| /******************************************************************************* |
| * 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 org.eclipse.jface.viewers; |
| |
| /** |
| * An interface to content providers for tree-structure-oriented |
| * viewers. |
| * |
| * @see AbstractTreeViewer |
| */ |
| public interface ITreeContentProvider extends IStructuredContentProvider { |
| /** |
| * Returns the child elements of the given parent element. |
| * <p> |
| * The difference between this method and <code>IStructuredContentProvider.getElements</code> |
| * is that <code>getElements</code> is called to obtain the |
| * tree viewer's root elements, whereas <code>getChildren</code> is used |
| * to obtain the children of a given parent element in the tree (including a root). |
| * </p> |
| * The result is not modified by the viewer. |
| * |
| * @param parentElement the parent element |
| * @return an array of child elements |
| */ |
| public Object[] getChildren(Object parentElement); |
| |
| /** |
| * Returns the parent for the given element, or <code>null</code> |
| * indicating that the parent can't be computed. |
| * In this case the tree-structured viewer can't expand |
| * a given node correctly if requested. |
| * |
| * @param element the element |
| * @return the parent element, or <code>null</code> if it |
| * has none or if the parent cannot be computed |
| */ |
| public Object getParent(Object element); |
| |
| /** |
| * Returns whether the given element has children. |
| * <p> |
| * Intended as an optimization for when the viewer does not |
| * need the actual children. Clients may be able to implement |
| * this more efficiently than <code>getChildren</code>. |
| * </p> |
| * |
| * @param element the element |
| * @return <code>true</code> if the given element has children, |
| * and <code>false</code> if it has no children |
| */ |
| public boolean hasChildren(Object element); |
| } |