bundles/org.simantics.diagram/src/org/simantics/diagram/handler/DeleteHandler.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.handler;
  13
  14 import java.util.ArrayDeque;
  15 import java.util.ArrayList;
  16 import java.util.Collection;
  17 import java.util.Deque;
  18 import java.util.HashMap;
  19 import java.util.HashSet;
  20 import java.util.Set;
  21
  22 import org.eclipse.core.runtime.IProgressMonitor;
  23 import org.eclipse.core.runtime.IStatus;
  24 import org.eclipse.core.runtime.Status;
  25 import org.eclipse.jface.action.IStatusLineManager;
  26 import org.eclipse.swt.widgets.Display;
  27 import org.simantics.DatabaseJob;
  28 import org.simantics.Simantics;
  29 import org.simantics.db.ReadGraph;
  30 import org.simantics.db.Resource;
  31 import org.simantics.db.WriteGraph;
  32 import org.simantics.db.common.request.WriteRequest;
  33 import org.simantics.db.exception.DatabaseException;
  34 import org.simantics.db.layer0.adapter.Remover;
  35 import org.simantics.db.layer0.exception.CannotRemoveException;
  36 import org.simantics.db.layer0.util.RemoverUtil;
  37 import org.simantics.diagram.adapter.ElementFactoryUtil;
  38 import org.simantics.diagram.content.ConnectionUtil;
  39 import org.simantics.diagram.content.EdgeResource;
  40 import org.simantics.diagram.internal.Activator;
  41 import org.simantics.diagram.synchronization.ISynchronizationContext;
  42 import org.simantics.diagram.synchronization.graph.RemoveBranchpoint;
  43 import org.simantics.diagram.synchronization.graph.RemoveElement;
  44 import org.simantics.diagram.ui.DiagramModelHints;
  45 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;
  46 import org.simantics.g2d.connection.ConnectionEntity;
  47 import org.simantics.g2d.connection.handler.ConnectionHandler;
  48 import org.simantics.g2d.diagram.IDiagram;
  49 import org.simantics.g2d.diagram.handler.PickRequest.PickFilter;
  50 import org.simantics.g2d.diagram.handler.Relationship;
  51 import org.simantics.g2d.diagram.handler.RelationshipHandler;
  52 import org.simantics.g2d.diagram.handler.RelationshipHandler.Relation;
  53 import org.simantics.g2d.diagram.handler.Topology;
  54 import org.simantics.g2d.diagram.handler.Topology.Connection;
  55 import org.simantics.g2d.diagram.handler.Topology.Terminal;
  56 import org.simantics.g2d.diagram.participant.AbstractDiagramParticipant;
  57 import org.simantics.g2d.diagram.participant.Selection;
  58 import org.simantics.g2d.element.ElementClass;
  59 import org.simantics.g2d.element.ElementHints;
  60 import org.simantics.g2d.element.ElementUtils;
  61 import org.simantics.g2d.element.IElement;
  62 import org.simantics.g2d.element.handler.BendsHandler;
  63 import org.simantics.g2d.element.handler.EdgeVisuals.EdgeEnd;
  64 import org.simantics.g2d.element.handler.TerminalTopology;
  65 import org.simantics.scenegraph.g2d.events.EventHandlerReflection.EventHandler;
  66 import org.simantics.scenegraph.g2d.events.command.CommandEvent;
  67 import org.simantics.scenegraph.g2d.events.command.Commands;
  68 import org.simantics.utils.logging.TimeLogger;
  69 import org.simantics.utils.strings.EString;
  70 import org.simantics.utils.threads.SWTThread;
  71 import org.simantics.utils.threads.ThreadUtils;
  72 import org.simantics.utils.ui.dialogs.ShowMessage;
  73
  74 /**
  75  * DeleteHandler is a canvas handler for Commands.DELETE commands for an
  76  * IDiagram.
  77  *
  78  * <p>
  79  * The handler attempts to delete the current selection for pointer 0, meaning
  80  * {@link Selection#SELECTION0}.
  81  * </p>
  82  *
  83  * <p>
  84  * The handler logic goes as follows:
  85  * </p>
  86  * <ol>
  87  * <li>Separate nodes and edges form the the removed selection</li>
  88  * <li>Find all edges attached to the removed nodes and remove them too</li>
  89  * <li>Delete connections that contain less than 2 terminal connections</li>
  90  * </ol>
  91  *
  92  * @see Selection for the current diagram selection source
  93  *
  94  * @author Tuukka Lehtonen
  95  *
  96  * TODO: start using WorkbenchStatusLine participant
  97  */
  98 public class DeleteHandler extends AbstractDiagramParticipant {
  99
 100     public static final boolean DEBUG_DELETE = false;
 101
 102     @Dependency Selection sel;
 103
 104     private final IStatusLineManager statusLine;
 105
 106     public DeleteHandler(IStatusLineManager statusLine) {
 107         this.statusLine = statusLine;
 108     }
 109
 110     @EventHandler(priority = 0)
 111     public boolean handleCommand(CommandEvent e) {
 112         if (Commands.DELETE.equals( e.command )) {
 113             IDiagram d = diagram;
 114             if (d == null)
 115                 return true;
 116
 117             Set<IElement> ss = sel.getSelection(0);
 118             if (ss.isEmpty())
 119                 return true;
 120
 121             if (delete(d, ss)) {
 122                 sel.clear(0);
 123             }
 124
 125             return true;
 126         }
 127         return false;
 128     }
 129
 130     public boolean delete(final IDiagram d, Collection<IElement> ss) {
 131         TimeLogger.resetTimeAndLog(getClass(), "delete");
 132
 133         Topology topology = d.getDiagramClass().getAtMostOneItemOfClass(Topology.class);
 134         RelationshipHandler erh = d.getDiagramClass().getAtMostOneItemOfClass(RelationshipHandler.class);
 135
 136         if (DEBUG_DELETE) {
 137             System.out.println("diagram: " + d);
 138             for (IElement e : d.getSnapshot()) {
 139                 ElementClass ec = e.getElementClass();
 140                 System.out.println("\t-element " + e);
 141                 System.out.println("\t  -class " + e.getElementClass());
 142                 if (ec.containsClass(ConnectionHandler.class)) {
 143                     ConnectionEntity ce = e.getHint(ElementHints.KEY_CONNECTION_ENTITY);
 144                     for (IElement child : ce.getBranchPoints(null)) {
 145                         System.out.println("\t\t-branch " + child);
 146                         System.out.println("\t\t  -class " + child.getElementClass());
 147                     }
 148                     for (IElement child : ce.getSegments(null)) {
 149                         System.out.println("\t\t-segment " + child);
 150                         System.out.println("\t\t  -class " + child.getElementClass());
 151                     }
 152                 }
 153             }
 154             System.out.println("delete requested for elements:");
 155             for (IElement e : ss)
 156                 System.out.println("\t-element " + e);
 157         }
 158
 159         // Analyze removals:
 160         //  - separate elements and connections
 161         //  - find all connections attached to the elements and remove them too
 162         Deque<IElement> elementsToProcess = new ArrayDeque<IElement>(ss);
 163         Set<IElement> processedElements = new HashSet<IElement>();
 164         Set<IElement> relationshipsProcessedForElement = new HashSet<IElement>();
 165
 166         final Collection<IElement> elements = new ArrayList<IElement>();
 167         final Set<IElement> edges = new HashSet<IElement>();
 168         Collection<Connection> connections = new ArrayList<Connection>();
 169         Collection<Terminal> terminals = new ArrayList<Terminal>();
 170         Collection<Relation> relations = new ArrayList<Relation>();
 171         while (!elementsToProcess.isEmpty()) {
 172             IElement el = elementsToProcess.pollFirst();
 173
 174             if (relationshipsProcessedForElement.add(el)) {
 175                 // Check for relationships to other elements and mark child
 176                 // elements to be removed before the parent element.
 177                 relations.clear();
 178                 erh.getRelations(d, el, relations);
 179                 if (!relations.isEmpty()) {
 180                     boolean restart = false;
 181                     for (Relation r : relations) {
 182                         //System.out.println("FOUND RELATION: " + r);
 183                         if (r.getRelationship() == Relationship.PARENT_OF) {
 184                             if ((r.getObject() instanceof IElement)) {
 185                                 IElement ee = (IElement) r.getObject();
 186                                 if (d.containsElement(ee)) {
 187                                     //System.out.println("DIAGRAM CONTAINS OBJECT: " + r.getObject());
 188
 189                                     // Mark the object also to be processed for removal.
 190                                     elementsToProcess.addFirst(ee);
 191                                     restart = true;
 192                                 }
 193                             }
 194                         }
 195                     }
 196                     if (restart) {
 197                         // Only process this element after we're sure that
 198                         // all its children have been processed.
 199                         elementsToProcess.addLast(el);
 200                         continue;
 201                     }
 202                 }
 203             }
 204
 205             if (!processedElements.add(el))
 206                 continue;
 207
 208             TerminalTopology tt = el.getElementClass().getAtMostOneItemOfClass(TerminalTopology.class);
 209             BendsHandler bh = el.getElementClass().getAtMostOneItemOfClass(BendsHandler.class);
 210
 211             if (bh != null) {
 212                 // Verify that the edge is NOT between two branch points.
 213                 // If it is, do not allow deletion because it is the only case
 214                 // which can break a connection tree into a connection forest.
 215                 // We do not want that to happen.
 216                 Connection begin = topology.getConnection(el, EdgeEnd.Begin);
 217                 Connection end = topology.getConnection(el, EdgeEnd.End);
 218
 219                 // Try to work with cases where the model is somewhat corrupt.
 220                 if (begin != null && end != null) {
 221                     if (PickFilter.FILTER_BRANCH_POINT.accept(begin.node) && PickFilter.FILTER_BRANCH_POINT.accept(end.node)) {
 222                         error("Deletion of branch point connecting edges is not allowed. Must be connected to a node terminal.");
 223                         return false;
 224                     }
 225                 }
 226
 227                 if (DEBUG_DELETE)
 228                     System.out.println("ADDED EDGE FOR REMOVAL: " + el);
 229                 edges.add(el);
 230             } else {
 231                 if (DEBUG_DELETE)
 232                     System.out.println("ADDED ELEMENT FOR REMOVAL: " + el);
 233                 elements.add(el);
 234
 235                 if (tt != null) {
 236                     terminals.clear();
 237                     tt.getTerminals(el, terminals);
 238                     connections.clear();
 239                     for (Terminal terminal : terminals)
 240                         topology.getConnections(el, terminal, connections);
 241                     for (Connection c : connections) {
 242                         if (c.edge != null) {
 243                             if (c.edge.getElementClass().containsClass(BendsHandler.class))
 244                                 edges.add(c.edge);
 245                             if (DEBUG_DELETE)
 246                                 System.out.println("TERMINAL CONNECTION WILL BE DISCONNECTED: " + c);
 247                         }
 248                     }
 249                 }
 250             }
 251         }
 252
 253         if (elements.isEmpty() && edges.isEmpty())
 254             return false;
 255
 256         if (DEBUG_DELETE) {
 257             System.out.println("gathered elements to delete:");
 258             System.out.println("\telements:");
 259             if (!elements.isEmpty())
 260                 for (IElement e : elements)
 261                     System.out.println("\t\t" + e);
 262             System.out.println("\tedges:");
 263             if (!edges.isEmpty())
 264                 for (IElement e : edges)
 265                     System.out.println("\t\t" + e);
 266         }
 267
 268         final IDiagram diagram = this.diagram;
 269         final ISynchronizationContext syncContext = ElementFactoryUtil.getContextChecked(diagram);
 270
 271         new DatabaseJob("Delete selection") {
 272             @Override
 273             protected IStatus run(IProgressMonitor monitor) {
 274                 try {
 275                     delete(monitor);
 276                     return Status.OK_STATUS;
 277                 } catch (CannotRemoveException e) {
 278                         ShowMessage.showInformation("Delete Selection Was Denied", e.getLocalizedMessage());
 279                     return new Status(IStatus.CANCEL, Activator.PLUGIN_ID, e.getLocalizedMessage(), e);
 280                 } catch (DatabaseException e) {
 281                     return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Unexpected error in delete.", e);
 282                 } finally {
 283                     error(null);
 284                     monitor.done();
 285                 }
 286             }
 287
 288             private void delete(IProgressMonitor monitor) throws DatabaseException {
 289                 Simantics.getSession().syncRequest(new WriteRequest() {
 290                     Set<Resource> connectionsToRemove = new HashSet<Resource>();
 291                     Set<Resource> touchedConnections = new HashSet<Resource>();
 292
 293                     @Override
 294                     public void perform(WriteGraph graph) throws DatabaseException {
 295                         validateRemoval(graph);
 296                         graph.markUndoPoint();
 297
 298                         ConnectionUtil cu = new ConnectionUtil(graph);
 299
 300                         // Remove edges
 301                         for (IElement edge : edges) {
 302                             ConnectionEntity ce = edge.getHint(ElementHints.KEY_CONNECTION_ENTITY);
 303                             touchConnection( ce.getConnection() );
 304
 305                             if (DEBUG_DELETE)
 306                                 System.out.println("REMOVING EDGE: " + edge);
 307                             Object obj = ElementUtils.getObject(edge);
 308                             if (obj instanceof EdgeResource) {
 309                                 cu.remove((EdgeResource) obj);
 310                             }
 311                         }
 312
 313                         // Remove elements
 314                         for (IElement element : elements) {
 315                             ConnectionHandler ch = element.getElementClass().getAtMostOneItemOfClass(ConnectionHandler.class);
 316                             if (ch != null) {
 317                                 if (DEBUG_DELETE)
 318                                     System.out.println("MARKING CONNECTION TO BE REMOVED: " + element);
 319                                 connectionsToRemove.add( (Resource) ElementUtils.getObject(element) );
 320                             } else {
 321                                 ConnectionEntity ce = element.getHint(ElementHints.KEY_CONNECTION_ENTITY);
 322                                 if(ce != null) {
 323                                     if (DEBUG_DELETE)
 324                                         System.out.println("REMOVING BRANCH POINT: " + element);
 325                                     new RemoveBranchpoint(element).perform(graph);
 326                                     touchConnection( ce.getConnection() );
 327                                 } else {
 328                                     if (DEBUG_DELETE)
 329                                         System.out.println("REMOVING ELEMENT: " + element);
 330
 331                                     Object obj = ElementUtils.getObject(element);
 332                                     if (obj instanceof Resource) {
 333                                         // Get terminal connections for element
 334                                         Collection<Resource> connectors = cu.getTerminalConnectors((Resource) obj, null);
 335                                         for (Resource connector : connectors) {
 336                                             Resource connection = ConnectionUtil.tryGetConnection(graph, connector);
 337                                             if (connection != null)
 338                                                 touchConnection( connection );
 339                                             cu.disconnectFromAllRouteNodes(connector);
 340                                         }
 341
 342                                         new RemoveElement((Resource)d.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE), (Resource)element.getHint(ElementHints.KEY_OBJECT)).perform(graph);
 343                                     }
 344                                 }
 345                             }
 346                         }
 347
 348                         // Check all touched connections to see if they are empty.
 349                         for (Resource connection : touchedConnections) {
 350                             int removedConnectors = cu.removeUnusedConnectors(connection);
 351                             if (DEBUG_DELETE)
 352                                 System.out.println("PRUNED " + removedConnectors + " CONNECTORS FROM TOUCHED CONNECTION " + connection);
 353                             while (true) {
 354                                 int removedInteriorRouteNodes = cu.removeExtraInteriorRouteNodes(connection);
 355                                 if (DEBUG_DELETE)
 356                                     System.out.println("PRUNED " + removedInteriorRouteNodes + " INTERIOR ROUTE NODES FROM TOUCHED CONNECTION " + connection);
 357                                 if (removedInteriorRouteNodes == 0)
 358                                     break;
 359                             }
 360                             int connectors = cu.getConnectedConnectors(connection, null).size();
 361                             if (DEBUG_DELETE)
 362                                 System.out.println("\t" + connectors + " CONNECTORS LEFT");
 363                             if (connectors < 2) {
 364                                 connectionsToRemove.add(connection);
 365                             }
 366                         }
 367
 368                         // Remove selected/left-over empty connections
 369                         for (Resource connection : connectionsToRemove) {
 370                             if (DEBUG_DELETE)
 371                                 System.out.println("REMOVING CONNECTION: " + connection);
 372                             RemoveElement.removeElement(graph, (Resource)d.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE), connection);
 373                         }
 374                     }
 375
 376                     private void validateRemoval(ReadGraph graph) throws DatabaseException, CannotRemoveException {
 377                         ArrayList<String> problems = new ArrayList<String>(elements.size());
 378                         for (IElement element : elements) {
 379                             Object obj = ElementUtils.getObject(element);
 380                             if (obj instanceof Resource) {
 381                                 Remover remover = RemoverUtil.getPossibleRemover(graph, (Resource) obj);
 382                                 if (remover != null) {
 383                                     String problem = remover.canRemove(graph, new HashMap<Object, Object>(4));
 384                                     if (problem != null) {
 385                                         problems.add(problem);
 386                                     }
 387                                 }
 388                             }
 389                         }
 390                         if (!problems.isEmpty()) {
 391                             throw new CannotRemoveException(EString.implode(problems));
 392                         }
 393                     }
 394
 395                     void touchConnection(Object c) {
 396                         if (DEBUG_DELETE)
 397                             System.out.println("TOUCHED CONNECTION: " + c);
 398                         if (c instanceof IElement) {
 399                             Object obj = ElementUtils.getObject((IElement) c);
 400                             if (obj instanceof Resource)
 401                                 touchedConnections.add((Resource) obj);
 402                         } else if (c instanceof Resource) {
 403                             touchedConnections.add((Resource) c);
 404                         }
 405                     }
 406                 });
 407             }
 408         }.schedule();
 409
 410         return true;
 411     }
 412
 413     void message(final String message) {
 414         if (statusLine == null)
 415             return;
 416         swtExec(new Runnable() {
 417             @Override
 418             public void run() {
 419                 statusLine.setMessage(message);
 420                 statusLine.setErrorMessage(null);
 421             }
 422         });
 423     }
 424
 425     void error(final String message) {
 426         if (statusLine == null)
 427             return;
 428         swtExec(new Runnable() {
 429             @Override
 430             public void run() {
 431                 statusLine.setErrorMessage(message);
 432             }
 433         });
 434     }
 435
 436     void swtExec(Runnable r) {
 437         ThreadUtils.asyncExec(SWTThread.getThreadAccess(Display.getDefault()), r);
 438     }
 439
 440 }