Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2016 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.swt.accessibility; /** * This adapter class provides default implementations for the * methods described by the <code>AccessibleListener</code> interface. * <p> * Classes that wish to deal with <code>AccessibleEvent</code>s can * extend this class and override only the methods that they are * interested in. * </p><p> * Note: Accessibility clients use child identifiers to specify * whether they want information about a control or one of its children. * Child identifiers are increasing integers beginning with 0. * The identifier CHILDID_SELF represents the control itself. * </p> * * @see AccessibleListener * @see AccessibleEvent * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> * * @since 2.0 */ public abstract class AccessibleAdapter implements AccessibleListener { /** * Sent when an accessibility client requests the name * of the control, or the name of a child of the control. * The default behavior is to do nothing. * <p> * Return the name of the control or specified child in the * <code>result</code> field of the event object. Returning * an empty string tells the client that the control or child * does not have a name, and returning null tells the client * to use the platform name. * </p> * * @param e an event object containing the following fields:<ul> * <li>childID [IN] - an identifier specifying the control or one of its children</li> * <li>result [OUT] - the requested name string, or null</li> * </ul> */ @Override public void getName(AccessibleEvent e) { } /** * Sent when an accessibility client requests the help string * of the control, or the help string of a child of the control. * The default behavior is to do nothing. * <p> * The information in this property should be similar to the help * provided by toolTipText. It describes what the control or child * does or how to use it, as opposed to getDescription, which * describes appearance. * </p><p> * Return the help string of the control or specified child in * the <code>result</code> field of the event object. Returning * an empty string tells the client that the control or child * does not have a help string, and returning null tells the * client to use the platform help string. * </p> * * @param e an event object containing the following fields:<ul> * <li>childID [IN] - an identifier specifying the control or one of its children</li> * <li>result [OUT] - the requested help string, or null</li> * </ul> */ @Override public void getHelp(AccessibleEvent e) { } /** * Sent when an accessibility client requests the keyboard shortcut * of the control, or the keyboard shortcut of a child of the control. * The default behavior is to do nothing. * <p> * A keyboard shortcut can either be a mnemonic, or an accelerator. * As a general rule, if the control or child can receive keyboard focus, * then you should expose its mnemonic, and if it cannot receive keyboard * focus, then you should expose its accelerator. * </p><p> * Return the keyboard shortcut string of the control or specified child * in the <code>result</code> field of the event object. Returning an * empty string tells the client that the control or child does not * have a keyboard shortcut string, and returning null tells the client * to use the platform keyboard shortcut string. * </p> * * @param e an event object containing the following fields:<ul> * <li>childID [IN] - an identifier specifying the control or one of its children</li> * <li>result [OUT] - the requested keyboard shortcut string (example: "ALT+N"), or null</li> * </ul> */ @Override public void getKeyboardShortcut(AccessibleEvent e) { } /** * Sent when an accessibility client requests a description * of the control, or a description of a child of the control. * The default behavior is to do nothing. * <p> * This is a textual description of the control or child's visual * appearance, which is typically only necessary if it cannot be * determined from other properties such as role. * </p><p> * Return the description of the control or specified child in * the <code>result</code> field of the event object. Returning * an empty string tells the client that the control or child * does not have a description, and returning null tells the * client to use the platform description. * </p> * * @param e an event object containing the following fields:<ul> * <li>childID [IN] - an identifier specifying the control or one of its children</li> * <li>result [OUT] - the requested description string, or null</li> * </ul> */ @Override public void getDescription(AccessibleEvent e) { } }