bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/contribution/FinalViewpointContributionImpl.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.browsing.ui.graph.impl.contribution;\r
  13 \r
  14 import java.util.Collection;\r
  15 \r
  16 import org.simantics.browsing.ui.BuiltinKeys;\r
  17 import org.simantics.browsing.ui.DataSource;\r
  18 import org.simantics.browsing.ui.NodeContext;\r
  19 import org.simantics.browsing.ui.PrimitiveQueryUpdater;\r
  20 import org.simantics.browsing.ui.Tester;\r
  21 import org.simantics.browsing.ui.content.ViewpointContribution;\r
  22 import org.simantics.browsing.ui.graph.impl.request.ResourceQuery;\r
  23 import org.simantics.db.AsyncReadGraph;\r
  24 import org.simantics.db.ReadGraph;\r
  25 import org.simantics.db.exception.DatabaseException;\r
  26 import org.simantics.db.procedure.Listener;\r
  27 import org.simantics.db.procedure.Procedure;\r
  28 import org.simantics.utils.ui.ErrorLogger;\r
  29 \r
  30 /**\r
  31  * Implement {@link #children(AsyncReadGraph)} and {@link #hasChildren(AsyncReadGraph)}.\r
  32  * \r
  33  * @author Tuukka Lehtonen\r
  34  */\r
  35 abstract public class FinalViewpointContributionImpl extends ContributionStub implements GraphContribution {\r
  36 \r
  37     final private ResourceQuery<Collection<NodeContext>> childQuery;\r
  38     final private Procedure<Collection<NodeContext>>     childProcedure;\r
  39 \r
  40     final protected PrimitiveQueryUpdater       updater;\r
  41     final private NodeContext                context;\r
  42     final private BuiltinKeys.ViewpointContributionKey    key;\r
  43 \r
  44     /**\r
  45      * This identity is used to give the back-end graph requests a\r
  46      * <em>properly unique</em> identity that so that the graph back-end caching\r
  47      * and graph explorer node context caching work together properly.\r
  48      * \r
  49      * Consider having two graph explorer instances that have the same\r
  50      * configuration (same evaluators) and are showing the same resource from\r
  51      * the graph database. In this case the requests are actually meant to have\r
  52      * an identical identity and performing the graph request will simply bind a\r
  53      * new listener for the one and same request.\r
  54      * \r
  55      * @return an additional identity for graph back-end requests to make them\r
  56      *         properly unique\r
  57      */\r
  58     public Object getIdentity() {\r
  59         return key;\r
  60     }\r
  61 \r
  62     public FinalViewpointContributionImpl(final PrimitiveQueryUpdater updater, NodeContext context, BuiltinKeys.ViewpointContributionKey key) {\r
  63 \r
  64         assert updater != null;\r
  65         assert context != null;\r
  66         assert key != null;\r
  67 \r
  68         this.updater = updater;\r
  69         this.context = context;\r
  70         this.key = key;\r
  71 \r
  72         this.childQuery = new ResourceQuery<Collection<NodeContext>>(getIdentity(), context) {\r
  73 \r
  74             @Override\r
  75             public Collection<NodeContext> perform(ReadGraph graph) throws DatabaseException {\r
  76                 try {\r
  77                     // Make sure that null is not returned.\r
  78                     Collection<NodeContext> result = children(graph, context);\r
  79                     if (result == null)\r
  80                         throw new NullPointerException("LazyContributionImpl.children is not allowed to return null, but " + FinalViewpointContributionImpl.this.getClass() + " just did it");\r
  81                     return result;\r
  82                 } catch (DatabaseException e) {\r
  83                     throw e;\r
  84                 } catch (Throwable t) {\r
  85                     ErrorLogger.defaultLogError("LazyContributionImpl.childQuery produced unexpected exception.", t);\r
  86                     return ViewpointContribution.NO_CONTRIBUTION;\r
  87                 }\r
  88             }\r
  89 \r
  90             @Override\r
  91             public String toString() {\r
  92                 return "LazyContributionImpl[" + System.identityHashCode(FinalViewpointContributionImpl.this) + "].childQuery";\r
  93             }\r
  94 \r
  95         };\r
  96 \r
  97         childProcedure = createProcedure();\r
  98         \r
  99     }\r
 100     \r
 101     protected Procedure<Collection<NodeContext>> createProcedure() {\r
 102 \r
 103         return new Procedure<Collection<NodeContext>>() {\r
 104 \r
 105             @Override\r
 106             public void execute(Collection<NodeContext> result) {\r
 107                 replaceChildrenResult(result);\r
 108             }\r
 109 \r
 110             public void exception(Throwable t) {\r
 111                 ErrorLogger.defaultLogError("LazyContributionImpl.childQuery failed, see exception for details.", t);\r
 112             }\r
 113 \r
 114             @Override\r
 115             public String toString() {\r
 116                 return "LazyContributionImpl[" + System.identityHashCode(FinalViewpointContributionImpl.this) + "].childProcedure";\r
 117             }\r
 118 \r
 119         };\r
 120         \r
 121     }\r
 122 \r
 123     public NodeContext getContext() {\r
 124         return context;\r
 125     }\r
 126 \r
 127     @Override\r
 128     public Collection<NodeContext> getContribution() {\r
 129 \r
 130         //System.out.println("LazyViewpoint2@" + System.identityHashCode(this) + " getChildren() = " + children.length);\r
 131 \r
 132         if (children == org.simantics.browsing.ui.content.ViewpointContribution.PENDING_CONTRIBUTION) {\r
 133             DataSource<ReadGraph> source = updater.getDataSource(ReadGraph.class);\r
 134             if (source != null) {\r
 135                 source.schedule(graph -> {\r
 136                     if(childProcedure instanceof Listener<?>)\r
 137                         graph.asyncRequest(childQuery, (Listener<Collection<NodeContext>>)childProcedure);\r
 138                     else \r
 139                         graph.asyncRequest(childQuery, childProcedure);\r
 140                 });\r
 141             }\r
 142         }\r
 143 \r
 144         //System.out.println("LazyViewpoint.getChildren returns " + children);\r
 145 \r
 146         return children;\r
 147 \r
 148     }\r
 149 \r
 150     protected void replaceChildrenResult(Collection<NodeContext> result) {\r
 151         setChildren(updater, result);\r
 152         updater.scheduleReplace(context, key, this);\r
 153     }\r
 154 \r
 155     /**\r
 156      * @param <T>\r
 157      * @param clazz\r
 158      * @return input of the specified class\r
 159      * @throws ClassCastException if the input class does not match the\r
 160      *         specified class\r
 161      * @throws NullPointerException if the input is null\r
 162      */\r
 163     @SuppressWarnings("unchecked")\r
 164     protected <T> T getInput(Class<T> clazz) throws ClassCastException {\r
 165         Object o = context.getConstant(BuiltinKeys.INPUT);\r
 166         if (o == null)\r
 167             throw new NullPointerException("null input");\r
 168 //        return clazz.cast(o);\r
 169         return (T) o;\r
 170     }\r
 171 \r
 172     /**\r
 173      * @param <T>\r
 174      * @param clazz\r
 175      * @return <code>null</code> if input is <code>null</code> or if the class does not match\r
 176      */\r
 177     @SuppressWarnings("unchecked")\r
 178     protected <T> T tryGetInput(Class<T> clazz) {\r
 179         Object o = context.getConstant(BuiltinKeys.INPUT);\r
 180         if (o != null && clazz.isInstance(o))\r
 181 //            return clazz.cast(o);\r
 182             return (T) o;\r
 183         return null;\r
 184     }\r
 185 \r
 186     @Override\r
 187     public Tester getNodeContextTester() {\r
 188         return null;\r
 189     }\r
 190 \r
 191 }\r