Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.common / src / org / simantics / db / common / procedure / single / StagedSingleSetSyncListener.java

diff --git a/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/StagedSingleSetSyncListener.java b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/StagedSingleSetSyncListener.java
new file mode 100644 (file)
index 0000000..92331ee
--- /dev/null
+++ b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/StagedSingleSetSyncListener.java
@@ -0,0 +1,58 @@
+/*******************************************************************************\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.db.common.procedure.single;\r
+\r
+import java.util.Collection;\r
+import java.util.HashSet;\r
+\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.common.utils.Logger;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.db.procedure.SyncListener;\r
+\r
+abstract public class StagedSingleSetSyncListener<T> implements SyncListener<Collection<T>>{\r
+    \r
+    private Collection<T> previous = null;\r
+    \r
+    public void start(ReadGraph graph, Collection<T> items) throws DatabaseException {}\r
+    public void add(ReadGraph graph, T item) throws DatabaseException {}\r
+    public void remove(ReadGraph graph, T item) throws DatabaseException {}\r
+    \r
+    @Override\r
+    public synchronized void execute(ReadGraph graph, final Collection<T> result) throws DatabaseException {\r
+       \r
+        if(previous == null) {\r
+\r
+            start(graph, result);\r
+\r
+        } else {\r
+\r
+            HashSet<T> added = new HashSet<T>(result);\r
+            added.removeAll(previous);\r
+            HashSet<T> removed = new HashSet<T>(previous);\r
+            removed.removeAll(result);\r
+\r
+            for(T t : added) add(graph, t);\r
+            for(T t : removed) remove(graph, t);\r
+\r
+        }\r
+\r
+        previous = result;\r
+        \r
+    }\r
+    \r
+    @Override\r
+    public void exception(ReadGraph graph, Throwable throwable) throws DatabaseException {\r
+               Logger.defaultLogError(throwable);\r
+    }\r
+    \r
+}\r