bundles/org.simantics.diagram/src/org/simantics/diagram/connection/ModelledConnectionAdvisor.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.connection;\r
  13 \r
  14 import java.util.ArrayList;\r
  15 import java.util.Arrays;\r
  16 \r
  17 import org.simantics.db.ReadGraph;\r
  18 import org.simantics.db.RequestProcessor;\r
  19 import org.simantics.db.Resource;\r
  20 import org.simantics.db.Session;\r
  21 import org.simantics.db.exception.DatabaseException;\r
  22 import org.simantics.db.request.Read;\r
  23 import org.simantics.diagram.content.ConnectionUtil;\r
  24 import org.simantics.g2d.connection.IConnectionAdvisor;\r
  25 import org.simantics.g2d.diagram.handler.Topology.Terminal;\r
  26 import org.simantics.g2d.element.ElementUtils;\r
  27 import org.simantics.g2d.element.IElement;\r
  28 import org.simantics.g2d.elementclass.FlagHandler;\r
  29 import org.simantics.structural2.modelingRules.CPIgnore;\r
  30 import org.simantics.structural2.modelingRules.ConnectionJudgement;\r
  31 import org.simantics.structural2.modelingRules.ConnectionJudgementType;\r
  32 import org.simantics.structural2.modelingRules.IConnectionPoint;\r
  33 import org.simantics.structural2.modelingRules.IModelingRules;\r
  34 \r
  35 /**\r
  36  * To customize, prefer overriding\r
  37  * {@link #canBeConnected(ReadGraph, IElement, Terminal, IElement, Terminal)}\r
  38  * and {@link #canBeginConnection(ReadGraph, IElement, Terminal)}.\r
  39  * \r
  40  * @author Hannu Niemist&ouml;\r
  41  */\r
  42 public class ModelledConnectionAdvisor implements IConnectionAdvisor {\r
  43 \r
  44     protected IModelingRules modelingRules;\r
  45     protected Session        session;\r
  46 \r
  47     /**\r
  48      * @param modelingRules\r
  49      * @param session\r
  50      */\r
  51     public ModelledConnectionAdvisor(IModelingRules modelingRules,\r
  52             Session session) {\r
  53         this.modelingRules = modelingRules;\r
  54         this.session = session;\r
  55     }\r
  56 \r
  57     protected IConnectionPoint getConnectionPoint(ReadGraph g, IElement element, Terminal term) throws DatabaseException {\r
  58         return getConnectionPoint(g, element, term, false);\r
  59     }\r
  60 \r
  61     protected IConnectionPoint getConnectionPoint(ReadGraph g, IElement element, Terminal term, boolean ignoreUnrecognized) throws DatabaseException {\r
  62         Object obj = null;\r
  63         if (element != null)\r
  64             obj = ElementUtils.getObject(element);\r
  65 \r
  66         if (obj instanceof Resource) {\r
  67             Resource elementResource = (Resource) obj;\r
  68             return ConnectionUtil.toConnectionPoint(g, elementResource, term);\r
  69         }\r
  70 \r
  71         // FIXME: this currently allows connections to begin from flags\r
  72         // but is rather hackish.\r
  73         if (element.getElementClass().containsClass(FlagHandler.class)) {\r
  74             return CPIgnore.NULL_INSTANCE;\r
  75         }\r
  76 \r
  77         if (ignoreUnrecognized)\r
  78             return CPIgnore.NULL_INSTANCE;\r
  79 \r
  80         throw new IllegalArgumentException("Cannot get IConnectionPoint for (element,terminal) pair:\n\t" + element + "\n\t" + term);\r
  81     }\r
  82 \r
  83     @Override\r
  84     public Object canBeConnected(Object backend,\r
  85             final IElement element1, final Terminal term1,\r
  86             final IElement element2, final Terminal term2) {\r
  87         try {\r
  88             if (backend == null)\r
  89                 backend = session;\r
  90             return ((RequestProcessor)backend).syncRequest(new Read<Object>() {\r
  91                 @Override\r
  92                 public Object perform(ReadGraph g) throws DatabaseException {\r
  93                     return canBeConnected(g, element1, term1, element2, term2);\r
  94                 }\r
  95             });\r
  96         } catch(DatabaseException e) {\r
  97             e.printStackTrace();\r
  98             return null;\r
  99         }\r
 100     }\r
 101 \r
 102     @Override\r
 103     public boolean canBeginConnection(Object backend,\r
 104             final IElement element, final Terminal term) {\r
 105         try {\r
 106             if (backend == null)\r
 107                 backend = session;\r
 108             return ((RequestProcessor)backend).syncRequest(new Read<Boolean>() {\r
 109                 @Override\r
 110                 public Boolean perform(ReadGraph g) throws DatabaseException {\r
 111                     return canBeginConnection(g, element, term);\r
 112                 }\r
 113             });\r
 114         } catch (DatabaseException e) {\r
 115             e.printStackTrace();\r
 116             return false;\r
 117         }\r
 118     }\r
 119 \r
 120     protected Object canBeConnected(ReadGraph graph,\r
 121             IElement element1, Terminal term1,\r
 122             IElement element2, Terminal term2) throws DatabaseException {\r
 123         ArrayList<IConnectionPoint> cps = new ArrayList<IConnectionPoint>(2);\r
 124         if (element1 != null)\r
 125             cps.add(getConnectionPoint(graph, element1, term1, true));\r
 126         if (element2 != null)\r
 127             cps.add(getConnectionPoint(graph, element2, term2, true));\r
 128 \r
 129         ConnectionJudgement judgement = modelingRules.judgeConnection(graph, cps);\r
 130         if (judgement.type == ConnectionJudgementType.LEGAL)\r
 131             return judgement;\r
 132         return null;\r
 133     }\r
 134 \r
 135     protected boolean canBeginConnection(ReadGraph graph,\r
 136             IElement element, Terminal term) throws DatabaseException {\r
 137         return modelingRules.judgeConnection(graph,\r
 138                 Arrays.asList(getConnectionPoint(graph, element, term)))\r
 139                 .type != ConnectionJudgementType.ILLEGAL;\r
 140     }\r
 141 \r
 142 }\r