bundles/org.simantics.diagram/src/org/simantics/diagram/handler/DeleteHandler.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.diagram.handler;\r
  13 \r
  14 import java.util.ArrayDeque;\r
  15 import java.util.ArrayList;\r
  16 import java.util.Collection;\r
  17 import java.util.Deque;\r
  18 import java.util.HashMap;\r
  19 import java.util.HashSet;\r
  20 import java.util.Set;\r
  21 \r
  22 import org.eclipse.core.runtime.IProgressMonitor;\r
  23 import org.eclipse.core.runtime.IStatus;\r
  24 import org.eclipse.core.runtime.Status;\r
  25 import org.eclipse.jface.action.IStatusLineManager;\r
  26 import org.eclipse.swt.widgets.Display;\r
  27 import org.simantics.DatabaseJob;\r
  28 import org.simantics.Simantics;\r
  29 import org.simantics.db.ReadGraph;\r
  30 import org.simantics.db.Resource;\r
  31 import org.simantics.db.WriteGraph;\r
  32 import org.simantics.db.common.request.WriteRequest;\r
  33 import org.simantics.db.exception.DatabaseException;\r
  34 import org.simantics.db.layer0.adapter.Remover;\r
  35 import org.simantics.db.layer0.exception.CannotRemoveException;\r
  36 import org.simantics.db.layer0.util.RemoverUtil;\r
  37 import org.simantics.diagram.adapter.ElementFactoryUtil;\r
  38 import org.simantics.diagram.content.ConnectionUtil;\r
  39 import org.simantics.diagram.content.EdgeResource;\r
  40 import org.simantics.diagram.internal.Activator;\r
  41 import org.simantics.diagram.synchronization.ISynchronizationContext;\r
  42 import org.simantics.diagram.synchronization.graph.RemoveBranchpoint;\r
  43 import org.simantics.diagram.synchronization.graph.RemoveElement;\r
  44 import org.simantics.diagram.ui.DiagramModelHints;\r
  45 import org.simantics.g2d.canvas.impl.DependencyReflection.Dependency;\r
  46 import org.simantics.g2d.connection.ConnectionEntity;\r
  47 import org.simantics.g2d.connection.handler.ConnectionHandler;\r
  48 import org.simantics.g2d.diagram.IDiagram;\r
  49 import org.simantics.g2d.diagram.handler.PickRequest.PickFilter;\r
  50 import org.simantics.g2d.diagram.handler.Relationship;\r
  51 import org.simantics.g2d.diagram.handler.RelationshipHandler;\r
  52 import org.simantics.g2d.diagram.handler.RelationshipHandler.Relation;\r
  53 import org.simantics.g2d.diagram.handler.Topology;\r
  54 import org.simantics.g2d.diagram.handler.Topology.Connection;\r
  55 import org.simantics.g2d.diagram.handler.Topology.Terminal;\r
  56 import org.simantics.g2d.diagram.participant.AbstractDiagramParticipant;\r
  57 import org.simantics.g2d.diagram.participant.Selection;\r
  58 import org.simantics.g2d.element.ElementClass;\r
  59 import org.simantics.g2d.element.ElementHints;\r
  60 import org.simantics.g2d.element.ElementUtils;\r
  61 import org.simantics.g2d.element.IElement;\r
  62 import org.simantics.g2d.element.handler.BendsHandler;\r
  63 import org.simantics.g2d.element.handler.EdgeVisuals.EdgeEnd;\r
  64 import org.simantics.g2d.element.handler.TerminalTopology;\r
  65 import org.simantics.scenegraph.g2d.events.EventHandlerReflection.EventHandler;\r
  66 import org.simantics.scenegraph.g2d.events.command.CommandEvent;\r
  67 import org.simantics.scenegraph.g2d.events.command.Commands;\r
  68 import org.simantics.utils.logging.TimeLogger;\r
  69 import org.simantics.utils.strings.EString;\r
  70 import org.simantics.utils.threads.SWTThread;\r
  71 import org.simantics.utils.threads.ThreadUtils;\r
  72 import org.simantics.utils.ui.dialogs.ShowMessage;\r
  73 \r
  74 /**\r
  75  * DeleteHandler is a canvas handler for Commands.DELETE commands for an\r
  76  * IDiagram.\r
  77  * \r
  78  * <p>\r
  79  * The handler attempts to delete the current selection for pointer 0, meaning\r
  80  * {@link Selection#SELECTION0}.\r
  81  * </p>\r
  82  * \r
  83  * <p>\r
  84  * The handler logic goes as follows:\r
  85  * </p>\r
  86  * <ol>\r
  87  * <li>Separate nodes and edges form the the removed selection</li>\r
  88  * <li>Find all edges attached to the removed nodes and remove them too</li>\r
  89  * <li>Delete connections that contain less than 2 terminal connections</li>\r
  90  * </ol>\r
  91  * \r
  92  * @see Selection for the current diagram selection source\r
  93  * \r
  94  * @author Tuukka Lehtonen\r
  95  * \r
  96  * TODO: start using WorkbenchStatusLine participant\r
  97  */\r
  98 public class DeleteHandler extends AbstractDiagramParticipant {\r
  99 \r
 100     public static final boolean DEBUG_DELETE = false;\r
 101 \r
 102     @Dependency Selection sel;\r
 103 \r
 104     private final IStatusLineManager statusLine;\r
 105 \r
 106     public DeleteHandler(IStatusLineManager statusLine) {\r
 107         this.statusLine = statusLine;\r
 108     }\r
 109 \r
 110     @EventHandler(priority = 0)\r
 111     public boolean handleCommand(CommandEvent e) {\r
 112         if (Commands.DELETE.equals( e.command )) {\r
 113             IDiagram d = diagram;\r
 114             if (d == null)\r
 115                 return true;\r
 116 \r
 117             Set<IElement> ss = sel.getSelection(0);\r
 118             if (ss.isEmpty())\r
 119                 return true;\r
 120 \r
 121             if (delete(d, ss)) {\r
 122                 sel.clear(0);\r
 123             }\r
 124 \r
 125             return true;\r
 126         }\r
 127         return false;\r
 128     }\r
 129 \r
 130     public boolean delete(final IDiagram d, Collection<IElement> ss) {\r
 131         TimeLogger.resetTimeAndLog(getClass(), "delete");\r
 132         \r
 133         Topology topology = d.getDiagramClass().getAtMostOneItemOfClass(Topology.class);\r
 134         RelationshipHandler erh = d.getDiagramClass().getAtMostOneItemOfClass(RelationshipHandler.class);\r
 135 \r
 136         if (DEBUG_DELETE) {\r
 137             System.out.println("diagram: " + d);\r
 138             for (IElement e : d.getSnapshot()) {\r
 139                 ElementClass ec = e.getElementClass();\r
 140                 System.out.println("\t-element " + e);\r
 141                 System.out.println("\t  -class " + e.getElementClass());\r
 142                 if (ec.containsClass(ConnectionHandler.class)) {\r
 143                     ConnectionEntity ce = e.getHint(ElementHints.KEY_CONNECTION_ENTITY);\r
 144                     for (IElement child : ce.getBranchPoints(null)) {\r
 145                         System.out.println("\t\t-branch " + child);\r
 146                         System.out.println("\t\t  -class " + child.getElementClass());\r
 147                     }\r
 148                     for (IElement child : ce.getSegments(null)) {\r
 149                         System.out.println("\t\t-segment " + child);\r
 150                         System.out.println("\t\t  -class " + child.getElementClass());\r
 151                     }\r
 152                 }\r
 153             }\r
 154             System.out.println("delete requested for elements:");\r
 155             for (IElement e : ss)\r
 156                 System.out.println("\t-element " + e);\r
 157         }\r
 158 \r
 159         // Analyze removals:\r
 160         //  - separate elements and connections\r
 161         //  - find all connections attached to the elements and remove them too\r
 162         Deque<IElement> elementsToProcess = new ArrayDeque<IElement>(ss);\r
 163         Set<IElement> processedElements = new HashSet<IElement>();\r
 164         Set<IElement> relationshipsProcessedForElement = new HashSet<IElement>();\r
 165 \r
 166         final Collection<IElement> elements = new ArrayList<IElement>();\r
 167         final Set<IElement> edges = new HashSet<IElement>();\r
 168         Collection<Connection> connections = new ArrayList<Connection>();\r
 169         Collection<Terminal> terminals = new ArrayList<Terminal>();\r
 170         Collection<Relation> relations = new ArrayList<Relation>();\r
 171         while (!elementsToProcess.isEmpty()) {\r
 172             IElement el = elementsToProcess.pollFirst();\r
 173 \r
 174             if (relationshipsProcessedForElement.add(el)) {\r
 175                 // Check for relationships to other elements and mark child\r
 176                 // elements to be removed before the parent element.\r
 177                 relations.clear();\r
 178                 erh.getRelations(d, el, relations);\r
 179                 if (!relations.isEmpty()) {\r
 180                     boolean restart = false;\r
 181                     for (Relation r : relations) {\r
 182                         //System.out.println("FOUND RELATION: " + r);\r
 183                         if (r.getRelationship() == Relationship.PARENT_OF) {\r
 184                             if ((r.getObject() instanceof IElement)) {\r
 185                                 IElement ee = (IElement) r.getObject();\r
 186                                 if (d.containsElement(ee)) {\r
 187                                     //System.out.println("DIAGRAM CONTAINS OBJECT: " + r.getObject());\r
 188 \r
 189                                     // Mark the object also to be processed for removal.\r
 190                                     elementsToProcess.addFirst(ee);\r
 191                                     restart = true;\r
 192                                 }\r
 193                             }\r
 194                         }\r
 195                     }\r
 196                     if (restart) {\r
 197                         // Only process this element after we're sure that\r
 198                         // all its children have been processed.\r
 199                         elementsToProcess.addLast(el);\r
 200                         continue;\r
 201                     }\r
 202                 }\r
 203             }\r
 204 \r
 205             if (!processedElements.add(el))\r
 206                 continue;\r
 207 \r
 208             TerminalTopology tt = el.getElementClass().getAtMostOneItemOfClass(TerminalTopology.class);\r
 209             BendsHandler bh = el.getElementClass().getAtMostOneItemOfClass(BendsHandler.class);\r
 210 \r
 211             if (bh != null) {\r
 212                 // Verify that the edge is NOT between two branch points.\r
 213                 // If it is, do not allow deletion because it is the only case\r
 214                 // which can break a connection tree into a connection forest.\r
 215                 // We do not want that to happen.\r
 216                 Connection begin = topology.getConnection(el, EdgeEnd.Begin);\r
 217                 Connection end = topology.getConnection(el, EdgeEnd.End);\r
 218 \r
 219                 // Try to work with cases where the model is somewhat corrupt.\r
 220                 if (begin != null && end != null) {\r
 221                     if (PickFilter.FILTER_BRANCH_POINT.accept(begin.node) && PickFilter.FILTER_BRANCH_POINT.accept(end.node)) {\r
 222                         error("Deletion of branch point connecting edges is not allowed. Must be connected to a node terminal.");\r
 223                         return false;\r
 224                     }\r
 225                 }\r
 226 \r
 227                 if (DEBUG_DELETE)\r
 228                     System.out.println("ADDED EDGE FOR REMOVAL: " + el);\r
 229                 edges.add(el);\r
 230             } else {\r
 231                 if (DEBUG_DELETE)\r
 232                     System.out.println("ADDED ELEMENT FOR REMOVAL: " + el);\r
 233                 elements.add(el);\r
 234 \r
 235                 if (tt != null) {\r
 236                     terminals.clear();\r
 237                     tt.getTerminals(el, terminals);\r
 238                     connections.clear();\r
 239                     for (Terminal terminal : terminals)\r
 240                         topology.getConnections(el, terminal, connections);\r
 241                     for (Connection c : connections) {\r
 242                         if (c.edge != null) {\r
 243                             if (c.edge.getElementClass().containsClass(BendsHandler.class))\r
 244                                 edges.add(c.edge);\r
 245                             if (DEBUG_DELETE)\r
 246                                 System.out.println("TERMINAL CONNECTION WILL BE DISCONNECTED: " + c);\r
 247                         }\r
 248                     }\r
 249                 }\r
 250             }\r
 251         }\r
 252 \r
 253         if (elements.isEmpty() && edges.isEmpty())\r
 254             return false;\r
 255 \r
 256         if (DEBUG_DELETE) {\r
 257             System.out.println("gathered elements to delete:");\r
 258             System.out.println("\telements:");\r
 259             if (!elements.isEmpty())\r
 260                 for (IElement e : elements)\r
 261                     System.out.println("\t\t" + e);\r
 262             System.out.println("\tedges:");\r
 263             if (!edges.isEmpty())\r
 264                 for (IElement e : edges)\r
 265                     System.out.println("\t\t" + e);\r
 266         }\r
 267 \r
 268         final IDiagram diagram = this.diagram;\r
 269         final ISynchronizationContext syncContext = ElementFactoryUtil.getContextChecked(diagram); \r
 270 \r
 271         new DatabaseJob("Delete selection") {\r
 272             @Override\r
 273             protected IStatus run(IProgressMonitor monitor) {\r
 274                 try {\r
 275                     delete(monitor);\r
 276                     return Status.OK_STATUS;\r
 277                 } catch (CannotRemoveException e) {\r
 278                         ShowMessage.showInformation("Delete Selection Was Denied", e.getLocalizedMessage());\r
 279                     return new Status(IStatus.CANCEL, Activator.PLUGIN_ID, e.getLocalizedMessage(), e);\r
 280                 } catch (DatabaseException e) {\r
 281                     return new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Unexpected error in delete.", e);\r
 282                 } finally {\r
 283                     error(null);\r
 284                     monitor.done();\r
 285                 }\r
 286             }\r
 287 \r
 288             private void delete(IProgressMonitor monitor) throws DatabaseException {\r
 289                 Simantics.getSession().syncRequest(new WriteRequest() {\r
 290                     Set<Resource> connectionsToRemove = new HashSet<Resource>();\r
 291                     Set<Resource> touchedConnections = new HashSet<Resource>();\r
 292 \r
 293                     @Override\r
 294                     public void perform(WriteGraph graph) throws DatabaseException {\r
 295                         validateRemoval(graph);\r
 296                         graph.markUndoPoint();\r
 297 \r
 298                         ConnectionUtil cu = new ConnectionUtil(graph);\r
 299 \r
 300                         // Remove edges\r
 301                         for (IElement edge : edges) {\r
 302                             ConnectionEntity ce = edge.getHint(ElementHints.KEY_CONNECTION_ENTITY);\r
 303                             touchConnection( ce.getConnection() );\r
 304 \r
 305                             if (DEBUG_DELETE)\r
 306                                 System.out.println("REMOVING EDGE: " + edge);\r
 307                             Object obj = ElementUtils.getObject(edge);\r
 308                             if (obj instanceof EdgeResource) {\r
 309                                 cu.remove((EdgeResource) obj);\r
 310                             }\r
 311                         }\r
 312 \r
 313                         // Remove elements\r
 314                         for (IElement element : elements) {\r
 315                             ConnectionHandler ch = element.getElementClass().getAtMostOneItemOfClass(ConnectionHandler.class);\r
 316                             if (ch != null) {\r
 317                                 if (DEBUG_DELETE)\r
 318                                     System.out.println("MARKING CONNECTION TO BE REMOVED: " + element);\r
 319                                 connectionsToRemove.add( (Resource) ElementUtils.getObject(element) );\r
 320                             } else {\r
 321                                 ConnectionEntity ce = element.getHint(ElementHints.KEY_CONNECTION_ENTITY);\r
 322                                 if(ce != null) {\r
 323                                     if (DEBUG_DELETE)\r
 324                                         System.out.println("REMOVING BRANCH POINT: " + element);\r
 325                                     new RemoveBranchpoint(element).perform(graph);\r
 326                                     touchConnection( ce.getConnection() );\r
 327                                 } else {\r
 328                                     if (DEBUG_DELETE)\r
 329                                         System.out.println("REMOVING ELEMENT: " + element);\r
 330 \r
 331                                     Object obj = ElementUtils.getObject(element);\r
 332                                     if (obj instanceof Resource) {\r
 333                                         // Get terminal connections for element\r
 334                                         Collection<Resource> connectors = cu.getTerminalConnectors((Resource) obj, null);\r
 335                                         for (Resource connector : connectors) {\r
 336                                             Resource connection = ConnectionUtil.tryGetConnection(graph, connector);\r
 337                                             if (connection != null)\r
 338                                                 touchConnection( connection );\r
 339                                             cu.disconnectFromAllRouteNodes(connector);\r
 340                                         }\r
 341 \r
 342                                         new RemoveElement((Resource)d.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE), (Resource)element.getHint(ElementHints.KEY_OBJECT)).perform(graph);\r
 343                                     }\r
 344                                 }\r
 345                             }\r
 346                         }\r
 347 \r
 348                         // Check all touched connections to see if they are empty.\r
 349                         for (Resource connection : touchedConnections) {\r
 350                             int removedConnectors = cu.removeUnusedConnectors(connection);\r
 351                             if (DEBUG_DELETE)\r
 352                                 System.out.println("PRUNED " + removedConnectors + " CONNECTORS FROM TOUCHED CONNECTION " + connection);\r
 353                             while (true) {\r
 354                                 int removedInteriorRouteNodes = cu.removeExtraInteriorRouteNodes(connection);\r
 355                                 if (DEBUG_DELETE)\r
 356                                     System.out.println("PRUNED " + removedInteriorRouteNodes + " INTERIOR ROUTE NODES FROM TOUCHED CONNECTION " + connection);\r
 357                                 if (removedInteriorRouteNodes == 0)\r
 358                                     break;\r
 359                             }\r
 360                             int connectors = cu.getConnectedConnectors(connection, null).size();\r
 361                             if (DEBUG_DELETE)\r
 362                                 System.out.println("\t" + connectors + " CONNECTORS LEFT");\r
 363                             if (connectors < 2) {\r
 364                                 connectionsToRemove.add(connection);\r
 365                             }\r
 366                         }\r
 367 \r
 368                         // Remove selected/left-over empty connections\r
 369                         for (Resource connection : connectionsToRemove) {\r
 370                             if (DEBUG_DELETE)\r
 371                                 System.out.println("REMOVING CONNECTION: " + connection);\r
 372                             RemoveElement.removeElement(graph, (Resource)d.getHint(DiagramModelHints.KEY_DIAGRAM_RESOURCE), connection);\r
 373                         }\r
 374                     }\r
 375 \r
 376                     private void validateRemoval(ReadGraph graph) throws DatabaseException, CannotRemoveException {\r
 377                         ArrayList<String> problems = new ArrayList<String>(elements.size());\r
 378                         for (IElement element : elements) {\r
 379                             Object obj = ElementUtils.getObject(element);\r
 380                             if (obj instanceof Resource) {\r
 381                                 Remover remover = RemoverUtil.getPossibleRemover(graph, (Resource) obj);\r
 382                                 if (remover != null) {\r
 383                                     String problem = remover.canRemove(graph, new HashMap<Object, Object>(4));\r
 384                                     if (problem != null) {\r
 385                                         problems.add(problem);\r
 386                                     }\r
 387                                 }\r
 388                             }\r
 389                         }\r
 390                         if (!problems.isEmpty()) {\r
 391                             throw new CannotRemoveException(EString.implode(problems));\r
 392                         }\r
 393                     }\r
 394 \r
 395                     void touchConnection(Object c) {\r
 396                         if (DEBUG_DELETE)\r
 397                             System.out.println("TOUCHED CONNECTION: " + c);\r
 398                         if (c instanceof IElement) {\r
 399                             Object obj = ElementUtils.getObject((IElement) c);\r
 400                             if (obj instanceof Resource)\r
 401                                 touchedConnections.add((Resource) obj);\r
 402                         } else if (c instanceof Resource) {\r
 403                             touchedConnections.add((Resource) c);\r
 404                         }\r
 405                     }\r
 406                 });\r
 407             }\r
 408         }.schedule();\r
 409 \r
 410         return true;\r
 411     }\r
 412 \r
 413     void message(final String message) {\r
 414         if (statusLine == null)\r
 415             return;\r
 416         swtExec(new Runnable() {\r
 417             @Override\r
 418             public void run() {\r
 419                 statusLine.setMessage(message);\r
 420                 statusLine.setErrorMessage(null);\r
 421             }\r
 422         });\r
 423     }\r
 424 \r
 425     void error(final String message) {\r
 426         if (statusLine == null)\r
 427             return;\r
 428         swtExec(new Runnable() {\r
 429             @Override\r
 430             public void run() {\r
 431                 statusLine.setErrorMessage(message);\r
 432             }\r
 433         });\r
 434     }\r
 435 \r
 436     void swtExec(Runnable r) {\r
 437         ThreadUtils.asyncExec(SWTThread.getThreadAccess(Display.getDefault()), r);\r
 438     }\r
 439 \r
 440 }\r