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TrayIcon (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档


Java™ Platform
Standard Ed. 6

java.awt
Class TrayIcon

java.lang.Object
  extended by java.awt.TrayIcon

public class TrayIcon
extends Object

A TrayIcon object represents a tray icon that can be added to the system tray. A TrayIcon can have a tooltip (text), an image, a popup menu, and a set of listeners associated with it.

A TrayIcon can generate various MouseEvents and supports adding corresponding listeners to receive notification of these events. TrayIcon processes some of the events by itself. For example, by default, when the right-mouse click is performed on the TrayIcon it displays the specified popup menu. When the mouse hovers over the TrayIcon the tooltip is displayed.

Note: When the MouseEvent is dispatched to its registered listeners its component property will be set to null. (See ComponentEvent.getComponent()) The source property will be set to this TrayIcon. (See EventObject.getSource())

Note: A well-behaved TrayIcon implementation will assign different gestures to showing a popup menu and selecting a tray icon.

A TrayIcon can generate an ActionEvent. On some platforms, this occurs when the user selects the tray icon using either the mouse or keyboard.

If a SecurityManager is installed, the AWTPermission accessSystemTray must be granted in order to create a TrayIcon. Otherwise the constructor will throw a SecurityException.

See the SystemTray class overview for an example on how to use the TrayIcon API.

Since:
1.6
See Also:
SystemTray.add(java.awt.TrayIcon), ComponentEvent.getComponent(), EventObject.getSource()

Nested Class Summary
static class TrayIcon.MessageType
          The message type determines which icon will be displayed in the caption of the message, and a possible system sound a message may generate upon showing.
 
Constructor Summary
TrayIcon(Image image)
          Creates a TrayIcon with the specified image.
TrayIcon(Image image, String tooltip)
          Creates a TrayIcon with the specified image and tooltip text.
TrayIcon(Image image, String tooltip, PopupMenu popup)
          Creates a TrayIcon with the specified image, tooltip and popup menu.
 
Method Summary
 void addActionListener(ActionListener listener)
          Adds the specified action listener to receive ActionEvents from this TrayIcon.
 void addMouseListener(MouseListener listener)
          Adds the specified mouse listener to receive mouse events from this TrayIcon.
 void addMouseMotionListener(MouseMotionListener listener)
          Adds the specified mouse listener to receive mouse-motion events from this TrayIcon.
 void displayMessage(String caption, String text, TrayIcon.MessageType messageType)
          Displays a popup message near the tray icon.
 String getActionCommand()
          Returns the command name of the action event fired by this tray icon.
 ActionListener[] getActionListeners()
          Returns an array of all the action listeners registered on this TrayIcon.
 Image getImage()
          Returns the current image used for this TrayIcon.
 MouseListener[] getMouseListeners()
          Returns an array of all the mouse listeners registered on this TrayIcon.
 MouseMotionListener[] getMouseMotionListeners()
          Returns an array of all the mouse-motion listeners registered on this TrayIcon.
 PopupMenu getPopupMenu()
          Returns the popup menu associated with this TrayIcon.
 Dimension getSize()
          Returns the size, in pixels, of the space that the tray icon occupies in the system tray.
 String getToolTip()
          Returns the tooltip string associated with this TrayIcon.
 boolean isImageAutoSize()
          Returns the value of the auto-size property.
 void removeActionListener(ActionListener listener)
          Removes the specified action listener.
 void removeMouseListener(MouseListener listener)
          Removes the specified mouse listener.
 void removeMouseMotionListener(MouseMotionListener listener)
          Removes the specified mouse-motion listener.
 void setActionCommand(String command)
          Sets the command name for the action event fired by this tray icon.
 void setImage(Image image)
          Sets the image for this TrayIcon.
 void setImageAutoSize(boolean autosize)
          Sets the auto-size property.
 void setPopupMenu(PopupMenu popup)
          Sets the popup menu for this TrayIcon.
 void setToolTip(String tooltip)
          Sets the tooltip string for this TrayIcon.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TrayIcon

public TrayIcon(Image image)
Creates a TrayIcon with the specified image.

Parameters:
image - the Image to be used
Throws:
IllegalArgumentException - if image is null
UnsupportedOperationException - if the system tray isn't supported by the current platform
HeadlessException - if GraphicsEnvironment.isHeadless() returns true
SecurityException - if accessSystemTray permission is not granted
See Also:
SystemTray.add(TrayIcon), TrayIcon(Image, String, PopupMenu), TrayIcon(Image, String), SecurityManager.checkPermission(java.security.Permission), AWTPermission

TrayIcon

public TrayIcon(Image image,
                String tooltip)
Creates a TrayIcon with the specified image and tooltip text.

Parameters:
image - the Image to be used
tooltip - the string to be used as tooltip text; if the value is null no tooltip is shown
Throws:
IllegalArgumentException - if image is null
UnsupportedOperationException - if the system tray isn't supported by the current platform
HeadlessException - if GraphicsEnvironment.isHeadless() returns true
SecurityException - if accessSystemTray permission is not granted
See Also:
SystemTray.add(TrayIcon), TrayIcon(Image), TrayIcon(Image, String, PopupMenu), SecurityManager.checkPermission(java.security.Permission), AWTPermission

TrayIcon

public TrayIcon(Image image,
                String tooltip,
                PopupMenu popup)
Creates a TrayIcon with the specified image, tooltip and popup menu.

Parameters:
image - the Image to be used
tooltip - the string to be used as tooltip text; if the value is null no tooltip is shown
popup - the menu to be used for the tray icon's popup menu; if the value is null no popup menu is shown
Throws:
IllegalArgumentException - if image is null
UnsupportedOperationException - if the system tray isn't supported by the current platform
HeadlessException - if GraphicsEnvironment.isHeadless() returns true
SecurityException - if accessSystemTray permission is not granted
See Also:
SystemTray.add(TrayIcon), TrayIcon(Image, String), TrayIcon(Image), PopupMenu, MouseListener, addMouseListener(MouseListener), SecurityManager.checkPermission(java.security.Permission), AWTPermission
Method Detail

setImage

public void setImage(Image image)
Sets the image for this TrayIcon. The previous tray icon image is discarded without calling the Image.flush() method — you will need to call it manually.

If the image represents an animated image, it will be animated automatically.

See the setImageAutoSize(boolean) property for details on the size of the displayed image.

Calling this method with the same image that is currently being used has no effect.

Parameters:
image - the non-null Image to be used
Throws:
NullPointerException - if image is null
See Also:
getImage(), Image, SystemTray.add(TrayIcon), TrayIcon(Image, String)

getImage

public Image getImage()
Returns the current image used for this TrayIcon.

Returns:
the image
See Also:
setImage(Image), Image

setPopupMenu

public void setPopupMenu(PopupMenu popup)
Sets the popup menu for this TrayIcon. If popup is null, no popup menu will be associated with this TrayIcon.

Note that this popup must not be added to any parent before or after it is set on the tray icon. If you add it to some parent, the popup may be removed from that parent.

The popup can be set on one TrayIcon only. Setting the same popup on multiple TrayIcons will cause an IllegalArgumentException.

Note: Some platforms may not support showing the user-specified popup menu component when the user right-clicks the tray icon. In this situation, either no menu will be displayed or, on some systems, a native version of the menu may be displayed.

Parameters:
popup - a PopupMenu or null to remove any popup menu
Throws:
IllegalArgumentException - if the popup is already set for another TrayIcon
See Also:
getPopupMenu()

getPopupMenu

public PopupMenu getPopupMenu()
Returns the popup menu associated with this TrayIcon.

Returns:
the popup menu or null if none exists
See Also:
setPopupMenu(PopupMenu)

setToolTip

public void setToolTip(String tooltip)
Sets the tooltip string for this TrayIcon. The tooltip is displayed automatically when the mouse hovers over the icon. Setting the tooltip to null removes any tooltip text. When displayed, the tooltip string may be truncated on some platforms; the number of characters that may be displayed is platform-dependent.

Parameters:
tooltip - the string for the tooltip; if the value is null no tooltip is shown
See Also:
getToolTip()

getToolTip

public String getToolTip()
Returns the tooltip string associated with this TrayIcon.

Returns:
the tooltip string or null if none exists
See Also:
setToolTip(String)

setImageAutoSize

public void setImageAutoSize(boolean autosize)
Sets the auto-size property. Auto-size determines whether the tray image is automatically sized to fit the space allocated for the image on the tray. By default, the auto-size property is set to false.

If auto-size is false, and the image size doesn't match the tray icon space, the image is painted as-is inside that space — if larger than the allocated space, it will be cropped.

If auto-size is true, the image is stretched or shrunk to fit the tray icon space.

Parameters:
autosize - true to auto-size the image, false otherwise
See Also:
isImageAutoSize()

isImageAutoSize

public boolean isImageAutoSize()
Returns the value of the auto-size property.

Returns:
true if the image will be auto-sized, false otherwise
See Also:
setImageAutoSize(boolean)

addMouseListener

public void addMouseListener(MouseListener listener)
Adds the specified mouse listener to receive mouse events from this TrayIcon. Calling this method with a null value has no effect.

Note: The MouseEvent's coordinates (received from the TrayIcon) are relative to the screen, not the TrayIcon.

Note: The MOUSE_ENTERED and MOUSE_EXITED mouse events are not supported.

Refer to AWT Threading Issues for details on AWT's threading model.

Parameters:
listener - the mouse listener
See Also:
MouseEvent, MouseListener, removeMouseListener(MouseListener), getMouseListeners()

removeMouseListener

public void removeMouseListener(MouseListener listener)
Removes the specified mouse listener. Calling this method with null or an invalid value has no effect.

Refer to AWT Threading Issues for details on AWT's threading model.

Parameters:
listener - the mouse listener
See Also:
MouseEvent, MouseListener, addMouseListener(MouseListener), getMouseListeners()

getMouseListeners

public MouseListener[] getMouseListeners()
Returns an array of all the mouse listeners registered on this TrayIcon.

Returns:
all of the MouseListeners registered on this TrayIcon or an empty array if no mouse listeners are currently registered
See Also:
addMouseListener(MouseListener), removeMouseListener(MouseListener), MouseListener

addMouseMotionListener

public void addMouseMotionListener(MouseMotionListener listener)
Adds the specified mouse listener to receive mouse-motion events from this TrayIcon. Calling this method with a null value has no effect.

Note: The MouseEvent's coordinates (received from the TrayIcon) are relative to the screen, not the TrayIcon.

Note: The MOUSE_DRAGGED mouse event is not supported.

Refer to AWT Threading Issues for details on AWT's threading model.

Parameters:
listener - the mouse listener
See Also:
MouseEvent, MouseMotionListener, removeMouseMotionListener(MouseMotionListener), getMouseMotionListeners()

removeMouseMotionListener

public void removeMouseMotionListener(MouseMotionListener listener)
Removes the specified mouse-motion listener. Calling this method with null or an invalid value has no effect.

Refer to AWT Threading Issues for details on AWT's threading model.

Parameters:
listener - the mouse listener
See Also:
MouseEvent, MouseMotionListener, addMouseMotionListener(MouseMotionListener), getMouseMotionListeners()

getMouseMotionListeners

public MouseMotionListener[] getMouseMotionListeners()
Returns an array of all the mouse-motion listeners registered on this TrayIcon.

Returns:
all of the MouseInputListeners registered on this TrayIcon or an empty array if no mouse listeners are currently registered
See Also:
addMouseMotionListener(MouseMotionListener), removeMouseMotionListener(MouseMotionListener), MouseMotionListener

getActionCommand

public String getActionCommand()
Returns the command name of the action event fired by this tray icon.

Returns:
the action command name, or null if none exists
See Also:
addActionListener(ActionListener), setActionCommand(String)

setActionCommand

public void setActionCommand(String command)
Sets the command name for the action event fired by this tray icon. By default, this action command is set to null.

Parameters:
command - a string used to set the tray icon's action command.
See Also:
ActionEvent, addActionListener(ActionListener), getActionCommand()

addActionListener

public void addActionListener(ActionListener listener)
Adds the specified action listener to receive ActionEvents from this TrayIcon. Action events usually occur when a user selects the tray icon, using either the mouse or keyboard. The conditions in which action events are generated are platform-dependent.

Calling this method with a null value has no effect.

Refer to AWT Threading Issues for details on AWT's threading model.

Parameters:
listener - the action listener
See Also:
removeActionListener(java.awt.event.ActionListener), getActionListeners(), ActionListener, setActionCommand(String)

removeActionListener

public void removeActionListener(ActionListener listener)
Removes the specified action listener. Calling this method with null or an invalid value has no effect.

Refer to AWT Threading Issues for details on AWT's threading model.

Parameters:
listener - the action listener
See Also:
ActionEvent, ActionListener, addActionListener(ActionListener), getActionListeners(), setActionCommand(String)

getActionListeners

public ActionListener[] getActionListeners()
Returns an array of all the action listeners registered on this TrayIcon.

Returns:
all of the ActionListeners registered on this TrayIcon or an empty array if no action listeners are currently registered
See Also:
addActionListener(ActionListener), removeActionListener(ActionListener), ActionListener

displayMessage

public void displayMessage(String caption,
                           String text,
                           TrayIcon.MessageType messageType)
Displays a popup message near the tray icon. The message will disappear after a time or if the user clicks on it. Clicking on the message may trigger an ActionEvent.

Either the caption or the text may be null, but an NullPointerException is thrown if both are null. When displayed, the caption or text strings may be truncated on some platforms; the number of characters that may be displayed is platform-dependent.

Note: Some platforms may not support showing a message.

Parameters:
caption - the caption displayed above the text, usually in bold; may be null
text - the text displayed for the particular message; may be null
messageType - an enum indicating the message type
Throws:
NullPointerException - if both caption and text are null

getSize

public Dimension getSize()
Returns the size, in pixels, of the space that the tray icon occupies in the system tray. For the tray icon that is not yet added to the system tray, the returned size is equal to the result of the SystemTray.getTrayIconSize().

Returns:
the size of the tray icon, in pixels
See Also:
setImageAutoSize(boolean), Image, getSize()

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.