Class MenuItem

java.lang.Object

org.eclipse.swt.widgets.Widget

org.eclipse.swt.widgets.Item

org.eclipse.swt.widgets.MenuItem

public class MenuItem
extends Item

Instances of this class represent a selectable user interface object that issues notification when pressed and released.

Styles:

CHECK, CASCADE, PUSH, RADIO, SEPARATOR

Events:

Arm, Help, Selection

Note: Only one of the styles CHECK, CASCADE, PUSH, RADIO and SEPARATOR may be specified.

IMPORTANT: This class is not intended to be subclassed.

See Also:

• Sample code and further information

Constructor Summary

Constructors

Constructor	Description
MenuItem(Menu parent, int style)	Constructs a new instance of this class given its parent (which must be a Menu) and a style value describing its behavior and appearance.
MenuItem(Menu parent, int style, int index)	Constructs a new instance of this class given its parent (which must be a Menu), a style value describing its behavior and appearance, and the index at which to place it in the items maintained by its parent.

Method Summary

Modifier and Type	Method	Description
void	addArmListener(ArmListener listener)	Adds the listener to the collection of listeners who will be notified when the arm events are generated for the control, by sending it one of the messages defined in the ArmListener interface.
void	addHelpListener(HelpListener listener)	Adds the listener to the collection of listeners who will be notified when the help events are generated for the control, by sending it one of the messages defined in the HelpListener interface.
void	addSelectionListener(SelectionListener listener)	Adds the listener to the collection of listeners who will be notified when the menu item is selected by the user, by sending it one of the messages defined in the SelectionListener interface.
protected void	checkSubclass()	Checks that this class can be subclassed.
int	getAccelerator()	Returns the widget accelerator.
boolean	getEnabled()	Returns true if the receiver is enabled, and false otherwise.
int	getID()	Gets the identifier associated with the receiver.
Menu	getMenu()	Returns the receiver's cascade menu if it has one or null if it does not.
Menu	getParent()	Returns the receiver's parent, which must be a Menu.
boolean	getSelection()	Returns true if the receiver is selected, and false otherwise.
String	getToolTipText()	Returns the receiver's tool tip text, or null if it has not been set.
boolean	isEnabled()	Returns true if the receiver is enabled and all of the receiver's ancestors are enabled, and false otherwise.
void	removeArmListener(ArmListener listener)	Removes the listener from the collection of listeners who will be notified when the arm events are generated for the control.
void	removeHelpListener(HelpListener listener)	Removes the listener from the collection of listeners who will be notified when the help events are generated for the control.
void	removeSelectionListener(SelectionListener listener)	Removes the listener from the collection of listeners who will be notified when the control is selected by the user.
void	setAccelerator(int accelerator)	Sets the widget accelerator.
void	setEnabled(boolean enabled)	Enables the receiver if the argument is true, and disables it otherwise.
void	setID(int id)	Sets the identifier associated with the receiver to the argument.
void	setImage(Image image)	Sets the receiver's image to the argument, which may be null indicating that no image should be displayed.
void	setMenu(Menu menu)	Sets the receiver's pull down menu to the argument.
void	setSelection(boolean selected)	Sets the selection state of the receiver.
void	setText(String string)	Sets the receiver's text.
void	setToolTipText(String toolTip)	Sets the receiver's tool tip text to the argument, which may be null indicating that the default tool tip for the control will be shown.

Methods inherited from class Item

getImage, getText

Methods inherited from class Widget

addDisposeListener, addListener, checkWidget, dispose, getData, getData, getDisplay, getListeners, getStyle, isAutoDirection, isDisposed, isListening, notifyListeners, removeDisposeListener, removeListener, removeListener, reskin, setData, setData, toString

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

MenuItem

public MenuItem(Menu parent,
 int style)

Constructs a new instance of this class given its parent (which must be a Menu) and a style value describing its behavior and appearance. The item is added to the end of the items maintained by its parent.

The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

Parameters:

parent - a menu control which will be the parent of the new instance (cannot be null)

style - the style of control to construct

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
• ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass

See Also:

• SWT.CHECK
• SWT.CASCADE
• SWT.PUSH
• SWT.RADIO
• SWT.SEPARATOR
• Widget.checkSubclass()
• Widget.getStyle()

MenuItem

public MenuItem(Menu parent,
 int style,
 int index)

Constructs a new instance of this class given its parent (which must be a Menu), a style value describing its behavior and appearance, and the index at which to place it in the items maintained by its parent.

The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

Parameters:

parent - a menu control which will be the parent of the new instance (cannot be null)

style - the style of control to construct

index - the zero-relative index to store the receiver in its parent

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the parent is null
• ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the parent (inclusive)

SWTException -

• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
• ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass

See Also:

• SWT.CHECK
• SWT.CASCADE
• SWT.PUSH
• SWT.RADIO
• SWT.SEPARATOR
• Widget.checkSubclass()
• Widget.getStyle()

Method Details

addArmListener

public void addArmListener(ArmListener listener)

Adds the listener to the collection of listeners who will be notified when the arm events are generated for the control, by sending it one of the messages defined in the ArmListener interface.

Parameters:

listener - the listener which should be notified

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

• ArmListener
• removeArmListener(ArmListener)

addHelpListener

public void addHelpListener(HelpListener listener)

Adds the listener to the collection of listeners who will be notified when the help events are generated for the control, by sending it one of the messages defined in the HelpListener interface.

Parameters:

listener - the listener which should be notified

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

• HelpListener
• removeHelpListener(HelpListener)

addSelectionListener

public void addSelectionListener(SelectionListener listener)

Adds the listener to the collection of listeners who will be notified when the menu item is selected by the user, by sending it one of the messages defined in the SelectionListener interface.

When widgetSelected is called, the stateMask field of the event object is valid. widgetDefaultSelected is not called.

When the SWT.RADIO style bit is set, the widgetSelected method is also called when the receiver loses selection because another item in the same radio group was selected by the user. During widgetSelected the application can use getSelection() to determine the current selected state of the receiver.

Parameters:

listener - the listener which should be notified when the menu item is selected by the user

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

See Also:

• SelectionListener
• removeSelectionListener(SelectionListener)
• SelectionEvent

checkSubclass

protected void checkSubclass()

Description copied from class: Widget

Checks that this class can be subclassed.

The SWT class library is intended to be subclassed only at specific, controlled points (most notably, Composite and Canvas when implementing new widgets). This method enforces this rule unless it is overridden.

IMPORTANT: By providing an implementation of this method that allows a subclass of a class which does not normally allow subclassing to be created, the implementer agrees to be fully responsible for the fact that any such subclass will likely fail between SWT releases and will be strongly platform specific. No support is provided for user-written classes which are implemented in this fashion.

The ability to subclass outside of the allowed SWT classes is intended purely to enable those not on the SWT development team to implement patches in order to get around specific limitations in advance of when those limitations can be addressed by the team. Subclassing should not be attempted without an intimate and detailed understanding of the hierarchy.

Overrides:

checkSubclass in class Item

getAccelerator

public int getAccelerator()

Returns the widget accelerator. An accelerator is the bit-wise OR of zero or more modifier masks and a key. Examples: SWT.CONTROL | SWT.SHIFT | 'T', SWT.ALT | SWT.F2. The default value is zero, indicating that the menu item does not have an accelerator.

Returns:

the accelerator or 0

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver