Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.browsing.ui.graph.impl / src / org / simantics / browsing / ui / graph / impl / LazyViewpointFactory.java

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
new file mode 100644 (file)
index 0000000..1af52fe
--- /dev/null
+++ b/bundles/org.simantics.browsing.ui.graph.impl/src/org/simantics/browsing/ui/graph/impl/LazyViewpointFactory.java
@@ -0,0 +1,65 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.browsing.ui.graph.impl;\r
+\r
+import java.util.Collection;\r
+\r
+import org.simantics.browsing.ui.NodeContext;\r
+import org.simantics.browsing.ui.PrimitiveQueryUpdater;\r
+import org.simantics.browsing.ui.BuiltinKeys.ViewpointKey;\r
+import org.simantics.browsing.ui.content.Viewpoint;\r
+import org.simantics.browsing.ui.content.ViewpointFactory;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.exception.DatabaseException;\r
+\r
+/**\r
+ * Extend and implement {@link #getChildren(ReadGraph, NodeContext)} to create a\r
+ * viewpoint factory that reads from the graph database.\r
+ * \r
+ * @author Antti Villberg\r
+ */\r
+public abstract class LazyViewpointFactory implements ViewpointFactory {\r
+\r
+    @Override\r
+    public Viewpoint create(PrimitiveQueryUpdater updater,\r
+            NodeContext context, ViewpointKey key) {\r
+        return new LazyViewpoint(updater, context, key) {\r
+            @Override\r
+            public NodeContext[] children(ReadGraph graph) throws DatabaseException {\r
+                return toContextsWithInput(LazyViewpointFactory.this.\r
+                        getChildren(graph, context));\r
+            }\r
+\r
+            @Override\r
+            public Boolean hasChildren(ReadGraph graph) throws DatabaseException {\r
+                return children(graph).length > 0;\r
+            }\r
+\r
+            @Override\r
+            public String toString() {\r
+                return LazyViewpointFactory.this.toString();\r
+            }\r
+\r
+            @Override\r
+            public Object getIdentity() {\r
+                return LazyViewpointFactory.this.getClass();\r
+            }\r
+        };\r
+    }\r
+\r
+    abstract protected Collection<?> getChildren(ReadGraph g, NodeContext context) throws DatabaseException;\r
+\r
+    protected boolean hasChildren(ReadGraph g, NodeContext context) throws DatabaseException {\r
+        return !getChildren(g, context).isEmpty();\r
+    }\r
+\r
+}\r