bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/contribution/FinalImageDecoratorContributionImpl.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.browsing.ui.graph.impl.contribution;
  13
  14 import org.simantics.browsing.ui.BuiltinKeys.ImageDecoratorKey;
  15 import org.simantics.browsing.ui.DataSource;
  16 import org.simantics.browsing.ui.NodeContext;
  17 import org.simantics.browsing.ui.PrimitiveQueryUpdater;
  18 import org.simantics.browsing.ui.content.ImageDecorator;
  19 import org.simantics.browsing.ui.graph.impl.request.ResourceQuery;
  20 import org.simantics.db.ReadGraph;
  21 import org.simantics.db.exception.DatabaseException;
  22 import org.simantics.db.layer0.exception.PendingVariableException;
  23 import org.simantics.db.procedure.Listener;
  24 import org.simantics.db.procedure.Procedure;
  25 import org.simantics.utils.ui.ErrorLogger;
  26
  27 public abstract class FinalImageDecoratorContributionImpl implements ImageDecorator {
  28
  29     final ImageDecorator FRESH = new ImageDecorator.Stub();
  30     final ImageDecorator PENDING = new ImageDecorator.Stub();
  31     final ImageDecorator NO_DECORATION = new ImageDecorator.Stub();
  32
  33     protected final PrimitiveQueryUpdater       updater;
  34     private final ResourceQuery<ImageDecorator> imageQuery;
  35     private final ImageDecoratorKey             key;
  36
  37     /**
  38      * The current decorator result produced for this contribution. The value
  39      * should never be <code>null</code>, but one of {@link #FRESH},
  40      * {@link #PENDING}, {@link #NO_DECORATION} instead.
  41      */
  42     protected ImageDecorator                      decorator = FRESH;
  43
  44     final protected NodeContext                   context;
  45
  46     public Object getIdentity(ImageDecoratorKey key) {
  47         return key;
  48     }
  49
  50     private void request() {
  51
  52         final DataSource<ReadGraph> source = updater.getDataSource(ReadGraph.class);
  53         assert(source != null);
  54
  55         final Procedure<ImageDecorator> procedure = createProcedure();
  56
  57         source.schedule(graph -> {
  58             if(procedure instanceof Listener<?>)
  59                 graph.asyncRequest(imageQuery, (Listener<ImageDecorator>)procedure);
  60             else
  61                 graph.asyncRequest(imageQuery, procedure);
  62         });
  63
  64     }
  65
  66     @Override
  67     public <Image> Image decorateImage(Image image, String column, int itemIndex) {
  68         if(FRESH == decorator) {
  69             decorator = PENDING;
  70             request();
  71         }
  72         return decorator.decorateImage(image, column, itemIndex);
  73     }
  74
  75     public FinalImageDecoratorContributionImpl(final PrimitiveQueryUpdater updater, final NodeContext context, final ImageDecoratorKey key) {
  76
  77         this.updater = updater;
  78         this.context = context;
  79         this.key = key;
  80
  81         imageQuery = new ResourceQuery<ImageDecorator>(getIdentity(key), context) {
  82
  83             @Override
  84             public ImageDecorator perform(ReadGraph graph) throws DatabaseException {
  85                 try {
  86                     return getDecorator(graph, context);
  87                 } catch (PendingVariableException e) {
  88                     return PENDING;
  89                 } catch (DatabaseException e) {
  90                     throw e;
  91                 } catch (Throwable t) {
  92                     ErrorLogger.defaultLogError("FinalImageDecoratorContributionImpl.imageQuery produced unexpected exception.", t);
  93                     return null;
  94                 }
  95             }
  96
  97             @Override
  98             public String toString() {
  99                 return FinalImageDecoratorContributionImpl.this + " with context " + context;
 100             }
 101
 102         };
 103
 104     }
 105
 106     protected Procedure<ImageDecorator> createProcedure() {
 107
 108         return new Procedure<ImageDecorator>() {
 109
 110             @Override
 111             public void execute(ImageDecorator result) {
 112                 replaceResult(result);
 113             }
 114
 115             @Override
 116             public void exception(Throwable t) {
 117                 ErrorLogger.defaultLogError("FinalImageDecoratorContributionImpl.imageQuery failed, see exception for details.", t);
 118             }
 119
 120         };
 121
 122     }
 123
 124     protected void replaceResult(ImageDecorator result) {
 125         // Never let decorator become null, use a stub decorator instead.
 126         if (result == null)
 127             result = NO_DECORATION;
 128
 129         decorator = result;
 130         updater.scheduleReplace(context, key, this);
 131     }
 132
 133     // OVERRIDE
 134
 135     public abstract ImageDecorator getDecorator(ReadGraph graph, NodeContext context) throws DatabaseException;
 136
 137 }