Bug 5677 Hierarchy outline has empty space
I opened a hierarchy view on IActionDelegate. Selected a few of the subinterfaces, changed the expansion state of the tree. Then, no matter which item I selected in the top window (the hierarchy tree), the bottom window (the outline table) always had exactly four empty rows before the first item was listed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/MethodsViewer.java
* @see IProblemChangedListener#problemsChanged
	 */
	public void problemsChanged(final Set changed) {
		Control control= getControl();
		if (control != null && !control.isDisposed()) {
			control.getDisplay().asyncExec(new Runnable() {
				public void run() {
					fProblemItemMapper.problemsChanged(changed, (ILabelProvider)getLabelProvider());
				}
			});
		}
	}
		
	/*
	 * @see StructuredViewer#associate(Object, Item)
	 */
	protected void associate(Object element, Item item) {
		if (item.getData() != element) {
			fProblemItemMapper.addToMap(element, item);	
		}
		super.associate(element, item);		
	}
	/*
	 * @see StructuredViewer#disassociate(Item)
	 */
	protected void disassociate(Item item) {
		fProblemItemMapper.removeFromMap(item.getData(), item);
		super.disassociate(item);	
	}
}