Bug 34335 DND doesn't work
RC2 Linux-GTK Drag and drop doesn't work. I've tried it in the DNDExample and in the package explorer and drags are never initiated.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/browsing/JavaBrowsingPart.java
* Answers if the given <code>element</code> is a valid
	 * input for this part.
	 * 
	 * @param 	element	the object to test
	 * @return	<true> if the given element is a valid input
	 */
	abstract protected boolean isValidInput(Object element);
	/**
	 * Answers if the given <code>element</code> is a valid
	 * element for this part.
	 * 
	 * @param 	element	the object to test
	 * @return	<true> if the given element is a valid element
	 */
	protected boolean isValidElement(Object element) {
		if (element == null)
			return false;
		element= getSuitableJavaElement(element);
		if (element == null)
			return false;
		Object input= getViewer().getInput();
		if (input == null)
			return false;
		if (input instanceof Collection)
			return ((Collection)input).contains(element);
		else
			return input.equals(element);
	}
	private boolean isInputResetBy(Object newInput, Object input, IWorkbenchPart part) {
		if (newInput == null)