bundles/org.simantics.diagram/src/org/simantics/diagram/symbolcontribution/ElementSymbolItem.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.symbolcontribution;
  13
  14 import org.simantics.Simantics;
  15 import org.simantics.db.ReadGraph;
  16 import org.simantics.db.RequestProcessor;
  17 import org.simantics.db.Resource;
  18 import org.simantics.db.common.request.ResourceRead;
  19 import org.simantics.db.exception.DatabaseException;
  20 import org.simantics.db.procedure.Listener;
  21 import org.simantics.db.request.Read;
  22 import org.simantics.diagram.query.DiagramRequests;
  23 import org.simantics.diagram.symbollibrary.ISymbolGroup;
  24 import org.simantics.diagram.symbollibrary.ISymbolItem;
  25 import org.simantics.diagram.synchronization.graph.BasicResources;
  26 import org.simantics.g2d.element.ElementClass;
  27 import org.simantics.g2d.element.handler.StaticSymbol;
  28 import org.simantics.utils.datastructures.cache.ProvisionException;
  29 import org.simantics.utils.datastructures.hints.IHintObservable;
  30
  31 /**
  32  * @author Tuukka Lehtonen
  33  */
  34 public class ElementSymbolItem extends SymbolItem {
  35
  36     public ElementSymbolItem(Resource item, String name, ISymbolGroup group) {
  37         super(
  38                 AdaptableTriple.make(
  39                         item,
  40                         // Prevents infinite recursion which will happen
  41                         // if SymbolGroup is used as group ID.
  42                         group instanceof IIdentifiedObject ? ((IIdentifiedObject) group).getId() : group,
  43                         // Name is in the identification so that name
  44                         // changes refresh the symbol library
  45                         name),
  46                 name,
  47                 group);
  48     }
  49
  50     public ElementSymbolItem(Resource item, String name, String description, ISymbolGroup group) {
  51         super(
  52                 AdaptableTriple.make(
  53                         item,
  54                         // Prevents infinite recursion which will happen
  55                         // if SymbolGroup is used as group ID.
  56                         group instanceof IIdentifiedObject ? ((IIdentifiedObject) group).getId() : group,
  57                         // Name is in the identification so that name
  58                         // changes refresh the symbol library
  59                         name),
  60                 name,
  61                 description,
  62                 group);
  63     }
  64
  65     @Override
  66     public ElementClass getElementClass(IHintObservable hints) {
  67         Resource item = adapt(Resource.class);
  68         RequestProcessor sgrp = Simantics.peekSession();
  69         if (sgrp == null)
  70             throw new ProvisionException("No RequestProcessor available for querying an ElementClass for resource " + item);
  71         try {
  72             Listener<ElementClass> listener = hints.getHint(ISymbolItem.KEY_ELEMENT_CLASS_LISTENER);
  73             ElementClass ec = listener == null
  74                     ? sgrp.syncRequest(createRequest(item, hints))
  75                     : sgrp.syncRequest(createRequest(item, hints), listener);
  76             if (ec == null)
  77                 throw new ProvisionException("ElementClass query failed, returned null");
  78             if (!ec.containsClass(StaticSymbol.class))
  79                 throw new ProvisionException("ElementClass " + ec + " does not provide a StaticSymbol handler");
  80             return ec;
  81         } catch (DatabaseException e) {
  82             throw new ProvisionException(e);
  83         }
  84     }
  85
  86     private Read<ElementClass> createRequest(Resource item, final IHintObservable hints) {
  87         return new ResourceRead<ElementClass>(item) {
  88             @Override
  89             public ElementClass perform(ReadGraph graph) throws DatabaseException {
  90                 BasicResources.getInstance(graph);
  91                 return graph.syncRequest( DiagramRequests.getElementClass(resource, hints) );
  92             }
  93         };
  94     }
  95
  96 }