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diff --git a/bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/LazyViewpointFactory.java b/bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/LazyViewpointFactory.java
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+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.browsing.ui.graph.impl;
+
+import java.util.Collection;
+
+import org.simantics.browsing.ui.NodeContext;
+import org.simantics.browsing.ui.PrimitiveQueryUpdater;
+import org.simantics.browsing.ui.BuiltinKeys.ViewpointKey;
+import org.simantics.browsing.ui.content.Viewpoint;
+import org.simantics.browsing.ui.content.ViewpointFactory;
+import org.simantics.db.ReadGraph;
+import org.simantics.db.exception.DatabaseException;
+
+/**
+ * Extend and implement {@link #getChildren(ReadGraph, NodeContext)} to create a
+ * viewpoint factory that reads from the graph database.
+ * 
+ * @author Antti Villberg
+ */
+public abstract class LazyViewpointFactory implements ViewpointFactory {
+
+    @Override
+    public Viewpoint create(PrimitiveQueryUpdater updater,
+            NodeContext context, ViewpointKey key) {
+        return new LazyViewpoint(updater, context, key) {
+            @Override
+            public NodeContext[] children(ReadGraph graph) throws DatabaseException {
+                return toContextsWithInput(LazyViewpointFactory.this.
+                        getChildren(graph, context));
+            }
+
+            @Override
+            public Boolean hasChildren(ReadGraph graph) throws DatabaseException {
+                return children(graph).length > 0;
+            }
+
+            @Override
+            public String toString() {
+                return LazyViewpointFactory.this.toString();
+            }
+
+            @Override
+            public Object getIdentity() {
+                return LazyViewpointFactory.this.getClass();
+            }
+        };
+    }
+
+    abstract protected Collection<?> getChildren(ReadGraph g, NodeContext context) throws DatabaseException;
+
+    protected boolean hasChildren(ReadGraph g, NodeContext context) throws DatabaseException {
+        return !getChildren(g, context).isEmpty();
+    }
+
+}