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.core.runtime.SubMonitor;
  26 import org.eclipse.jface.action.IStatusLineManager;
  27 import org.eclipse.swt.widgets.Display;
  28 import org.simantics.DatabaseJob;
  29 import org.simantics.Simantics;
  30 import org.simantics.db.ReadGraph;
  31 import org.simantics.db.Resource;
  32 import org.simantics.db.WriteGraph;
  33 import org.simantics.db.common.request.WriteRequest;
  34 import org.simantics.db.exception.DatabaseException;
  35 import org.simantics.db.layer0.adapter.Remover;
  36 import org.simantics.db.layer0.exception.CannotRemoveException;
  37 import org.simantics.db.layer0.util.RemoverUtil;
  38 import org.simantics.diagram.adapter.ElementFactoryUtil;
  39 import org.simantics.diagram.content.ConnectionUtil;
  40 import org.simantics.diagram.content.EdgeResource;
  41 import org.simantics.diagram.internal.Activator;
  42 import org.simantics.diagram.synchronization.ISynchronizationContext;
  43 import org.simantics.diagram.synchronization.graph.RemoveBranchpoint;
  44 import org.simantics.diagram.synchronization.graph.RemoveElement;
  45 import org.simantics.diagram.ui.DiagramModelHints;
  46 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;
  47 import org.simantics.g2d.connection.ConnectionEntity;
  48 import org.simantics.g2d.connection.handler.ConnectionHandler;
  49 import org.simantics.g2d.diagram.IDiagram;
  50 import org.simantics.g2d.diagram.handler.PickRequest.PickFilter;
  51 import org.simantics.g2d.diagram.handler.Relationship;
  52 import org.simantics.g2d.diagram.handler.RelationshipHandler;
  53 import org.simantics.g2d.diagram.handler.RelationshipHandler.Relation;
  54 import org.simantics.g2d.diagram.handler.Topology;
  55 import org.simantics.g2d.diagram.handler.Topology.Connection;
  56 import org.simantics.g2d.diagram.handler.Topology.Terminal;
  57 import org.simantics.g2d.diagram.participant.AbstractDiagramParticipant;
  58 import org.simantics.g2d.diagram.participant.Selection;
  59 import org.simantics.g2d.element.ElementClass;
  60 import org.simantics.g2d.element.ElementHints;
  61 import org.simantics.g2d.element.ElementUtils;
  62 import org.simantics.g2d.element.IElement;
  63 import org.simantics.g2d.element.handler.BendsHandler;
  64 import org.simantics.g2d.element.handler.EdgeVisuals.EdgeEnd;
  65 import org.simantics.g2d.element.handler.TerminalTopology;
  66 import org.simantics.scenegraph.g2d.events.EventHandlerReflection.EventHandler;
  67 import org.simantics.scenegraph.g2d.events.command.CommandEvent;
  68 import org.simantics.scenegraph.g2d.events.command.Commands;
  69 import org.simantics.utils.logging.TimeLogger;
  70 import org.simantics.utils.strings.EString;
  71 import org.simantics.utils.threads.SWTThread;
  72 import org.simantics.utils.threads.ThreadUtils;
  73 import org.simantics.utils.ui.dialogs.ShowMessage;
  74
  75 /**
  76  * DeleteHandler is a canvas handler for Commands.DELETE commands for an
  77  * IDiagram.
  78  *
  79  * <p>
  80  * The handler attempts to delete the current selection for pointer 0, meaning
  81  * {@link Selection#SELECTION0}.
  82  * </p>
  83  *
  84  * <p>
  85  * The handler logic goes as follows:
  86  * </p>
  87  * <ol>
  88  * <li>Separate nodes and edges form the the removed selection</li>
  89  * <li>Find all edges attached to the removed nodes and remove them too</li>
  90  * <li>Delete connections that contain less than 2 terminal connections</li>
  91  * </ol>
  92  *
  93  * @see Selection for the current diagram selection source
  94  *
  95  * @author Tuukka Lehtonen
  96  *
  97  * TODO: start using WorkbenchStatusLine participant
  98  */
  99 public class DeleteHandler extends AbstractDiagramParticipant {
 100
 101     public static final boolean DEBUG_DELETE = false;
 102
 103     @Dependency Selection sel;
 104
 105     private final IStatusLineManager statusLine;
 106
 107     public DeleteHandler(IStatusLineManager statusLine) {
 108         this.statusLine = statusLine;
 109     }
 110
 111     @EventHandler(priority = 0)
 112     public boolean handleCommand(CommandEvent e) {
 113         if (Commands.DELETE.equals( e.command )) {
 114             IDiagram d = diagram;
 115             if (d == null)
 116                 return true;
 117
 118             Set<IElement> ss = sel.getSelection(0);
 119             if (ss.isEmpty())
 120                 return true;
 121
 122             if (delete(d, ss)) {
 123                 sel.clear(0);
 124             }
 125
 126             return true;
 127         }
 128         return false;
 129     }
 130
 131     public boolean delete(final IDiagram d, Collection<IElement> ss) {
 132         TimeLogger.resetTimeAndLog(getClass(), "delete");
 133
 134         Topology topology = d.getDiagramClass().getAtMostOneItemOfClass(Topology.class);
 135         RelationshipHandler erh = d.getDiagramClass().getAtMostOneItemOfClass(RelationshipHandler.class);
 136
 137         if (DEBUG_DELETE) {
 138             System.out.println("diagram: " + d);
 139             for (IElement e : d.getSnapshot()) {
 140                 ElementClass ec = e.getElementClass();
 141                 System.out.println("\t-element " + e);
 142                 System.out.println("\t  -class " + e.getElementClass());
 143                 if (ec.containsClass(ConnectionHandler.class)) {
 144                     ConnectionEntity ce = e.getHint(ElementHints.KEY_CONNECTION_ENTITY);
 145                     for (IElement child : ce.getBranchPoints(null)) {
 146                         System.out.println("\t\t-branch " + child);
 147                         System.out.println("\t\t  -class " + child.getElementClass());
 148                     }
 149                     for (IElement child : ce.getSegments(null)) {
 150                         System.out.println("\t\t-segment " + child);
 151                         System.out.println("\t\t  -class " + child.getElementClass());
 152                     }
 153                 }
 154             }
 155             System.out.println("delete requested for elements:");
 156             for (IElement e : ss)
 157                 System.out.println("\t-element " + e);
 158         }
 159
 160         // Analyze removals:
 161         //  - separate elements and connections
 162         //  - find all connections attached to the elements and remove them too
 163         Deque<IElement> elementsToProcess = new ArrayDeque<IElement>(ss);
 164         Set<IElement> processedElements = new HashSet<IElement>();
 165         Set<IElement> relationshipsProcessedForElement = new HashSet<IElement>();
 166
 167         final Collection<IElement> elements = new ArrayList<IElement>();
 168         final Set<IElement> edges = new HashSet<IElement>();
 169         Collection<Connection> connections = new ArrayList<Connection>();
 170         Collection<Terminal> terminals = new ArrayList<Terminal>();
 171         Collection<Relation> relations = new ArrayList<Relation>();
 172         while (!elementsToProcess.isEmpty()) {
 173             IElement el = elementsToProcess.pollFirst();
 174
 175             if (relationshipsProcessedForElement.add(el)) {
 176                 // Check for relationships to other elements and mark child
 177                 // elements to be removed before the parent element.
 178                 relations.clear();
 179                 erh.getRelations(d, el, relations);
 180                 if (!relations.isEmpty()) {
 181                     boolean restart = false;
 182                     for (Relation r : relations) {
 183                         //System.out.println("FOUND RELATION: " + r);
 184                         if (r.getRelationship() == Relationship.PARENT_OF) {
 185                             if ((r.getObject() instanceof IElement)) {
 186                                 IElement ee = (IElement) r.getObject();
 187                                 if (d.containsElement(ee)) {
 188                                     //System.out.println("DIAGRAM CONTAINS OBJECT: " + r.getObject());
 189
 190                                     // Mark the object also to be processed for removal.
 191                                     elementsToProcess.addFirst(ee);
 192                                     restart = true;
 193                                 }
 194                             }
 195                         }
 196                     }
 197                     if (restart) {
 198                         // Only process this element after we're sure that
 199                         // all its children have been processed.
 200                         elementsToProcess.addLast(el);
 201                         continue;
 202                     }
 203                 }
 204             }
 205
 206             if (!processedElements.add(el))
 207                 continue;
 208
 209             TerminalTopology tt = el.getElementClass().getAtMostOneItemOfClass(TerminalTopology.class);
 210             BendsHandler bh = el.getElementClass().getAtMostOneItemOfClass(BendsHandler.class);
 211
 212             if (bh != null) {
 213                 // Verify that the edge is NOT between two branch points.
 214                 // If it is, do not allow deletion because it is the only case
 215                 // which can break a connection tree into a connection forest.
 216                 // We do not want that to happen.
 217                 Connection begin = topology.getConnection(el, EdgeEnd.Begin);
 218                 Connection end = topology.getConnection(el, EdgeEnd.End);
 219
 220                 // Try to work with cases where the model is somewhat corrupt.
 221                 if (begin != null && end != null) {
 222                     if (PickFilter.FILTER_BRANCH_POINT.accept(begin.node) && PickFilter.FILTER_BRANCH_POINT.accept(end.node)) {
 223                         error("Deletion of branch point connecting edges is not allowed. Must be connected to a node terminal.");
 224                         return false;
 225                     }
 226                 }
 227
 228                 if (DEBUG_DELETE)
 229                     System.out.println("ADDED EDGE FOR REMOVAL: " + el);
 230                 edges.add(el);
 231             } else {
 232                 if (DEBUG_DELETE)
 233                     System.out.println("ADDED ELEMENT FOR REMOVAL: " + el);
 234                 elements.add(el);
 235
 236                 if (tt != null) {
 237                     terminals.clear();
 238                     tt.getTerminals(el, terminals);
 239                     connections.clear();
 240                     for (Terminal terminal : terminals)
 241                         topology.getConnections(el, terminal, connections);
 242                     for (Connection c : connections) {
 243                         if (c.edge != null) {
 244                             if (c.edge.getElementClass().containsClass(BendsHandler.class))
 245                                 edges.add(c.edge);
 246                             if (DEBUG_DELETE)
 247                                 System.out.println("TERMINAL CONNECTION WILL BE DISCONNECTED: " + c);
 248                         }
 249                     }
 250                 }
 251             }
 252         }
 253
 254         if (elements.isEmpty() && edges.isEmpty())
 255             return false;
 256
 257         if (DEBUG_DELETE) {
 258             System.out.println("gathered elements to delete:");
 259             System.out.println("\telements:");
 260             if (!elements.isEmpty())
 261                 for (IElement e : elements)
 262                     System.out.println("\t\t" + e);
 263             System.out.println("\tedges:");
 264             if (!edges.isEmpty())
 265                 for (IElement e : edges)
 266                     System.out.println("\t\t" + e);
 267         }
 268
 269         final IDiagram diagram = this.diagram;
 270         final ISynchronizationContext syncContext = ElementFactoryUtil.getContextChecked(diagram);
 271
 272         new DatabaseJob("Delete selection") {
 273             @Override
 274             protected IStatus run(IProgressMonitor monitor) {
 275                 try {
 276                     delete(monitor);
 277                     return Status.OK_STATUS;
 278                 } catch (CannotRemoveException e) {
 279                         ShowMessage.showInformation("Delete Selection Was Denied", e.getLocalizedMessage());
 280                     return new Status(IStatus.CANCEL, Activator.PLUGIN_ID, e.getLocalizedMessage(), e);
 281                 } catch (DatabaseException e) {
 282                     return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Unexpected error in delete.", e);
 283                 } finally {
 284                     error(null);
 285                     monitor.done();
 286                 }
 287             }
 288
 289             private void delete(IProgressMonitor monitor) throws DatabaseException {
 290                 SubMonitor subMonitor = SubMonitor.convert(monitor, 4);
 291                 Simantics.getSession().syncRequest(new WriteRequest() {
 292                     Set<Resource> connectionsToRemove = new HashSet<Resource>();
 293                     Set<Resource> touchedConnections = new HashSet<Resource>();
 294
 295                     @Override
 296                     public void perform(WriteGraph graph) throws DatabaseException {
 297                         validateRemoval(graph);
 298                         graph.markUndoPoint();
 299
 300                         ConnectionUtil cu = new ConnectionUtil(graph);
 301                         SubMonitor edgeElementMonitor = subMonitor.split(2); // Consume 50 % of the monitor
 302                         edgeElementMonitor.setWorkRemaining(edges.size() + elements.size()); // set work remaining to size of edges and elements
 303                         edgeElementMonitor.setTaskName("Removing edges");
 304                         // Remove edges
 305                         for (IElement edge : edges) {
 306                             ConnectionEntity ce = edge.getHint(ElementHints.KEY_CONNECTION_ENTITY);
 307                             touchConnection( ce.getConnection() );
 308
 309                             if (DEBUG_DELETE)
 310                                 System.out.println("REMOVING EDGE: " + edge);
 311                             Object obj = ElementUtils.getObject(edge);
 312                             if (obj instanceof EdgeResource) {
 313                                 cu.remove((EdgeResource) obj);
 314                             }
 315                             edgeElementMonitor.worked(1);
 316                         }
 317                         edgeElementMonitor.setTaskName("Removing elements");
 318                         // Remove elements
 319                         for (IElement element : elements) {
 320                             ConnectionHandler ch = element.getElementClass().getAtMostOneItemOfClass(ConnectionHandler.class);
 321                             if (ch != null) {
 322                                 if (DEBUG_DELETE)
 323                                     System.out.println("MARKING CONNECTION TO BE REMOVED: " + element);
 324                                 connectionsToRemove.add( (Resource) ElementUtils.getObject(element) );
 325                             } else {
 326                                 ConnectionEntity ce = element.getHint(ElementHints.KEY_CONNECTION_ENTITY);
 327                                 if(ce != null) {
 328                                     if (DEBUG_DELETE)
 329                                         System.out.println("REMOVING BRANCH POINT: " + element);
 330                                     new RemoveBranchpoint(element).perform(graph);
 331                                     touchConnection( ce.getConnection() );
 332                                 } else {
 333                                     if (DEBUG_DELETE)
 334                                         System.out.println("REMOVING ELEMENT: " + element);
 335
 336                                     Object obj = ElementUtils.getObject(element);
 337                                     if (obj instanceof Resource) {
 338                                         // Get terminal connections for element
 339                                         Collection<Resource> connectors = cu.getTerminalConnectors((Resource) obj, null);
 340                                         for (Resource connector : connectors) {
 341                                             Resource connection = ConnectionUtil.tryGetConnection(graph, connector);
 342                                             if (connection != null)
 343                                                 touchConnection( connection );
 344                                             cu.disconnectFromAllRouteNodes(connector);
 345                                         }
 346
 347                                         new RemoveElement((Resource)d.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE), (Resource)element.getHint(ElementHints.KEY_OBJECT)).perform(graph);
 348                                     }
 349                                 }
 350                             }
 351                             edgeElementMonitor.worked(1);
 352                         }
 353                         SubMonitor connectionsMonitor = subMonitor.split(1); // Consume 50 % of the monitor
 354                         connectionsMonitor.setWorkRemaining(touchedConnections.size()); // set work remaining to size of edges and elements
 355                         connectionsMonitor.setTaskName("Pruning connectors");
 356                         // Check all touched connections to see if they are empty.
 357                         for (Resource connection : touchedConnections) {
 358                             int removedConnectors = cu.removeUnusedConnectors(connection);
 359                             if (DEBUG_DELETE)
 360                                 System.out.println("PRUNED " + removedConnectors + " CONNECTORS FROM TOUCHED CONNECTION " + connection);
 361                             while (true) {
 362                                 int removedInteriorRouteNodes = cu.removeExtraInteriorRouteNodes(connection);
 363                                 if (DEBUG_DELETE)
 364                                     System.out.println("PRUNED " + removedInteriorRouteNodes + " INTERIOR ROUTE NODES FROM TOUCHED CONNECTION " + connection);
 365                                 if (removedInteriorRouteNodes == 0)
 366                                     break;
 367                             }
 368                             int connectors = cu.getConnectedConnectors(connection, null).size();
 369                             if (DEBUG_DELETE)
 370                                 System.out.println("\t" + connectors + " CONNECTORS LEFT");
 371                             if (connectors < 2) {
 372                                 connectionsToRemove.add(connection);
 373                             }
 374                             connectionsMonitor.worked(1);
 375                         }
 376                         SubMonitor connectionsMonitor2 = subMonitor.split(1); // Consume 50 % of the monitor
 377                         connectionsMonitor2.setWorkRemaining(connectionsToRemove.size()); // set work remaini
 378                         connectionsMonitor2.setTaskName("Removing leftover connections");
 379                         // Remove selected/left-over empty connections
 380                         for (Resource connection : connectionsToRemove) {
 381                             if (DEBUG_DELETE)
 382                                 System.out.println("REMOVING CONNECTION: " + connection);
 383                             RemoveElement.removeElement(graph, (Resource)d.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE), connection);
 384                             connectionsMonitor2.worked(1);
 385                         }
 386                     }
 387
 388                     private void validateRemoval(ReadGraph graph) throws DatabaseException, CannotRemoveException {
 389                         ArrayList<String> problems = new ArrayList<String>(elements.size());
 390                         for (IElement element : elements) {
 391                             Object obj = ElementUtils.getObject(element);
 392                             if (obj instanceof Resource) {
 393                                 Remover remover = RemoverUtil.getPossibleRemover(graph, (Resource) obj);
 394                                 if (remover != null) {
 395                                     String problem = remover.canRemove(graph, new HashMap<Object, Object>(4));
 396                                     if (problem != null) {
 397                                         problems.add(problem);
 398                                     }
 399                                 }
 400                             }
 401                         }
 402                         if (!problems.isEmpty()) {
 403                             throw new CannotRemoveException(EString.implode(problems));
 404                         }
 405                     }
 406
 407                     void touchConnection(Object c) {
 408                         if (DEBUG_DELETE)
 409                             System.out.println("TOUCHED CONNECTION: " + c);
 410                         if (c instanceof IElement) {
 411                             Object obj = ElementUtils.getObject((IElement) c);
 412                             if (obj instanceof Resource)
 413                                 touchedConnections.add((Resource) obj);
 414                         } else if (c instanceof Resource) {
 415                             touchedConnections.add((Resource) c);
 416                         }
 417                     }
 418                 });
 419             }
 420         }.schedule();
 421
 422         return true;
 423     }
 424
 425     void message(final String message) {
 426         if (statusLine == null)
 427             return;
 428         swtExec(new Runnable() {
 429             @Override
 430             public void run() {
 431                 statusLine.setMessage(message);
 432                 statusLine.setErrorMessage(null);
 433             }
 434         });
 435     }
 436
 437     void error(final String message) {
 438         if (statusLine == null)
 439             return;
 440         swtExec(new Runnable() {
 441             @Override
 442             public void run() {
 443                 statusLine.setErrorMessage(message);
 444             }
 445         });
 446     }
 447
 448     void swtExec(Runnable r) {
 449         ThreadUtils.asyncExec(SWTThread.getThreadAccess(Display.getDefault()), r);
 450     }
 451
 452 }