bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/contribution/FinalImageDecoratorContributionImpl.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 org.simantics.browsing.ui.BuiltinKeys.ImageDecoratorKey;\r
  15 import org.simantics.browsing.ui.DataSource;\r
  16 import org.simantics.browsing.ui.NodeContext;\r
  17 import org.simantics.browsing.ui.PrimitiveQueryUpdater;\r
  18 import org.simantics.browsing.ui.content.ImageDecorator;\r
  19 import org.simantics.browsing.ui.graph.impl.request.ResourceQuery;\r
  20 import org.simantics.db.ReadGraph;\r
  21 import org.simantics.db.exception.DatabaseException;\r
  22 import org.simantics.db.layer0.exception.PendingVariableException;\r
  23 import org.simantics.db.procedure.Listener;\r
  24 import org.simantics.db.procedure.Procedure;\r
  25 import org.simantics.utils.ui.ErrorLogger;\r
  26 \r
  27 public abstract class FinalImageDecoratorContributionImpl implements ImageDecorator {\r
  28 \r
  29     final ImageDecorator FRESH = new ImageDecorator.Stub();\r
  30     final ImageDecorator PENDING = new ImageDecorator.Stub();\r
  31     final ImageDecorator NO_DECORATION = new ImageDecorator.Stub();\r
  32 \r
  33     protected final PrimitiveQueryUpdater       updater;\r
  34     private final ResourceQuery<ImageDecorator> imageQuery;\r
  35     private final ImageDecoratorKey             key;\r
  36 \r
  37     /**\r
  38      * The current decorator result produced for this contribution. The value\r
  39      * should never be <code>null</code>, but one of {@link #FRESH},\r
  40      * {@link #PENDING}, {@link #NO_DECORATION} instead.\r
  41      */\r
  42     protected ImageDecorator                      decorator = FRESH;\r
  43 \r
  44     final protected NodeContext                   context;\r
  45 \r
  46     public Object getIdentity(ImageDecoratorKey key) {\r
  47         return key;\r
  48     }\r
  49 \r
  50     private void request() {\r
  51 \r
  52         final DataSource<ReadGraph> source = updater.getDataSource(ReadGraph.class);\r
  53         assert(source != null);\r
  54 \r
  55         final Procedure<ImageDecorator> procedure = createProcedure();\r
  56         \r
  57         source.schedule(graph -> {\r
  58             if(procedure instanceof Listener<?>)\r
  59                 graph.asyncRequest(imageQuery, (Listener<ImageDecorator>)procedure);\r
  60             else\r
  61                 graph.asyncRequest(imageQuery, procedure);\r
  62         });\r
  63 \r
  64     }\r
  65 \r
  66     @Override\r
  67     public <Image> Image decorateImage(Image image, String column, int itemIndex) {\r
  68         if(FRESH == decorator) {\r
  69             decorator = PENDING;\r
  70             request();\r
  71         }\r
  72         return decorator.decorateImage(image, column, itemIndex);\r
  73     }\r
  74 \r
  75     public FinalImageDecoratorContributionImpl(final PrimitiveQueryUpdater updater, final NodeContext context, final ImageDecoratorKey key) {\r
  76 \r
  77         this.updater = updater;\r
  78         this.context = context;\r
  79         this.key = key;\r
  80 \r
  81         imageQuery = new ResourceQuery<ImageDecorator>(getIdentity(key), context) {\r
  82 \r
  83             @Override\r
  84             public ImageDecorator perform(ReadGraph graph) throws DatabaseException {\r
  85                 try {\r
  86                     return getDecorator(graph, context);\r
  87                 } catch (PendingVariableException e) {\r
  88                     return PENDING;\r
  89                 } catch (DatabaseException e) {\r
  90                     throw e;\r
  91                 } catch (Throwable t) {\r
  92                     ErrorLogger.defaultLogError("FinalImageDecoratorContributionImpl.imageQuery produced unexpected exception.", t);\r
  93                     return null;\r
  94                 }\r
  95             }\r
  96 \r
  97             @Override\r
  98             public String toString() {\r
  99                 return FinalImageDecoratorContributionImpl.this + " with context " + context;\r
 100             }\r
 101 \r
 102         };\r
 103         \r
 104     }\r
 105 \r
 106     protected Procedure<ImageDecorator> createProcedure() {\r
 107 \r
 108         return new Procedure<ImageDecorator>() {\r
 109 \r
 110             @Override\r
 111             public void execute(ImageDecorator result) {\r
 112                 replaceResult(result);\r
 113             }\r
 114 \r
 115             @Override\r
 116             public void exception(Throwable t) {\r
 117                 ErrorLogger.defaultLogError("FinalImageDecoratorContributionImpl.imageQuery failed, see exception for details.", t);\r
 118             }\r
 119 \r
 120         };\r
 121 \r
 122     }\r
 123 \r
 124     protected void replaceResult(ImageDecorator result) {\r
 125         // Never let decorator become null, use a stub decorator instead.\r
 126         if (result == null)\r
 127             result = NO_DECORATION;\r
 128 \r
 129         decorator = result;\r
 130         updater.scheduleReplace(context, key, this);\r
 131     }\r
 132 \r
 133     // OVERRIDE\r
 134 \r
 135     public abstract ImageDecorator getDecorator(ReadGraph graph, NodeContext context) throws DatabaseException;\r
 136 \r
 137 }\r