X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=bundles%2Forg.simantics.utils.datastructures%2Fsrc%2Forg%2Fsimantics%2Futils%2Fdatastructures%2FSingletonCollection.java;fp=bundles%2Forg.simantics.utils.datastructures%2Fsrc%2Forg%2Fsimantics%2Futils%2Fdatastructures%2FSingletonCollection.java;h=0ad53c592e87e761bd7fcb27d286b482c06889f9;hb=969bd23cab98a79ca9101af33334000879fb60c5;hp=0000000000000000000000000000000000000000;hpb=866dba5cd5a3929bbeae85991796acb212338a08;p=simantics%2Fplatform.git

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
index 000000000..0ad53c592
--- /dev/null
+++ b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/SingletonCollection.java
@@ -0,0 +1,78 @@
+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.utils.datastructures;
+
+import java.util.Collection;
+import java.util.Iterator;
+
+public class SingletonCollection<T> extends ImmutableSet<T> {
+
+    T content;        
+    
+    public SingletonCollection(T content) {
+        this.content = content;
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return content.equals(o);
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> c) {
+        for(Object o : c)
+            if(!content.equals(o))
+                return false;
+        return true;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return content == null;
+    }
+    
+    static class SingletonIterator<T> extends ImmutableIterator<T> {
+
+        T content;
+        
+        public SingletonIterator(T content) {
+            this.content = content;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return(content != null);
+        }
+
+        @Override
+        public T next() {
+            T ret = content;
+            content = null;
+            return ret;
+        }
+        
+    }
+
+    @Override
+    public Iterator<T> iterator() {
+        return new SingletonIterator<T>(content);
+    }
+
+    @Override
+    public int size() {
+        if(content == null)
+            return 0;
+        else
+            return 1;
+    }
+
+}