1 files changed, 73 insertions, 0 deletions
diff --git a/plugins/views/validation/org.eclipse.papyrus.views.validation/src/org/eclipse/papyrus/views/validation/internal/providers/InvertedViewerComparator.java b/plugins/views/validation/org.eclipse.papyrus.views.validation/src/org/eclipse/papyrus/views/validation/internal/providers/InvertedViewerComparator.java
new file mode 100644
index 00000000000..e9a8fe65c06
--- /dev/null
+++ b/plugins/views/validation/org.eclipse.papyrus.views.validation/src/org/eclipse/papyrus/views/validation/internal/providers/InvertedViewerComparator.java
@@ -0,0 +1,73 @@
+/*****************************************************************************
+ * Copyright (c) 2013 CEA LIST.
+ * 
+ * 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:
+ *   CEA LIST - Initial API and implementation
+ *****************************************************************************/
+package org.eclipse.papyrus.views.validation.internal.providers;
+
+import org.eclipse.jface.viewers.Viewer;
+import org.eclipse.jface.viewers.ViewerComparator;
+import org.eclipse.swt.SWT;
+
+/**
+ * This is the InvertedViewerComparator type. Enjoy.
+ */
+public class InvertedViewerComparator
+		extends ViewerComparator {
+
+	private final ViewerComparator comparator;
+
+	private InvertedViewerComparator(ViewerComparator comparator) {
+		this.comparator = comparator;
+	}
+
+	public static ViewerComparator invert(ViewerComparator comparator) {
+		return (comparator instanceof InvertedViewerComparator)
+			? ((InvertedViewerComparator) comparator).comparator
+			: new InvertedViewerComparator(comparator);
+	}
+
+	public static ViewerComparator unwrap(ViewerComparator comparator) {
+		return (comparator instanceof InvertedViewerComparator)
+			? ((InvertedViewerComparator) comparator).comparator
+			: comparator;
+	}
+	
+	public static int direction(ViewerComparator comparator) {
+		return (comparator instanceof InvertedViewerComparator)
+			? SWT.DOWN
+			: SWT.UP;
+	}
+
+	@Override
+	public boolean isSorterProperty(Object element, String property) {
+		return comparator.isSorterProperty(element, property);
+	}
+
+	@Override
+	public int compare(Viewer viewer, Object e1, Object e2) {
+		return -comparator.compare(viewer, e1, e2);
+	}
+
+	@Override
+	public int category(Object element) {
+		return comparator.category(element);
+	}
+
+	@Override
+	public int hashCode() {
+		return -comparator.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		return (obj instanceof InvertedViewerComparator)
+			&& ((InvertedViewerComparator) obj).comparator.equals(comparator);
+	}
+}