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.AsyncReadGraph;
  21 import org.simantics.db.ReadGraph;
  22 import org.simantics.db.exception.DatabaseException;
  23 import org.simantics.db.layer0.exception.PendingVariableException;
  24 import org.simantics.db.procedure.Listener;
  25 import org.simantics.db.procedure.Procedure;
  26 import org.simantics.utils.ui.ErrorLogger;
  27
  28 public abstract class FinalImageDecoratorContributionImpl implements ImageDecorator {
  29
  30     final ImageDecorator FRESH = new ImageDecorator.Stub();
  31     final ImageDecorator PENDING = new ImageDecorator.Stub();
  32     final ImageDecorator NO_DECORATION = new ImageDecorator.Stub();
  33
  34     protected final PrimitiveQueryUpdater       updater;
  35     private final ResourceQuery<ImageDecorator> imageQuery;
  36     private final ImageDecoratorKey             key;
  37
  38     /**
  39      * The current decorator result produced for this contribution. The value
  40      * should never be <code>null</code>, but one of {@link #FRESH},
  41      * {@link #PENDING}, {@link #NO_DECORATION} instead.
  42      */
  43     protected ImageDecorator                      decorator = FRESH;
  44
  45     final protected NodeContext                   context;
  46
  47     public Object getIdentity(ImageDecoratorKey key) {
  48         return key;
  49     }
  50
  51     private void request() {
  52
  53         final DataSource<AsyncReadGraph> source = updater.getDataSource(AsyncReadGraph.class);
  54         assert(source != null);
  55
  56         final Procedure<ImageDecorator> procedure = createProcedure();
  57
  58         source.schedule(graph -> {
  59             if(procedure instanceof Listener<?>)
  60                 graph.asyncRequest(imageQuery, (Listener<ImageDecorator>)procedure);
  61             else
  62                 graph.asyncRequest(imageQuery, procedure);
  63         });
  64
  65     }
  66
  67     @Override
  68     public <Image> Image decorateImage(Image image, String column, int itemIndex) {
  69         if(FRESH == decorator) {
  70             decorator = PENDING;
  71             request();
  72         }
  73         return decorator.decorateImage(image, column, itemIndex);
  74     }
  75
  76     public FinalImageDecoratorContributionImpl(final PrimitiveQueryUpdater updater, final NodeContext context, final ImageDecoratorKey key) {
  77
  78         this.updater = updater;
  79         this.context = context;
  80         this.key = key;
  81
  82         imageQuery = new ResourceQuery<ImageDecorator>(getIdentity(key), context) {
  83
  84             @Override
  85             public ImageDecorator perform(ReadGraph graph) throws DatabaseException {
  86                 try {
  87                     return getDecorator(graph, context);
  88                 } catch (PendingVariableException e) {
  89                     return PENDING;
  90                 } catch (DatabaseException e) {
  91                     throw e;
  92                 } catch (Throwable t) {
  93                     ErrorLogger.defaultLogError("FinalImageDecoratorContributionImpl.imageQuery produced unexpected exception.", t);
  94                     return null;
  95                 }
  96             }
  97
  98             @Override
  99             public String toString() {
 100                 return FinalImageDecoratorContributionImpl.this + " with context " + context;
 101             }
 102
 103         };
 104
 105     }
 106
 107     protected Procedure<ImageDecorator> createProcedure() {
 108
 109         return new Procedure<ImageDecorator>() {
 110
 111             @Override
 112             public void execute(ImageDecorator result) {
 113                 replaceResult(result);
 114             }
 115
 116             @Override
 117             public void exception(Throwable t) {
 118                 ErrorLogger.defaultLogError("FinalImageDecoratorContributionImpl.imageQuery failed, see exception for details.", t);
 119             }
 120
 121         };
 122
 123     }
 124
 125     protected void replaceResult(ImageDecorator result) {
 126         // Never let decorator become null, use a stub decorator instead.
 127         if (result == null)
 128             result = NO_DECORATION;
 129
 130         decorator = result;
 131         updater.scheduleReplace(context, key, this);
 132     }
 133
 134     // OVERRIDE
 135
 136     public abstract ImageDecorator getDecorator(ReadGraph graph, NodeContext context) throws DatabaseException;
 137
 138 }