Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.utils.datastructures / src / org / simantics / utils / datastructures / SingletonCollection.java

diff --git a/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/SingletonCollection.java b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/SingletonCollection.java
new file mode 100644 (file)
index 0000000..0ad53c5
--- /dev/null
+++ b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/SingletonCollection.java
@@ -0,0 +1,78 @@
+/*******************************************************************************\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.utils.datastructures;\r
+\r
+import java.util.Collection;\r
+import java.util.Iterator;\r
+\r
+public class SingletonCollection<T> extends ImmutableSet<T> {\r
+\r
+    T content;        \r
+    \r
+    public SingletonCollection(T content) {\r
+        this.content = content;\r
+    }\r
+\r
+    @Override\r
+    public boolean contains(Object o) {\r
+        return content.equals(o);\r
+    }\r
+\r
+    @Override\r
+    public boolean containsAll(Collection<?> c) {\r
+        for(Object o : c)\r
+            if(!content.equals(o))\r
+                return false;\r
+        return true;\r
+    }\r
+\r
+    @Override\r
+    public boolean isEmpty() {\r
+        return content == null;\r
+    }\r
+    \r
+    static class SingletonIterator<T> extends ImmutableIterator<T> {\r
+\r
+        T content;\r
+        \r
+        public SingletonIterator(T content) {\r
+            this.content = content;\r
+        }\r
+\r
+        @Override\r
+        public boolean hasNext() {\r
+            return(content != null);\r
+        }\r
+\r
+        @Override\r
+        public T next() {\r
+            T ret = content;\r
+            content = null;\r
+            return ret;\r
+        }\r
+        \r
+    }\r
+\r
+    @Override\r
+    public Iterator<T> iterator() {\r
+        return new SingletonIterator<T>(content);\r
+    }\r
+\r
+    @Override\r
+    public int size() {\r
+        if(content == null)\r
+            return 0;\r
+        else\r
+            return 1;\r
+    }\r
+\r
+}\r