| /******************************************************************************* |
| * Copyright (c) 2000, 2009 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.accessibility; |
| |
| |
| import java.util.*; |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.events.*; |
| import org.eclipse.swt.widgets.*; |
| |
| /** |
| * Instances of this class provide a bridge between application |
| * code and assistive technology clients. Many platforms provide |
| * default accessible behavior for most widgets, and this class |
| * allows that default behavior to be overridden. Applications |
| * can get the default Accessible object for a control by sending |
| * it <code>getAccessible</code>, and then add an accessible listener |
| * to override simple items like the name and help string, or they |
| * can add an accessible control listener to override complex items. |
| * As a rule of thumb, an application would only want to use the |
| * accessible control listener to implement accessibility for a |
| * custom control. |
| * |
| * @see Control#getAccessible |
| * @see AccessibleListener |
| * @see AccessibleEvent |
| * @see AccessibleControlListener |
| * @see AccessibleControlEvent |
| * @see <a href="http://www.eclipse.org/swt/snippets/#accessibility">Accessibility snippets</a> |
| * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> |
| * |
| * @since 2.0 |
| */ |
| public class Accessible { |
| Vector accessibleListeners = new Vector (); |
| Vector controlListeners = new Vector (); |
| Vector textListeners = new Vector (); |
| AccessibleObject accessibleObject; |
| Control control; |
| |
| /** |
| * @since 3.5 |
| */ |
| protected Accessible() { |
| } |
| |
| Accessible (Control control) { |
| super (); |
| this.control = control; |
| AccessibleFactory.registerAccessible (this); |
| control.addDisposeListener (new DisposeListener () { |
| public void widgetDisposed (DisposeEvent e) { |
| release (); |
| } |
| }); |
| } |
| |
| /** |
| * Adds the listener to the collection of listeners who will |
| * be notified when an accessible client asks for certain strings, |
| * such as name, description, help, or keyboard shortcut. The |
| * listener is notified by sending it one of the messages defined |
| * in the <code>AccessibleListener</code> interface. |
| * |
| * @param listener the listener that should be notified when the receiver |
| * is asked for a name, description, help, or keyboard shortcut string |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see AccessibleListener |
| * @see #removeAccessibleListener |
| */ |
| public void addAccessibleListener (AccessibleListener listener) { |
| checkWidget (); |
| if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT); |
| accessibleListeners.addElement (listener); |
| } |
| |
| /** |
| * Adds the listener to the collection of listeners who will |
| * be notified when an accessible client asks for custom control |
| * specific information. The listener is notified by sending it |
| * one of the messages defined in the <code>AccessibleControlListener</code> |
| * interface. |
| * |
| * @param listener the listener that should be notified when the receiver |
| * is asked for custom control specific information |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see AccessibleControlListener |
| * @see #removeAccessibleControlListener |
| */ |
| public void addAccessibleControlListener (AccessibleControlListener listener) { |
| checkWidget (); |
| if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT); |
| controlListeners.addElement (listener); |
| } |
| |
| /** |
| * Adds the listener to the collection of listeners who will |
| * be notified when an accessible client asks for custom text control |
| * specific information. The listener is notified by sending it |
| * one of the messages defined in the <code>AccessibleTextListener</code> |
| * interface. |
| * |
| * @param listener the listener that should be notified when the receiver |
| * is asked for custom text control specific information |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see AccessibleTextListener |
| * @see #removeAccessibleTextListener |
| * |
| * @since 3.0 |
| */ |
| public void addAccessibleTextListener (AccessibleTextListener listener) { |
| checkWidget (); |
| if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT); |
| textListeners.addElement (listener); |
| } |
| |
| /** |
| * Returns the control for this Accessible object. |
| * |
| * @return the receiver's control |
| * @since 3.0 |
| */ |
| public Control getControl() { |
| return control; |
| } |
| |
| /* checkWidget was copied from Widget, and rewritten to work in this package */ |
| void checkWidget () { |
| if (!isValidThread ()) SWT.error (SWT.ERROR_THREAD_INVALID_ACCESS); |
| if (control.isDisposed ()) SWT.error (SWT.ERROR_WIDGET_DISPOSED); |
| } |
| |
| AccessibleListener[] getAccessibleListeners () { |
| if (accessibleListeners == null) return null; |
| AccessibleListener[] result = new AccessibleListener [accessibleListeners.size ()]; |
| accessibleListeners.copyInto (result); |
| return result; |
| } |
| |
| int /*long*/ getControlHandle () { |
| return control.handle; |
| } |
| |
| AccessibleControlListener[] getControlListeners () { |
| if (controlListeners == null) return null; |
| AccessibleControlListener[] result = new AccessibleControlListener [controlListeners.size ()]; |
| controlListeners.copyInto (result); |
| return result; |
| } |
| |
| AccessibleTextListener[] getTextListeners () { |
| if (textListeners == null) return null; |
| AccessibleTextListener[] result = new AccessibleTextListener [textListeners.size ()]; |
| textListeners.copyInto (result); |
| return result; |
| } |
| |
| /** |
| * Invokes platform specific functionality to allocate a new accessible object. |
| * <p> |
| * <b>IMPORTANT:</b> This method is <em>not</em> part of the public |
| * API for <code>Accessible</code>. It is marked public only so that it |
| * can be shared within the packages provided by SWT. It is not |
| * available on all platforms, and should never be called from |
| * application code. |
| * </p> |
| * |
| * @param control the control to get the accessible object for |
| * @return the platform specific accessible object |
| */ |
| public static Accessible internal_new_Accessible (Control control) { |
| return new Accessible (control); |
| } |
| |
| /* isValidThread was copied from Widget, and rewritten to work in this package */ |
| boolean isValidThread () { |
| return control.getDisplay ().getThread () == Thread.currentThread (); |
| } |
| |
| void release () { |
| AccessibleFactory.unregisterAccessible (Accessible.this); |
| if (accessibleObject != null) { |
| accessibleObject.release (); |
| accessibleObject = null; |
| } |
| } |
| /** |
| * Removes the listener from the collection of listeners who will |
| * be notified when an accessible client asks for custom control |
| * specific information. |
| * |
| * @param listener the listener that should no longer be notified when the receiver |
| * is asked for custom control specific information |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see AccessibleControlListener |
| * @see #addAccessibleControlListener |
| */ |
| public void removeAccessibleControlListener (AccessibleControlListener listener) { |
| checkWidget (); |
| if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT); |
| controlListeners.removeElement (listener); |
| } |
| |
| /** |
| * Removes the listener from the collection of listeners who will |
| * be notified when an accessible client asks for certain strings, |
| * such as name, description, help, or keyboard shortcut. |
| * |
| * @param listener the listener that should no longer be notified when the receiver |
| * is asked for a name, description, help, or keyboard shortcut string |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see AccessibleListener |
| * @see #addAccessibleListener |
| */ |
| public void removeAccessibleListener (AccessibleListener listener) { |
| checkWidget (); |
| if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT); |
| accessibleListeners.removeElement (listener); |
| } |
| |
| /** |
| * Removes the listener from the collection of listeners who will |
| * be notified when an accessible client asks for custom text control |
| * specific information. |
| * |
| * @param listener the listener that should no longer be notified when the receiver |
| * is asked for custom text control specific information |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> |
| * </ul> |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see AccessibleTextListener |
| * @see #addAccessibleTextListener |
| * |
| * @since 3.0 |
| */ |
| public void removeAccessibleTextListener (AccessibleTextListener listener) { |
| checkWidget (); |
| if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT); |
| textListeners.removeElement (listener); |
| } |
| |
| /** |
| * Sends a message to accessible clients that the child selection |
| * within a custom container control has changed. |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @since 3.0 |
| */ |
| public void selectionChanged () { |
| checkWidget (); |
| if (accessibleObject != null) { |
| accessibleObject.selectionChanged (); |
| } |
| } |
| |
| /** |
| * Sends a message to accessible clients indicating that the focus |
| * has changed within a custom control. |
| * |
| * @param childID an identifier specifying a child of the control |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| */ |
| public void setFocus (int childID) { |
| checkWidget (); |
| if (accessibleObject != null) { |
| accessibleObject.setFocus (childID); |
| } |
| } |
| |
| /** |
| * Sends a message to accessible clients that the text |
| * caret has moved within a custom control. |
| * |
| * @param index the new caret index within the control |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @since 3.0 |
| */ |
| public void textCaretMoved (int index) { |
| checkWidget (); |
| if (accessibleObject != null) { |
| accessibleObject.textCaretMoved (index); |
| } |
| } |
| |
| /** |
| * Sends a message to accessible clients that the text |
| * within a custom control has changed. |
| * |
| * @param type the type of change, one of <code>ACC.NOTIFY_TEXT_INSERT</code> |
| * or <code>ACC.NOTIFY_TEXT_DELETE</code> |
| * @param startIndex the text index within the control where the insertion or deletion begins |
| * @param length the non-negative length in characters of the insertion or deletion |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @see ACC#TEXT_INSERT |
| * @see ACC#TEXT_DELETE |
| * |
| * @since 3.0 |
| */ |
| public void textChanged (int type, int startIndex, int length) { |
| checkWidget (); |
| if (accessibleObject != null) { |
| accessibleObject.textChanged (type, startIndex, length); |
| } |
| } |
| |
| /** |
| * Sends a message to accessible clients that the text |
| * selection has changed within a custom control. |
| * |
| * @exception SWTException <ul> |
| * <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> |
| * </ul> |
| * |
| * @since 3.0 |
| */ |
| public void textSelectionChanged () { |
| checkWidget (); |
| if (accessibleObject != null) { |
| accessibleObject.textSelectionChanged (); |
| } |
| } |
| } |