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