/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.preference;

import org.eclipse.swt.graphics.Image;

/**
 * Interface to a node in a preference dialog.
 * A preference node maintains a label and image used to display the
 * node in a preference dialog (usually in the form of a tree),
 * as well as the preference page this node stands for.
 *
 * The node may use lazy creation for its page
 *
 * Note that all preference nodes must be dispose their resources.
 * The node must dispose the page managed by this node, and any SWT resources
 * allocated by this node (Images, Fonts, etc).
 * However the node itself may be reused.
 */
public interface IPreferenceNode {
	/**
	 * Adds the given preference node as a subnode of this
	 * preference node.
	 *
	 * @param node the node to add
	 */
	public void add(IPreferenceNode node);

	/**
	 * Creates the preference page for this node.
	 */
	public void createPage();

	/**
	 * Release the page managed by this node, and any SWT resources
	 * held onto by this node (Images, Fonts, etc).
	 *
	 * Note that nodes are reused so this is not a call to dispose the
	 * node itself.
	 */
	public void disposeResources();

	/**
	 * Returns the subnode of this contribution node with the given node id.
	 *
	 * @param id the preference node id
	 * @return the subnode, or <code>null</code> if none
	 */
	public IPreferenceNode findSubNode(String id);

	/**
	 * Returns the id of this contribution node.
	 * This id identifies a contribution node relative to its parent.
	 *
	 * @return the node id
	 */
	public String getId();

	/**
	 * Returns the image used to present this node in a preference dialog.
	 *
	 * @return the image for this node, or <code>null</code>
	 *   if there is no image for this node
	 */
	public Image getLabelImage();

	/**
	 * Returns the text label used to present this node in a preference dialog.
	 *
	 * @return the text label for this node, or <code>null</code>
	 *   if there is no label for this node
	 */
	public String getLabelText();

	/**
	 * Returns the preference page for this node.
	 *
	 * @return the preference page
	 */
	public IPreferencePage getPage();

	/**
	 * Returns an iterator over the subnodes (immediate children)
	 * of this contribution node.
	 *
	 * @return an IPreferenceNode array containing the child nodes
	 */
	public IPreferenceNode[] getSubNodes();

	/**
	 * Removes the subnode of this preference node with the given node id.
	 *
	 * @param id the subnode id
	 * @return the removed subnode, or <code>null</code> if none
	 */
	public IPreferenceNode remove(String id);

	/**
	 * Removes the given preference node from the list of subnodes
	 * (immediate children) of this node.
	 *
	 * @param node the node to remove
	 * @return <code>true</code> if the node was removed,
	 *  and <code>false</code> otherwise
	 */
	public boolean remove(IPreferenceNode node);
}
