Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.db.common / src / org / simantics / db / common / procedure / adapter / StagedAsyncListener.java

diff --git a/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/adapter/StagedAsyncListener.java b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/adapter/StagedAsyncListener.java
new file mode 100644 (file)
index 0000000..15c5b62
--- /dev/null
+++ b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/adapter/StagedAsyncListener.java
@@ -0,0 +1,44 @@
+/*******************************************************************************\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.adapter;\r
+\r
+import java.util.concurrent.atomic.AtomicBoolean;\r
+\r
+import org.simantics.db.AsyncReadGraph;\r
+import org.simantics.db.procedure.AsyncListener;\r
+\r
+abstract public class StagedAsyncListener<T> implements AsyncListener<T> {\r
+\r
+       final private AtomicBoolean first = new AtomicBoolean(true); \r
+       \r
+       @Override\r
+    public void exception(AsyncReadGraph graph, Throwable t) {\r
+    }\r
+\r
+    @Override\r
+    final public void execute(AsyncReadGraph graph, T result) {\r
+       if(first.compareAndSet(true, false)) {\r
+               first(graph, result);\r
+       } else {\r
+               rest(graph, result);\r
+       }\r
+    }\r
+\r
+    @Override\r
+    public boolean isDisposed() {\r
+        return false;\r
+    }\r
+\r
+    abstract public void first(AsyncReadGraph graph, T result);\r
+    abstract public void rest(AsyncReadGraph graph, T result);\r
+\r
+}\r