+/*******************************************************************************\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.function.Consumer;\r
+\r
+import org.simantics.browsing.ui.BuiltinKeys;\r
+import org.simantics.browsing.ui.DataSource;\r
+import org.simantics.browsing.ui.NodeContext;\r
+import org.simantics.browsing.ui.PrimitiveQueryUpdater;\r
+import org.simantics.browsing.ui.common.viewpoints.ViewpointStub;\r
+import org.simantics.browsing.ui.content.Viewpoint;\r
+import org.simantics.browsing.ui.graph.impl.request.ParametrizedResourceQuery;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.procedure.Listener;\r
+import org.simantics.utils.datastructures.Pair;\r
+\r
+/**\r
+ * Implement {@link #children(ReadGraph)} and {@link #hasChildren(ReadGraph)}.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ */\r
+public abstract class LazyParametrizedViewpoint extends ViewpointStub {\r
+\r
+ /**\r
+ * Needed for separating childQuery and hasChildQuery from each other in the\r
+ * equals sense.\r
+ */\r
+ private static final Object CHILDREN = new Object();\r
+ private static final Object HAS_CHILDREN = new Object();\r
+\r
+ private final ParametrizedResourceQuery<NodeContext[]> childQuery;\r
+ private final ParametrizedResourceQuery<Boolean> hasChildQuery;\r
+\r
+ private final Listener<NodeContext[]> childQueryProcedure;\r
+ private final Listener<Boolean> hasChildQueryProcedure;\r
+\r
+ private final PrimitiveQueryUpdater updater;\r
+ private final NodeContext context;\r
+ private final BuiltinKeys.ViewpointKey key;\r
+\r
+ /**\r
+ * @return\r
+ */\r
+ public abstract NodeContext[] children(ReadGraph graph) throws DatabaseException;\r
+\r
+ /**\r
+ * @param graph\r
+ * @return\r
+ */\r
+ public abstract Boolean hasChildren(ReadGraph graph) throws DatabaseException;\r
+\r
+\r
+ public LazyParametrizedViewpoint(PrimitiveQueryUpdater updater, NodeContext context, BuiltinKeys.ViewpointKey key, Object... parameters) {\r
+ assert updater != null;\r
+ assert context != null;\r
+ assert key != null;\r
+\r
+ this.updater = updater;\r
+ this.context = context;\r
+ this.key = key;\r
+\r
+ this.childQuery = new ParametrizedResourceQuery<NodeContext[]>(Pair.make(getClass(), CHILDREN), context, parameters) {\r
+\r
+ @Override\r
+ public NodeContext[] perform(ReadGraph graph) throws DatabaseException {\r
+ return children(graph);\r
+ }\r
+\r
+ };\r
+\r
+ this.childQueryProcedure = new Listener<NodeContext[]>() {\r
+\r
+ @Override\r
+ public void execute(NodeContext[] result) {\r
+ replaceChildrenResult(result);\r
+ }\r
+\r
+ @Override\r
+ public boolean isDisposed() {\r
+ return LazyParametrizedViewpoint.this.updater.isDisposed();\r
+ }\r
+\r
+ public void exception(Throwable t) {\r
+ System.out.print("LazyParametrizedViewpoint2.childQuery failed: ");\r
+ t.printStackTrace();\r
+ }\r
+\r
+ };\r
+\r
+ this.hasChildQuery = new ParametrizedResourceQuery<Boolean>(Pair.make(getClass(), HAS_CHILDREN), context, parameters) {\r
+\r
+ @Override\r
+ public Boolean perform(ReadGraph graph) throws DatabaseException {\r
+ return hasChildren(graph);\r
+ }\r
+\r
+ };\r
+\r
+ this.hasChildQueryProcedure = new Listener<Boolean>() {\r
+\r
+ @Override\r
+ public void execute(Boolean result) {\r
+ replaceHasChildrenResult(result);\r
+ }\r
+\r
+ @Override\r
+ public boolean isDisposed() {\r
+ return LazyParametrizedViewpoint.this.updater.isDisposed();\r
+ }\r
+\r
+ public void exception(Throwable t) {\r
+ System.out.print("LazyParametrizedViewpoint2.hasChildQuery failed: ");\r
+ t.printStackTrace();\r
+ }\r
+\r
+ };\r
+\r
+ }\r
+\r
+ public NodeContext getContext() {\r
+ return context;\r
+ }\r
+\r
+ @Override\r
+ public NodeContext[] getChildren() {\r
+ if (children == Viewpoint.PENDING_CHILDREN) {\r
+ DataSource<ReadGraph> source = updater.getDataSource(ReadGraph.class);\r
+ if (source != null) {\r
+ source.schedule(graph -> graph.asyncRequest(childQuery, childQueryProcedure));\r
+ }\r
+ }\r
+\r
+ return children;\r
+ }\r
+\r
+ @Override\r
+ public Boolean getHasChildren() {\r
+ if (hasChildren == Viewpoint.PENDING_HAS_CHILDREN) {\r
+ DataSource<ReadGraph> source = updater.getDataSource(ReadGraph.class);\r
+ if (source != null) {\r
+ source.schedule(new Consumer<ReadGraph>() {\r
+ @Override\r
+ public void accept(ReadGraph source) {\r
+ source.asyncRequest(hasChildQuery, hasChildQueryProcedure);\r
+ }\r
+ });\r
+ }\r
+ }\r
+\r
+ return hasChildren;\r
+ }\r
+\r
+ protected void replaceChildrenResult(NodeContext[] result) {\r
+ setChildren(updater, result);\r
+ updater.scheduleReplace(context, key, this);\r
+ }\r
+\r
+ protected void replaceHasChildrenResult(Boolean result) {\r
+ setHasChildren(result);\r
+ updater.scheduleReplace(context, key, this);\r
+ }\r
+\r
+ /**\r
+ * @param <T>\r
+ * @param clazz\r
+ * @return input of the specified class\r
+ * @throws ClassCastException if the input class does not match the\r
+ * specified class\r
+ * @throws NullPointerException if the input is null\r
+ */\r
+ protected <T> T getInput(Class<T> clazz) throws ClassCastException {\r
+ Object o = context.getConstant(BuiltinKeys.INPUT);\r
+ if (o == null)\r
+ throw new NullPointerException("null input");\r
+ return clazz.cast(o);\r
+ }\r
+\r
+ /**\r
+ * @param <T>\r
+ * @param clazz\r
+ * @return <code>null</code> if input is <code>null</code> or if the class does not match\r
+ */\r
+ protected <T> T tryGetInput(Class<T> clazz) {\r
+ Object o = context.getConstant(BuiltinKeys.INPUT);\r
+ if (o != null && clazz.isInstance(o))\r
+ return clazz.cast(o);\r
+ return null;\r
+ }\r
+\r
+}\r