bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/contribution/CallbackViewpointContributionImpl.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 java.util.Collection;
  15 import java.util.function.Consumer;
  16
  17 import org.simantics.browsing.ui.BuiltinKeys;
  18 import org.simantics.browsing.ui.BuiltinKeys.ViewpointContributionKey;
  19 import org.simantics.browsing.ui.DataSource;
  20 import org.simantics.browsing.ui.NodeContext;
  21 import org.simantics.browsing.ui.PrimitiveQueryUpdater;
  22 import org.simantics.browsing.ui.Tester;
  23 import org.simantics.browsing.ui.common.NodeContextUtil;
  24 import org.simantics.db.AsyncReadGraph;
  25 import org.simantics.db.ReadGraph;
  26 import org.simantics.db.common.request.ReadRequest;
  27 import org.simantics.db.exception.DatabaseException;
  28 import org.simantics.utils.ui.ErrorLogger;
  29
  30 /**
  31  * Implement {@link #children(AsyncReadGraph)} and {@link #hasChildren(AsyncReadGraph)}.
  32  *
  33  * @author Tuukka Lehtonen
  34  */
  35 abstract public class CallbackViewpointContributionImpl extends ContributionStub {
  36
  37     /**
  38      * @param graph
  39      * @param context
  40      * @return a collection of contributions, must not be <code>null</code>
  41      * @throws DatabaseException
  42      */
  43     abstract public void children(ReadGraph graph, NodeContext context, Consumer<Collection<?>> callback) throws DatabaseException;
  44
  45     public CallbackViewpointContributionImpl(PrimitiveQueryUpdater updater,
  46             NodeContext context, ViewpointContributionKey key) {
  47
  48         assert updater != null;
  49         assert context != null;
  50         assert key != null;
  51
  52         this.updater = updater;
  53         this.context = context;
  54         this.key = key;
  55
  56     }
  57
  58     final protected PrimitiveQueryUpdater       updater;
  59     final private NodeContext                context;
  60     final private BuiltinKeys.ViewpointContributionKey    key;
  61
  62     public NodeContext getContext() {
  63         return context;
  64     }
  65
  66     @Override
  67     public Collection<NodeContext> getContribution() {
  68
  69         //System.out.println("LazyViewpoint2@" + System.identityHashCode(this) + " getChildren() = " + children.length);
  70
  71         if (children == org.simantics.browsing.ui.content.ViewpointContribution.PENDING_CONTRIBUTION) {
  72             DataSource<AsyncReadGraph> source = updater.getDataSource(AsyncReadGraph.class);
  73             if (source != null) {
  74                 source.schedule(graph -> {
  75                     ReadRequest childQuery = new ReadRequest() {
  76
  77                         @Override
  78                         public void run(ReadGraph graph) throws DatabaseException {
  79                             try {
  80                                 children(graph, context,
  81                                         result -> replaceChildrenResult(NodeContextUtil.toContextCollectionWithInput(CallbackViewpointContributionImpl.this, result)));
  82                             } catch (DatabaseException e) {
  83                                 throw e;
  84                             } catch (Throwable t) {
  85                                 ErrorLogger.defaultLogError("LazyContributionImpl.childQuery produced unexpected exception.", t);
  86                             }
  87                         }
  88
  89                         @Override
  90                         public String toString() {
  91                             return "LazyContributionImpl[" + System.identityHashCode(CallbackViewpointContributionImpl.this) + "].childQuery";
  92                         }
  93
  94                     };
  95
  96                     graph.asyncRequest(childQuery);
  97                 });
  98             }
  99         }
 100
 101         //System.out.println("LazyViewpoint.getChildren returns " + children);
 102
 103         return children;
 104
 105     }
 106
 107     protected void replaceChildrenResult(Collection<NodeContext> result) {
 108         setChildren(updater, result);
 109         updater.scheduleReplace(context, key, this);
 110     }
 111
 112     /**
 113      * @param <T>
 114      * @param clazz
 115      * @return input of the specified class
 116      * @throws ClassCastException if the input class does not match the
 117      *         specified class
 118      * @throws NullPointerException if the input is null
 119      */
 120     @SuppressWarnings("unchecked")
 121     protected <T> T getInput(Class<T> clazz) throws ClassCastException {
 122         Object o = context.getConstant(BuiltinKeys.INPUT);
 123         if (o == null)
 124             throw new NullPointerException("null input");
 125 //        return clazz.cast(o);
 126         return (T) o;
 127     }
 128
 129     /**
 130      * @param <T>
 131      * @param clazz
 132      * @return <code>null</code> if input is <code>null</code> or if the class does not match
 133      */
 134     @SuppressWarnings("unchecked")
 135     protected <T> T tryGetInput(Class<T> clazz) {
 136         Object o = context.getConstant(BuiltinKeys.INPUT);
 137         if (o != null && clazz.isInstance(o))
 138 //            return clazz.cast(o);
 139             return (T) o;
 140         return null;
 141     }
 142
 143     @Override
 144     public Tester getNodeContextTester() {
 145         return null;
 146     }
 147
 148 }