Bug 96952 [build path] project settings: library tab enablement and focus
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/LibrariesWorkbookPage.java
public Object[] getChildren(TreeListDialogField field, Object element) {
			if (element instanceof CPListElement) {
				return ((CPListElement) element).getChildren(false);
			} else if (element instanceof CPListElementAttribute) {
				CPListElementAttribute attribute= (CPListElementAttribute) element;
				if (CPListElement.ACCESSRULES.equals(attribute.getKey())) {
					return (IAccessRule[]) attribute.getValue();
				}
			}
			return EMPTY_ARR;
		}
		public Object getParent(TreeListDialogField field, Object element) {
			if (element instanceof CPListElementAttribute) {
				return ((CPListElementAttribute) element).getParent();
			}
			return null;
		}
		public boolean hasChildren(TreeListDialogField field, Object element) {
			return getChildren(field, element).length > 0;
		}		
			
		
	
		public void dialogFieldChanged(DialogField field) {
			libaryPageDialogFieldChanged(field);
		}
	}
	
	private void libaryPageCustomButtonPressed(DialogField field, int index) {
		CPListElement[] libentries= null;