1 files changed, 71 insertions, 0 deletions
diff --git a/plugins/org.eclipse.net4j.ui/src/org/eclipse/net4j/ui/DelegatingContentProvider.java b/plugins/org.eclipse.net4j.ui/src/org/eclipse/net4j/ui/DelegatingContentProvider.java
new file mode 100644
index 0000000000..b32a7fa639
--- /dev/null
+++ b/plugins/org.eclipse.net4j.ui/src/org/eclipse/net4j/ui/DelegatingContentProvider.java
@@ -0,0 +1,71 @@
+/***************************************************************************
+ * Copyright (c) 2004-2007 Eike Stepper, Germany.
+ * 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:
+ *    Eike Stepper - initial API and implementation
+ **************************************************************************/
+package org.eclipse.net4j.ui;
+
+import org.eclipse.jface.viewers.IStructuredContentProvider;
+import org.eclipse.jface.viewers.Viewer;
+
+/**
+ * @author Eike Stepper
+ */
+public class DelegatingContentProvider implements IStructuredContentProvider
+{
+  public static final String NONE = "";
+
+  private IStructuredContentProvider delegate;
+
+  private boolean optional;
+
+  public DelegatingContentProvider(IStructuredContentProvider delegate, boolean optional)
+  {
+    this.delegate = delegate;
+    this.optional = optional;
+  }
+
+  public DelegatingContentProvider(IStructuredContentProvider delegate)
+  {
+    this(delegate, false);
+  }
+
+  public IStructuredContentProvider getDelegate()
+  {
+    return delegate;
+  }
+
+  public boolean isOptional()
+  {
+    return optional;
+  }
+
+  public void dispose()
+  {
+    delegate.dispose();
+  }
+
+  public Object[] getElements(Object inputElement)
+  {
+    Object[] elements = delegate.getElements(inputElement);
+    if (optional)
+    {
+      Object[] newElements = new Object[elements.length + 1];
+      newElements[0] = NONE;
+      System.arraycopy(elements, 0, newElements, 1, elements.length);
+      elements = newElements;
+    }
+
+    return elements;
+  }
+
+  public void inputChanged(Viewer viewer, Object oldInput, Object newInput)
+  {
+    delegate.inputChanged(viewer, oldInput, newInput);
+  }
+}