bundles/org.simantics.diagram/src/org/simantics/diagram/symbollibrary/ui/SymbolLibraryComposite.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.diagram.symbollibrary.ui;
  13
  14 import java.awt.datatransfer.StringSelection;
  15 import java.awt.datatransfer.Transferable;
  16 import java.awt.dnd.DnDConstants;
  17 import java.awt.dnd.DragGestureEvent;
  18 import java.awt.dnd.DragSourceDragEvent;
  19 import java.awt.dnd.DragSourceDropEvent;
  20 import java.awt.dnd.DragSourceEvent;
  21 import java.lang.ref.SoftReference;
  22 import java.util.ArrayList;
  23 import java.util.Collection;
  24 import java.util.Collections;
  25 import java.util.Comparator;
  26 import java.util.EnumSet;
  27 import java.util.HashMap;
  28 import java.util.Iterator;
  29 import java.util.List;
  30 import java.util.Map;
  31 import java.util.Set;
  32 import java.util.TreeSet;
  33 import java.util.WeakHashMap;
  34 import java.util.concurrent.ExecutorService;
  35 import java.util.concurrent.Semaphore;
  36 import java.util.concurrent.SynchronousQueue;
  37 import java.util.concurrent.ThreadFactory;
  38 import java.util.concurrent.ThreadPoolExecutor;
  39 import java.util.concurrent.TimeUnit;
  40 import java.util.concurrent.atomic.AtomicBoolean;
  41 import java.util.concurrent.atomic.AtomicInteger;
  42 import java.util.regex.Matcher;
  43 import java.util.regex.Pattern;
  44
  45 import org.eclipse.core.runtime.IAdaptable;
  46 import org.eclipse.core.runtime.IStatus;
  47 import org.eclipse.core.runtime.Status;
  48 import org.eclipse.jface.layout.GridDataFactory;
  49 import org.eclipse.jface.layout.GridLayoutFactory;
  50 import org.eclipse.jface.resource.FontDescriptor;
  51 import org.eclipse.jface.resource.JFaceResources;
  52 import org.eclipse.jface.resource.LocalResourceManager;
  53 import org.eclipse.jface.viewers.AcceptAllFilter;
  54 import org.eclipse.jface.viewers.BaseLabelProvider;
  55 import org.eclipse.jface.viewers.IFilter;
  56 import org.eclipse.jface.viewers.ISelection;
  57 import org.eclipse.jface.viewers.IStructuredContentProvider;
  58 import org.eclipse.jface.viewers.StructuredSelection;
  59 import org.eclipse.jface.viewers.Viewer;
  60 import org.eclipse.jface.viewers.ViewerFilter;
  61 import org.eclipse.nebula.widgets.pgroup.PGroup;
  62 import org.eclipse.swt.SWT;
  63 import org.eclipse.swt.custom.ScrolledComposite;
  64 import org.eclipse.swt.events.ControlAdapter;
  65 import org.eclipse.swt.events.ControlEvent;
  66 import org.eclipse.swt.events.DisposeEvent;
  67 import org.eclipse.swt.events.DisposeListener;
  68 import org.eclipse.swt.events.ExpandEvent;
  69 import org.eclipse.swt.events.ExpandListener;
  70 import org.eclipse.swt.events.ModifyEvent;
  71 import org.eclipse.swt.events.ModifyListener;
  72 import org.eclipse.swt.graphics.Color;
  73 import org.eclipse.swt.graphics.Point;
  74 import org.eclipse.swt.graphics.Rectangle;
  75 import org.eclipse.swt.layout.GridData;
  76 import org.eclipse.swt.widgets.Composite;
  77 import org.eclipse.swt.widgets.Control;
  78 import org.eclipse.swt.widgets.Event;
  79 import org.eclipse.swt.widgets.Listener;
  80 import org.eclipse.swt.widgets.Widget;
  81 import org.simantics.db.ReadGraph;
  82 import org.simantics.db.Resource;
  83 import org.simantics.db.common.procedure.adapter.ListenerAdapter;
  84 import org.simantics.db.common.request.UnaryRead;
  85 import org.simantics.db.exception.DatabaseException;
  86 import org.simantics.diagram.internal.Activator;
  87 import org.simantics.diagram.symbolcontribution.CompositeSymbolGroup;
  88 import org.simantics.diagram.symbolcontribution.IIdentifiedObject;
  89 import org.simantics.diagram.symbolcontribution.ISymbolProvider;
  90 import org.simantics.diagram.symbolcontribution.IdentifiedObject;
  91 import org.simantics.diagram.symbolcontribution.SymbolProviderFactory;
  92 import org.simantics.diagram.symbollibrary.IModifiableSymbolGroup;
  93 import org.simantics.diagram.symbollibrary.ISymbolGroup;
  94 import org.simantics.diagram.symbollibrary.ISymbolGroupListener;
  95 import org.simantics.diagram.symbollibrary.ISymbolItem;
  96 import org.simantics.diagram.symbollibrary.ui.FilterConfiguration.Mode;
  97 import org.simantics.diagram.synchronization.ErrorHandler;
  98 import org.simantics.diagram.synchronization.LogErrorHandler;
  99 import org.simantics.diagram.synchronization.SynchronizationHints;
 100 import org.simantics.g2d.canvas.Hints;
 101 import org.simantics.g2d.canvas.ICanvasContext;
 102 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;
 103 import org.simantics.g2d.canvas.impl.DependencyReflection.Reference;
 104 import org.simantics.g2d.chassis.AWTChassis;
 105 import org.simantics.g2d.diagram.DiagramUtils;
 106 import org.simantics.g2d.diagram.handler.PickContext;
 107 import org.simantics.g2d.diagram.handler.PickRequest;
 108 import org.simantics.g2d.diagram.handler.layout.FlowLayout;
 109 import org.simantics.g2d.diagram.participant.AbstractDiagramParticipant;
 110 import org.simantics.g2d.diagram.participant.Selection;
 111 import org.simantics.g2d.diagram.participant.pointertool.PointerInteractor;
 112 import org.simantics.g2d.dnd.IDragSourceParticipant;
 113 import org.simantics.g2d.element.ElementClass;
 114 import org.simantics.g2d.element.ElementHints;
 115 import org.simantics.g2d.element.IElement;
 116 import org.simantics.g2d.element.handler.StaticSymbol;
 117 import org.simantics.g2d.event.adapter.SWTMouseEventAdapter;
 118 import org.simantics.g2d.gallery.GalleryViewer;
 119 import org.simantics.g2d.gallery.ILabelProvider;
 120 import org.simantics.g2d.image.DefaultImages;
 121 import org.simantics.g2d.image.Image;
 122 import org.simantics.g2d.image.Image.Feature;
 123 import org.simantics.g2d.image.impl.ImageProxy;
 124 import org.simantics.g2d.participant.TransformUtil;
 125 import org.simantics.scenegraph.g2d.events.EventTypes;
 126 import org.simantics.scenegraph.g2d.events.IEventHandler;
 127 import org.simantics.scenegraph.g2d.events.MouseEvent;
 128 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseDoubleClickedEvent;
 129 import org.simantics.scenegraph.g2d.events.MouseEvent.MouseDragBegin;
 130 import org.simantics.scl.runtime.tuple.Tuple2;
 131 import org.simantics.ui.SimanticsUI;
 132 import org.simantics.ui.dnd.LocalObjectTransfer;
 133 import org.simantics.ui.dnd.LocalObjectTransferable;
 134 import org.simantics.ui.dnd.MultiTransferable;
 135 import org.simantics.ui.dnd.PlaintextTransfer;
 136 import org.simantics.utils.datastructures.cache.ProvisionException;
 137 import org.simantics.utils.datastructures.hints.IHintContext;
 138 import org.simantics.utils.threads.AWTThread;
 139 import org.simantics.utils.threads.IThreadWorkQueue;
 140 import org.simantics.utils.threads.SWTThread;
 141 import org.simantics.utils.threads.ThreadUtils;
 142 import org.simantics.utils.ui.ErrorLogger;
 143 import org.simantics.utils.ui.ExceptionUtils;
 144
 145 /**
 146  * @author Tuukka Lehtonen
 147  */
 148 public class SymbolLibraryComposite extends Composite {
 149
 150     private static final int    FILTER_DELAY           = 500;
 151
 152     private static final String KEY_VIEWER_INITIALIZED = "viewer.initialized";
 153     private static final String KEY_USER_EXPANDED      = "userExpanded";
 154     private static final String KEY_GROUP_FILTERED     = "groupFiltered";
 155
 156     /** Root composite */
 157     ScrolledComposite           sc;
 158     Composite                   c;
 159     IThreadWorkQueue            swtThread;
 160     boolean                     defaultExpanded = false;
 161     ISymbolProvider             symbolProvider;
 162     AtomicBoolean               disposed = new AtomicBoolean(false);
 163
 164     /**
 165      * This value is incremented each time a load method is called and symbol
 166      * group population is started. It can be used by
 167      * {@link #populateGroups(ExecutorService, Control, Iterator, IFilter)} to
 168      * tell whether it should stop its population job because a later load
 169      * will override its results anyway.
 170      */
 171     AtomicInteger                               loadCount              = new AtomicInteger();
 172
 173     Map<ISymbolGroup, PGroup>                   groups                 = new HashMap<>();
 174     Map<ISymbolGroup, GalleryViewer>            groupViewers           = new HashMap<>();
 175     Map<Object, Boolean>                        expandedGroups         = new HashMap<>();
 176     LocalResourceManager                        resourceManager;
 177     FilterArea                                  filter;
 178
 179     ThreadFactory threadFactory = new ThreadFactory() {
 180         @Override
 181         public Thread newThread(Runnable r) {
 182             Thread t = new Thread(r, "Symbol Library Loader");
 183             t.setDaemon(false);
 184             t.setPriority(Thread.NORM_PRIORITY);
 185             return t;
 186         }
 187     };
 188
 189     Semaphore                                   loaderSemaphore        = new Semaphore(1);
 190     ExecutorService                             loaderExecutor         = new ThreadPoolExecutor(0, Integer.MAX_VALUE,
 191             2L, TimeUnit.SECONDS,
 192             new SynchronousQueue<Runnable>(),
 193             threadFactory);
 194
 195     /**
 196      * Used to prevent annoying reloading of symbols when groups are closed and
 197      * reopened by not always having to schedule an {@link ImageLoader} in
 198      * {@link LabelProvider#getImage(Object)}.
 199      */
 200     Map<ISymbolItem, SoftReference<ImageProxy>> imageCache = new WeakHashMap<ISymbolItem, SoftReference<ImageProxy>>();
 201
 202     static final Pattern                        ANY                    = Pattern.compile(".*");
 203     Pattern                                     currentFilterPattern   = ANY;
 204
 205     FilterConfiguration                         config                 = new FilterConfiguration();
 206     IFilter                                     currentGroupFilter     = AcceptAllFilter.getInstance();
 207
 208     ErrorHandler                                errorHandler           = LogErrorHandler.INSTANCE;
 209
 210     static class GroupDescriptor {
 211         public final ISymbolGroup lib;
 212         public final String       label;
 213         public final String       description;
 214         public final PGroup       group;
 215
 216         public GroupDescriptor(ISymbolGroup lib, String label, String description, PGroup group) {
 217             assert(lib != null);
 218             assert(label != null);
 219             this.lib = lib;
 220             this.label = label;
 221             this.description = description;
 222             this.group = group;
 223         }
 224     }
 225
 226     Comparator<GroupDescriptor> groupComparator = new Comparator<GroupDescriptor>() {
 227         @Override
 228         public int compare(GroupDescriptor o1, GroupDescriptor o2) {
 229             return o1.label.compareToIgnoreCase(o2.label);
 230         }
 231     };
 232
 233     static final EnumSet<Feature> VOLATILE = EnumSet.of(Feature.Volatile);
 234
 235     static class PendingImage extends ImageProxy {
 236         EnumSet<Feature> features;
 237         PendingImage(Image source, EnumSet<Feature> features) {
 238             super(source);
 239             this.features = features;
 240         }
 241         @Override
 242         public EnumSet<Feature> getFeatures() {
 243             return features;
 244         }
 245     }
 246
 247     class LabelProvider extends BaseLabelProvider implements ILabelProvider {
 248         @Override
 249         public Image getImage(final Object element) {
 250             ISymbolItem item = (ISymbolItem) element;
 251             // Use a volatile ImageProxy to make the image loading asynchronous.
 252             ImageProxy proxy = null;
 253             SoftReference<ImageProxy> proxyRef = imageCache.get(item);
 254             if (proxyRef != null)
 255                 proxy = proxyRef.get();
 256             if (proxy == null) {
 257                 proxy = new PendingImage(DefaultImages.HOURGLASS.get(), VOLATILE);
 258                 imageCache.put(item, new SoftReference<ImageProxy>(proxy));
 259                 ThreadUtils.getNonBlockingWorkExecutor().schedule(new ImageLoader(proxy, item), 100, TimeUnit.MILLISECONDS);
 260             }
 261             return proxy;
 262         }
 263         @Override
 264         public String getText(final Object element) {
 265             return ((ISymbolItem) element).getName();
 266         }
 267         @Override
 268         public String getToolTipText(Object element) {
 269             ISymbolItem item = (ISymbolItem) element;
 270             String name = item.getName();
 271             String desc = item.getDescription();
 272             return name.equals(desc) ? name : name + " - " + desc;
 273         }
 274
 275         @Override
 276         public java.awt.Image getToolTipImage(Object object) {
 277             return null;
 278         }
 279         @Override
 280         public Color getToolTipBackgroundColor(Object object) {
 281             return null;
 282         }
 283
 284         @Override
 285         public Color getToolTipForegroundColor(Object object) {
 286             return null;
 287         }
 288     }
 289
 290     public SymbolLibraryComposite(final Composite parent, int style, SymbolProviderFactory symbolProvider) {
 291         super(parent, style);
 292         init(parent, style);
 293         SimanticsUI.getSession().asyncRequest(new CreateSymbolProvider(symbolProvider), new SymbolProviderListener());
 294         addDisposeListener(new DisposeListener() {
 295             @Override
 296             public void widgetDisposed(DisposeEvent e) {
 297                 disposed.set(true);
 298             }
 299         });
 300     }
 301
 302     /**
 303      *
 304      */
 305     static class CreateSymbolProvider extends UnaryRead<SymbolProviderFactory, ISymbolProvider> {
 306         public CreateSymbolProvider(SymbolProviderFactory factory) {
 307             super(factory);
 308         }
 309         @Override
 310         public ISymbolProvider perform(ReadGraph graph) throws DatabaseException {
 311             //System.out.println("CreateSymbolProvider.perform: " + parameter);
 312             ISymbolProvider provider = parameter.create(graph);
 313             //print(provider);
 314             return provider;
 315         }
 316     }
 317
 318     @SuppressWarnings("unused")
 319     private static void print(ISymbolProvider provider) {
 320         for (ISymbolGroup grp : provider.getSymbolGroups()) {
 321             System.out.println("GROUP: " + grp);
 322             if (grp instanceof CompositeSymbolGroup) {
 323                 CompositeSymbolGroup cgrp = (CompositeSymbolGroup) grp;
 324                 for (ISymbolGroup grp2 : cgrp.getGroups()) {
 325                     System.out.println("\tGROUP: " + grp2);
 326                 }
 327             }
 328         }
 329     }
 330
 331     /**
 332      *
 333      */
 334     class SymbolProviderListener extends ListenerAdapter<ISymbolProvider> {
 335         @Override
 336         public void exception(Throwable t) {
 337             ErrorLogger.defaultLogError(t);
 338         }
 339         @Override
 340         public void execute(ISymbolProvider result) {
 341             //System.out.println("SymbolProviderListener: " + result);
 342             symbolProvider = result;
 343             if (result != null) {
 344                 Collection<ISymbolGroup> groups = result.getSymbolGroups();
 345                 //print(result);
 346                 load(groups);
 347             }
 348         }
 349         public boolean isDisposed() {
 350                 boolean result = SymbolLibraryComposite.this.isDisposed();
 351             return result;
 352         }
 353     }
 354
 355     private void init(final Composite parent, int style) {
 356         GridLayoutFactory.fillDefaults().spacing(0,0).applyTo(this);
 357 //        setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_RED));
 358
 359         this.resourceManager = new LocalResourceManager(JFaceResources.getResources(getDisplay()), this);
 360         swtThread = SWTThread.getThreadAccess(this);
 361
 362         filter = new FilterArea(this, SWT.NONE);
 363         GridDataFactory.fillDefaults().grab(true, false).applyTo(filter);
 364         filter.getText().addModifyListener(new ModifyListener() {
 365             int modCount = 0;
 366             //long lastModificationTime = -1000;
 367             @Override
 368             public void modifyText(ModifyEvent e) {
 369                 scheduleDelayedFilter(FILTER_DELAY, TimeUnit.MILLISECONDS);
 370             }
 371             private void scheduleDelayedFilter(long filterDelay, TimeUnit delayUnit) {
 372                 final String text = filter.getText().getText();
 373
 374                 //long time = System.currentTimeMillis();
 375                 //long delta = time - lastModificationTime;
 376                 //lastModificationTime = time;
 377
 378                 final int count = ++modCount;
 379                 ThreadUtils.getNonBlockingWorkExecutor().schedule(new Runnable() {
 380                     @Override
 381                     public void run() {
 382                         int newCount = modCount;
 383                         if (newCount != count)
 384                             return;
 385
 386                         ThreadUtils.asyncExec(swtThread, new Runnable() {
 387                             @Override
 388                             public void run() {
 389                                 if (sc.isDisposed())
 390                                     return;
 391                                 if (!filterGroups(text)) {
 392                                     scheduleDelayedFilter(100, TimeUnit.MILLISECONDS);
 393                                 }
 394                             }
 395                         });
 396                     }
 397                 }, filterDelay, delayUnit);
 398             }
 399         });
 400
 401         sc = new ScrolledComposite(this, SWT.V_SCROLL);
 402         GridDataFactory.fillDefaults().grab(true, true).applyTo(sc);
 403         sc.setAlwaysShowScrollBars(false);
 404         sc.setExpandHorizontal(false);
 405         sc.setExpandVertical(false);
 406         sc.getVerticalBar().setIncrement(30);
 407         sc.getVerticalBar().setPageIncrement(200);
 408         sc.addControlListener( new ControlAdapter() {
 409             @Override
 410             public void controlResized(ControlEvent e) {
 411                 //System.out.println("ScrolledComposite resized: " + sc.getSize());
 412                 refreshScrolledComposite();
 413             }
 414         });
 415         //sc.setBackground(sc.getDisplay().getSystemColor(SWT.COLOR_RED));
 416
 417         c = new Composite(sc, 0);
 418         c.setVisible(false);
 419         GridLayoutFactory.fillDefaults().spacing(0, 0).applyTo(c);
 420         //c.setBackground(c.getDisplay().getSystemColor(SWT.COLOR_BLUE));
 421
 422         sc.setContent(c);
 423
 424         // No event context <-> mouse on empty space in symbol library
 425         SWTMouseEventAdapter noContextEventAdapter = new SWTMouseEventAdapter(null, externalEventHandler);
 426         installMouseEventAdapter(sc, noContextEventAdapter);
 427         installMouseEventAdapter(c, noContextEventAdapter);
 428
 429         c.addDisposeListener(new DisposeListener() {
 430             @Override
 431             public void widgetDisposed(DisposeEvent e) {
 432                 // Remember to shutdown the executor
 433                 loaderExecutor.shutdown();
 434                 groupViewers.clear();
 435             }
 436         });
 437     }
 438
 439     void refreshScrolledComposite() {
 440         // Execute asynchronously to give the UI events triggering this method
 441         // call time to run through before actually doing any resizing.
 442         // Otherwise the result will lag behind reality when scrollbar
 443         // visibility is toggled by the toolkit.
 444         ThreadUtils.asyncExec(swtThread, new Runnable() {
 445             @Override
 446             public void run() {
 447                 if (sc.isDisposed())
 448                     return;
 449                 syncRefreshScrolledComposite();
 450             }
 451         });
 452     }
 453
 454     void syncRefreshScrolledComposite() {
 455         // Execute asynchronously to give the UI events triggering this method
 456         // call time to run through before actually doing any resizing.
 457         // Otherwise the result will lag behind reality when scrollbar
 458         // visibility is toggled by the toolkit.
 459         Rectangle r = sc.getClientArea();
 460         Point contentSize = c.computeSize(r.width, SWT.DEFAULT);
 461         //System.out.println("[" + Thread.currentThread() + "] computed content size: " + contentSize + ", " + r);
 462         c.setSize(contentSize);
 463     }
 464
 465     /**
 466      * (Re-)Load symbol groups, refresh the content
 467      */
 468     void load(Collection<ISymbolGroup> _libraries) {
 469         if (_libraries == null)
 470             _libraries = Collections.emptyList();
 471         final Collection<ISymbolGroup> libraries = _libraries;
 472         if (loaderExecutor.isShutdown())
 473             return;
 474         loaderExecutor.execute(new Runnable() {
 475             @Override
 476             public void run() {
 477                 // Increment loadCount to signal that a new load cycle is on the way.
 478                 Integer loadId = loadCount.incrementAndGet();
 479                 try {
 480                     loaderSemaphore.acquire();
 481                     beginPopulate(loadId);
 482                 } catch (InterruptedException e) {
 483                     ExceptionUtils.logError(e);
 484                 } catch (RuntimeException e) {
 485                     loaderSemaphore.release();
 486                     ExceptionUtils.logAndShowError(e);
 487                 } catch (Error e) {
 488                     loaderSemaphore.release();
 489                     ExceptionUtils.logAndShowError(e);
 490                 }
 491             }
 492
 493             void beginPopulate(Integer loadId) {
 494                 synchronized (groups) {
 495                     // Must use toArray since groups are removed within the loop
 496                     for (Iterator<Map.Entry<ISymbolGroup, PGroup>> it = groups.entrySet().iterator(); it.hasNext();) {
 497                         Map.Entry<ISymbolGroup, PGroup> entry = it.next();
 498                         if (!libraries.contains(entry.getKey())) {
 499                             PGroup group = entry.getValue();
 500                             it.remove();
 501                             groupViewers.remove(entry.getKey());
 502                             if (group != null && !group.isDisposed())
 503                                 ThreadUtils.asyncExec(swtThread, disposer(group));
 504                         }
 505                     }
 506                     Set<GroupDescriptor> groupDescs = new TreeSet<GroupDescriptor>(groupComparator);
 507                     for (ISymbolGroup lib : libraries) {
 508                         PGroup group = groups.get(lib);
 509                         //String label = group != null ? group.getText() : lib.getName();
 510                         String label = lib.getName();
 511                         String description = lib.getDescription();
 512                         groupDescs.add(new GroupDescriptor(lib, label, description, group));
 513                     }
 514
 515                     // Populate all the missing groups.
 516                     IFilter groupFilter = currentGroupFilter;
 517                     populateGroups(
 518                             loaderExecutor,
 519                             null,
 520                             groupDescs.iterator(),
 521                             groupFilter,
 522                             loadId,
 523                             new Runnable() {
 524                                 @Override
 525                                 public void run() {
 526                                     loaderSemaphore.release();
 527                                 }
 528                             });
 529                 }
 530             }
 531         });
 532     }
 533
 534     void populateGroups(
 535             final ExecutorService exec,
 536             final Control lastGroup,
 537             final Iterator<GroupDescriptor> iter,
 538             final IFilter groupFilter,
 539             final Integer loadId,
 540             final Runnable loadComplete)
 541     {
 542         // Check whether to still continue this population or not.
 543         int currentLoadId = loadCount.get();
 544         if (currentLoadId != loadId) {
 545             loadComplete.run();
 546             return;
 547         }
 548
 549         if (!iter.hasNext()) {
 550             ThreadUtils.asyncExec(swtThread, new Runnable() {
 551                 @Override
 552                 public void run() {
 553                     if (filter.isDisposed() || c.isDisposed())
 554                         return;
 555                     //filter.focus();
 556                     c.setVisible(true);
 557                 }
 558             });
 559             loadComplete.run();
 560             return;
 561         }
 562
 563         final GroupDescriptor desc = iter.next();
 564
 565         ThreadUtils.asyncExec(swtThread, new Runnable() {
 566             @Override
 567             public void run() {
 568                 // Must make sure that loadComplete is invoked under error
 569                 // circumstances.
 570                 try {
 571                     populateGroup();
 572                 } catch (RuntimeException e) {
 573                     loadComplete.run();
 574                     ExceptionUtils.logAndShowError(e);
 575                 } catch (Error e) {
 576                     loadComplete.run();
 577                     ExceptionUtils.logAndShowError(e);
 578                 }
 579             }
 580
 581             public void populateGroup() {
 582                 if (c.isDisposed()) {
 583                     loadComplete.run();
 584                     return;
 585                 }
 586                 // $ SWT-begin
 587                 //System.out.println("populating: " + desc.label);
 588                 PGroup group = desc.group;
 589                 Runnable chainedCompletionCallback = loadComplete;
 590                 if (group == null || group.isDisposed()) {
 591
 592                     group = new PGroup(c, SWT.NONE);
 593 //                    group.addListener(SWT.KeyUp, filterActivationListener);
 594 //                    group.addListener(SWT.KeyDown, filterActivationListener);
 595 //                    group.addListener(SWT.FocusIn, filterActivationListener);
 596 //                    group.addListener(SWT.FocusOut, filterActivationListener);
 597 //                    group.addListener(SWT.MouseDown, filterActivationListener);
 598 //                    group.addListener(SWT.MouseUp, filterActivationListener);
 599 //                    group.addListener(SWT.MouseDoubleClick, filterActivationListener);
 600 //                    group.addListener(SWT.Arm, filterActivationListener);
 601                     if (lastGroup != null) {
 602                         group.moveBelow(lastGroup);
 603                     } else {
 604                         group.moveAbove(null);
 605                     }
 606
 607                     installMouseEventAdapter(group, new SWTMouseEventAdapter(group, externalEventHandler));
 608
 609                     groups.put(desc.lib, group);
 610
 611                     Boolean shouldBeExpanded = expandedGroups.get(symbolGroupToKey(desc.lib));
 612                     if (shouldBeExpanded == null)
 613                         shouldBeExpanded = defaultExpanded;
 614                     group.setData(KEY_USER_EXPANDED, shouldBeExpanded);
 615
 616                     group.setExpanded(shouldBeExpanded);
 617                     group.setFont(resourceManager.createFont(FontDescriptor.createFrom(group.getFont()).setStyle(SWT.NORMAL).increaseHeight(-1)));
 618                     GridDataFactory.fillDefaults().align(SWT.FILL, SWT.BEGINNING).grab(true, false).applyTo(group);
 619                     GridLayoutFactory.fillDefaults().spacing(0, 0).applyTo(group);
 620                     group.addExpandListener(groupExpandListener);
 621
 622                     // Track group content changes if possible.
 623                     if (desc.lib instanceof IModifiableSymbolGroup) {
 624                         IModifiableSymbolGroup mod = (IModifiableSymbolGroup) desc.lib;
 625                         mod.addListener(groupListener);
 626                     }
 627
 628                     if (shouldBeExpanded) {
 629                         //System.out.println("WAS EXPANDED(" + desc.label + ", " + symbolGroupToKey(desc.lib) + ", " + shouldBeExpanded + ")");
 630                         PGroup expandedGroup = group;
 631                         chainedCompletionCallback = () -> {
 632                             // Chain callback to expand this group when the loading is otherwise completed.
 633                             ThreadUtils.asyncExec(swtThread, () -> setExpandedState(expandedGroup, true, true));
 634                             loadComplete.run();
 635                         };
 636                     }
 637                 }
 638
 639                 group.setData(SymbolLibraryKeys.KEY_GROUP, desc.lib);
 640                 group.setText(desc.label);
 641                 group.setToolTipText(desc.description);
 642
 643                 // Hide the group immediately if necessary.
 644                 boolean groupFiltered = !groupFilter.select(desc.label);
 645                 group.setData(KEY_GROUP_FILTERED, Boolean.valueOf(groupFiltered));
 646                 if (groupFiltered)
 647                     setGroupVisible(group, false);
 648
 649                 syncRefreshScrolledComposite();
 650
 651                 final PGroup group_ = group;
 652                 Runnable newCompletionCallback = chainedCompletionCallback;
 653                 exec.execute(() -> {
 654                     populateGroups(exec, group_, iter, groupFilter, loadId, newCompletionCallback);
 655                 });
 656             }
 657         });
 658     }
 659
 660     protected void installMouseEventAdapter(Control onControl, SWTMouseEventAdapter eventAdapter) {
 661         onControl.addMouseListener(eventAdapter);
 662         onControl.addMouseTrackListener(eventAdapter);
 663         onControl.addMouseMoveListener(eventAdapter);
 664         onControl.addMouseWheelListener(eventAdapter);
 665     }
 666
 667     /**
 668      * @param group
 669      * @return <code>null</code> if GalleryViewer is currently being created
 670      */
 671     GalleryViewer initializeGroup(final PGroup group) {
 672         if (group.isDisposed())
 673             return null;
 674
 675         //System.out.println("initializeGroup(" + group.getText() + ")");
 676
 677         synchronized (group) {
 678             if (group.getData(KEY_VIEWER_INITIALIZED) != null) {
 679                 return (GalleryViewer) group.getData(SymbolLibraryKeys.KEY_GALLERY);
 680             }
 681             group.setData(KEY_VIEWER_INITIALIZED, Boolean.TRUE);
 682         }
 683
 684         //System.out.println("initializing group: " + group.getText());
 685
 686         // NOTE: this will NOT stop to wait until the SWT/AWT UI
 687         // population has been completed.
 688         GalleryViewer viewer = new GalleryViewer(group);
 689
 690         ISymbolGroup input = (ISymbolGroup) group.getData(SymbolLibraryKeys.KEY_GROUP);
 691         initializeViewer(group, input, viewer);
 692
 693         groupViewers.put(input, viewer);
 694         group.setData(SymbolLibraryKeys.KEY_GALLERY, viewer);
 695
 696         //System.out.println("initialized group: " + group.getText());
 697
 698         return viewer;
 699     }
 700
 701     void initializeViewer(final PGroup group, final ISymbolGroup input, final GalleryViewer viewer) {
 702         GridDataFactory.fillDefaults().align(SWT.FILL, SWT.BEGINNING).grab(true, false).applyTo(viewer.getControl());
 703         viewer.addDragSupport(new DragSourceParticipant());
 704         viewer.setAlign(FlowLayout.Align.Left);
 705         viewer.getDiagram().setHint(SynchronizationHints.ERROR_HANDLER, errorHandler);
 706
 707         viewer.setContentProvider(new IStructuredContentProvider() {
 708
 709             /**
 710              * Returns the elements in the input, which must be either an array or a
 711              * <code>Collection</code>.
 712              */
 713             @Override
 714             public Object[] getElements(Object inputElement) {
 715                 if(inputElement == null) return new Object[0];
 716                 return ((ISymbolGroup)inputElement).getItems();
 717             }
 718
 719             /**
 720              * This implementation does nothing.
 721              */
 722             @Override
 723             public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
 724                 // do nothing.
 725             }
 726
 727             /**
 728              * This implementation does nothing.
 729              */
 730             @Override
 731             public void dispose() {
 732                 // do nothing.
 733             }
 734
 735         });
 736         viewer.setLabelProvider(new LabelProvider());
 737         viewer.setInput(input);
 738
 739         // Add event handler that closes libraries on double clicks into empty
 740         // space in library.
 741         viewer.getCanvasContext().getEventHandlerStack().add(new IEventHandler() {
 742             @Override
 743             public int getEventMask() {
 744                 return EventTypes.MouseDoubleClickMask;
 745             }
 746
 747             @Override
 748             public boolean handleEvent(org.simantics.scenegraph.g2d.events.Event e) {
 749                 if (externalEventHandler.handleEvent(e))
 750                     return true;
 751
 752                 if (e instanceof MouseDoubleClickedEvent) {
 753                     PickRequest req = new PickRequest(((MouseDoubleClickedEvent) e).controlPosition);
 754                     Collection<IElement> result = new ArrayList<IElement>();
 755                     DiagramUtils.pick(viewer.getDiagram(), req, result);
 756                     if (!result.isEmpty())
 757                         return false;
 758
 759                     //System.out.println("NOTHING CLICKED");
 760                     if (group.isDisposed())
 761                         return false;
 762                     group.getDisplay().asyncExec(() -> {
 763                         if (group.isDisposed())
 764                             return;
 765
 766                         boolean exp = !group.getExpanded();
 767                         group.setData(KEY_USER_EXPANDED, Boolean.valueOf(exp));
 768                         setGroupExpandedWithoutNotification(group, exp);
 769                         refreshScrolledComposite();
 770                     });
 771                     return true;
 772                 }
 773                 return false;
 774             }
 775         }, 0);
 776     }
 777
 778     static String toPatternString(String filter) {
 779         return DefaultFilterStrategy.defaultToPatternString(filter, true);
 780     }
 781
 782     static class SymbolItemFilter extends ViewerFilter {
 783         private final String string;
 784         private final Matcher m;
 785
 786         public SymbolItemFilter(String string, Pattern pattern) {
 787             this.string = string;
 788             this.m = pattern.matcher("");
 789         }
 790
 791         @Override
 792         public boolean select(Viewer viewer, Object parentElement, Object element) {
 793             if (element instanceof ISymbolItem) {
 794                 ISymbolItem item = (ISymbolItem) element;
 795                 return matchesFilter(item.getName()) || matchesFilter(item.getDescription());
 796             } else if (element instanceof ISymbolGroup) {
 797                 ISymbolGroup group = (ISymbolGroup) element;
 798                 return matchesFilter(group.getName());
 799             }
 800             return false;
 801         }
 802
 803         private boolean matchesFilter(String str) {
 804             m.reset(str.toLowerCase());
 805             boolean matches = m.matches();
 806             //System.out.println(pattern + ": " + str + ": " + (matches ? "PASS" : "FAIL"));
 807             return matches;
 808         }
 809
 810         @Override
 811         public int hashCode() {
 812             return string == null ? 0 : string.hashCode();
 813         }
 814
 815         @Override
 816         public boolean equals(Object obj) {
 817             if (this == obj)
 818                 return true;
 819             if (obj == null)
 820                 return false;
 821             if (getClass() != obj.getClass())
 822                 return false;
 823             SymbolItemFilter other = (SymbolItemFilter) obj;
 824             if (string == null) {
 825                 if (other.string != null)
 826                     return false;
 827             } else if (!string.equals(other.string))
 828                 return false;
 829             return true;
 830         }
 831     }
 832
 833     static Pattern toPattern(String filterText) {
 834         String regExFilter = toPatternString(filterText);
 835         Pattern pattern = regExFilter != null ? Pattern.compile(regExFilter) : ANY;
 836         return pattern;
 837     }
 838
 839     static IFilter composeFilter(final FilterConfiguration config) {
 840         final Mode mode = config.getMode();
 841         final List<Pattern> patterns = new ArrayList<Pattern>();
 842         for (GroupFilter f : config.getFilters()) {
 843             if (f.isActive())
 844                 patterns.add(toPattern(f.getFilterText()));
 845         }
 846         return new IFilter() {
 847             @Override
 848             public boolean select(Object toTest) {
 849                 if (patterns.isEmpty())
 850                     return true;
 851
 852                 String s = (String) toTest;
 853                 switch (mode) {
 854                     case AND:
 855                         for (Pattern pat : patterns) {
 856                             Matcher m = pat.matcher(s.toLowerCase());
 857                             //System.out.println(s + ": " + (m.matches() ? "PASS" : "FAIL"));
 858                             if (!m.matches())
 859                                 return false;
 860                         }
 861                         return true;
 862                     case OR:
 863                         for (Pattern pat : patterns) {
 864                             Matcher m = pat.matcher(s.toLowerCase());
 865                             //System.out.println(s + ": " + (m.matches() ? "PASS" : "FAIL"));
 866                             if (m.matches())
 867                                 return true;
 868                         }
 869                         return false;
 870                     default:
 871                         throw new Error("Shouldn't happen");
 872                 }
 873             }
 874         };
 875     }
 876
 877     void updateFilterConfiguration(FilterConfiguration config) {
 878         this.config = config;
 879         IFilter filter = composeFilter(config);
 880         this.currentGroupFilter = filter;
 881     }
 882
 883     void applyGroupFilters() {
 884         IFilter groupFilter = this.currentGroupFilter;
 885         final boolean[] changed = new boolean[] { false };
 886
 887         Control[] grps = c.getChildren();
 888         for (Control ctrl : grps) {
 889             final PGroup grp = (PGroup) ctrl;
 890             boolean visible = grp.getVisible();
 891             boolean shouldBeVisible = groupFilter.select(grp.getText());
 892             boolean change = visible != shouldBeVisible;
 893             changed[0] |= change;
 894
 895             grp.setData(KEY_GROUP_FILTERED, Boolean.valueOf(!shouldBeVisible));
 896             if (change) {
 897                 setGroupVisible(grp, shouldBeVisible);
 898             }
 899         }
 900
 901         ThreadUtils.asyncExec(swtThread, new Runnable() {
 902             @Override
 903             public void run() {
 904                 if (c.isDisposed())
 905                     return;
 906                 if (changed[0]) {
 907                     c.layout(true);
 908                     syncRefreshScrolledComposite();
 909                 }
 910             }
 911         });
 912     }
 913
 914     /**
 915      * Filters the symbol groups and makes them visible/invisible as necessary.
 916      * Invoke only from the SWT thread.
 917      *
 918      * @param text the filter text given by the client
 919      * @return <code>true</code> if all groups were successfully filtered
 920      *         without asynchronous results
 921      */
 922     boolean filterGroups(String text) {
 923         //System.out.println("FILTERING WITH TEXT: " + text);
 924
 925         String regExFilter = toPatternString(text);
 926         Pattern pattern = regExFilter != null ? Pattern.compile(regExFilter) : ANY;
 927
 928         this.currentFilterPattern = pattern;
 929         final boolean[] changed = new boolean[] { false };
 930         boolean filteringComplete = true;
 931
 932         ViewerFilter filter = null;
 933         if (regExFilter != null)
 934             filter = new SymbolItemFilter(regExFilter, pattern);
 935
 936         Control[] grps = c.getChildren();
 937         for (Control ctrl : grps) {
 938             final PGroup grp = (PGroup) ctrl;
 939             if (grp.isDisposed())
 940                 continue;
 941             Boolean contentsChanged = filterGroup(grp, filter);
 942             if (contentsChanged == null)
 943                 filteringComplete = false;
 944             else
 945                 changed[0] = contentsChanged;
 946         }
 947
 948         ThreadUtils.asyncExec(swtThread, new Runnable() {
 949             @Override
 950             public void run() {
 951                 if (c.isDisposed())
 952                     return;
 953                 if (changed[0]) {
 954                     c.layout(true);
 955                     syncRefreshScrolledComposite();
 956                 }
 957             }
 958         });
 959
 960         return filteringComplete;
 961     }
 962
 963     static boolean objectEquals(Object o1, Object o2) {
 964         if (o1==o2) return true;
 965         if (o1==null && o2==null) return true;
 966         if (o1==null || o2==null) return false;
 967         return o1.equals(o2);
 968     }
 969
 970     /**
 971      * @param grp
 972      * @return <code>true</code> if the filtering caused changes in the group,
 973      *         <code>false</code> if not, and <code>null</code> if filtering
 974      *         could not be performed yet, meaning results need to be asked
 975      *         later
 976      */
 977     private Boolean filterGroup(PGroup grp, ViewerFilter filter) {
 978         boolean changed = false;
 979         GalleryViewer viewer = initializeGroup(grp);
 980         if (viewer == null)
 981             return null;
 982
 983         ViewerFilter lastFilter = viewer.getFilter();
 984
 985         boolean groupFiltered = Boolean.TRUE.equals(grp.getData(KEY_GROUP_FILTERED));
 986         boolean userExpanded = Boolean.TRUE.equals(grp.getData(KEY_USER_EXPANDED));
 987         final boolean expanded = grp.getExpanded();
 988         final boolean visible = grp.getVisible();
 989         final boolean filterChanged = !objectEquals(filter, lastFilter);
 990
 991         // Find out how much data would be shown with the new filter.
 992         viewer.setFilter(filter);
 993         Object[] elements = viewer.getFilteredElements();
 994
 995         ISymbolGroup symbolGroup = (ISymbolGroup) grp.getData(SymbolLibraryKeys.KEY_GROUP);
 996         boolean filterMatchesGroup = filter != null && filter.select(viewer, null, symbolGroup);
 997         boolean shouldBeVisible = !groupFiltered && (elements.length > 0 || filterMatchesGroup);
 998         boolean shouldBeExpanded = shouldBeVisible && (filter != null || userExpanded);
 999
1000 //        System.out.format("%40s: visible/should be = %5s %5s,  expanded/user expanded/should be = %5s %5s %5s\n",
1001 //                grp.getText(),
1002 //                String.valueOf(visible),
1003 //                String.valueOf(shouldBeVisible),
1004 //                String.valueOf(expanded),
1005 //                String.valueOf(userExpanded),
1006 //                String.valueOf(shouldBeExpanded));
1007
1008         if (filterChanged || visible != shouldBeVisible || expanded != shouldBeExpanded) {
1009             changed = true;
1010
1011             if (shouldBeVisible == userExpanded) {
1012                 if (expanded != shouldBeExpanded)
1013                     setGroupExpandedWithoutNotification(grp, shouldBeExpanded);
1014                 setGroupVisible(grp, shouldBeVisible);
1015             } else {
1016                 if (filter != null) {
1017                     if (shouldBeVisible) {
1018                         // The user has not expanded this group but the group contains
1019                         // stuff that matches the non-empty filter => show the group.
1020                         setGroupExpandedWithoutNotification(grp, true);
1021                         setGroupVisible(grp, true);
1022                     } else {
1023                         // The user has expanded this group but it does not contain items
1024                         // should should be shown with the current non-empty filter => hide the group.
1025                         setGroupExpandedWithoutNotification(grp, true);
1026                         setGroupVisible(grp, false);
1027                     }
1028                 } else {
1029                     // All groups should be visible. Some should be expanded and others not.
1030                     if (expanded != userExpanded)
1031                         setGroupExpandedWithoutNotification(grp, userExpanded);
1032                     if (!visible)
1033                         setGroupVisible(grp, true);
1034                 }
1035             }
1036
1037             if (shouldBeExpanded) {
1038                 viewer.refreshWithContent(elements);
1039             }
1040         }
1041
1042 //        String label = grp.getText();
1043 //        Matcher m = pattern.matcher(label.toLowerCase());
1044 //        boolean visible = m.matches();
1045 //        if (visible != grp.getVisible()) {
1046 //            changed = true;
1047 //            setGroupVisible(grp, visible);
1048 //        }
1049
1050         return changed;
1051     }
1052
1053     void setGroupExpandedWithoutNotification(PGroup grp, boolean expanded) {
1054         // Ok, don't need to remove/add expand listener, PGroup will not notify
1055         // listeners when setExpanded is invoked.
1056         //grp.removeExpandListener(groupExpandListener);
1057         storeGroupExpandedState(grp, expanded);
1058         grp.setExpanded(expanded);
1059         //grp.addExpandListener(groupExpandListener);
1060     }
1061
1062     void setGroupVisible(PGroup group, boolean visible) {
1063         GridData gd = (GridData) group.getLayoutData();
1064         gd.exclude = !visible;
1065         group.setVisible(visible);
1066     }
1067
1068     boolean isGroupFiltered(String label) {
1069         return !currentFilterPattern.matcher(label.toLowerCase()).matches();
1070     }
1071
1072     class DragSourceParticipant extends AbstractDiagramParticipant implements IDragSourceParticipant {
1073         @Reference  Selection selection;
1074         @Dependency PointerInteractor pi;
1075         @Dependency TransformUtil util;
1076         @Dependency PickContext pickContext;
1077
1078         @Override
1079         public int canDrag(MouseDragBegin me) {
1080             if (me.button != MouseEvent.LEFT_BUTTON) return 0;
1081             if (getHint(Hints.KEY_TOOL) != Hints.POINTERTOOL) return 0;
1082             assertDependencies();
1083
1084             PickRequest         req                     = new PickRequest(me.startCanvasPos);
1085             req.pickPolicy = PickRequest.PickPolicy.PICK_INTERSECTING_OBJECTS;
1086             List<IElement>      picks                   = new ArrayList<IElement>();
1087             pickContext.pick(diagram, req, picks);
1088             Set<IElement>       sel                     = selection.getSelection(me.mouseId);
1089
1090             if (Collections.disjoint(sel, picks)) return 0;
1091             // Box Select
1092             return DnDConstants.ACTION_COPY;
1093         }
1094
1095         @Override
1096         public Transferable dragStart(DragGestureEvent e) {
1097
1098             AWTChassis chassis = (AWTChassis) e.getComponent();
1099             ICanvasContext cc = chassis.getCanvasContext();
1100             Selection sel = cc.getSingleItem(Selection.class);
1101
1102             Set<IElement> ss = sel.getSelection(0);
1103             if (ss.isEmpty()) return null;
1104             Object[] res = new Object[ss.size()];
1105             int index = 0;
1106             for (IElement ee : ss)
1107                 res[index++] = ee.getHint(ElementHints.KEY_OBJECT);
1108
1109             ISelection object = new StructuredSelection(res);
1110
1111             LocalObjectTransferable local = new LocalObjectTransferable(object);
1112
1113             StringBuilder json = new StringBuilder();
1114             json.append("{");
1115             json.append(" \"type\" : \"Symbol\",");
1116             json.append(" \"res\" : [");
1117             int pos = 0;
1118             for(int i=0;i<res.length;i++) {
1119                 if(pos > 0) json.append(",");
1120                 Object r = res[i];
1121                 if(r instanceof IdentifiedObject) {
1122                         Object id = ((IdentifiedObject) r).getId();
1123                         if(id instanceof IAdaptable) {
1124                                 Object resource = ((IAdaptable) id).getAdapter(Resource.class);
1125                                 if(resource != null) {
1126                                         long rid = ((Resource)resource).getResourceId();
1127                                 json.append(Long.toString(rid));
1128                                 pos++;
1129                                 }
1130                         }
1131                 }
1132             }
1133             json.append("] }");
1134
1135             StringSelection text = new StringSelection(json.toString());
1136             PlaintextTransfer plainText = new PlaintextTransfer(json.toString());
1137
1138             return new MultiTransferable(local, text, plainText);
1139
1140         }
1141
1142         @Override
1143         public int getAllowedOps() {
1144             return DnDConstants.ACTION_COPY;
1145         }
1146         @Override
1147         public void dragDropEnd(DragSourceDropEvent dsde) {
1148 //            System.out.println("dragDropEnd: " + dsde);
1149             LocalObjectTransfer.getTransfer().clear();
1150         }
1151         @Override
1152         public void dragEnter(DragSourceDragEvent dsde) {
1153         }
1154         @Override
1155         public void dragExit(DragSourceEvent dse) {
1156         }
1157         @Override
1158         public void dragOver(DragSourceDragEvent dsde) {
1159         }
1160         @Override
1161         public void dropActionChanged(DragSourceDragEvent dsde) {
1162         }
1163     }
1164
1165     ExpandListener groupExpandListener = new ExpandListener() {
1166         @Override
1167         public void itemCollapsed(ExpandEvent e) {
1168             final PGroup group = (PGroup) e.widget;
1169             group.setData(KEY_USER_EXPANDED, Boolean.FALSE);
1170             storeGroupExpandedState(group, false);
1171             //System.out.println("item collapsed: " + group + ", " + sc.getClientArea());
1172             refreshScrolledComposite();
1173         }
1174         @Override
1175         public void itemExpanded(ExpandEvent e) {
1176             final PGroup group = (PGroup) e.widget;
1177             group.setData(KEY_USER_EXPANDED, Boolean.TRUE);
1178             storeGroupExpandedState(group, true);
1179             //System.out.println("item expanded: " + group + ", " + sc.getClientArea());
1180             ThreadUtils.asyncExec(swtThread, () -> {
1181                 GalleryViewer viewer = initializeGroup(group);
1182                 if (viewer == null)
1183                     return;
1184                 ThreadUtils.asyncExec(swtThread, () -> {
1185                     if (viewer.getControl().isDisposed())
1186                         return;
1187                     viewer.refresh();
1188                     refreshScrolledComposite();
1189                 });
1190             });
1191         }
1192     };
1193
1194     public boolean isDefaultExpanded() {
1195         return defaultExpanded;
1196     }
1197
1198     public void setDefaultExpanded(boolean defaultExpanded) {
1199         this.defaultExpanded = defaultExpanded;
1200     }
1201
1202     Runnable disposer(final Widget w) {
1203         return new Runnable() {
1204             @Override
1205             public void run() {
1206                 if (w.isDisposed())
1207                     return;
1208                 w.dispose();
1209             }
1210         };
1211     }
1212
1213     /**
1214      * Invoke from SWT thread only.
1215      *
1216      * @param targetState
1217      */
1218     public void setAllExpandedStates(boolean targetState) {
1219         setDefaultExpanded(targetState);
1220         Control[] grps = c.getChildren();
1221         boolean changed = false;
1222         for (Control control : grps)
1223             changed |= setExpandedState((PGroup) control, targetState, false);
1224         if (changed)
1225             refreshScrolledComposite();
1226     }
1227
1228     /**
1229      * Invoke from SWT thread only.
1230      *
1231      * @param grp
1232      * @param targetState
1233      * @return
1234      */
1235     boolean setExpandedState(PGroup grp, boolean targetState, boolean force) {
1236         if (grp.isDisposed())
1237             return false;
1238
1239         storeGroupExpandedState(grp, targetState);
1240         grp.setData(KEY_USER_EXPANDED, Boolean.valueOf(targetState));
1241         if ((force || grp.getExpanded() != targetState) && grp.getVisible()) {
1242             final GalleryViewer viewer = initializeGroup(grp);
1243             setGroupExpandedWithoutNotification(grp, targetState);
1244             ThreadUtils.asyncExec(swtThread, () -> {
1245                 if (!grp.isDisposed()) {
1246                     if (viewer != null)
1247                         viewer.refresh();
1248                     refreshScrolledComposite();
1249                 }
1250             });
1251             return true;
1252         }
1253         return false;
1254     }
1255
1256     class ImageLoader implements Runnable {
1257
1258         private final ImageProxy  imageProxy;
1259         private final ISymbolItem item;
1260
1261         public ImageLoader(ImageProxy imageProxy, ISymbolItem item) {
1262             this.imageProxy = imageProxy;
1263             this.item = item;
1264         }
1265
1266         @Override
1267         public void run() {
1268             // SVG images using the SVGUniverse in SVGCache must use
1269             // AWT thread for all operations.
1270             ThreadUtils.asyncExec(AWTThread.getThreadAccess(), () -> runBlocking());
1271         }
1272
1273         private void runBlocking() {
1274             try {
1275                 ISymbolGroup group = item.getGroup();
1276                 if (group == null)
1277                     throw new ProvisionException("No ISymbolGroup available for ISymbolItem " + item);
1278
1279                 GalleryViewer viewer = groupViewers.get(group);
1280                 if (viewer == null) {
1281                     // This is normal if this composite has been disposed while these are being ran.
1282                     //throw new ProvisionException("No GalleryViewer available ISymbolGroup " + group);
1283                     imageProxy.setSource(DefaultImages.UNKNOWN2.get());
1284                     return;
1285                 }
1286
1287                 IHintContext hints = viewer.getDiagram();
1288                 if (hints == null)
1289                     throw new ProvisionException("No diagram available for GalleryViewer of group " + group);
1290
1291                 hints.setHint(ISymbolItem.KEY_ELEMENT_CLASS_LISTENER, new ElementClassListener(imageCache, disposed, item));
1292                 final ElementClass ec = item.getElementClass(hints);
1293
1294                 // Without this the symbol library will at times
1295                 // not update the final graphics for the symbol.
1296                 // It will keep displaying the hourglass pending icon instead.
1297                 symbolUpdate(disposed, imageProxy, ec);
1298             } catch (ProvisionException e) {
1299                 ExceptionUtils.logWarning("Failed to provide element class for symbol item " + item, e);
1300                 imageProxy.setSource(DefaultImages.ERROR_DECORATOR.get());
1301             } catch (Exception e) {
1302                 ExceptionUtils.logError(e);
1303                 imageProxy.setSource(DefaultImages.ERROR_DECORATOR.get());
1304             } finally {
1305             }
1306         }
1307     }
1308
1309     static class ElementClassListener implements org.simantics.db.procedure.Listener<ElementClass> {
1310         private Map<ISymbolItem, SoftReference<ImageProxy>> imageCache;
1311         private final AtomicBoolean disposed;
1312         private final ISymbolItem item;
1313
1314         public ElementClassListener(Map<ISymbolItem, SoftReference<ImageProxy>> imageCache, AtomicBoolean disposed, ISymbolItem item) {
1315             this.imageCache = imageCache;
1316             this.disposed = disposed;
1317             this.item = item;
1318         }
1319
1320         @Override
1321         public void execute(final ElementClass ec) {
1322             //System.out.println("SYMBOL CHANGED: " + item + " - disposed=" + disposed + " - " + ec);
1323
1324             final ImageProxy[] imageProxy = { null };
1325             SoftReference<ImageProxy> proxyRef = imageCache.get(item);
1326             if (proxyRef != null)
1327                 imageProxy[0] = proxyRef.get();
1328             if (imageProxy[0] != null)
1329                 scheduleSymbolUpdate(disposed, imageProxy[0], ec);
1330         }
1331
1332         @Override
1333         public void exception(Throwable t) {
1334             Activator.getDefault().getLog().log(new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Error in ElementClass request.", t));
1335         }
1336
1337         @Override
1338         public boolean isDisposed() {
1339             //System.out.println("ElementClassListener.isDisposed " + item + " - " + disposed.get());
1340             return disposed.get();
1341         }
1342     }
1343
1344     public FilterArea getFilterArea() {
1345         return filter;
1346     }
1347
1348     public static void scheduleSymbolUpdate(final AtomicBoolean disposed, final ImageProxy imageProxy, final ElementClass ec) {
1349         if (disposed.get())
1350             return;
1351         ThreadUtils.asyncExec(AWTThread.getThreadAccess(), new Runnable() {
1352             @Override
1353             public void run() {
1354                 if (disposed.get())
1355                     return;
1356                 symbolUpdate(disposed, imageProxy, ec);
1357             }
1358         });
1359     }
1360
1361     public static void symbolUpdate(final AtomicBoolean disposed, final ImageProxy imageProxy, final ElementClass ec) {
1362         StaticSymbol ss = ec.getSingleItem(StaticSymbol.class);
1363         Image source = ss == null ? DefaultImages.UNKNOWN2.get() : ss.getImage();
1364         imageProxy.setSource(source);
1365     }
1366
1367     Runnable filterActivator = new Runnable() {
1368         @Override
1369         public void run() {
1370             filter.focus();
1371         }
1372     };
1373     Listener filterActivationListener = new Listener() {
1374         @Override
1375         public void handleEvent(Event event) {
1376             //System.out.println("event: " + event);
1377             filterActivator.run();
1378         }
1379     };
1380
1381     ISymbolGroupListener groupListener = new ISymbolGroupListener() {
1382         @Override
1383         public void itemsChanged(ISymbolGroup group) {
1384             //System.out.println("symbol group changed: " + group);
1385             GalleryViewer viewer = groupViewers.get(group);
1386             if (viewer != null) {
1387                 ISymbolItem[] input = group.getItems();
1388                 viewer.setInput(input);
1389             }
1390         }
1391     };
1392
1393     IEventHandler externalEventHandler = new IEventHandler() {
1394         @Override
1395         public int getEventMask() {
1396             return EventTypes.AnyMask;
1397         }
1398         @Override
1399         public boolean handleEvent(org.simantics.scenegraph.g2d.events.Event e) {
1400             IEventHandler handler = SymbolLibraryComposite.this.eventHandler;
1401             return handler != null && EventTypes.passes(handler, e) ? handler.handleEvent(e) : false;
1402         }
1403     };
1404
1405     protected volatile IEventHandler eventHandler;
1406
1407     /**
1408      * @param eventHandler
1409      */
1410     public void setEventHandler(IEventHandler eventHandler) {
1411         this.eventHandler = eventHandler;
1412     }
1413
1414     protected void storeGroupExpandedState(PGroup group, boolean expanded) {
1415         ISymbolGroup symbolGroup = (ISymbolGroup) group.getData(SymbolLibraryKeys.KEY_GROUP);
1416         //System.out.println("setGroupExpandedWithoutNotification(" + group + ", " + expanded + ", " + symbolGroup + ")");
1417         if (symbolGroup != null) {
1418             Object key = symbolGroupToKey(symbolGroup);
1419             expandedGroups.put(key, expanded ? Boolean.TRUE : Boolean.FALSE);
1420         }
1421     }
1422
1423     private static Object symbolGroupToKey(ISymbolGroup symbolGroup) {
1424         if (symbolGroup instanceof IIdentifiedObject)
1425             return ((IIdentifiedObject) symbolGroup).getId();
1426         return new Tuple2(symbolGroup.getName(), symbolGroup.getDescription());
1427     }
1428
1429 }