing a quiet
1621      * time for selection changes.
1622      */
1623     long lastSelectionModTime = System.currentTimeMillis() - 10000;
1624
1625     /**
1626      * Current target time for the selection to be set. Calculated
1627      * according to the set quiet time and last selection modification
1628      * time.
1629      */
1630     long selectionSetTargetTime = 0;
1631
1632     /**
1633      * <code>true</code> if delayed selection runnable is current scheduled or
1634      * running.
1635      */
1636     boolean delayedSelectionScheduled = false;
1637
1638     Runnable SELECTION_DELAY = new Runnable() {
1639         @Override
1640         public void run() {
1641             if (tree.isDisposed())
1642                 return;
1643             long now = System.currentTimeMillis();
1644             long waitTimeLeft = selectionSetTargetTime - now;
1645             if (waitTimeLeft > 0) {
1646                 // Not enough quiet time, reschedule.
1647                 delayedSelectionScheduled = true;
1648                 tree.getDisplay().timerExec((int) waitTimeLeft, this);
1649             } else {
1650                 // Time to perform selection, stop rescheduling.
1651                 delayedSelectionScheduled = false;
1652                 resetSelection();
1653             }
1654         }
1655     };
1656
1657     private void widgetSelectionChanged(boolean forceSelectionChange) {
1658         long modTime = System.currentTimeMillis();
1659         long delta = modTime - lastSelectionModTime;
1660         lastSelectionModTime = modTime;
1661         if (!forceSelectionChange && delta < SELECTION_CHANGE_QUIET_TIME) {
1662             long msToWait = SELECTION_CHANGE_QUIET_TIME - delta;
1663             selectionSetTargetTime = modTime + msToWait;
1664             if (!delayedSelectionScheduled) {
1665                 delayedSelectionScheduled = true;
1666                 tree.getDisplay().timerExec((int) msToWait, SELECTION_DELAY);
1667             }
1668             // Make sure that post selection change events do not fire.
1669             ++postSelectionModCount;
1670             return;
1671         }
1672
1673         // Immediate selection reconstruction.
1674         resetSelection();
1675     }
1676
1677     private void resetSelection() {
1678         final ISelection selection = getWidgetSelection();
1679
1680         //System.out.println("resetSelection(" + postSelectionModCount + ")");
1681         //System.out.println("    provider selection: " + selectionProvider.getSelection());
1682         //System.out.println("    widget selection:   " + selection);
1683
1684         selectionProvider.setAndFireNonEqualSelection(selection);
1685
1686         // Implement deferred firing of post selection events
1687         final int count = ++postSelectionModCount;
1688         //System.out.println("[" + System.currentTimeMillis() + "] scheduling postSelectionChanged " + count + ": " + selection);
1689         ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {
1690             @Override
1691             public void run() {
1692                 int newCount = postSelectionModCount;
1693                 // Don't publish selection yet, there's another change incoming.
1694                 //System.out.println("[" + System.currentTimeMillis() + "] checking post selection publish: " + count + " vs. " + newCount + ": " + selection);
1695                 if (newCount != count)
1696                     return;
1697                 //System.out.println("[" + System.currentTimeMillis() + "] " + count + " count equals, firing post selection listeners: " + selection);
1698
1699                 if (tree.isDisposed())
1700                     return;
1701
1702                 //System.out.println("scheduling fire post selection changed: " + selection);
1703                 tree.getDisplay().asyncExec(new Runnable() {
1704                     @Override
1705                     public void run() {
1706                         if (tree.isDisposed() || selectionProvider == null)
1707                             return;
1708                         //System.out.println("firing post selection changed: " + selection);
1709                         selectionProvider.firePostSelection(selection);
1710                     }
1711                 });
1712             }
1713         }, POST_SELECTION_DELAY, TimeUnit.MILLISECONDS);
1714     }
1715
1716     protected void setDefaultProcessors() {
1717         // Add a simple IMAGER query processor that always returns null.
1718         // With this processor no images will ever be shown.
1719 //        setPrimitiveProcessor(new StaticImagerProcessor(null));
1720
1721         setProcessor(new DefaultComparableChildrenProcessor());
1722         setProcessor(new DefaultLabelDecoratorsProcessor());
1723         setProcessor(new DefaultImageDecoratorsProcessor());
1724         setProcessor(new DefaultSelectedLabelerProcessor());
1725         setProcessor(new DefaultLabelerFactoriesProcessor());
1726         setProcessor(new DefaultSelectedImagerProcessor());
1727         setProcessor(new DefaultImagerFactoriesProcessor());
1728         setPrimitiveProcessor(new DefaultLabelerProcessor());
1729         setPrimitiveProcessor(new DefaultCheckedStateProcessor());
1730         setPrimitiveProcessor(new DefaultImagerProcessor());
1731         setPrimitiveProcessor(new DefaultLabelDecoratorProcessor());
1732         setPrimitiveProcessor(new DefaultImageDecoratorProcessor());
1733         setPrimitiveProcessor(new NoSelectionRequestProcessor());
1734
1735         setProcessor(new DefaultFinalChildrenProcessor(this));
1736
1737         setProcessor(new DefaultPrunedChildrenProcessor());
1738         setProcessor(new DefaultSelectedViewpointProcessor());
1739         setProcessor(new DefaultSelectedLabelDecoratorFactoriesProcessor());
1740         setProcessor(new DefaultSelectedImageDecoratorFactoriesProcessor());
1741         setProcessor(new DefaultViewpointContributionsProcessor());
1742
1743         setPrimitiveProcessor(new DefaultViewpointProcessor());
1744         setPrimitiveProcessor(new DefaultViewpointContributionProcessor());
1745         setPrimitiveProcessor(new DefaultSelectedViewpointFactoryProcessor());
1746         setPrimitiveProcessor(new DefaultIsExpandedProcessor());
1747         setPrimitiveProcessor(new DefaultShowMaxChildrenProcessor());
1748     }
1749
1750     @Override
1751     public <T> void setProcessor(NodeQueryProcessor<T> processor) {
1752         assertNotDisposed();
1753         if (processor == null)
1754             throw new IllegalArgumentException("null processor");
1755
1756         processors.put(processor.getIdentifier(), processor);
1757     }
1758
1759     @Override
1760     public <T> void setPrimitiveProcessor(PrimitiveQueryProcessor<T> processor) {
1761         assertNotDisposed();
1762         if (processor == null)
1763             throw new IllegalArgumentException("null processor");
1764
1765         PrimitiveQueryProcessor<?> oldProcessor = primitiveProcessors.put(processor.getIdentifier(), processor);
1766
1767         if (oldProcessor instanceof ProcessorLifecycle)
1768             ((ProcessorLifecycle) oldProcessor).detached(this);
1769         if (processor instanceof ProcessorLifecycle)
1770             ((ProcessorLifecycle) processor).attached(this);
1771     }
1772
1773     @Override
1774     public <T> void setDataSource(DataSource<T> provider) {
1775         assertNotDisposed();
1776         if (provider == null)
1777             throw new IllegalArgumentException("null provider");
1778         dataSources.put(provider.getProvidedClass(), provider);
1779     }
1780
1781     @SuppressWarnings("unchecked")
1782     @Override
1783     public <T> DataSource<T> removeDataSource(Class<T> forProvidedClass) {
1784         assertNotDisposed();
1785         if (forProvidedClass == null)
1786             throw new IllegalArgumentException("null class");
1787         return dataSources.remove(forProvidedClass);
1788     }
1789
1790     @Override
1791     public void setPersistor(StatePersistor persistor) {
1792         this.persistor = persistor;
1793     }
1794
1795     @Override
1796     public SelectionDataResolver getSelectionDataResolver() {
1797         return selectionDataResolver;
1798     }
1799
1800     @Override
1801     public void setSelectionDataResolver(SelectionDataResolver r) {
1802         this.selectionDataResolver = r;
1803     }
1804
1805     @Override
1806     public SelectionFilter getSelectionFilter() {
1807         return selectionFilter;
1808     }
1809
1810     @Override
1811     public void setSelectionFilter(SelectionFilter f) {
1812         this.selectionFilter = f;
1813         // TODO: re-filter current selection?
1814     }
1815
1816     @Override
1817     public void setSelectionTransformation(BiFunction<GraphExplorer, Object[], Object[]> f) {
1818         this.selectionTransformation = f;
1819     }
1820
1821     @Override
1822     public <T> void addListener(T listener) {
1823         if(listener instanceof FocusListener) {
1824             focusListeners.add((FocusListener)listener);
1825         } else if(listener instanceof MouseListener) {
1826             mouseListeners.add((MouseListener)listener);
1827         } else if(listener instanceof KeyListener) {
1828             keyListeners.add((KeyListener)listener);
1829         }
1830     }
1831
1832     @Override
1833     public <T> void removeListener(T listener) {
1834         if(listener instanceof FocusListener) {
1835             focusListeners.remove(listener);
1836         } else if(listener instanceof MouseListener) {
1837             mouseListeners.remove(listener);
1838         } else if(listener instanceof KeyListener) {
1839             keyListeners.remove(listener);
1840         }
1841     }
1842
1843     public void addSelectionListener(SelectionListener listener) {
1844         tree.addSelectionListener(listener);
1845     }
1846
1847     public void removeSelectionListener(SelectionListener listener) {
1848         tree.removeSelectionListener(listener);
1849     }
1850
1851     private Set<String> uiContexts;
1852
1853     @Override
1854     public void setUIContexts(Set<String> contexts) {
1855         this.uiContexts = contexts;
1856     }
1857
1858     @Override
1859     public void setRoot(final Object root) {
1860         if(uiContexts != null && uiContexts.size() == 1)
1861                 setRootContext0(NodeContextBuilder.buildWithData(BuiltinKeys.INPUT, root, BuiltinKeys.UI_CONTEXT, uiContexts.iterator().next()));
1862         else
1863                 setRootContext0(NodeContextBuilder.buildWithData(BuiltinKeys.INPUT, root));
1864     }
1865
1866     @Override
1867     public void setRootContext(final NodeContext context) {
1868         setRootContext0(context);
1869     }
1870
1871     private void setRootContext0(final NodeContext context) {
1872         Assert.isNotNull(context, "root must not be null");
1873         if (isDisposed() || tree.isDisposed())
1874             return;
1875         Display display = tree.getDisplay();
1876         if (display.getThread() == Thread.currentThread()) {
1877             doSetRoot(context);
1878         } else {
1879             display.asyncExec(new Runnable() {
1880                 @Override
1881                 public void run() {
1882                     doSetRoot(context);
1883                 }
1884             });
1885         }
1886     }
1887
1888     private void initializeState() {
1889         if (persistor == null)
1890             return;
1891         ExplorerStates.scheduleRead(getRoot(), persistor)
1892         .thenAccept(state -> SWTUtils.asyncExec(tree, () -> restoreState(state)));
1893     }
1894
1895     private void restoreState(ExplorerState state) {
1896         // topNodeToSet will be processed by #setData when it encounters a
1897         // NodeContext that matches this one.
1898 //        topNodePath = state.topNodePath;
1899 //        topNodePathChildIndex = state.topNodePathChildIndex;
1900 //        currentTopNodePathIndex = 0;
1901
1902         Object processor = getPrimitiveProcessor(BuiltinKeys.IS_EXPANDED);
1903         if (processor instanceof DefaultIsExpandedProcessor) {
1904             DefaultIsExpandedProcessor isExpandedProcessor = (DefaultIsExpandedProcessor)processor;
1905             for(NodeContext expanded : state.expandedNodes) {
1906                 isExpandedProcessor.replaceExpanded(expanded, true);
1907             }
1908         }
1909     }
1910
1911     private void saveState() {
1912         if (persistor == null)
1913             return;
1914
1915         NodeContext[] topNodePath = NodeContext.NONE;
1916         int[] topNodePathChildIndex = {};
1917         Collection<NodeContext> expandedNodes = Collections.emptyList();
1918         Map<String, Integer> columnWidths = Collections.<String, Integer> emptyMap();
1919
1920         // Resolve top node path
1921         TreeItem topItem = tree.getTopItem();
1922         if (topItem != null) {
1923             NodeContext topNode = (NodeContext) topItem.getData();
1924             if (topNode != null) {
1925                 topNodePath = getNodeContextPathSegments(topNode);
1926                 topNodePathChildIndex = new int[topNodePath.length];
1927                 for (int i = 0; i < topNodePath.length; ++i) {
1928                     // TODO: get child indexes
1929                     topNodePathChildIndex[i] = 0;
1930                 }
1931             }
1932         }
1933
1934         // Resolve expanded nodes
1935         Object processor = getPrimitiveProcessor(BuiltinKeys.IS_EXPANDED);
1936         if (processor instanceof IsExpandedProcessor) {
1937             IsExpandedProcessor isExpandedProcessor = (IsExpandedProcessor) processor;
1938             expandedNodes = isExpandedProcessor.getExpanded();
1939         }
1940
1941         // Column widths
1942         TreeColumn[] columns = tree.getColumns();
1943         if (columns.length > 1) {
1944                     columnWidths = new HashMap<String, Integer>();
1945                     for (int i = 0; i < columns.length; ++i) {
1946                         columnWidths.put(columns[i].getText(), columns[i].getWidth());
1947                     }
1948         }
1949
1950         persistor.serialize(
1951                 ExplorerStates.explorerStateLocation(),
1952                 getRoot(),
1953                 new ExplorerState(topNodePath, topNodePathChildIndex, expandedNodes, columnWidths));
1954     }
1955
1956     /**
1957      * Invoke only from SWT thread to reset the root of the graph explorer tree.
1958      *
1959      * @param root
1960      */
1961     private void doSetRoot(NodeContext root) {
1962         if (tree.isDisposed())
1963             return;
1964         if (root.getConstant(BuiltinKeys.INPUT) == null) {
1965             ErrorLogger.defaultLogError("root node context does not contain BuiltinKeys.INPUT key. Node = " + root, new Exception("trace"));
1966             return;
1967         }
1968
1969         // Empty caches, release queries.
1970         GraphExplorerContext oldContext = explorerContext;
1971         GraphExplorerContext newContext = new GraphExplorerContext();
1972         GENodeQueryManager manager = new GENodeQueryManager(newContext, null, null, TreeItemReference.create(null));
1973         this.explorerContext = newContext;
1974         oldContext.safeDispose();
1975         toolTip.setGraphExplorerContext(explorerContext);
1976
1977         // Need to empty these or otherwise they won't be emptied until the
1978         // explorer is disposed which would mean that many unwanted references
1979         // will be held by this map.
1980         clearPrimitiveProcessors();
1981
1982         this.rootContext = root.getConstant(BuiltinKeys.IS_ROOT) != null ? root
1983                 : NodeContextUtil.withConstant(root, BuiltinKeys.IS_ROOT, Boolean.TRUE);
1984
1985         explorerContext.getCache().incRef(this.rootContext);
1986
1987         initializeState();
1988
1989         NodeContext[] contexts = manager.query(rootContext, BuiltinKeys.FINAL_CHILDREN);
1990
1991         tree.setItemCount(contexts.length);
1992
1993         select(rootContext);
1994         refreshColumnSizes();
1995     }
1996
1997     @Override
1998     public NodeContext getRoot() {
1999         return rootContext;
2000     }
2001
2002     @Override
2003     public NodeContext getParentContext(NodeContext context) {
2004         if (disposed)
2005             throw new IllegalStateException("disposed");
2006         if (!thread.currentThreadAccess())
2007             throw new IllegalStateException("not in SWT display thread " + thread.getThread());
2008
2009         TreeItem item = contextToItem.getRight(context);
2010         if(item == null) return null;
2011         TreeItem parentItem = item.getParentItem();
2012         if(parentItem == null) return null;
2013         return (NodeContext)parentItem.getData();
2014     }
2015
2016     Point previousTreeSize;
2017     Point previousTreeParentSize;
2018     boolean activatedBefore = false;
2019
2020     @Override
2021     public void handleEvent(Event event) {
2022         //System.out.println("EVENT: " + event);
2023         switch(event.type) {
2024             case SWT.Expand:
2025                 //System.out.println("EXPAND: " + event.item);
2026                 if ((tree.getStyle() & SWT.VIRTUAL) != 0) {
2027                     expandVirtual(event);
2028                 } else {
2029                     System.out.println("TODO: non-virtual tree item expand");
2030                 }
2031                 break;
2032             case SWT.SetData:
2033                 // Only invoked for SWT.VIRTUAL trees
2034                 if (disposed)
2035                     // Happened for Hannu once during program startup.
2036                     // java.lang.AssertionError
2037                     //   at org.simantics.browsing.ui.common.internal.GENodeQueryManager.query(GENodeQueryManager.java:190)
2038                     //   at org.simantics.browsing.ui.swt.GraphExplorerImpl.setData(GraphExplorerImpl.java:2315)
2039                     //   at org.simantics.browsing.ui.swt.GraphExplorerImpl.handleEvent(GraphExplorerImpl.java:2039)
2040                     // I do not know whether SWT guarantees that SetData events
2041                     // don't come after Dispose event has been issued, but I
2042                     // think its better to have this check here just incase.
2043                     return;
2044                 setData(event);
2045                 break;
2046             case SWT.Activate:
2047                 // This ensures that column sizes are refreshed at
2048                 // least once when the GE is first shown.
2049                 if (!activatedBefore) {
2050                     refreshColumnSizes();
2051                     activatedBefore = true;
2052                 }
2053                 break;
2054             case SWT.Dispose:
2055                 //new Exception().printStackTrace();
2056                 if (disposed)
2057                     return;
2058                 disposed = true;
2059                 doDispose();
2060                 break;
2061             case SWT.Resize:
2062                 if (event.widget == tree) {
2063                     // This case is meant for listening to tree width increase.
2064                     // The column resizing must be performed only after the tree
2065                     // itself as been resized.
2066                     Point size = tree.getSize();
2067                     int dx = 0;
2068                     if (previousTreeSize != null) {
2069                         dx = size.x - previousTreeSize.x;
2070                     }
2071                     previousTreeSize = size;
2072                     //System.out.println("RESIZE: " + dx + " - size=" + size);
2073
2074                     if (dx > 0) {
2075                         tree.setRedraw(false);
2076                         refreshColumnSizes(size);
2077                         tree.setRedraw(true);
2078                     }
2079                 } else if (event.widget == tree.getParent()) {
2080                     // This case is meant for listening to tree width decrease.
2081                     // The columns must be resized before the tree widget itself
2082                     // is resized to prevent scroll bar flicker. This can be achieved
2083                     // by listening to the resize events of the tree parent widget.
2084                     Composite parent = tree.getParent();
2085                     Point size = parent.getSize();
2086
2087                     // We must subtract the parent's border and possible
2088                     // scroll bar width from the new target width of the columns.
2089                     size.x -= tree.getParent().getBorderWidth() * 2;
2090                     ScrollBar vBar = parent.getVerticalBar();
2091                     if (vBar != null && vBar.isVisible())
2092                         size.x -= vBar.getSize().x;
2093
2094                     int dx = 0;
2095                     if (previousTreeParentSize != null) {
2096                         dx = size.x - previousTreeParentSize.x;
2097                     }
2098                     previousTreeParentSize = size;
2099                     //System.out.println("RESIZE: " + dx + " - size=" + size);
2100
2101                     if (dx < 0) {
2102                         tree.setRedraw(false);
2103                         refreshColumnSizes(size);
2104                         tree.setRedraw(true);
2105                     }
2106                 }
2107                 break;
2108             default:
2109                 break;
2110         }
2111
2112     }
2113
2114     protected void refreshColumnSizes() {
2115 //        Composite treeParent = tree.getParent();
2116 //        Point size = treeParent.getSize();
2117 //        size.x -= treeParent.getBorderWidth() * 2;
2118         Point size = tree.getSize();
2119         refreshColumnSizes(size);
2120         tree.getParent().layout();
2121     }
2122
2123     /**
2124      * This has been disabled since the logic of handling column widths has been
2125      * externalized to parties creating {@link GraphExplorerImpl} instances.
2126      */
2127     protected void refreshColumnSizes(Point toSize) {
2128         /*
2129         refreshingColumnSizes = true;
2130         try {
2131             int columnCount = tree.getColumnCount();
2132             if (columnCount > 0) {
2133                 Point size = toSize;
2134                 int targetWidth = size.x - tree.getBorderWidth() * 2;
2135                 targetWidth -= 0;
2136
2137                 // Take the vertical scroll bar existence into to account when
2138                 // calculating the overflow column width.
2139                 ScrollBar vBar = tree.getVerticalBar();
2140                 //if (vBar != null && vBar.isVisible())
2141                 if (vBar != null)
2142                     targetWidth -= vBar.getSize().x;
2143
2144                 List<TreeColumn> resizing = new ArrayList<TreeColumn>();
2145                 int usedWidth = 0;
2146                 int resizingWidth = 0;
2147                 int totalWeight = 0;
2148                 for (int i = 0; i < columnCount - 1; ++i) {
2149                     TreeColumn col = tree.getColumn(i);
2150                     //System.out.println("  " + col.getText() + ": " + col.getWidth());
2151                     int width = col.getWidth();
2152                     usedWidth += width;
2153                     Column c = (Column) col.getData();
2154                     if (c.hasGrab()) {
2155                         resizing.add(col);
2156                         resizingWidth += width;
2157                         totalWeight += c.getWeight();
2158                     }
2159                 }
2160
2161                 int requiredWidthAdjustment = targetWidth - usedWidth;
2162                 if (requiredWidthAdjustment < 0)
2163                     requiredWidthAdjustment = Math.min(requiredWidthAdjustment, -resizing.size());
2164                 double diff = requiredWidthAdjustment;
2165                 //System.out.println("REQUIRED WIDTH ADJUSTMENT: " + requiredWidthAdjustment);
2166
2167                 // Decide how much to give space to / take space from each grabbing column
2168                 double wrel = 1.0 / resizing.size();
2169
2170                 double[] weightedShares = new double[resizing.size()];
2171                 for (int i = 0; i < resizing.size(); ++i) {
2172                     TreeColumn col = resizing.get(i);
2173                     Column c = (Column) col.getData();
2174                     if (totalWeight == 0) {
2175                         weightedShares[i] = wrel;
2176                     } else {
2177                         weightedShares[i] = (double) c.getWeight() / (double) totalWeight;
2178                     }
2179                 }
2180                 //System.out.println("grabbing columns:" + resizing);
2181                 //System.out.println("weighted space distribution: " + Arrays.toString(weightedShares));
2182
2183                 // Always shrink the columns if necessary, but don't enlarge before
2184                 // there is sufficient space to at least give all resizable columns
2185                 // some more width.
2186                 if (diff < 0 || (diff > 0 && diff > resizing.size())) {
2187                     // Need to either shrink or enlarge the resizable columns if possible.
2188                     for (int i = 0; i < resizing.size(); ++i) {
2189                         TreeColumn col = resizing.get(i);
2190                         Column c = (Column) col.getData();
2191                         int cw = col.getWidth();
2192                         //double wrel = (double) cw / (double) resizingWidth;
2193                         //int delta = Math.min((int) Math.round(wrel * diff), requiredWidthAdjustment);
2194                         double ddelta = weightedShares[i] * diff;
2195                         int delta = 0;
2196                         if (diff < 0) {
2197                             delta = (int) Math.floor(ddelta);
2198                         } else {
2199                             delta = Math.min((int) Math.floor(ddelta), requiredWidthAdjustment);
2200                         }
2201                         //System.out.println("size delta(" + col.getText() + "): " + ddelta + " => " + delta);
2202                         //System.out.println("argh(" + col.getText() + "): " + c.getWidth() +  " vs. " + col.getWidth() + " vs. " + (cw+delta));
2203                         int newWidth = Math.max(c.getWidth(), cw + delta);
2204                         requiredWidthAdjustment -= (newWidth - cw);
2205                         col.setWidth(newWidth);
2206                     }
2207                 }
2208
2209                 //System.out.println("FILLER WIDTH LEFT: " + requiredWidthAdjustment);
2210
2211                 TreeColumn last = tree.getColumn(columnCount - 1);
2212                 // HACK: see #setColumns for why this is here.
2213                 if (FILLER.equals(last.getText())) {
2214                     last.setWidth(Math.max(0, requiredWidthAdjustment));
2215                 }
2216             }
2217         } finally {
2218             refreshingColumnSizes = false;
2219         }
2220          */
2221     }
2222
2223     private void doDispose() {
2224         explorerContext.dispose();
2225
2226         // No longer necessary, the used executors are shared.
2227         //scheduler.shutdown();
2228         //scheduler2.shutdown();
2229
2230         processors.clear();
2231         detachPrimitiveProcessors();
2232         primitiveProcessors.clear();
2233         dataSources.clear();
2234
2235         pendingItems.clear();
2236
2237         rootContext = null;
2238
2239         contextToItem.clear();
2240
2241         mouseListeners.clear();
2242
2243         selectionProvider.clearListeners();
2244         selectionProvider = null;
2245         selectionDataResolver = null;
2246         selectionRefreshContexts.clear();
2247         selectedItems.clear();
2248         originalFont = null;
2249
2250         localResourceManager.dispose();
2251
2252         // Must shutdown image loader job before disposing its ResourceManager
2253         imageLoaderJob.dispose();
2254         imageLoaderJob.cancel();
2255         try {
2256             imageLoaderJob.join();
2257         } catch (InterruptedException e) {
2258             ErrorLogger.defaultLogError(e);
2259         }
2260         resourceManager.dispose();
2261
2262         postSelectionProvider.dispose();
2263
2264     }
2265
2266     private void expandVirtual(final Event event) {
2267         TreeItem item = (TreeItem) event.item;
2268         assert (item != null);
2269         NodeContext context = (NodeContext) item.getData();
2270         assert (context != null);
2271
2272         GENodeQueryManager manager = new GENodeQueryManager(this.explorerContext, null, null, TreeItemReference.create(item));
2273         NodeContext[] children = manager.query(context, BuiltinKeys.FINAL_CHILDREN);
2274         int maxChildren = getMaxChildren(manager, context);
2275         item.setItemCount(children.length < maxChildren ? children.length : maxChildren);
2276     }
2277
2278     private NodeContext getNodeContext(TreeItem item) {
2279         assert(item != null);
2280
2281         NodeContext context = (NodeContext)item.getData();
2282         assert(context != null);
2283
2284         return context;
2285     }
2286
2287     private NodeContext getParentContext(TreeItem item) {
2288         TreeItem parentItem = item.getParentItem();
2289         if(parentItem != null) {
2290             return getNodeContext(parentItem);
2291         } else {
2292             return rootContext;
2293         }
2294     }
2295
2296     private static final String LISTENER_SET_INDICATOR = "LSI";
2297     private static final String PENDING = "PENDING";
2298     private int contextSelectionChangeModCount = 0;
2299
2300     /**
2301      * Only invoked for SWT.VIRTUAL widgets.
2302      *
2303      * @param event
2304      */
2305     private void setData(final Event event) {
2306         assert (event != null);
2307         TreeItem item = (TreeItem) event.item;
2308         assert (item != null);
2309
2310         // Based on experience it seems to be possible that
2311         // SetData events are sent for disposed TreeItems.
2312         if (item.isDisposed() || item.getData(PENDING) != null)
2313             return;
2314
2315         //System.out.println("GE.SetData " + item);
2316
2317         GENodeQueryManager manager = new GENodeQueryManager(this.explorerContext, null, null, TreeItemReference.create(item.getParentItem()));
2318
2319         NodeContext parentContext = getParentContext(item);
2320         assert (parentContext != null);
2321
2322         NodeContext[] parentChildren = manager.query(parentContext, BuiltinKeys.FINAL_CHILDREN);
2323
2324         // Some children have disappeared since counting
2325         if (event.index < 0) {
2326             ErrorLogger.defaultLogError("GraphExplorer.setData: how can event.index be < 0: " + event.index + " ??", new Exception());
2327             return;
2328         }
2329         if (event.index >= parentChildren.length)
2330             return;
2331
2332         NodeContext context = parentChildren[event.index];
2333         assert (context != null);
2334         item.setData(context);
2335
2336         // Manage NodeContext -> TreeItem mappings
2337         contextToItem.map(context, item);
2338         if (item.getData(LISTENER_SET_INDICATOR) == null) {
2339             // This "if" exists because setData will get called many
2340             // times for the same (NodeContext, TreeItem) pairs.
2341             // Each TreeItem only needs one listener, but this
2342             // is needed to tell whether it already has a listener
2343             // or not.
2344             item.setData(LISTENER_SET_INDICATOR, LISTENER_SET_INDICATOR);
2345             item.addListener(SWT.Dispose, itemDisposeListener);
2346         }
2347
2348         boolean isExpanded = manager.query(context, BuiltinKeys.IS_EXPANDED);
2349
2350         PrunedChildrenResult children = manager.query(context, BuiltinKeys.PRUNED_CHILDREN);
2351         int maxChildren = getMaxChildren(manager, context);
2352         //item.setItemCount(children.getPrunedChildren().length < maxChildren ? children.getPrunedChildren().length : maxChildren);
2353
2354      NodeContext[] pruned = children.getPrunedChildren();
2355      int count = Math.min(pruned.length, maxChildren);
2356
2357         if (isExpanded || item.getItemCount() > 1) {
2358             item.setItemCount(count);
2359             TreeItem[] childItems = item.getItems();
2360          for(int i=0;i<count;i++)
2361              contextToItem.map(pruned[i], childItems[i]);
2362         } else {
2363             if (children.getPrunedChildren().length == 0) {
2364                 item.setItemCount(0);
2365             } else {
2366 //                item.setItemCount(1);
2367                 item.setItemCount(count);
2368                 TreeItem[] childItems = item.getItems();
2369              for(int i=0;i<count;i++)
2370                  contextToItem.map(pruned[i], childItems[i]);
2371 //                item.getItem(0).setData(PENDING, PENDING);
2372 //                item.getItem(0).setItemCount(o);
2373             }
2374         }
2375
2376         setTextAndImage(item, manager, context, event.index);
2377
2378         // Check if the node should be auto-expanded?
2379         if ((autoExpandLevel == ALL_LEVELS || autoExpandLevel > 1) && !isExpanded) {
2380             //System.out.println("NOT EXPANDED(" +context + ", " + item + ")");
2381             int level = getTreeItemLevel(item);
2382             if ((autoExpandLevel == ALL_LEVELS || level <= autoExpandLevel)
2383                     && !explorerContext.autoExpanded.containsKey(context))
2384             {
2385                 //System.out.println("AUTO-EXPANDING(" + context + ", " + item + ")");
2386                 explorerContext.autoExpanded.put(context, Boolean.TRUE);
2387                 setExpanded(context, true);
2388             }
2389         }
2390
2391         item.setExpanded(isExpanded);
2392
2393         if ((tree.getStyle() & SWT.CHECK) != 0) {
2394             CheckedState checked = manager.query(context, BuiltinKeys.IS_CHECKED);
2395             item.setChecked(CheckedState.CHECKED_STATES.contains(checked));
2396             item.setGrayed(CheckedState.GRAYED == checked);
2397         }
2398
2399         //System.out.println("GE.SetData completed " + item);
2400
2401         // This test makes sure that selectionProvider holds the correct
2402         // selection with respect to the actual selection stored by the virtual
2403         // SWT Tree widget.
2404         // The data items shown below the items occupied by the selected and now removed data
2405         // will be squeezed to use the tree items previously used for the now
2406         // removed data. When this happens, the NodeContext items stored by the
2407         // tree items will be different from what the GraphExplorer's
2408         // ISelectionProvider thinks the selection currently is. To compensate,
2409         // 1. Recognize the situation
2410         // 2. ASAP set the selection provider selection to what is actually
2411         // offered by the tree widget.
2412         NodeContext selectedContext = selectedItems.get(item);
2413 //        System.out.println("selectedContext(" + item + "): " + selectedContext);
2414         if (selectedContext != null && !selectedContext.equals(context)) {
2415                 final int modCount = ++contextSelectionChangeModCount;
2416 //            System.out.println("SELECTION MUST BE UPDATED (modCount=" + modCount + "): " + item);
2417 //            System.out.println("    old context: " + selectedContext);
2418 //            System.out.println("    new context: " + context);
2419 //            System.out.println("    provider selection: " + selectionProvider.getSelection());
2420 //            System.out.println("    widget   selection: " + getWidgetSelection());
2421             ThreadUtils.asyncExec(thread, new Runnable() {
2422                 @Override
2423                 public void run() {
2424                     if (isDisposed())
2425                         return;
2426                     int count = contextSelectionChangeModCount;
2427 //                    System.out.println("MODCOUNT: " + modCount + " vs. " + count);
2428                     if (modCount != count)
2429                         return;
2430                     widgetSelectionChanged(true);
2431                 }
2432             });
2433         }
2434
2435         // This must be done to keep the visible tree selection properly
2436         // in sync with the selectionProvider JFace proxy of this class in
2437         // cases where an in-line editor was previously active for the node
2438         // context.
2439         if (selectionRefreshContexts.remove(context)) {
2440             final ISelection currentSelection = selectionProvider.getSelection();
2441             // asyncExec is here to prevent ui glitches that
2442             // seem to occur if the selection setting is done
2443             // directly here in between setData invocations.
2444             ThreadUtils.asyncExec(thread, new Runnable() {
2445                 @Override
2446                 public void run() {
2447                     if (isDisposed())
2448                         return;
2449 //                    System.out.println("REFRESHING SELECTION: " + currentSelection);
2450 //                    System.out.println("BEFORE setSelection: " + Arrays.toString(tree.getSelection()));
2451 //                    System.out.println("BEFORE setSelection: " + selectionProvider.getSelection());
2452                     setSelection(currentSelection, true);
2453 //                    System.out.println("AFTER setSelection: " + Arrays.toString(tree.getSelection()));
2454 //                    System.out.println("AFTER setSelection: " + selectionProvider.getSelection());
2455                 }
2456             });
2457         }
2458
2459         // TODO: doesn't work if any part of the node path that should be
2460         // revealed is out of view.
2461         // Disabled until a better solution is devised.
2462         // Suggestion: include item indexes into the stored node context path
2463         // to make it possible for this method to know whether the current
2464         // node path segment is currently out of view based on event.index.
2465         // If out of view, this code needs to scroll the view programmatically
2466         // onwards.
2467 //        if (currentTopNodePathIndex >= 0 && topNodePath.length > 0) {
2468 //            NodeContext topNode = topNodePath[currentTopNodePathIndex];
2469 //            if (topNode.equals(context)) {
2470 //                final TreeItem topItem = item;
2471 //                ++currentTopNodePathIndex;
2472 //                if (currentTopNodePathIndex >= topNodePath.length) {
2473 //                    // Mission accomplished. End search for top node here.
2474 //                    topNodePath = NodeContext.NONE;
2475 //                    currentTopNodePathIndex = -1;
2476 //                }
2477 //                ThreadUtils.asyncExec(thread, new Runnable() {
2478 //                    @Override
2479 //                    public void run() {
2480 //                        if (isDisposed())
2481 //                            return;
2482 //                        tree.setTopItem(topItem);
2483 //                    }
2484 //                });
2485 //            }
2486 //        }
2487
2488         // Check if vertical scroll bar has become visible and refresh layout.
2489         ScrollBar verticalBar = tree.getVerticalBar();
2490         if(verticalBar != null) {
2491                 boolean currentlyVerticalBarVisible = verticalBar.isVisible();
2492                 if (verticalBarVisible != currentlyVerticalBarVisible) {
2493                     verticalBarVisible = currentlyVerticalBarVisible;
2494                     Composite parent = tree.getParent();
2495                     if (parent != null)
2496                         parent.layout();
2497                 }
2498         }
2499     }
2500
2501     /**
2502      * @return see {@link GraphExplorer#setAutoExpandLevel(int)} for how the
2503      *         return value is calculated. Items without parents have level=2,
2504      *         their children level=3, etc. Returns 0 for invalid items
2505      */
2506     private int getTreeItemLevel(TreeItem item) {
2507         if (item == null)
2508             return 0;
2509         int level = 1;
2510         for (TreeItem parent = item; parent != null; parent = parent.getParentItem(), ++level);
2511         //System.out.println("\tgetTreeItemLevel(" + parent + ")");
2512         //System.out.println("level(" + item + "): " + level);
2513         return level;
2514     }
2515
2516     /**
2517      * @param node
2518      * @return
2519      */
2520     private NodeContext[] getNodeContextPathSegments(NodeContext node) {
2521         TreeItem item = contextToItem.getRight(node);
2522         if (item == null)
2523             return NodeContext.NONE;
2524         int level = getTreeItemLevel(item);
2525         if (level == 0)
2526             return NodeContext.NONE;
2527         // Exclude root from the saved node path.
2528         --level;
2529         NodeContext[] segments = new NodeContext[level];
2530         for (TreeItem parent = item; parent != null; parent = parent.getParentItem(), --level) {
2531             NodeContext ctx = (NodeContext) item.getData();
2532             if (ctx == null)
2533                 return NodeContext.NONE;
2534             segments[level-1] = ctx;
2535         }
2536         return segments;
2537     }
2538
2539     /**
2540      * @param node
2541      * @return
2542      */
2543     @SuppressWarnings("unused")
2544     private NodeContextPath getNodeContextPath(NodeContext node) {
2545         NodeContext[] path = getNodeContextPathSegments(node);
2546         return new NodeContextPath(path);
2547     }
2548
2549     void setImage(NodeContext node, TreeItem item, Imager imager, Collection<ImageDecorator> decorators, int itemIndex) {
2550         Image[] images = columnImageArray;
2551         Arrays.fill(images, null);
2552         if (imager == null) {
2553             item.setImage(images);
2554             return;
2555         }
2556
2557         Object[] descOrImage = columnDescOrImageArray;
2558         Arrays.fill(descOrImage, null);
2559         boolean finishLoadingInJob = false;
2560         int index = 0;
2561         for (Column column : columns) {
2562             String key = column.getKey();
2563             ImageDescriptor desc = imager.getImage(key);
2564             if (desc != null) {
2565                 // Attempt to decorate the label
2566                 if (!decorators.isEmpty()) {
2567                     for (ImageDecorator id : decorators) {
2568                         ImageDescriptor ds = id.decorateImage(desc, key, itemIndex);
2569                         if (ds != null)
2570                             desc = ds;
2571                     }
2572                 }
2573
2574                 // Try resolving only cached images here and now
2575                 Object img = localResourceManager.find(desc);
2576                 if (img == null)
2577                     img = resourceManager.find(desc);
2578
2579                 images[index] = img != null ? (Image) img : null;
2580                 descOrImage[index] = img == null ? desc : img;
2581                 finishLoadingInJob |= img == null;
2582             }
2583             ++index;
2584         }
2585
2586         // Finish loading the final image in the image loader job if necessary.
2587         if (finishLoadingInJob) {
2588             // Prevent UI from flashing unnecessarily by reusing the old image
2589             // in the item if it exists.
2590             for (int c = 0; c < columns.length; ++c) {
2591                 Image img = item.getImage(c);
2592                 if (img != null)
2593                     images[c] = img;
2594             }
2595             item.setImage(images);
2596
2597             // Schedule loading to another thread to refrain from blocking
2598             // the UI with database operations.
2599             queueImageTask(item, new ImageTask(
2600                     node,
2601                     item,
2602                     Arrays.copyOf(descOrImage, descOrImage.length)));
2603         } else {
2604             // Set any images that were resolved.
2605             item.setImage(images);
2606         }
2607     }
2608
2609     private void queueImageTask(TreeItem item, ImageTask task) {
2610         synchronized (imageTasks) {
2611             imageTasks.put(item, task);
2612         }
2613         imageLoaderJob.scheduleIfNecessary(100);
2614     }
2615
2616     /**
2617      * Invoked in a job worker thread.
2618      *
2619      * @param monitor
2620      * @see ImageLoaderJob
2621      */
2622     @Override
2623         protected IStatus setPendingImages(IProgressMonitor monitor) {
2624         ImageTask[] tasks = null;
2625         synchronized (imageTasks) {
2626             tasks = imageTasks.values().toArray(new ImageTask[imageTasks.size()]);
2627             imageTasks.clear();
2628         }
2629         if (tasks.length == 0)
2630             return Status.OK_STATUS;
2631
2632         MultiStatus status = null;
2633
2634         // Load missing images
2635         for (ImageTask task : tasks) {
2636             Object[] descs = task.descsOrImages;
2637             for (int i = 0; i < descs.length; ++i) {
2638                 Object obj = descs[i];
2639                 if (obj instanceof ImageDescriptor) {
2640                     ImageDescriptor desc = (ImageDescriptor) obj;
2641                     try {
2642                         descs[i] = resourceManager.get((ImageDescriptor) desc);
2643                     } catch (DeviceResourceException e) {
2644                         if (status == null)
2645                             status = new MultiStatus(Activator.PLUGIN_ID, 0, "Problems loading images:", null);
2646                         status.add(new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Image descriptor loading failed: " + desc, e));
2647                     }
2648                 }
2649             }
2650         }
2651
2652         // Perform final UI updates in the UI thread.
2653         final ImageTask[] _tasks = tasks;
2654         thread.asyncExec(new Runnable() {
2655             @Override
2656             public void run() {
2657                 if (!tree.isDisposed()) {
2658                     tree.setRedraw(false);
2659                     setImages(_tasks);
2660                     tree.setRedraw(true);
2661                 }
2662             }
2663         });
2664
2665         return status != null ? status : Status.OK_STATUS;
2666     }
2667
2668     /**
2669      * Invoked in the UI thread only.
2670      *
2671      * @param task
2672      */
2673     void setImages(ImageTask[] tasks) {
2674         for (ImageTask task : tasks)
2675             if (task != null)
2676                 setImage(task);
2677     }
2678
2679     /**
2680      * Invoked in the UI thread only.
2681      *
2682      * @param task
2683      */
2684     void setImage(ImageTask task) {
2685         // Be sure not to process disposed items.
2686         if (task.item.isDisposed())
2687             return;
2688         // Discard this task if the TreeItem has switched owning NodeContext.
2689         if (!contextToItem.contains(task.node, task.item))
2690             return;
2691
2692         Object[] descs = task.descsOrImages;
2693         Image[] images = columnImageArray;
2694         Arrays.fill(images, null);
2695         for (int i = 0; i < descs.length; ++i) {
2696             Object desc = descs[i];
2697             if (desc instanceof Image) {
2698                 images[i] = (Image) desc;
2699             }
2700         }
2701         task.item.setImage(images);
2702     }
2703
2704     void setText(TreeItem item, Labeler labeler, Collection<LabelDecorator> decorators, int itemIndex) {
2705         if (labeler != null) {
2706             String[] texts = new String[columns.length];
2707             int index = 0;
2708             Map<String, String> labels = labeler.getLabels();
2709             Map<String, String> runtimeLabels = labeler.getRuntimeLabels();
2710             for (Column column : columns) {
2711                 String key = column.getKey();
2712                 String s = null;
2713                 if (runtimeLabels != null) s = runtimeLabels.get(key);
2714                 if (s == null) s = labels.get(key);
2715                 if (s != null) {
2716                     FontDescriptor font = originalFont;
2717                     ColorDescriptor bg = originalBackground;
2718                     ColorDescriptor fg = originalForeground;
2719
2720                     // Attempt to decorate the label
2721                     if (!decorators.isEmpty()) {
2722                         for (LabelDecorator ld : decorators) {
2723                             String ds = ld.decorateLabel(s, key, itemIndex);
2724                             if (ds != null)
2725                                 s = ds;
2726
2727                             FontDescriptor dfont = ld.decorateFont(font, key, itemIndex);
2728                             if (dfont != null)
2729                                 font = dfont;
2730
2731                             ColorDescriptor dbg = ld.decorateBackground(bg, key, itemIndex);
2732                             if (dbg != null)
2733                                 bg = dbg;
2734
2735                             ColorDescriptor dfg = ld.decorateForeground(fg, key, itemIndex);
2736                             if (dfg != null)
2737                                 fg = dfg;
2738                         }
2739                     }
2740
2741                     if (font != originalFont) {
2742                         //System.out.println("set font: " + index + ": " + font);
2743                         item.setFont(index, (Font) localResourceManager.get(font));
2744                     }
2745                     if (bg != originalBackground)
2746                         item.setBackground(index, (Color) localResourceManager.get(bg));
2747                     if (fg != originalForeground)
2748                         item.setForeground(index, (Color) localResourceManager.get(fg));
2749
2750                     texts[index] = s;
2751                 }
2752                 ++index;
2753             }
2754             item.setText(texts);
2755         } else {
2756             item.setText(Labeler.NO_LABEL);
2757         }
2758     }
2759
2760     void setTextAndImage(TreeItem item, NodeQueryManager manager, NodeContext context, int itemIndex) {
2761         Labeler labeler = manager.query(context, BuiltinKeys.SELECTED_LABELER);
2762         if (labeler != null) {
2763             labeler.setListener(labelListener);
2764         }
2765         Imager imager = manager.query(context, BuiltinKeys.SELECTED_IMAGER);
2766         Collection<LabelDecorator> labelDecorators = manager.query(context, BuiltinKeys.LABEL_DECORATORS);
2767         Collection<ImageDecorator> imageDecorators = manager.query(context, BuiltinKeys.IMAGE_DECORATORS);
2768
2769         setText(item, labeler, labelDecorators, itemIndex);
2770         setImage(context, item, imager, imageDecorators, itemIndex);
2771     }
2772
2773     @Override
2774     public void setFocus() {
2775         tree.setFocus();
2776     }
2777
2778     @Override
2779     public <T> T query(NodeContext context, CacheKey<T> key) {
2780         return this.explorerContext.cache.get(context, key);
2781     }
2782
2783     @Override
2784     public boolean isDisposed() {
2785         return disposed;
2786     }
2787
2788     protected void assertNotDisposed() {
2789         if (isDisposed())
2790             throw new IllegalStateException("disposed");
2791     }
2792
2793
2794
2795     /**
2796      * @param selection
2797      * @param forceControlUpdate
2798      * @thread any
2799      */
2800     public void setSelection(final ISelection selection, boolean forceControlUpdate) {
2801         assertNotDisposed();
2802         boolean equalsOld = selectionProvider.selectionEquals(selection);
2803         if (equalsOld && !forceControlUpdate) {
2804             // Just set the selection object instance, fire no events nor update
2805             // the viewer selection.
2806             selectionProvider.setSelection(selection);
2807         } else {
2808             // Schedule viewer and selection update if necessary.
2809             if (tree.isDisposed())
2810                 return;
2811             Display d = tree.getDisplay();
2812             if (d.getThread() == Thread.currentThread()) {
2813                 updateSelectionToControl(selection);
2814             } else {
2815                 d.asyncExec(new Runnable() {
2816                     @Override
2817                     public void run() {
2818                         if (tree.isDisposed())
2819                             return;
2820                         updateSelectionToControl(selection);
2821                     }
2822                 });
2823             }
2824         }
2825     }
2826
2827
2828     /* Contains the best currently found tree item and its priority
2829      */
2830     private static class SelectionResolutionStatus {
2831         int bestPriority = Integer.MAX_VALUE;
2832         TreeItem bestItem;
2833     }
2834
2835     /**
2836      * @param selection
2837      * @thread SWT
2838      */
2839     private void updateSelectionToControl(ISelection selection) {
2840         if (selectionDataResolver == null)
2841             return;
2842         if (!(selection instanceof IStructuredSelection))
2843             return;
2844
2845         // Initialize selection resolution status map
2846         IStructuredSelection iss = (IStructuredSelection) selection;
2847         final THashMap<Object,SelectionResolutionStatus> statusMap =
2848                 new THashMap<Object,SelectionResolutionStatus>(iss.size());
2849         for(Iterator<?> it = iss.iterator(); it.hasNext();) {
2850             Object selectionElement = it.next();
2851             Object resolvedElement = selectionDataResolver.resolve(selectionElement);
2852             statusMap.put(
2853                     resolvedElement,
2854                     new SelectionResolutionStatus());
2855         }
2856
2857         // Iterate all tree items and try to match them to the selection
2858         iterateTreeItems(new TObjectProcedure<TreeItem>() {
2859             @Override
2860             public boolean execute(TreeItem treeItem) {
2861                 NodeContext nodeContext = (NodeContext)treeItem.getData();
2862                 if(nodeContext == null)
2863                     return true;
2864                 SelectionResolutionStatus status = statusMap.get(nodeContext);
2865                 if(status != null) {
2866                     status.bestPriority = 0; // best possible match
2867                     status.bestItem = treeItem;
2868                     return true;
2869                 }
2870
2871                 Object input = nodeContext.getConstant(BuiltinKeys.INPUT);
2872                 status = statusMap.get(input);
2873                 if(status != null) {
2874                     NodeType nodeType = nodeContext.getConstant(NodeType.TYPE);
2875                     int curPriority = nodeType instanceof EntityNodeType
2876                             ? 1 // Prefer EntityNodeType matches to other node types
2877                             : 2;
2878                     if(curPriority < status.bestPriority) {
2879                         status.bestPriority = curPriority;
2880                         status.bestItem = treeItem;
2881                     }
2882                 }
2883                 return true;
2884             }
2885         });
2886
2887         // Update selection
2888         ArrayList<TreeItem> items = new ArrayList<TreeItem>(statusMap.size());
2889         for(SelectionResolutionStatus status : statusMap.values())
2890             if(status.bestItem != null)
2891                 items.add(status.bestItem);
2892         select(items.toArray(new TreeItem[items.size()]));
2893     }
2894
2895     /**
2896      * @thread SWT
2897      */
2898     public ISelection getWidgetSelection() {
2899         TreeItem[] items = tree.getSelection();
2900         if (items.length == 0)
2901             return StructuredSelection.EMPTY;
2902
2903         List<NodeContext> nodes = new ArrayList<NodeContext>(items.length);
2904
2905         // Caches for resolving node contexts the hard way if necessary.
2906         GENodeQueryManager manager = null;
2907         NodeContext lastParentContext = null;
2908         NodeContext[] lastChildren = null;
2909
2910         for (int i = 0; i < items.length; i++) {
2911             TreeItem item = items[i];
2912             NodeContext ctx = (NodeContext) item.getData();
2913             // It may happen due to the virtual nature of the tree control
2914             // that it contains TreeItems which have not yet been ran through
2915             // #setData(Event).
2916             if (ctx != null) {
2917                 nodes.add(ctx);
2918             } else {
2919                 TreeItem parentItem = item.getParentItem();
2920                 NodeContext parentContext = parentItem != null ? getNodeContext(parentItem) : rootContext;
2921                 if (parentContext != null) {
2922                     NodeContext[] children = lastChildren;
2923                     if (parentContext != lastParentContext) {
2924                         if (manager == null)
2925                             manager = new GENodeQueryManager(this.explorerContext, null, null, null);
2926                         lastChildren = children = manager.query(parentContext, BuiltinKeys.FINAL_CHILDREN);
2927                         lastParentContext = parentContext;
2928                     }
2929                     int index = parentItem != null ? parentItem.indexOf(item) : tree.indexOf(item);
2930                     if (index >= 0 && index < children.length) {
2931                         NodeContext child = children[index];
2932                         if (child != null) {
2933                             nodes.add(child);
2934                             // Cache NodeContext in TreeItem for faster access
2935                             item.setData(child);
2936                         }
2937                     }
2938                 }
2939             }
2940         }
2941         //System.out.println("widget selection " + items.length + " items / " + nodes.size() + " node contexts");
2942         ISelection selection = constructSelection(nodes.toArray(NodeContext.NONE));
2943         return selection;
2944     }
2945
2946     @Override
2947     public TransientExplorerState getTransientState() {
2948         if (!thread.currentThreadAccess())
2949             throw new AssertionError(getClass().getSimpleName() + ".getActiveColumn called from non SWT-thread: " + Thread.currentThread());
2950         return transientState;
2951     }
2952
2953     /**
2954      * @param item
2955      * @thread SWT
2956      */
2957     private void select(TreeItem item) {
2958         tree.setSelection(item);
2959         tree.showSelection();
2960         selectionProvider.setAndFireNonEqualSelection(constructSelection((NodeContext) item.getData()));
2961     }
2962
2963     /**
2964      * @param items
2965      * @thread SWT
2966      */
2967     private void select(TreeItem[] items) {
2968         //System.out.println("Select: " + Arrays.toString(items));
2969         tree.setSelection(items);
2970         tree.showSelection();
2971         NodeContext[] data = new NodeContext[items.length];
2972         for (int i = 0; i < data.length; i++) {
2973             data[i] = (NodeContext) items[i].getData();
2974         }
2975         selectionProvider.setAndFireNonEqualSelection(constructSelection(data));
2976     }
2977
2978     private void iterateTreeItems(TObjectProcedure<TreeItem> procedure) {
2979         for(TreeItem item : tree.getItems())
2980             if(!iterateTreeItems(item, procedure))
2981                 return;
2982     }
2983
2984     private boolean iterateTreeItems(TreeItem item,
2985             TObjectProcedure<TreeItem> procedure) {
2986         if(!procedure.execute(item))
2987             return false;
2988         if(item.getExpanded())
2989             for(TreeItem child : item.getItems())
2990                 if(!iterateTreeItems(child, procedure))
2991                     return false;
2992         return true;
2993     }
2994
2995     /**
2996      * @param item
2997      * @param context
2998      * @return
2999      */
3000     private boolean trySelect(TreeItem item, Object input) {
3001         NodeContext itemCtx = (NodeContext) item.getData();
3002         if (itemCtx != null) {
3003             if (input.equals(itemCtx.getConstant(BuiltinKeys.INPUT))) {
3004                 select(item);
3005                 return true;
3006             }
3007         }
3008         if (item.getExpanded()) {
3009             for (TreeItem child : item.getItems()) {
3010                 if (trySelect(child, input))
3011                     return true;
3012             }
3013         }
3014         return false;
3015     }
3016
3017     private boolean equalsEnough(NodeContext c1, NodeContext c2) {
3018
3019         Object input1 = c1.getConstant(BuiltinKeys.INPUT);
3020         Object input2 = c2.getConstant(BuiltinKeys.INPUT);
3021         if(!ObjectUtils.objectEquals(input1, input2))
3022                 return false;
3023
3024         Object type1 = c1.getConstant(NodeType.TYPE);
3025         Object type2 = c2.getConstant(NodeType.TYPE);
3026         if(!ObjectUtils.objectEquals(type1, type2))
3027                 return false;
3028
3029         return true;
3030
3031     }
3032
3033     private NodeContext tryFind(NodeContext context) {
3034         for (TreeItem item : tree.getItems()) {
3035                 NodeContext found = tryFind(item, context);
3036                 if(found != null) return found;
3037         }
3038         return null;
3039     }
3040
3041     private NodeContext tryFind(TreeItem item, NodeContext context) {
3042         NodeContext itemCtx = (NodeContext) item.getData();
3043         if (itemCtx != null) {
3044             if (equalsEnough(context, itemCtx)) {
3045                 return itemCtx;
3046             }
3047         }
3048         if (item.getExpanded()) {
3049             for (TreeItem child : item.getItems()) {
3050                 NodeContext found = tryFind(child, context);
3051                 if(found != null) return found;
3052             }
3053         }
3054         return null;
3055     }
3056
3057     @Override
3058     public boolean select(NodeContext context) {
3059
3060         assertNotDisposed();
3061
3062         if (context == null || context.equals(rootContext)) {
3063             tree.deselectAll();
3064             selectionProvider.setAndFireNonEqualSelection(TreeSelection.EMPTY);
3065             return true;
3066         }
3067
3068 //        if (context.equals(rootContext)) {
3069 //            tree.deselectAll();
3070 //            selectionProvider.setAndFireNonEqualSelection(constructSelection(context));
3071 //            return;
3072 //        }
3073
3074         Object input = context.getConstant(BuiltinKeys.INPUT);
3075
3076         for (TreeItem item : tree.getItems()) {
3077             if (trySelect(item, input))
3078                 return true;
3079         }
3080
3081         return false;
3082
3083     }
3084
3085     private NodeContext tryFind2(NodeContext context) {
3086         Set<NodeContext> ctxs = contextToItem.getLeftSet();
3087         for(NodeContext c : ctxs)
3088                 if(equalsEnough(c, context))
3089                         return c;
3090         return null;
3091     }
3092
3093     private boolean waitVisible(NodeContext parent, NodeContext context) {
3094         long start = System.nanoTime();
3095
3096         TreeItem parentItem = contextToItem.getRight(parent);
3097
3098         if(parentItem == null)
3099                 return false;
3100
3101         while(true) {
3102                 NodeContext target = tryFind2(context);
3103                 if(target != null) {
3104                         TreeItem item = contextToItem.getRight(target);
3105                         if (!(item.getParentItem().equals(parentItem)))
3106                                 return false;
3107                         tree.setTopItem(item);
3108                         return true;
3109                 }
3110
3111                 Display.getCurrent().readAndDispatch();
3112                 long duration = System.nanoTime() - start;
3113                 if(duration > 10e9)
3114                         return false;
3115         }
3116     }
3117
3118     private boolean selectPathInternal(NodeContext[] contexts, int position) {
3119         //System.out.println("NodeContext path : " + contexts);
3120
3121         NodeContext head = tryFind(contexts[position]);
3122
3123         if(position == contexts.length-1) {
3124                 return select(head);
3125
3126         }
3127
3128         //setExpanded(head, true);
3129
3130         if(!waitVisible(head, contexts[position+1]))
3131                 return false;
3132
3133         setExpanded(head, true);
3134
3135         return selectPathInternal(contexts, position+1);
3136
3137     }
3138
3139     @Override
3140     public boolean selectPath(Collection<NodeContext> contexts) {
3141
3142         if(contexts == null) throw new IllegalArgumentException("Null list is not allowed");
3143         if(contexts.isEmpty()) throw new IllegalArgumentException("Empty list is not allowed");
3144
3145         return selectPathInternal(contexts.toArray(new NodeContext[contexts.size()]), 0);
3146
3147     }
3148
3149     @Override
3150     public boolean isVisible(NodeContext context) {
3151
3152         for (TreeItem item : tree.getItems()) {
3153                 NodeContext found = tryFind(item, context);
3154                 if(found != null)
3155                         return true;
3156         }
3157
3158         return false;
3159
3160     }
3161
3162     protected ISelection constructSelection(NodeContext... contexts) {
3163         if (contexts ==  null)
3164             throw new IllegalArgumentException("null contexts");
3165         if (contexts.length == 0)
3166             return StructuredSelection.EMPTY;
3167         if (selectionFilter == null)
3168             return new StructuredSelection(transformSelection(contexts));
3169         return new StructuredSelection( transformSelection(filter(selectionFilter, contexts)) );
3170     }
3171
3172     protected Object[] transformSelection(Object[] objects) {
3173         return selectionTransformation.apply(this, objects);
3174     }
3175
3176     protected static Object[] filter(SelectionFilter filter, NodeContext[] contexts) {
3177         int len = contexts.length;
3178         Object[] objects = new Object[len];
3179         for (int i = 0; i < len; ++i)
3180             objects[i] = filter.filter(contexts[i]);
3181         return objects;
3182     }
3183
3184     @Override
3185     public void setExpanded(final NodeContext context, final boolean expanded) {
3186         assertNotDisposed();
3187         ThreadUtils.asyncExec(thread, new Runnable() {
3188             @Override
3189             public void run() {
3190                 if (!isDisposed())
3191                     doSetExpanded(context, expanded);
3192             }
3193         });
3194     }
3195
3196     private void doSetExpanded(NodeContext context, boolean expanded) {
3197         //System.out.println("doSetExpanded(" + context + ", " + expanded + ")");
3198         TreeItem item = contextToItem.getRight(context);
3199         if (item != null) {
3200             item.setExpanded(expanded);
3201         }
3202         PrimitiveQueryProcessor<?> pqp = explorerContext.getPrimitiveProcessor(BuiltinKeys.IS_EXPANDED);
3203         if (pqp instanceof IsExpandedProcessor) {
3204             IsExpandedProcessor iep = (IsExpandedProcessor) pqp;
3205             iep.replaceExpanded(context, expanded);
3206         }
3207     }
3208
3209     @Override
3210     public void setColumnsVisible(boolean visible) {
3211         columnsAreVisible = visible;
3212         if(tree != null) tree.setHeaderVisible(columnsAreVisible);
3213     }
3214
3215     @Override
3216     public void setColumns(final Column[] columns) {
3217         setColumns(columns, null);
3218     }
3219
3220     @Override
3221     public void setColumns(final Column[] columns, Consumer<Map<Column, Object>> callback) {
3222         assertNotDisposed();
3223         checkUniqueColumnKeys(columns);
3224
3225         Display d = tree.getDisplay();
3226         if (d.getThread() == Thread.currentThread())
3227             doSetColumns(columns, callback);
3228         else
3229             d.asyncExec(() -> {
3230                 if (tree.isDisposed())
3231                     return;
3232                 doSetColumns(columns, callback);
3233             });
3234     }
3235
3236     private void checkUniqueColumnKeys(Column[] cols) {
3237         Set<String> usedColumnKeys = new HashSet<String>();
3238         List<Column> duplicateColumns = new ArrayList<Column>();
3239         for (Column c : cols) {
3240             if (!usedColumnKeys.add(c.getKey()))
3241                 duplicateColumns.add(c);
3242         }
3243         if (!duplicateColumns.isEmpty()) {
3244             throw new IllegalArgumentException("All columns do not have unique keys: " + cols + ", overlapping: " + duplicateColumns);
3245         }
3246     }
3247
3248     /**
3249      * Only meant to be invoked from the SWT UI thread.
3250      *
3251      * @param cols
3252      */
3253     private void doSetColumns(Column[] cols, Consumer<Map<Column, Object>> callback) {
3254         // Attempt to keep previous column widths.
3255         Map<String, Integer> prevWidths = new HashMap<>();
3256         for (TreeColumn column : tree.getColumns()) {
3257             Column c = (Column) column.getData();
3258             if (c != null) {
3259                 prevWidths.put(c.getKey(), column.getWidth());
3260                 column.dispose();
3261             }
3262         }
3263
3264         HashMap<String, Integer> keyToIndex = new HashMap<>();
3265         for (int i = 0; i < cols.length; ++i) {
3266             keyToIndex.put(cols[i].getKey(), i);
3267         }
3268
3269         this.columns = Arrays.copyOf(cols, cols.length);
3270         //this.columns[cols.length] = FILLER_COLUMN;
3271         this.columnKeyToIndex = keyToIndex;
3272         this.columnImageArray = new Image[cols.length];
3273         this.columnDescOrImageArray = new Object[cols.length];
3274
3275         Map<Column, Object> map = new HashMap<>();
3276
3277         tree.setHeaderVisible(columnsAreVisible);
3278         for (Column column : columns) {
3279             TreeColumn c = new TreeColumn(tree, toSWT(column.getAlignment()));
3280             map.put(column, c);
3281             c.setData(column);
3282             c.setText(column.getLabel());
3283             c.setToolTipText(column.getTooltip());
3284
3285             int cw = column.getWidth();
3286
3287             // Try to keep previous widths
3288             Integer w = prevWidths.get(column.getKey());
3289             if (w != null)
3290                 c.setWidth(w);
3291             else if (cw != Column.DEFAULT_CONTROL_WIDTH)
3292                 c.setWidth(cw);
3293             else {
3294                 // Go for some kind of default settings then...
3295                 if (ColumnKeys.PROPERTY.equals(column.getKey()))
3296                     c.setWidth(150);
3297                 else
3298                     c.setWidth(50);
3299             }
3300
3301 //            if (!column.hasGrab() && !FILLER.equals(column.getKey())) {
3302 //                c.addListener(SWT.Resize, resizeListener);
3303 //                c.setResizable(true);
3304 //            } else {
3305 //                //c.setResizable(false);
3306 //            }
3307
3308         }
3309
3310         if(callback != null) callback.accept(map);
3311
3312         // Make sure the explorer fits the columns properly after initialization.
3313         SWTUtils.asyncExec(tree, () -> {
3314             if (!tree.isDisposed())
3315                 refreshColumnSizes();
3316         });
3317     }
3318
3319     int toSWT(Align alignment) {
3320         switch (alignment) {
3321             case LEFT: return SWT.LEFT;
3322             case CENTER: return SWT.CENTER;
3323             case RIGHT: return SWT.RIGHT;
3324             default: throw new Error("unhandled alignment: " + alignment);
3325         }
3326     }
3327
3328     @Override
3329     public Column[] getColumns() {
3330         return Arrays.copyOf(columns, columns.length);
3331     }
3332
3333     private void detachPrimitiveProcessors() {
3334         for (PrimitiveQueryProcessor<?> p : primitiveProcessors.values()) {
3335             if (p instanceof ProcessorLifecycle) {
3336                 ((ProcessorLifecycle) p).detached(this);
3337             }
3338         }
3339     }
3340
3341     private void clearPrimitiveProcessors() {
3342         for (PrimitiveQueryProcessor<?> p : primitiveProcessors.values()) {
3343             if (p instanceof ProcessorLifecycle) {
3344                 ((ProcessorLifecycle) p).clear();
3345             }
3346         }
3347     }
3348
3349     Listener resizeListener = new Listener() {
3350         @Override
3351         public void handleEvent(Event event) {
3352             // Prevent infinite recursion.
3353             if (refreshingColumnSizes)
3354                 return;
3355             //TreeColumn column = (TreeColumn) event.widget;
3356             //Column c = (Column) column.getData();
3357             refreshColumnSizes();
3358         }
3359     };
3360
3361     Listener itemDisposeListener = new Listener() {
3362         @Override
3363         public void handleEvent(Event event) {
3364             if (event.type == SWT.Dispose) {
3365                 if (event.widget instanceof TreeItem) {
3366                     TreeItem ti = (TreeItem) event.widget;
3367                     //NodeContext ctx = (NodeContext) ti.getData();
3368 //                    System.out.println("DISPOSE CONTEXT TO ITEM: " + ctx + " -> " + System.identityHashCode(ti));
3369 //                    System.out.println("  map size BEFORE: " + contextToItem.size());
3370                     @SuppressWarnings("unused")
3371                     NodeContext removed = contextToItem.removeWithRight(ti);
3372 //                    System.out.println("  REMOVED: " + removed);
3373 //                    System.out.println("  map size AFTER: " + contextToItem.size());
3374                 }
3375             }
3376         }
3377     };
3378
3379     /**
3380      *
3381      */
3382     LabelerListener labelListener = new LabelerListener() {
3383         @Override
3384         public boolean columnModified(final NodeContext context, final String key, final String newLabel) {
3385             //System.out.println("column " + key + " modified for " + context + " to " + newLabel);
3386             if (tree.isDisposed())
3387                 return false;
3388
3389             synchronized (labelRefreshRunnables) {
3390                 Runnable refresher = new Runnable() {
3391                     @Override
3392                     public void run() {
3393                         // Tree is guaranteed to be non-disposed if this is invoked.
3394
3395                         // contextToItem should be accessed only in the SWT thread to keep things thread-safe.
3396                         final TreeItem item = contextToItem.getRight(context);
3397                         if (item == null || item.isDisposed())
3398                             return;
3399
3400                         final Integer index = columnKeyToIndex.get(key);
3401                         if (index == null)
3402                             return;
3403
3404                         //System.out.println(" found index: " + index);
3405                         //System.out.println("  found item: " + item);
3406                         try {
3407                             GENodeQueryManager manager = new GENodeQueryManager(explorerContext, null, null, null);
3408
3409                             // FIXME: indexOf is quadratic
3410                             int itemIndex = 0;
3411                             TreeItem parentItem = item.getParentItem();
3412                             if (parentItem == null) {
3413                                 itemIndex = tree.indexOf(item);
3414                                 //tree.clear(parentIndex, false);
3415                             } else {
3416                                 itemIndex = parentItem.indexOf(item);
3417                                 //item.clear(parentIndex, false);
3418                             }
3419                             setTextAndImage(item, manager, context, itemIndex);
3420                         } catch (SWTException e) {
3421                             ErrorLogger.defaultLogError(e);
3422                         }
3423                     }
3424                 };
3425                 //System.out.println(System.currentTimeMillis() + " queueing label refresher: " + refresher);
3426                 labelRefreshRunnables.put(context, refresher);
3427
3428                 if (!refreshIsQueued) {
3429                     refreshIsQueued = true;
3430                     long delay = 0;
3431                     long now = System.currentTimeMillis();
3432                     long elapsed = now - lastLabelRefreshScheduled;
3433                     if (elapsed < DEFAULT_CONSECUTIVE_LABEL_REFRESH_DELAY)
3434                         delay = DEFAULT_CONSECUTIVE_LABEL_REFRESH_DELAY - elapsed;
3435                     //System.out.println("scheduling with delay: " + delay + " (" + lastLabelRefreshScheduled + " -> " + now + " = " + elapsed + ")");
3436                     if (delay > 0) {
3437                         ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {
3438                             @Override
3439                             public void run() {
3440                                 scheduleImmediateLabelRefresh();
3441                             }
3442                         }, delay, TimeUnit.MILLISECONDS);
3443                     } else {
3444                         scheduleImmediateLabelRefresh();
3445                     }
3446                     lastLabelRefreshScheduled = now;
3447                 }
3448             }
3449             return true;
3450         }
3451
3452         @Override
3453         public boolean columnsModified(final NodeContext context, final Map<String, String> columns) {
3454             System.out.println("TODO: implement GraphExplorerImpl.labelListener.columnsModified");
3455             return false;
3456         }
3457     };
3458
3459     private void scheduleImmediateLabelRefresh() {
3460         Runnable[] runnables = null;
3461         synchronized (labelRefreshRunnables) {
3462             if (labelRefreshRunnables.isEmpty())
3463                 return;
3464
3465             runnables = labelRefreshRunnables.values().toArray(new Runnable[labelRefreshRunnables.size()]);
3466             labelRefreshRunnables.clear();
3467             refreshIsQueued = false;
3468         }
3469         final Runnable[] rs = runnables;
3470
3471         if (tree.isDisposed())
3472             return;
3473         tree.getDisplay().asyncExec(new Runnable() {
3474             @Override
3475             public void run() {
3476                 if (tree.isDisposed())
3477                     return;
3478                 //System.out.println(System.currentTimeMillis() + " EXECUTING " + rs.length + " label refresh runnables");
3479                 tree.setRedraw(false);
3480                 for (Runnable r : rs) {
3481                     r.run();
3482                 }
3483                 tree.setRedraw(true);
3484             }
3485         });
3486     }
3487
3488     long                       lastLabelRefreshScheduled = 0;
3489     boolean                    refreshIsQueued           = false;
3490     Map<NodeContext, Runnable> labelRefreshRunnables     = new HashMap<NodeContext, Runnable>();
3491
3492     @SuppressWarnings("unchecked")
3493     @Override
3494     public <T> T getAdapter(Class<T> adapter) {
3495         if(ISelectionProvider.class == adapter) return (T) postSelectionProvider;
3496         else if(IPostSelectionProvider.class == adapter) return (T) postSelectionProvider;
3497         return null;
3498     }
3499
3500     @SuppressWarnings("unchecked")
3501     @Override
3502     public <T> T getControl() {
3503         return (T) tree;
3504     }
3505
3506     /* (non-Javadoc)
3507      * @see org.simantics.browsing.ui.GraphExplorer#setAutoExpandLevel(int)
3508      */
3509     @Override
3510     public void setAutoExpandLevel(int level) {
3511         this.autoExpandLevel = level;
3512     }
3513
3514     @Override
3515     public <T> NodeQueryProcessor<T> getProcessor(QueryKey<T> key) {
3516         return explorerContext.getProcessor(key);
3517     }
3518
3519     @Override
3520     public <T> PrimitiveQueryProcessor<T> getPrimitiveProcessor(PrimitiveQueryKey<T> key) {
3521         return explorerContext.getPrimitiveProcessor(key);
3522     }
3523
3524     @Override
3525     public boolean isEditable() {
3526         return editable;
3527     }
3528
3529     @Override
3530     public void setEditable(boolean editable) {
3531         if (!thread.currentThreadAccess())
3532             throw new IllegalStateException("not in SWT display thread " + thread.getThread());
3533
3534         this.editable = editable;
3535         Display display = tree.getDisplay();
3536         tree.setBackground(editable ? null : display.getSystemColor(SWT.COLOR_WIDGET_BACKGROUND));
3537     }
3538
3539     /**
3540      * For setting a more local service locator for the explorer than the global
3541      * workbench service locator. Sometimes required to give this implementation
3542      * access to local workbench services like IFocusService.
3543      *
3544      * <p>
3545      * Must be invoked during right after construction.
3546      *
3547      * @param serviceLocator
3548      *            a specific service locator or <code>null</code> to use the
3549      *            workbench global service locator
3550      */
3551     public void setServiceLocator(IServiceLocator serviceLocator) {
3552         if (serviceLocator == null && PlatformUI.isWorkbenchRunning())
3553             serviceLocator = PlatformUI.getWorkbench();
3554         this.serviceLocator = serviceLocator;
3555         if (serviceLocator != null) {
3556             this.contextService = (IContextService) serviceLocator.getService(IContextService.class);
3557             this.focusService = (IFocusService) serviceLocator.getService(IFocusService.class);
3558         }
3559     }
3560
3561     @Override
3562     public Object getClicked(Object event) {
3563         MouseEvent e = (MouseEvent)event;
3564         final Tree tree = (Tree) e.getSource();
3565         Point point = new Point(e.x, e.y);
3566         TreeItem item = tree.getItem(point);
3567
3568         // No selectable item at point?
3569         if (item == null)
3570             return null;
3571
3572         Object data = item.getData();
3573         return data;
3574     }
3575
3576 }