--- /dev/null
+/*******************************************************************************\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.concurrent.Semaphore;\r
+\r
+import org.simantics.browsing.ui.BuiltinKeys;\r
+import org.simantics.browsing.ui.NodeContext;\r
+import org.simantics.browsing.ui.content.Labeler.Modifier;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.Session;\r
+import org.simantics.db.WriteGraph;\r
+import org.simantics.db.common.request.ReadRequest;\r
+import org.simantics.db.common.request.WriteRequest;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.layer0.adapter.StringIndexModifier;\r
+import org.simantics.db.layer0.adapter.StringModifier;\r
+import org.simantics.db.layer0.adapter.TObjectIntPair;\r
+import org.simantics.layer0.utils.representation.StringRepresentation2;\r
+import org.simantics.utils.datastructures.Callback;\r
+import org.simantics.utils.ui.ErrorLogger;\r
+\r
+/**\r
+ * Please implement:\r
+ * <ul>\r
+ * <li>{@link #createModifierInput(String)} - constructs an input for\r
+ * {@link org.simantics.db.layer0.adapter.Modifier#modify(WriteGraph, Object)}\r
+ * from the specified label given by the user.\r
+ * <li>{@link #doModify(WriteGraph, String)} - perform the requested modification\r
+ * into the graph.</li>\r
+ * </ul>\r
+ * \r
+ * <p>\r
+ * Other points of customization:\r
+ * </p>\r
+ * <ul>\r
+ * <li>{@link #getInitialValue(ReadGraph)} - returns the value that should be shown\r
+ * initially when editing. The default implementation just adapts the input to\r
+ * its String representation, but you may want to customize this.</li>\r
+ * <li>{@link #initializeGraphModifier(ReadGraph)} - allows you to perform custom\r
+ * initialization of the modifier which uses the graph</li>\r
+ * <li>{@link #getResourceToModify()} - allows you to customize the way in which\r
+ * the input INodeContext is resolved into a Resource. The default\r
+ * implementation uses the IAdaptable interface of INodeContext to get the\r
+ * Resource.</li>\r
+ * <li>{@link #verifyModification(String)} - allows for last chance denial of\r
+ * the modification after the user has signalled approval of the modification.</li>\r
+ * </ul>\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ * \r
+ * @param <T> the input class of the used\r
+ * {@link org.simantics.db.layer0.adapter.Modifier}\r
+ */\r
+public abstract class GraphStringIndexModifier implements Modifier {\r
+\r
+ protected NodeContext context;\r
+\r
+ protected Session session;\r
+\r
+ protected int index;\r
+\r
+ protected String initialValue;\r
+\r
+ protected StringIndexModifier modifier;\r
+\r
+ /**\r
+ * Used to synchronize {@link #isValid(String)} and {@link #modify(String)}\r
+ * with the asynchronous modifier fetch.\r
+ */\r
+ protected Semaphore modifierReady = new Semaphore(0);\r
+\r
+ /**\r
+ * If <code>non-null</code>, the modifier could not be fetched, e.g. adapted\r
+ * from the specified INodeContext.\r
+ */\r
+ protected Throwable modifierFailed;\r
+\r
+\r
+ /**\r
+ * @param context\r
+ * @param session\r
+ */\r
+ public GraphStringIndexModifier(NodeContext context, Session session, int index) throws DatabaseException {\r
+ this.context = context;\r
+ this.session = session;\r
+ this.index = index;\r
+\r
+ final Resource r = getResourceToModify();\r
+ if (r == null)\r
+ throw new IllegalArgumentException("This modifier does not work for INodeContexts that are not adaptable to a Resource. The context input is: " + context.getConstant(BuiltinKeys.INPUT));\r
+\r
+ session.syncRequest(new ReadRequest() {\r
+ @Override\r
+ public void run(ReadGraph g) throws DatabaseException {\r
+ initialValue = getInitialValue(g);\r
+ GraphStringIndexModifier.this.modifier = g.adapt(r, StringIndexModifier.class);\r
+ initializeGraphModifier(g);\r
+ modifierReady.release();\r
+ }\r
+ });\r
+\r
+ }\r
+\r
+ /**\r
+ * @param g\r
+ * @return the value that shall be returned by {@link #getValue()}\r
+ */\r
+ protected String getInitialValue(ReadGraph g) throws DatabaseException {\r
+ StringRepresentation2 sr = g.adapt(getResourceToModify(), StringRepresentation2.class);\r
+ String s = sr.get(g, index);\r
+ return s;\r
+ }\r
+\r
+ /**\r
+ * Override to perform graph-based initialization actions for this modifier.\r
+ * \r
+ * @param g the graph handle\r
+ */\r
+ protected void initializeGraphModifier(ReadGraph g) {\r
+ }\r
+\r
+ /**\r
+ * @return the Resource to modify based on the input INodeContext. This\r
+ * resource must be adaptable to a {@link StringModifier} in order\r
+ * for this modifier to work.\r
+ */\r
+ protected Resource getResourceToModify() {\r
+ Resource r = (Resource) context.getAdapter(Resource.class);\r
+ if (r == null)\r
+ throw new AssertionError("context.getAdapter(Resource.class) returned null");\r
+ return r;\r
+ }\r
+\r
+ /**\r
+ * @return the modifier or <code>null</code> if the StringModifier adaption\r
+ * has not completed yet.\r
+ */\r
+ protected StringIndexModifier getModifier() {\r
+ return modifier;\r
+ }\r
+\r
+ @Override\r
+ public String getValue() {\r
+ return initialValue;\r
+ }\r
+\r
+ @Override\r
+ public String isValid(String label) {\r
+ if (modifierFailed != null)\r
+ return "Could not resolve validator for this value, modification denied. Reason: " + modifierFailed.getMessage();\r
+ if (modifier == null)\r
+ // Cannot validate yet, the validator has not been resolved.\r
+ // For the time being, consider the value invalid for no\r
+ // apparent reason to the user.\r
+ return "";\r
+ TObjectIntPair<String> t = createModifierInput(label);\r
+ return modifier.isValid(t);\r
+ }\r
+\r
+ @Override\r
+ public final void modify(String label) {\r
+ if (modifier == null) {\r
+ try {\r
+ modifierReady.acquire();\r
+ } catch (InterruptedException e) {\r
+ // TODO: throw exception?\r
+ return;\r
+ }\r
+ }\r
+ if (modifierFailed != null)\r
+ // TODO: throw exception?\r
+ return;\r
+ final TObjectIntPair<String> t = createModifierInput(label);\r
+ if (!verifyModification(t))\r
+ return;\r
+ session.asyncRequest(new WriteRequest() {\r
+ @Override\r
+ public void perform(WriteGraph graph) throws DatabaseException {\r
+ doModify(graph, t);\r
+ }\r
+ }, new Callback<DatabaseException>() {\r
+ @Override\r
+ public void run(DatabaseException parameter) {\r
+ if (parameter != null)\r
+ ErrorLogger.defaultLogError(parameter);\r
+ }\r
+ });\r
+ }\r
+\r
+ /**\r
+ * Called one last time before actually performing the modifying write\r
+ * transaction to verify whether this is really desired or not.\r
+ * \r
+ * <p>\r
+ * This default implementation will always allow the modification to proceed.\r
+ * </p>\r
+ * \r
+ * @param label the label to be given to the modifier\r
+ * @return <code>true</code> to go forward with the transaction,\r
+ * <code>false</code> to bail out\r
+ */\r
+ protected boolean verifyModification(TObjectIntPair<String> label) {\r
+ return true;\r
+ }\r
+\r
+ public abstract void doModify(WriteGraph graph, TObjectIntPair<String> label) throws DatabaseException;\r
+\r
+ /**\r
+ * Constructs T from the specified label which is then given to\r
+ * {@link #doModify(WriteGraph, Object)} as the class T argument.\r
+ * \r
+ * @param fromLabel the modified label specified by the user\r
+ * @return the\r
+ * {@link org.simantics.db.layer0.adapter.Modifier#modify(WriteGraph, Object)}\r
+ * input\r
+ */\r
+ public abstract TObjectIntPair<String> createModifierInput(String fromLabel);\r
+\r
+};\r
Code Review / simantics / platform.git / blobdiff