/*
* Copyright (c) 2005, 2010, 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
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*/
package java.awt;
import java.util.Vector;
import java.awt.peer.SystemTrayPeer;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import sun.awt.AppContext;
import sun.awt.SunToolkit;
import sun.awt.HeadlessToolkit;
import sun.security.util.SecurityConstants;
/** {@collect.stats}
* The <code>SystemTray</code> class represents the system tray for a
* desktop. On Microsoft Windows it is referred to as the "Taskbar
* Status Area", on Gnome it is referred to as the "Notification
* Area", on KDE it is referred to as the "System Tray". The system
* tray is shared by all applications running on the desktop.
*
* <p> On some platforms the system tray may not be present or may not
* be supported, in this case {@link SystemTray#getSystemTray()}
* throws {@link UnsupportedOperationException}. To detect whether the
* system tray is supported, use {@link SystemTray#isSupported}.
*
* <p>The <code>SystemTray</code> may contain one or more {@link
* TrayIcon TrayIcons}, which are added to the tray using the {@link
* #add} method, and removed when no longer needed, using the
* {@link #remove}. <code>TrayIcon</code> consists of an
* image, a popup menu and a set of associated listeners. Please see
* the {@link TrayIcon} class for details.
*
* <p>Every Java application has a single <code>SystemTray</code>
* instance that allows the app to interface with the system tray of
* the desktop while the app is running. The <code>SystemTray</code>
* instance can be obtained from the {@link #getSystemTray} method.
* An application may not create its own instance of
* <code>SystemTray</code>.
*
* <p>The following code snippet demonstrates how to access
* and customize the system tray:
* <code>
* <pre>
* {@link TrayIcon} trayIcon = null;
* if (SystemTray.isSupported()) {
* // get the SystemTray instance
* SystemTray tray = SystemTray.{@link #getSystemTray};
* // load an image
* {@link java.awt.Image} image = {@link java.awt.Toolkit#getImage(String) Toolkit.getDefaultToolkit().getImage}(...);
* // create a action listener to listen for default action executed on the tray icon
* {@link java.awt.event.ActionListener} listener = new {@link java.awt.event.ActionListener ActionListener}() {
* public void {@link java.awt.event.ActionListener#actionPerformed actionPerformed}({@link java.awt.event.ActionEvent} e) {
* // execute default action of the application
* // ...
* }
* };
* // create a popup menu
* {@link java.awt.PopupMenu} popup = new {@link java.awt.PopupMenu#PopupMenu PopupMenu}();
* // create menu item for the default action
* MenuItem defaultItem = new MenuItem(...);
* defaultItem.addActionListener(listener);
* popup.add(defaultItem);
* /// ... add other items
* // construct a TrayIcon
* trayIcon = new {@link TrayIcon#TrayIcon(java.awt.Image, String, java.awt.PopupMenu) TrayIcon}(image, "Tray Demo", popup);
* // set the TrayIcon properties
* trayIcon.{@link TrayIcon#addActionListener(java.awt.event.ActionListener) addActionListener}(listener);
* // ...
* // add the tray image
* try {
* tray.{@link SystemTray#add(TrayIcon) add}(trayIcon);
* } catch (AWTException e) {
* System.err.println(e);
* }
* // ...
* } else {
* // disable tray option in your application or
* // perform other actions
* ...
* }
* // ...
* // some time later
* // the application state has changed - update the image
* if (trayIcon != null) {
* trayIcon.{@link TrayIcon#setImage(java.awt.Image) setImage}(updatedImage);
* }
* // ...
* </pre>
* </code>
*
* @since 1.6
* @see TrayIcon
*
* @author Bino George
* @author Denis Mikhalkin
* @author Sharon Zakhour
* @author Anton Tarasov
*/
public class SystemTray {
private static SystemTray systemTray;
private int currentIconID = 0; // each TrayIcon added gets a unique ID
transient private SystemTrayPeer peer;
/** {@collect.stats}
* Private <code>SystemTray</code> constructor.
*
*/
private SystemTray() {
addNotify();
}
/** {@collect.stats}
* Gets the <code>SystemTray</code> instance that represents the
* desktop's tray area. This always returns the same instance per
* application. On some platforms the system tray may not be
* supported. You may use the {@link #isSupported} method to
* check if the system tray is supported.
*
* <p>If a SecurityManager is installed, the AWTPermission
* {@code accessSystemTray} must be granted in order to get the
* {@code SystemTray} instance. Otherwise this method will throw a
* SecurityException.
*
* @return the <code>SystemTray</code> instance that represents
* the desktop's tray area
* @throws UnsupportedOperationException if the system tray isn't
* supported by the current platform
* @throws HeadlessException if
* <code>GraphicsEnvironment.isHeadless()</code> returns <code>true</code>
* @throws SecurityException if {@code accessSystemTray} permission
* is not granted
* @see #add(TrayIcon)
* @see TrayIcon
* @see #isSupported
* @see SecurityManager#checkPermission
* @see AWTPermission
*/
public static SystemTray getSystemTray() {
checkSystemTrayAllowed();
if (GraphicsEnvironment.isHeadless()) {
throw new HeadlessException();
}
initializeSystemTrayIfNeeded();
if (!isSupported()) {
throw new UnsupportedOperationException(
"The system tray is not supported on the current platform.");
}
return systemTray;
}
/** {@collect.stats}
* Returns whether the system tray is supported on the current
* platform. In addition to displaying the tray icon, minimal
* system tray support includes either a popup menu (see {@link
* TrayIcon#setPopupMenu(PopupMenu)}) or an action event (see
* {@link TrayIcon#addActionListener(ActionListener)}).
*
* <p>Developers should not assume that all of the system tray
* functionality is supported. To guarantee that the tray icon's
* default action is always accessible, add the default action to
* both the action listener and the popup menu. See the {@link
* SystemTray example} for an example of how to do this.
*
* <p><b>Note</b>: When implementing <code>SystemTray</code> and
* <code>TrayIcon</code> it is <em>strongly recommended</em> that
* you assign different gestures to the popup menu and an action
* event. Overloading a gesture for both purposes is confusing
* and may prevent the user from accessing one or the other.
*
* @see #getSystemTray
* @return <code>false</code> if no system tray access is supported; this
* method returns <code>true</code> if the minimal system tray access is
* supported but does not guarantee that all system tray
* functionality is supported for the current platform
*/
public static boolean isSupported() {
if (Toolkit.getDefaultToolkit() instanceof SunToolkit) {
initializeSystemTrayIfNeeded();
return ((SunToolkit)Toolkit.getDefaultToolkit()).isTraySupported();
} else if (Toolkit.getDefaultToolkit() instanceof HeadlessToolkit) {
return ((HeadlessToolkit)Toolkit.getDefaultToolkit()).isTraySupported();
}
return false;
}
/** {@collect.stats}
* Adds a <code>TrayIcon</code> to the <code>SystemTray</code>.
* The tray icon becomes visible in the system tray once it is
* added. The order in which icons are displayed in a tray is not
* specified - it is platform and implementation-dependent.
*
* <p> All icons added by the application are automatically
* removed from the <code>SystemTray</code> upon application exit
* and also when the desktop system tray becomes unavailable.
*
* @param trayIcon the <code>TrayIcon</code> to be added
* @throws NullPointerException if <code>trayIcon</code> is
* <code>null</code>
* @throws IllegalArgumentException if the same instance of
* a <code>TrayIcon</code> is added more than once
* @throws AWTException if the desktop system tray is missing
* @see #remove(TrayIcon)
* @see #getSystemTray
* @see TrayIcon
* @see java.awt.Image
*/
public void add(TrayIcon trayIcon) throws AWTException {
if (trayIcon == null) {
throw new NullPointerException("adding null TrayIcon");
}
TrayIcon[] oldArray = null, newArray = null;
Vector<TrayIcon> icons = null;
synchronized (this) {
oldArray = systemTray.getTrayIcons();
icons = (Vector<TrayIcon>)AppContext.getAppContext().get(TrayIcon.class);
if (icons == null) {
icons = new Vector<TrayIcon>(3);
AppContext.getAppContext().put(TrayIcon.class, icons);
} else if (icons.contains(trayIcon)) {
throw new IllegalArgumentException("adding TrayIcon that is already added");
}
icons.add(trayIcon);
newArray = systemTray.getTrayIcons();
trayIcon.setID(++currentIconID);
}
try {
trayIcon.addNotify();
} catch (AWTException e) {
icons.remove(trayIcon);
throw e;
}
firePropertyChange("trayIcons", oldArray, newArray);
}
/** {@collect.stats}
* Removes the specified <code>TrayIcon</code> from the
* <code>SystemTray</code>.
*
* <p> All icons added by the application are automatically
* removed from the <code>SystemTray</code> upon application exit
* and also when the desktop system tray becomes unavailable.
*
* <p> If <code>trayIcon</code> is <code>null</code> or was not
* added to the system tray, no exception is thrown and no action
* is performed.
*
* @param trayIcon the <code>TrayIcon</code> to be removed
* @see #add(TrayIcon)
* @see TrayIcon
*/
public void remove(TrayIcon trayIcon) {
if (trayIcon == null) {
return;
}
TrayIcon[] oldArray = null, newArray = null;
synchronized (this) {
oldArray = systemTray.getTrayIcons();
Vector<TrayIcon> icons = (Vector<TrayIcon>)AppContext.getAppContext().get(TrayIcon.class);
// TrayIcon with no peer is not contained in the array.
if (icons == null || !icons.remove(trayIcon)) {
return;
}
trayIcon.removeNotify();
newArray = systemTray.getTrayIcons();
}
firePropertyChange("trayIcons", oldArray, newArray);
}
/** {@collect.stats}
* Returns an array of all icons added to the tray by this
* application. You can't access the icons added by another
* application. Some browsers partition applets in different
* code bases into separate contexts, and establish walls between
* these contexts. In such a scenario, only the tray icons added
* from this context will be returned.
*
* <p> The returned array is a copy of the actual array and may be
* modified in any way without affecting the system tray. To
* remove a <code>TrayIcon</code> from the
* <code>SystemTray</code>, use the {@link
* #remove(TrayIcon)} method.
*
* @return an array of all tray icons added to this tray, or an
* empty array if none has been added
* @see #add(TrayIcon)
* @see TrayIcon
*/
public TrayIcon[] getTrayIcons() {
Vector<TrayIcon> icons = (Vector<TrayIcon>)AppContext.getAppContext().get(TrayIcon.class);
if (icons != null) {
return (TrayIcon[])icons.toArray(new TrayIcon[icons.size()]);
}
return new TrayIcon[0];
}
/** {@collect.stats}
* Returns the size, in pixels, of the space that a tray icon will
* occupy in the system tray. Developers may use this methods to
* acquire the preferred size for the image property of a tray icon
* before it is created. For convenience, there is a similar
* method {@link TrayIcon#getSize} in the <code>TrayIcon</code> class.
*
* @return the default size of a tray icon, in pixels
* @see TrayIcon#setImageAutoSize(boolean)
* @see java.awt.Image
* @see TrayIcon#getSize()
*/
public Dimension getTrayIconSize() {
return peer.getTrayIconSize();
}
/** {@collect.stats}
* Adds a {@code PropertyChangeListener} to the listener list for a
* specific property. Currently supported property:
* <ul>
* <li>{@code trayIcons}<p>
* <p>
* This {@code SystemTray}'s array of {@code TrayIcon}s.
* The array is accessed via {@link SystemTray#getTrayIcons}.<br>
* This property is changed when a {@code TrayIcon} is added to
* (or removed from) the {@code SystemTray}.<br> For example, this property
* is changed when the native {@code SystemTray} becomes unavailable on the
* desktop<br> and the {@code TrayIcon}s are automatically removed.</li>
* </ul>
* <p>
* The {@code listener} listens to property changes only in this context.
* <p>
* If {@code listener} is {@code null}, no exception is thrown
* and no action is performed.
*
* @param propertyName the specified property
* @param listener the property change listener to be added
*
* @see #removePropertyChangeListener
* @see #getPropertyChangeListeners
*/
public synchronized void addPropertyChangeListener(String propertyName,
PropertyChangeListener listener)
{
if (listener == null) {
return;
}
getCurrentChangeSupport().addPropertyChangeListener(propertyName, listener);
}
/** {@collect.stats}
* Removes a {@code PropertyChangeListener} from the listener list
* for a specific property.
* <p>
* The {@code PropertyChangeListener} must be from this context.
* <p>
* If {@code propertyName} or {@code listener} is {@code null} or invalid,
* no exception is thrown and no action is taken.
*
* @param propertyName the specified property
* @param listener the PropertyChangeListener to be removed
*
* @see #addPropertyChangeListener
* @see #getPropertyChangeListeners
*/
public synchronized void removePropertyChangeListener(String propertyName,
PropertyChangeListener listener)
{
if (listener == null) {
return;
}
getCurrentChangeSupport().removePropertyChangeListener(propertyName, listener);
}
/** {@collect.stats}
* Returns an array of all the listeners that have been associated
* with the named property.
* <p>
* Only the listeners in this context are returned.
*
* @param propertyName the specified property
* @return all of the {@code PropertyChangeListener}s associated with
* the named property; if no such listeners have been added or
* if {@code propertyName} is {@code null} or invalid, an empty
* array is returned
*
* @see #addPropertyChangeListener
* @see #removePropertyChangeListener
*/
public synchronized PropertyChangeListener[] getPropertyChangeListeners(String propertyName) {
return getCurrentChangeSupport().getPropertyChangeListeners(propertyName);
}
// ***************************************************************
// ***************************************************************
/** {@collect.stats}
* Support for reporting bound property changes for Object properties.
* This method can be called when a bound property has changed and it will
* send the appropriate PropertyChangeEvent to any registered
* PropertyChangeListeners.
*
* @param propertyName the property whose value has changed
* @param oldValue the property's previous value
* @param newValue the property's new value
*/
private void firePropertyChange(String propertyName,
Object oldValue, Object newValue)
{
if (oldValue != null && newValue != null && oldValue.equals(newValue)) {
return;
}
getCurrentChangeSupport().firePropertyChange(propertyName, oldValue, newValue);
}
/** {@collect.stats}
* Returns the current PropertyChangeSupport instance for the
* calling thread's context.
*
* @return this thread's context's PropertyChangeSupport
*/
private synchronized PropertyChangeSupport getCurrentChangeSupport() {
PropertyChangeSupport changeSupport =
(PropertyChangeSupport)AppContext.getAppContext().get(SystemTray.class);
if (changeSupport == null) {
changeSupport = new PropertyChangeSupport(this);
AppContext.getAppContext().put(SystemTray.class, changeSupport);
}
return changeSupport;
}
synchronized void addNotify() {
if (peer == null) {
peer = ((SunToolkit)Toolkit.getDefaultToolkit()).createSystemTray(this);
}
}
static void checkSystemTrayAllowed() {
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkPermission(SecurityConstants.ACCESS_SYSTEM_TRAY_PERMISSION);
}
}
private static void initializeSystemTrayIfNeeded() {
synchronized (SystemTray.class) {
if (systemTray == null) {
systemTray = new SystemTray();
}
}
}
}