- java.lang.Object
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- java.awt.SystemTray
 
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 public class SystemTray extends Object TheSystemTrayclass 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.On some platforms the system tray may not be present or may not be supported, in this case getSystemTray()throwsUnsupportedOperationException. To detect whether the system tray is supported, useisSupported().The SystemTraymay contain one or moreTrayIcons, which are added to the tray using theadd(java.awt.TrayIcon)method, and removed when no longer needed, using theremove(java.awt.TrayIcon).TrayIconconsists of an image, a popup menu and a set of associated listeners. Please see theTrayIconclass for details.Every Java application has a single SystemTrayinstance that allows the app to interface with the system tray of the desktop while the app is running. TheSystemTrayinstance can be obtained from thegetSystemTray()method. An application may not create its own instance ofSystemTray.The following code snippet demonstrates how to access and customize the system tray: TrayIcontrayIcon = null; if (SystemTray.isSupported()) { // get the SystemTray instance SystemTray tray = SystemTray.getSystemTray(); // load an imageImageimage =Toolkit.getDefaultToolkit().getImage(...); // create a action listener to listen for default action executed on the tray iconActionListenerlistener = newActionListener() { public voidactionPerformed(ActionEvente) { // execute default action of the application // ... } }; // create a popup menuPopupMenupopup = newPopupMenu(); // create menu item for the default action MenuItem defaultItem = new MenuItem(...); defaultItem.addActionListener(listener); popup.add(defaultItem); /// ... add other items // construct a TrayIcon trayIcon = newTrayIcon(image, "Tray Demo", popup); // set the TrayIcon properties trayIcon.addActionListener(listener); // ... // add the tray image try { tray.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.setImage(updatedImage); } // ...- Since:
- 1.6
- See Also:
- TrayIcon
 
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Method SummaryAll Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description voidadd(TrayIcon trayIcon)Adds aTrayIconto theSystemTray.voidaddPropertyChangeListener(String propertyName, PropertyChangeListener listener)Adds aPropertyChangeListenerto the list of listeners for the specific property.PropertyChangeListener[]getPropertyChangeListeners(String propertyName)Returns an array of all the listeners that have been associated with the named property.static SystemTraygetSystemTray()Gets theSystemTrayinstance that represents the desktop's tray area.TrayIcon[]getTrayIcons()Returns an array of all icons added to the tray by this application.DimensiongetTrayIconSize()Returns the size, in pixels, of the space that a tray icon will occupy in the system tray.static booleanisSupported()Returns whether the system tray is supported on the current platform.voidremove(TrayIcon trayIcon)Removes the specifiedTrayIconfrom theSystemTray.voidremovePropertyChangeListener(String propertyName, PropertyChangeListener listener)Removes aPropertyChangeListenerfrom the listener list for a specific property.
 
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Method Detail- 
getSystemTraypublic static SystemTray getSystemTray() Gets theSystemTrayinstance 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 theisSupported()method to check if the system tray is supported.If a SecurityManager is installed, the AWTPermission accessSystemTraymust be granted in order to get theSystemTrayinstance. Otherwise this method will throw a SecurityException.- Returns:
- the SystemTrayinstance that represents the desktop's tray area
- Throws:
- UnsupportedOperationException- if the system tray isn't supported by the current platform
- HeadlessException- if- GraphicsEnvironment.isHeadless()returns- true
- SecurityException- if- accessSystemTraypermission is not granted
- See Also:
- add(TrayIcon),- TrayIcon,- isSupported(),- SecurityManager.checkPermission(java.security.Permission),- AWTPermission
 
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isSupportedpublic static boolean isSupported() 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 (seeTrayIcon.setPopupMenu(PopupMenu)) or an action event (seeTrayIcon.addActionListener(ActionListener)).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 examplefor an example of how to do this.Note: When implementing SystemTrayandTrayIconit is strongly recommended 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.- Returns:
- falseif no system tray access is supported; this method returns- trueif the minimal system tray access is supported but does not guarantee that all system tray functionality is supported for the current platform
- See Also:
- getSystemTray()
 
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addpublic void add(TrayIcon trayIcon) throws AWTException Adds aTrayIconto theSystemTray. 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.All icons added by the application are automatically removed from the SystemTrayupon application exit and also when the desktop system tray becomes unavailable.- Parameters:
- trayIcon- the- TrayIconto be added
- Throws:
- NullPointerException- if- trayIconis- null
- IllegalArgumentException- if the same instance of a- TrayIconis added more than once
- AWTException- if the desktop system tray is missing
- See Also:
- remove(TrayIcon),- getSystemTray(),- TrayIcon,- Image
 
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removepublic void remove(TrayIcon trayIcon) Removes the specifiedTrayIconfrom theSystemTray.All icons added by the application are automatically removed from the SystemTrayupon application exit and also when the desktop system tray becomes unavailable.If trayIconisnullor was not added to the system tray, no exception is thrown and no action is performed.- Parameters:
- trayIcon- the- TrayIconto be removed
- See Also:
- add(TrayIcon),- TrayIcon
 
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getTrayIconspublic TrayIcon[] getTrayIcons() 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.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 TrayIconfrom theSystemTray, use theremove(TrayIcon)method.- Returns:
- an array of all tray icons added to this tray, or an empty array if none has been added
- See Also:
- add(TrayIcon),- TrayIcon
 
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getTrayIconSizepublic Dimension getTrayIconSize() 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 methodTrayIcon.getSize()in theTrayIconclass.- Returns:
- the default size of a tray icon, in pixels
- See Also:
- TrayIcon.setImageAutoSize(boolean),- Image,- TrayIcon.getSize()
 
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addPropertyChangeListenerpublic void addPropertyChangeListener(String propertyName, PropertyChangeListener listener) Adds aPropertyChangeListenerto the list of listeners for the specific property. The following properties are currently supported:SystemTray properties Property Description trayIconsThe SystemTray's array ofTrayIconobjects. The array is accessed via thegetTrayIcons()method. This property is changed when a tray icon is added to (or removed from) the system tray. For example, this property is changed when the system tray becomes unavailable on the desktop and the tray icons are automatically removed.systemTrayThis property contains SystemTrayinstance when the system tray is available ornullotherwise. This property is changed when the system tray becomes available or unavailable on the desktop. The property is accessed by thegetSystemTray()method.The listenerlistens to property changes only in this context.If listenerisnull, no exception is thrown and no action is performed.- Parameters:
- propertyName- the specified property
- listener- the property change listener to be added
- See Also:
- removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener),- getPropertyChangeListeners(java.lang.String)
 
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removePropertyChangeListenerpublic void removePropertyChangeListener(String propertyName, PropertyChangeListener listener) Removes aPropertyChangeListenerfrom the listener list for a specific property.The PropertyChangeListenermust be from this context.If propertyNameorlistenerisnullor invalid, no exception is thrown and no action is taken.- Parameters:
- propertyName- the specified property
- listener- the PropertyChangeListener to be removed
- See Also:
- addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener),- getPropertyChangeListeners(java.lang.String)
 
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getPropertyChangeListenerspublic PropertyChangeListener[] getPropertyChangeListeners(String propertyName) Returns an array of all the listeners that have been associated with the named property.Only the listeners in this context are returned. - Parameters:
- propertyName- the specified property
- Returns:
- all of the PropertyChangeListeners associated with the named property; if no such listeners have been added or ifpropertyNameisnullor invalid, an empty array is returned
- See Also:
- addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener),- removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
 
 
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