Migrated source code from Simantics SVN

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

diff --git a/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/SingleSetListener.java b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/SingleSetListener.java
new file mode 100644 (file)
index 0000000..7da48ef
--- /dev/null
+++ b/bundles/org.simantics.db.common/src/org/simantics/db/common/procedure/single/SingleSetListener.java
@@ -0,0 +1,64 @@
+/*******************************************************************************\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.Disposable;\r
+import org.simantics.db.procedure.Listener;\r
+import org.simantics.db.procedure.SetListener;\r
+\r
+abstract public class SingleSetListener<T> implements Listener<Collection<T>>, SetListener<T>, Disposable {\r
+       \r
+    private boolean disposed = false;\r
+       \r
+    private Collection<T> previous = null;\r
+    \r
+    public void add(T result) {};\r
+    public void remove(T result) {};\r
+    \r
+    @Override\r
+    public void execute(Collection<T> result) {\r
+       \r
+       if(result == null) result = new HashSet<T>();\r
+       \r
+        if(previous == null) {\r
+\r
+            for(T t : result) add(t);\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(t);\r
+            for(T t : removed) remove(t);\r
+\r
+        }\r
+\r
+        previous = result;\r
+        \r
+    }\r
+       \r
+    public void dispose() {\r
+        disposed = true;\r
+    }\r
+\r
+    @Override\r
+    public boolean isDisposed() {\r
+        return disposed;\r
+    }\r
+    \r
+}\r