| /* |
| * Copyright (c) 1995, 2006, 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 java.awt; |
| |
| import java.awt.peer.CheckboxMenuItemPeer; |
| import java.awt.event.*; |
| import java.util.EventListener; |
| import java.io.ObjectOutputStream; |
| import java.io.ObjectInputStream; |
| import java.io.IOException; |
| import javax.accessibility.*; |
| import sun.awt.AWTAccessor; |
| |
| |
| /** |
| * This class represents a check box that can be included in a menu. |
| * Selecting the check box in the menu changes its state from |
| * "on" to "off" or from "off" to "on." |
| * <p> |
| * The following picture depicts a menu which contains an instance |
| * of <code>CheckBoxMenuItem</code>: |
| * <p> |
| * <img src="doc-files/MenuBar-1.gif" |
| * alt="Menu labeled Examples, containing items Basic, Simple, Check, and More Examples. The Check item is a CheckBoxMenuItem instance, in the off state." |
| * ALIGN=center HSPACE=10 VSPACE=7> |
| * <p> |
| * The item labeled <code>Check</code> shows a check box menu item |
| * in its "off" state. |
| * <p> |
| * When a check box menu item is selected, AWT sends an item event to |
| * the item. Since the event is an instance of <code>ItemEvent</code>, |
| * the <code>processEvent</code> method examines the event and passes |
| * it along to <code>processItemEvent</code>. The latter method redirects |
| * the event to any <code>ItemListener</code> objects that have |
| * registered an interest in item events generated by this menu item. |
| * |
| * @author Sami Shaio |
| * @see java.awt.event.ItemEvent |
| * @see java.awt.event.ItemListener |
| * @since JDK1.0 |
| */ |
| public class CheckboxMenuItem extends MenuItem implements ItemSelectable, Accessible { |
| |
| static { |
| /* ensure that the necessary native libraries are loaded */ |
| Toolkit.loadLibraries(); |
| if (!GraphicsEnvironment.isHeadless()) { |
| initIDs(); |
| } |
| |
| AWTAccessor.setCheckboxMenuItemAccessor( |
| new AWTAccessor.CheckboxMenuItemAccessor() { |
| public boolean getState(CheckboxMenuItem cmi) { |
| return cmi.state; |
| } |
| }); |
| } |
| |
| /** |
| * The state of a checkbox menu item |
| * @serial |
| * @see #getState() |
| * @see #setState(boolean) |
| */ |
| boolean state = false; |
| |
| transient ItemListener itemListener; |
| |
| private static final String base = "chkmenuitem"; |
| private static int nameCounter = 0; |
| |
| /* |
| * JDK 1.1 serialVersionUID |
| */ |
| private static final long serialVersionUID = 6190621106981774043L; |
| |
| /** |
| * Create a check box menu item with an empty label. |
| * The item's state is initially set to "off." |
| * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| * returns true |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| * @since JDK1.1 |
| */ |
| public CheckboxMenuItem() throws HeadlessException { |
| this("", false); |
| } |
| |
| /** |
| * Create a check box menu item with the specified label. |
| * The item's state is initially set to "off." |
| |
| * @param label a string label for the check box menu item, |
| * or <code>null</code> for an unlabeled menu item. |
| * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| * returns true |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| */ |
| public CheckboxMenuItem(String label) throws HeadlessException { |
| this(label, false); |
| } |
| |
| /** |
| * Create a check box menu item with the specified label and state. |
| * @param label a string label for the check box menu item, |
| * or <code>null</code> for an unlabeled menu item. |
| * @param state the initial state of the menu item, where |
| * <code>true</code> indicates "on" and |
| * <code>false</code> indicates "off." |
| * @exception HeadlessException if GraphicsEnvironment.isHeadless() |
| * returns true |
| * @see java.awt.GraphicsEnvironment#isHeadless |
| * @since JDK1.1 |
| */ |
| public CheckboxMenuItem(String label, boolean state) |
| throws HeadlessException { |
| super(label); |
| this.state = state; |
| } |
| |
| /** |
| * Construct a name for this MenuComponent. Called by getName() when |
| * the name is null. |
| */ |
| String constructComponentName() { |
| synchronized (CheckboxMenuItem.class) { |
| return base + nameCounter++; |
| } |
| } |
| |
| /** |
| * Creates the peer of the checkbox item. This peer allows us to |
| * change the look of the checkbox item without changing its |
| * functionality. |
| * Most applications do not call this method directly. |
| * @see java.awt.Toolkit#createCheckboxMenuItem(java.awt.CheckboxMenuItem) |
| * @see java.awt.Component#getToolkit() |
| */ |
| public void addNotify() { |
| synchronized (getTreeLock()) { |
| if (peer == null) |
| peer = Toolkit.getDefaultToolkit().createCheckboxMenuItem(this); |
| super.addNotify(); |
| } |
| } |
| |
| /** |
| * Determines whether the state of this check box menu item |
| * is "on" or "off." |
| * |
| * @return the state of this check box menu item, where |
| * <code>true</code> indicates "on" and |
| * <code>false</code> indicates "off" |
| * @see #setState |
| */ |
| public boolean getState() { |
| return state; |
| } |
| |
| /** |
| * Sets this check box menu item to the specifed state. |
| * The boolean value <code>true</code> indicates "on" while |
| * <code>false</code> indicates "off." |
| * |
| * <p>Note that this method should be primarily used to |
| * initialize the state of the check box menu item. |
| * Programmatically setting the state of the check box |
| * menu item will <i>not</i> trigger |
| * an <code>ItemEvent</code>. The only way to trigger an |
| * <code>ItemEvent</code> is by user interaction. |
| * |
| * @param b <code>true</code> if the check box |
| * menu item is on, otherwise <code>false</code> |
| * @see #getState |
| */ |
| public synchronized void setState(boolean b) { |
| state = b; |
| CheckboxMenuItemPeer peer = (CheckboxMenuItemPeer)this.peer; |
| if (peer != null) { |
| peer.setState(b); |
| } |
| } |
| |
| /** |
| * Returns the an array (length 1) containing the checkbox menu item |
| * label or null if the checkbox is not selected. |
| * @see ItemSelectable |
| */ |
| public synchronized Object[] getSelectedObjects() { |
| if (state) { |
| Object[] items = new Object[1]; |
| items[0] = label; |
| return items; |
| } |
| return null; |
| } |
| |
| /** |
| * Adds the specified item listener to receive item events from |
| * this check box menu item. Item events are sent in response to user |
| * actions, but not in response to calls to setState(). |
| * If l is null, no exception is thrown and no action is performed. |
| * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" |
| * >AWT Threading Issues</a> for details on AWT's threading model. |
| * |
| * @param l the item listener |
| * @see #removeItemListener |
| * @see #getItemListeners |
| * @see #setState |
| * @see java.awt.event.ItemEvent |
| * @see java.awt.event.ItemListener |
| * @since JDK1.1 |
| */ |
| public synchronized void addItemListener(ItemListener l) { |
| if (l == null) { |
| return; |
| } |
| itemListener = AWTEventMulticaster.add(itemListener, l); |
| newEventsOnly = true; |
| } |
| |
| /** |
| * Removes the specified item listener so that it no longer receives |
| * item events from this check box menu item. |
| * If l is null, no exception is thrown and no action is performed. |
| * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" |
| * >AWT Threading Issues</a> for details on AWT's threading model. |
| * |
| * @param l the item listener |
| * @see #addItemListener |
| * @see #getItemListeners |
| * @see java.awt.event.ItemEvent |
| * @see java.awt.event.ItemListener |
| * @since JDK1.1 |
| */ |
| public synchronized void removeItemListener(ItemListener l) { |
| if (l == null) { |
| return; |
| } |
| itemListener = AWTEventMulticaster.remove(itemListener, l); |
| } |
| |
| /** |
| * Returns an array of all the item listeners |
| * registered on this checkbox menuitem. |
| * |
| * @return all of this checkbox menuitem's <code>ItemListener</code>s |
| * or an empty array if no item |
| * listeners are currently registered |
| * |
| * @see #addItemListener |
| * @see #removeItemListener |
| * @see java.awt.event.ItemEvent |
| * @see java.awt.event.ItemListener |
| * @since 1.4 |
| */ |
| public synchronized ItemListener[] getItemListeners() { |
| return (ItemListener[])(getListeners(ItemListener.class)); |
| } |
| |
| /** |
| * Returns an array of all the objects currently registered |
| * as <code><em>Foo</em>Listener</code>s |
| * upon this <code>CheckboxMenuItem</code>. |
| * <code><em>Foo</em>Listener</code>s are registered using the |
| * <code>add<em>Foo</em>Listener</code> method. |
| * |
| * <p> |
| * You can specify the <code>listenerType</code> argument |
| * with a class literal, such as |
| * <code><em>Foo</em>Listener.class</code>. |
| * For example, you can query a |
| * <code>CheckboxMenuItem</code> <code>c</code> |
| * for its item listeners with the following code: |
| * |
| * <pre>ItemListener[] ils = (ItemListener[])(c.getListeners(ItemListener.class));</pre> |
| * |
| * If no such listeners exist, this method returns an empty array. |
| * |
| * @param listenerType the type of listeners requested; this parameter |
| * should specify an interface that descends from |
| * <code>java.util.EventListener</code> |
| * @return an array of all objects registered as |
| * <code><em>Foo</em>Listener</code>s on this checkbox menuitem, |
| * or an empty array if no such |
| * listeners have been added |
| * @exception ClassCastException if <code>listenerType</code> |
| * doesn't specify a class or interface that implements |
| * <code>java.util.EventListener</code> |
| * |
| * @see #getItemListeners |
| * @since 1.3 |
| */ |
| public <T extends EventListener> T[] getListeners(Class<T> listenerType) { |
| EventListener l = null; |
| if (listenerType == ItemListener.class) { |
| l = itemListener; |
| } else { |
| return super.getListeners(listenerType); |
| } |
| return AWTEventMulticaster.getListeners(l, listenerType); |
| } |
| |
| // REMIND: remove when filtering is done at lower level |
| boolean eventEnabled(AWTEvent e) { |
| if (e.id == ItemEvent.ITEM_STATE_CHANGED) { |
| if ((eventMask & AWTEvent.ITEM_EVENT_MASK) != 0 || |
| itemListener != null) { |
| return true; |
| } |
| return false; |
| } |
| return super.eventEnabled(e); |
| } |
| |
| /** |
| * Processes events on this check box menu item. |
| * If the event is an instance of <code>ItemEvent</code>, |
| * this method invokes the <code>processItemEvent</code> method. |
| * If the event is not an item event, |
| * it invokes <code>processEvent</code> on the superclass. |
| * <p> |
| * Check box menu items currently support only item events. |
| * <p>Note that if the event parameter is <code>null</code> |
| * the behavior is unspecified and may result in an |
| * exception. |
| * |
| * @param e the event |
| * @see java.awt.event.ItemEvent |
| * @see #processItemEvent |
| * @since JDK1.1 |
| */ |
| protected void processEvent(AWTEvent e) { |
| if (e instanceof ItemEvent) { |
| processItemEvent((ItemEvent)e); |
| return; |
| } |
| super.processEvent(e); |
| } |
| |
| /** |
| * Processes item events occurring on this check box menu item by |
| * dispatching them to any registered <code>ItemListener</code> objects. |
| * <p> |
| * This method is not called unless item events are |
| * enabled for this menu item. Item events are enabled |
| * when one of the following occurs: |
| * <p><ul> |
| * <li>An <code>ItemListener</code> object is registered |
| * via <code>addItemListener</code>. |
| * <li>Item events are enabled via <code>enableEvents</code>. |
| * </ul> |
| * <p>Note that if the event parameter is <code>null</code> |
| * the behavior is unspecified and may result in an |
| * exception. |
| * |
| * @param e the item event |
| * @see java.awt.event.ItemEvent |
| * @see java.awt.event.ItemListener |
| * @see #addItemListener |
| * @see java.awt.MenuItem#enableEvents |
| * @since JDK1.1 |
| */ |
| protected void processItemEvent(ItemEvent e) { |
| ItemListener listener = itemListener; |
| if (listener != null) { |
| listener.itemStateChanged(e); |
| } |
| } |
| |
| /* |
| * Post an ItemEvent and toggle state. |
| */ |
| void doMenuEvent(long when, int modifiers) { |
| setState(!state); |
| Toolkit.getEventQueue().postEvent( |
| new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED, |
| getLabel(), |
| state ? ItemEvent.SELECTED : |
| ItemEvent.DESELECTED)); |
| } |
| |
| /** |
| * Returns a string representing the state of this |
| * <code>CheckBoxMenuItem</code>. This |
| * method is intended to be used only for debugging purposes, and the |
| * content and format of the returned string may vary between |
| * implementations. The returned string may be empty but may not be |
| * <code>null</code>. |
| * |
| * @return the parameter string of this check box menu item |
| */ |
| public String paramString() { |
| return super.paramString() + ",state=" + state; |
| } |
| |
| /* Serialization support. |
| */ |
| |
| /* |
| * Serial Data Version |
| * @serial |
| */ |
| private int checkboxMenuItemSerializedDataVersion = 1; |
| |
| /** |
| * Writes default serializable fields to stream. Writes |
| * a list of serializable <code>ItemListeners</code> |
| * as optional data. The non-serializable |
| * <code>ItemListeners</code> are detected and |
| * no attempt is made to serialize them. |
| * |
| * @param s the <code>ObjectOutputStream</code> to write |
| * @serialData <code>null</code> terminated sequence of |
| * 0 or more pairs; the pair consists of a <code>String</code> |
| * and an <code>Object</code>; the <code>String</code> indicates |
| * the type of object and is one of the following: |
| * <code>itemListenerK</code> indicating an |
| * <code>ItemListener</code> object |
| * |
| * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) |
| * @see java.awt.Component#itemListenerK |
| * @see #readObject(ObjectInputStream) |
| */ |
| private void writeObject(ObjectOutputStream s) |
| throws java.io.IOException |
| { |
| s.defaultWriteObject(); |
| |
| AWTEventMulticaster.save(s, itemListenerK, itemListener); |
| s.writeObject(null); |
| } |
| |
| /* |
| * Reads the <code>ObjectInputStream</code> and if it |
| * isn't <code>null</code> adds a listener to receive |
| * item events fired by the <code>Checkbox</code> menu item. |
| * Unrecognized keys or values will be ignored. |
| * |
| * @param s the <code>ObjectInputStream</code> to read |
| * @serial |
| * @see removeActionListener() |
| * @see addActionListener() |
| * @see #writeObject |
| */ |
| private void readObject(ObjectInputStream s) |
| throws ClassNotFoundException, IOException |
| { |
| s.defaultReadObject(); |
| |
| Object keyOrNull; |
| while(null != (keyOrNull = s.readObject())) { |
| String key = ((String)keyOrNull).intern(); |
| |
| if (itemListenerK == key) |
| addItemListener((ItemListener)(s.readObject())); |
| |
| else // skip value for unrecognized key |
| s.readObject(); |
| } |
| } |
| |
| /** |
| * Initialize JNI field and method IDs |
| */ |
| private static native void initIDs(); |
| |
| |
| ///////////////// |
| // Accessibility support |
| //////////////// |
| |
| /** |
| * Gets the AccessibleContext associated with this CheckboxMenuItem. |
| * For checkbox menu items, the AccessibleContext takes the |
| * form of an AccessibleAWTCheckboxMenuItem. |
| * A new AccessibleAWTCheckboxMenuItem is created if necessary. |
| * |
| * @return an AccessibleAWTCheckboxMenuItem that serves as the |
| * AccessibleContext of this CheckboxMenuItem |
| * @since 1.3 |
| */ |
| public AccessibleContext getAccessibleContext() { |
| if (accessibleContext == null) { |
| accessibleContext = new AccessibleAWTCheckboxMenuItem(); |
| } |
| return accessibleContext; |
| } |
| |
| /** |
| * Inner class of CheckboxMenuItem used to provide default support for |
| * accessibility. This class is not meant to be used directly by |
| * application developers, but is instead meant only to be |
| * subclassed by menu component developers. |
| * <p> |
| * This class implements accessibility support for the |
| * <code>CheckboxMenuItem</code> class. It provides an implementation |
| * of the Java Accessibility API appropriate to checkbox menu item |
| * user-interface elements. |
| * @since 1.3 |
| */ |
| protected class AccessibleAWTCheckboxMenuItem extends AccessibleAWTMenuItem |
| implements AccessibleAction, AccessibleValue |
| { |
| /* |
| * JDK 1.3 serialVersionUID |
| */ |
| private static final long serialVersionUID = -1122642964303476L; |
| |
| /** |
| * Get the AccessibleAction associated with this object. In the |
| * implementation of the Java Accessibility API for this class, |
| * return this object, which is responsible for implementing the |
| * AccessibleAction interface on behalf of itself. |
| * |
| * @return this object |
| */ |
| public AccessibleAction getAccessibleAction() { |
| return this; |
| } |
| |
| /** |
| * Get the AccessibleValue associated with this object. In the |
| * implementation of the Java Accessibility API for this class, |
| * return this object, which is responsible for implementing the |
| * AccessibleValue interface on behalf of itself. |
| * |
| * @return this object |
| */ |
| public AccessibleValue getAccessibleValue() { |
| return this; |
| } |
| |
| /** |
| * Returns the number of Actions available in this object. |
| * If there is more than one, the first one is the "default" |
| * action. |
| * |
| * @return the number of Actions in this object |
| */ |
| public int getAccessibleActionCount() { |
| return 0; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Return a description of the specified action of the object. |
| * |
| * @param i zero-based index of the actions |
| */ |
| public String getAccessibleActionDescription(int i) { |
| return null; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Perform the specified Action on the object |
| * |
| * @param i zero-based index of actions |
| * @return true if the action was performed; otherwise false. |
| */ |
| public boolean doAccessibleAction(int i) { |
| return false; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Get the value of this object as a Number. If the value has not been |
| * set, the return value will be null. |
| * |
| * @return value of the object |
| * @see #setCurrentAccessibleValue |
| */ |
| public Number getCurrentAccessibleValue() { |
| return null; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Set the value of this object as a Number. |
| * |
| * @return true if the value was set; otherwise false |
| * @see #getCurrentAccessibleValue |
| */ |
| public boolean setCurrentAccessibleValue(Number n) { |
| return false; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Get the minimum value of this object as a Number. |
| * |
| * @return Minimum value of the object; null if this object does not |
| * have a minimum value |
| * @see #getMaximumAccessibleValue |
| */ |
| public Number getMinimumAccessibleValue() { |
| return null; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Get the maximum value of this object as a Number. |
| * |
| * @return Maximum value of the object; null if this object does not |
| * have a maximum value |
| * @see #getMinimumAccessibleValue |
| */ |
| public Number getMaximumAccessibleValue() { |
| return null; // To be fully implemented in a future release |
| } |
| |
| /** |
| * Get the role of this object. |
| * |
| * @return an instance of AccessibleRole describing the role of the |
| * object |
| */ |
| public AccessibleRole getAccessibleRole() { |
| return AccessibleRole.CHECK_BOX; |
| } |
| |
| } // class AccessibleAWTMenuItem |
| |
| } |
