Remove UI dependencies to JCR.

[lgpl/argeo-commons.git] / jcr / org.argeo.cms.jcr.ui / src / org / argeo / eclipse / ui / jcr / util / NodeViewerComparer.java

diff --git a/jcr/org.argeo.cms.jcr.ui/src/org/argeo/eclipse/ui/jcr/util/NodeViewerComparer.java b/jcr/org.argeo.cms.jcr.ui/src/org/argeo/eclipse/ui/jcr/util/NodeViewerComparer.java
new file mode 100644 (file)
index 0000000..54b795f
--- /dev/null
+++ b/jcr/org.argeo.cms.jcr.ui/src/org/argeo/eclipse/ui/jcr/util/NodeViewerComparer.java
@@ -0,0 +1,36 @@
+package org.argeo.eclipse.ui.jcr.util;
+
+import javax.jcr.Node;
+import javax.jcr.RepositoryException;
+
+import org.argeo.eclipse.ui.EclipseUiException;
+import org.eclipse.jface.viewers.IElementComparer;
+
+/** Compare JCR nodes based on their JCR identifiers, for use in JFace viewers. */
+public class NodeViewerComparer implements IElementComparer {
+
+       // force comparison on Node IDs only.
+       public boolean equals(Object elementA, Object elementB) {
+               if (!(elementA instanceof Node) || !(elementB instanceof Node)) {
+                       return elementA == null ? elementB == null : elementA
+                                       .equals(elementB);
+               } else {
+
+                       boolean result = false;
+                       try {
+                               String idA = ((Node) elementA).getIdentifier();
+                               String idB = ((Node) elementB).getIdentifier();
+                               result = idA == null ? idB == null : idA.equals(idB);
+                       } catch (RepositoryException re) {
+                               throw new EclipseUiException("cannot compare nodes", re);
+                       }
+
+                       return result;
+               }
+       }
+
+       public int hashCode(Object element) {
+               // TODO enhanced this method.
+               return element.getClass().toString().hashCode();
+       }
+}
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