Class MenuItem
- java.lang.Object
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- org.eclipse.swt.widgets.Widget
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- org.eclipse.swt.widgets.Item
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- org.eclipse.swt.widgets.MenuItem
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- All Implemented Interfaces:
Adaptable
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.
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Constructor Summary
Constructors Constructor Description MenuItem(Menu parent, int style)
Constructs a new instance of this class given its parent (which must be aMenu
) 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 aMenu
), a style value describing its behavior and appearance, and the index at which to place it in the items maintained by its parent.
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Method Summary
All Methods Instance Methods Concrete Methods 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 theArmListener
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 theHelpListener
interface.void
addSelectionListener(SelectionListener listener)
Adds the listener to the collection of listeners who will be notified when the menu item is selected, by sending it one of the messages defined in theSelectionListener
interface.int
getAccelerator()
Returns the widget accelerator.<T> T
getAdapter(java.lang.Class<T> adapter)
Implementation of theAdaptable
interface.boolean
getEnabled()
Returnstrue
if the receiver is enabled, andfalse
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 aMenu
.boolean
getSelection()
Returnstrue
if the receiver is selected, and false otherwise.boolean
isEnabled()
Returnstrue
if the receiver is enabled and all of the receiver's ancestors are enabled, andfalse
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.void
setAccelerator(int accelerator)
Sets the widget accelerator.void
setEnabled(boolean enabled)
Enables the receiver if the argument istrue
, and disables it otherwise.void
setID(int id)
Sets the identifier associated with the receiver to the argument.void
setImage(Image image)
Sets the image the receiver will display to the argument.void
setMenu(Menu menu)
Sets the receiver's pull down menu to the argument.void
setSelection(boolean selection)
Sets the selection state of the receiver.-
Methods inherited from class org.eclipse.swt.widgets.Widget
addDisposeListener, addListener, checkSubclass, checkWidget, dispose, getData, getData, getDisplay, getListeners, getStyle, isDisposed, isListening, notifyListeners, removeDisposeListener, removeListener, removeListener, reskin, setData, setData, toString
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Constructor Detail
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MenuItem
public MenuItem(Menu parent, int style)
Constructs a new instance of this class given its parent (which must be aMenu
) 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 theint
"|" operator) two or more of thoseSWT
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:
java.lang.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()
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MenuItem
public MenuItem(Menu parent, int style, int index)
Constructs a new instance of this class given its parent (which must be aMenu
), 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 theint
"|" operator) two or more of thoseSWT
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 constructindex
- the zero-relative index to store the receiver in its parent- Throws:
java.lang.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()
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Method Detail
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getParent
public Menu getParent()
Returns the receiver's parent, which must be aMenu
.- Returns:
- the receiver's parent
- 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
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setMenu
public void setMenu(Menu menu)
Sets the receiver's pull down menu to the argument. OnlyCASCADE
menu items can have a pull down menu. The sequence of key strokes, button presses and/or button releases that are used to request a pull down menu is platform specific.Note: Disposing of a menu item that has a pull down menu will dispose of the menu. To avoid this behavior, set the menu to null before the menu item is disposed.
- Parameters:
menu
- the new pull down menu- Throws:
java.lang.IllegalArgumentException
-- ERROR_MENU_NOT_DROP_DOWN - if the menu is not a drop down menu
- ERROR_MENUITEM_NOT_CASCADE - if the menu item is not a
CASCADE
- ERROR_INVALID_ARGUMENT - if the menu has been disposed
- ERROR_INVALID_PARENT - if the menu is not in the same widget tree
SWTException
-- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
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getMenu
public Menu getMenu()
Returns the receiver's cascade menu if it has one or null if it does not. OnlyCASCADE
menu items can have a pull down menu. The sequence of key strokes, button presses and/or button releases that are used to request a pull down menu is platform specific.- Returns:
- the receiver's menu
- 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
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setID
public void setID(int id)
Sets the identifier associated with the receiver to the argument.- Parameters:
id
- the new identifier. This must be a non-negative value. System-defined identifiers are negative values.- 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
- ERROR_INVALID_ARGUMENT - if called with an negative-valued argument.
- Since:
- 1.4
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getID
public int getID()
Gets the identifier associated with the receiver.- 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
- Since:
- 1.4
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setImage
public void setImage(Image image)
Sets the image the receiver will display to the argument.Note: This operation is a hint and is not supported on platforms that do not have this concept (for example, Windows NT).
- Overrides:
setImage
in classItem
- Parameters:
image
- the image to display- 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
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setAccelerator
public void setAccelerator(int accelerator)
Sets the widget accelerator. An accelerator is the bit-wise OR of zero or more modifier masks and a key. Examples:SWT.MOD1 | SWT.MOD2 | 'T', SWT.MOD3 | SWT.F2
.SWT.CONTROL | SWT.SHIFT | 'T', SWT.ALT | SWT.F2
. The default value is zero, indicating that the menu item does not have an accelerator.- Parameters:
accelerator
- an integer that is the bit-wise OR of masks and a key
- 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
- Since:
- 2.1
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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
- Since:
- 2.1
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setEnabled
public void setEnabled(boolean enabled)
Enables the receiver if the argument istrue
, and disables it otherwise. A disabled menu item is typically not selectable from the user interface and draws with an inactive or "grayed" look.- Parameters:
enabled
- the new enabled state- 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
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getEnabled
public boolean getEnabled()
Returnstrue
if the receiver is enabled, andfalse
otherwise. A disabled menu item is typically not selectable from the user interface and draws with an inactive or "grayed" look.- Returns:
- the receiver's enabled state
- 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
- See Also:
isEnabled()
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isEnabled
public boolean isEnabled()
Returnstrue
if the receiver is enabled and all of the receiver's ancestors are enabled, andfalse
otherwise. A disabled menu item is typically not selectable from the user interface and draws with an inactive or "grayed" look.- Returns:
- the receiver's enabled state
- 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
- See Also:
getEnabled()
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getSelection
public boolean getSelection()
Returnstrue
if the receiver is selected, and false otherwise.When the receiver is of type
CHECK
orRADIO
, it is selected when it is checked.- Returns:
- the selection state
- 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
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setSelection
public void setSelection(boolean selection)
Sets the selection state of the receiver.When the receiver is of type
CHECK
orRADIO
, it is selected when it is checked.- Parameters:
selection
- the new selection state- 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
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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 sending it one of the messages defined in theSelectionListener
interface.When
widgetSelected
is called, the stateMask field of the event object is valid.widgetDefaultSelected
is not called.- Parameters:
listener
- the listener which should be notified- Throws:
java.lang.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(org.eclipse.swt.events.SelectionListener)
,SelectionEvent
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removeSelectionListener
public void removeSelectionListener(SelectionListener listener)
Removes the listener from the collection of listeners who will be notified when the control is selected.- Parameters:
listener
- the listener which should no longer be notified- Throws:
java.lang.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
,addSelectionListener(org.eclipse.swt.events.SelectionListener)
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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 theHelpListener
interface.- Parameters:
listener
- the listener which should be notified- Throws:
java.lang.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
- Since:
- 1.3
- See Also:
HelpListener
,removeHelpListener(org.eclipse.swt.events.HelpListener)
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removeHelpListener
public 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.- Parameters:
listener
- the listener which should no longer be notified- Throws:
java.lang.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
- Since:
- 1.3
- See Also:
HelpListener
,addHelpListener(org.eclipse.swt.events.HelpListener)
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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 theArmListener
interface.- Parameters:
listener
- the listener which should be notified- Throws:
java.lang.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
- Since:
- 1.3
- See Also:
ArmListener
,removeArmListener(org.eclipse.swt.events.ArmListener)
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removeArmListener
public 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.- Parameters:
listener
- the listener which should no longer be notified- Throws:
java.lang.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
- Since:
- 1.3
- See Also:
ArmListener
,addArmListener(org.eclipse.swt.events.ArmListener)
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getAdapter
public <T> T getAdapter(java.lang.Class<T> adapter)
Description copied from class:Widget
Implementation of theAdaptable
interface.IMPORTANT: This method is not part of the RWT public API. It is marked public only so that it can be shared within the packages provided by RWT. It should never be accessed from application code.
- Specified by:
getAdapter
in interfaceAdaptable
- Overrides:
getAdapter
in classWidget
- Parameters:
adapter
- the lookup class- Returns:
- an object that can be cast to the given class or
null
if there is no adapter associated with the given class.