--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package net.sourceforge.phpdt.internal.ui.dnd;
+
+import org.eclipse.swt.dnd.DragSourceEvent;
+
+import org.eclipse.jface.util.Assert;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.jface.viewers.StructuredViewer;
+
+public class JdtViewerDragAdapter extends DelegatingDragAdapter {
+
+ private StructuredViewer fViewer;
+
+ public JdtViewerDragAdapter(StructuredViewer viewer, TransferDragSourceListener[] listeners) {
+ super(listeners);
+ Assert.isNotNull(viewer);
+ fViewer= viewer;
+ }
+
+ public void dragStart(DragSourceEvent event) {
+ IStructuredSelection selection= (IStructuredSelection)fViewer.getSelection();
+ if (selection.isEmpty()) {
+ event.doit= false;
+ return;
+ }
+ super.dragStart(event);
+ }
+}