bundles/org.simantics.browsing.ui.graph/src/org/simantics/browsing/ui/graph/contributor/viewpoint/ViewpointFactory.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.contributor.viewpoint;
  13
  14 import java.util.Collection;
  15
  16 import org.simantics.browsing.ui.BuiltinKeys;
  17 import org.simantics.browsing.ui.NodeContext;
  18 import org.simantics.browsing.ui.PrimitiveQueryUpdater;
  19 import org.simantics.browsing.ui.BuiltinKeys.ViewpointKey;
  20 import org.simantics.browsing.ui.content.Viewpoint;
  21 import org.simantics.browsing.ui.graph.impl.LazyViewpoint;
  22 import org.simantics.db.ReadGraph;
  23 import org.simantics.db.exception.DatabaseException;
  24
  25 /**
  26  * Extend and implement {@link #getChildren(ReadGraph, NodeContext)} to create a
  27  * viewpoint factory that reads from the graph database.
  28  *
  29  * @author Antti Villberg
  30  */
  31 public abstract class ViewpointFactory<T> implements org.simantics.browsing.ui.content.ViewpointFactory {
  32
  33     @Override
  34     public Viewpoint create(PrimitiveQueryUpdater updater, NodeContext context, ViewpointKey key) {
  35
  36         return new LazyViewpoint(updater, context, key) {
  37             @SuppressWarnings("unchecked")
  38             @Override
  39             public NodeContext[] children(ReadGraph graph) throws DatabaseException {
  40
  41                 T input = (T) context.getConstant(BuiltinKeys.INPUT);
  42
  43                 return toContextsWithInput(ViewpointFactory.this.
  44                         children(graph, input));
  45
  46             }
  47
  48             @Override
  49             public Boolean hasChildren(ReadGraph graph) throws DatabaseException {
  50                 return children(graph).length > 0;
  51             }
  52
  53             @Override
  54             public String toString() {
  55                 return ViewpointFactory.this.toString();
  56             }
  57
  58             @Override
  59             public Object getIdentity() {
  60                 return ViewpointFactory.this.getClass();
  61             }
  62         };
  63
  64     }
  65
  66     abstract protected Collection<?> children(ReadGraph g, T input) throws DatabaseException;
  67
  68 }