| /* |
| * Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.java.accessibility.util; |
| |
| import java.util.*; |
| import java.beans.*; |
| import java.awt.*; |
| import java.awt.event.*; |
| import javax.accessibility.*; |
| |
| /** |
| * <P>{@code AccessibilityEventMonitor} implements a PropertyChange listener |
| * on every UI object that implements interface {@code Accessible} in the Java |
| * Virtual Machine. The events captured by these listeners are made available |
| * through listeners supported by {@code AccessibilityEventMonitor}. |
| * With this, all the individual events on each of the UI object |
| * instances are funneled into one set of PropertyChange listeners. |
| * <p>This class depends upon {@link EventQueueMonitor}, which provides the base |
| * level support for capturing the top-level containers as they are created. |
| * |
| */ |
| |
| @jdk.Exported |
| public class AccessibilityEventMonitor { |
| |
| // listeners |
| /** |
| * The current list of registered {@link java.beans.PropertyChangeListener |
| * PropertyChangeListener} classes. |
| * |
| * @see #addPropertyChangeListener |
| * @see #removePropertyChangeListener |
| */ |
| static protected final AccessibilityListenerList listenerList = |
| new AccessibilityListenerList(); |
| |
| |
| /** |
| * The actual listener that is installed on the component instances. |
| * This listener calls the other registered listeners when an event |
| * occurs. By doing things this way, the actual number of listeners |
| * installed on a component instance is drastically reduced. |
| */ |
| static protected final AccessibilityEventListener accessibilityListener = |
| new AccessibilityEventListener(); |
| |
| /** |
| * Adds the specified listener to receive all PropertyChange events on |
| * each UI object instance in the Java Virtual Machine as they occur. |
| * <P>Note: This listener is automatically added to all component |
| * instances created after this method is called. In addition, it |
| * is only added to UI object instances that support this listener type. |
| * |
| * @param l the listener to add |
| * |
| * @see #removePropertyChangeListener |
| */ |
| static public void addPropertyChangeListener(PropertyChangeListener l) { |
| if (listenerList.getListenerCount(PropertyChangeListener.class) == 0) { |
| accessibilityListener.installListeners(); |
| } |
| listenerList.add(PropertyChangeListener.class, l); |
| } |
| |
| /** |
| * Removes the specified listener so it no longer receives PropertyChange |
| * events when they occur. |
| * @see #addPropertyChangeListener |
| * @param l the listener to remove |
| */ |
| static public void removePropertyChangeListener(PropertyChangeListener l) { |
| listenerList.remove(PropertyChangeListener.class, l); |
| if (listenerList.getListenerCount(PropertyChangeListener.class) == 0) { |
| accessibilityListener.removeListeners(); |
| } |
| } |
| |
| |
| /** |
| * AccessibilityEventListener is the class that does all the work for |
| * AccessibilityEventMonitor. It is not intended for use by any other |
| * class except AccessibilityEventMonitor. |
| * |
| */ |
| |
| static class AccessibilityEventListener implements TopLevelWindowListener, |
| PropertyChangeListener { |
| |
| /** |
| * Create a new instance of this class and install it on each component |
| * instance in the virtual machine that supports any of the currently |
| * registered listeners in AccessibilityEventMonitor. Also registers |
| * itself as a TopLevelWindowListener with EventQueueMonitor so it can |
| * automatically add new listeners to new components. |
| * @see EventQueueMonitor |
| * @see AccessibilityEventMonitor |
| */ |
| public AccessibilityEventListener() { |
| EventQueueMonitor.addTopLevelWindowListener(this); |
| } |
| |
| /** |
| * Installs PropertyChange listeners on all Accessible objects based |
| * upon the current topLevelWindows cached by EventQueueMonitor. |
| * @see EventQueueMonitor |
| * @see AWTEventMonitor |
| */ |
| protected void installListeners() { |
| Window topLevelWindows[] = EventQueueMonitor.getTopLevelWindows(); |
| if (topLevelWindows != null) { |
| for (int i = 0; i < topLevelWindows.length; i++) { |
| if (topLevelWindows[i] instanceof Accessible) { |
| installListeners((Accessible) topLevelWindows[i]); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Installs PropertyChange listeners to the Accessible object, and it's |
| * children (so long as the object isn't of TRANSIENT state). |
| * @param a the Accessible object to add listeners to |
| */ |
| protected void installListeners(Accessible a) { |
| installListeners(a.getAccessibleContext()); |
| } |
| |
| /** |
| * Installs PropertyChange listeners to the AccessibleContext object, |
| * and it's * children (so long as the object isn't of TRANSIENT state). |
| * @param a the Accessible object to add listeners to |
| */ |
| private void installListeners(AccessibleContext ac) { |
| |
| if (ac != null) { |
| AccessibleStateSet states = ac.getAccessibleStateSet(); |
| if (!states.contains(AccessibleState.TRANSIENT)) { |
| ac.addPropertyChangeListener(this); |
| /* |
| * Don't add listeners to transient children. Components |
| * with transient children should return an AccessibleStateSet |
| * containing AccessibleState.MANAGES_DESCENDANTS. Components |
| * may not explicitly return the MANAGES_DESCENDANTS state. |
| * In this case, don't add listeners to the children of |
| * lists, tables and trees. |
| */ |
| AccessibleStateSet set = ac.getAccessibleStateSet(); |
| if (set.contains(_AccessibleState.MANAGES_DESCENDANTS)) { |
| return; |
| } |
| AccessibleRole role = ac.getAccessibleRole(); |
| if (role == AccessibleRole.LIST || |
| role == AccessibleRole.TREE) { |
| return; |
| } |
| if (role == AccessibleRole.TABLE) { |
| // handle Oracle tables containing tables |
| Accessible child = ac.getAccessibleChild(0); |
| if (child != null) { |
| AccessibleContext ac2 = child.getAccessibleContext(); |
| if (ac2 != null) { |
| role = ac2.getAccessibleRole(); |
| if (role != null && role != AccessibleRole.TABLE) { |
| return; |
| } |
| } |
| } |
| } |
| int count = ac.getAccessibleChildrenCount(); |
| for (int i = 0; i < count; i++) { |
| Accessible child = ac.getAccessibleChild(i); |
| if (child != null) { |
| installListeners(child); |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Removes PropertyChange listeners on all Accessible objects based |
| * upon the topLevelWindows cached by EventQueueMonitor. |
| * @param eventID the event ID |
| * @see EventID |
| */ |
| protected void removeListeners() { |
| Window topLevelWindows[] = EventQueueMonitor.getTopLevelWindows(); |
| if (topLevelWindows != null) { |
| for (int i = 0; i < topLevelWindows.length; i++) { |
| if (topLevelWindows[i] instanceof Accessible) { |
| removeListeners((Accessible) topLevelWindows[i]); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Removes PropertyChange listeners for the given Accessible object, |
| * it's children (so long as the object isn't of TRANSIENT state). |
| * @param a the Accessible object to remove listeners from |
| */ |
| protected void removeListeners(Accessible a) { |
| removeListeners(a.getAccessibleContext()); |
| } |
| |
| /** |
| * Removes PropertyChange listeners for the given AccessibleContext |
| * object, it's children (so long as the object isn't of TRANSIENT |
| * state). |
| * @param a the Accessible object to remove listeners from |
| */ |
| private void removeListeners(AccessibleContext ac) { |
| |
| |
| if (ac != null) { |
| // Listeners are not added to transient components. |
| AccessibleStateSet states = ac.getAccessibleStateSet(); |
| if (!states.contains(AccessibleState.TRANSIENT)) { |
| ac.removePropertyChangeListener(this); |
| /* |
| * Listeners are not added to transient children. Components |
| * with transient children should return an AccessibleStateSet |
| * containing AccessibleState.MANAGES_DESCENDANTS. Components |
| * may not explicitly return the MANAGES_DESCENDANTS state. |
| * In this case, don't remove listeners from the children of |
| * lists, tables and trees. |
| */ |
| if (states.contains(_AccessibleState.MANAGES_DESCENDANTS)) { |
| return; |
| } |
| AccessibleRole role = ac.getAccessibleRole(); |
| if (role == AccessibleRole.LIST || |
| role == AccessibleRole.TABLE || |
| role == AccessibleRole.TREE) { |
| return; |
| } |
| int count = ac.getAccessibleChildrenCount(); |
| for (int i = 0; i < count; i++) { |
| Accessible child = ac.getAccessibleChild(i); |
| if (child != null) { |
| removeListeners(child); |
| } |
| } |
| } |
| } |
| } |
| |
| /********************************************************************/ |
| /* */ |
| /* Listener Interface Methods */ |
| /* */ |
| /********************************************************************/ |
| |
| /* TopLevelWindow Methods ***************************************/ |
| |
| /** |
| * Called when top level window is created. |
| * @see EventQueueMonitor |
| * @see EventQueueMonitor#addTopLevelWindowListener |
| */ |
| public void topLevelWindowCreated(Window w) { |
| if (w instanceof Accessible) { |
| installListeners((Accessible) w); |
| } |
| } |
| |
| /** |
| * Called when top level window is destroyed. |
| * @see EventQueueMonitor |
| * @see EventQueueMonitor#addTopLevelWindowListener |
| */ |
| public void topLevelWindowDestroyed(Window w) { |
| if (w instanceof Accessible) { |
| removeListeners((Accessible) w); |
| } |
| } |
| |
| |
| /* PropertyChangeListener Methods **************************************/ |
| |
| public void propertyChange(PropertyChangeEvent e) { |
| // propogate the event |
| Object[] listeners = |
| AccessibilityEventMonitor.listenerList.getListenerList(); |
| for (int i = listeners.length-2; i>=0; i-=2) { |
| if (listeners[i]==PropertyChangeListener.class) { |
| ((PropertyChangeListener)listeners[i+1]).propertyChange(e); |
| } |
| } |
| |
| // handle childbirth/death |
| String name = e.getPropertyName(); |
| if (name.compareTo(AccessibleContext.ACCESSIBLE_CHILD_PROPERTY) == 0) { |
| Object oldValue = e.getOldValue(); |
| Object newValue = e.getNewValue(); |
| |
| if ((oldValue == null) ^ (newValue == null)) { // one null, not both |
| if (oldValue != null) { |
| // this Accessible is a child that's going away |
| if (oldValue instanceof Accessible) { |
| Accessible a = (Accessible) oldValue; |
| removeListeners(a.getAccessibleContext()); |
| } else if (oldValue instanceof AccessibleContext) { |
| removeListeners((AccessibleContext) oldValue); |
| } |
| } else if (newValue != null) { |
| // this Accessible is a child was just born |
| if (newValue instanceof Accessible) { |
| Accessible a = (Accessible) newValue; |
| installListeners(a.getAccessibleContext()); |
| } else if (newValue instanceof AccessibleContext) { |
| installListeners((AccessibleContext) newValue); |
| } |
| } |
| } else { |
| System.out.println("ERROR in usage of PropertyChangeEvents for: " + e.toString()); |
| } |
| } |
| } |
| } |
| } |
| |
| /* |
| * workaround for no public AccessibleState constructor |
| */ |
| class _AccessibleState extends AccessibleState { |
| /** |
| * Indicates this object is responsible for managing its |
| * subcomponents. This is typically used for trees and tables |
| * that have a large number of subcomponents and where the |
| * objects are created only when needed and otherwise remain virtual. |
| * The application should not manage the subcomponents directly. |
| */ |
| public static final _AccessibleState MANAGES_DESCENDANTS |
| = new _AccessibleState ("managesDescendants"); |
| |
| /** |
| * Creates a new AccessibleState using the given locale independent key. |
| * This should not be a public method. Instead, it is used to create |
| * the constants in this file to make it a strongly typed enumeration. |
| * Subclasses of this class should enforce similar policy. |
| * <p> |
| * The key String should be a locale independent key for the state. |
| * It is not intended to be used as the actual String to display |
| * to the user. To get the localized string, use toDisplayString. |
| * |
| * @param key the locale independent name of the state. |
| * @see AccessibleBundle#toDisplayString |
| */ |
| protected _AccessibleState(String key) { |
| super(key); |
| } |
| } |
