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org.eclipse.swt.widgets
Class Menu
java.lang.Object
org.eclipse.swt.widgets.Widget
org.eclipse.swt.widgets.Menu
-
public class Menu
- extends
Widget
Instances of this class are user interface objects that contain
menu items.
-
Styles:
- BAR, DROP_DOWN, POP_UP, NO_RADIO_GROUP
- LEFT_TO_RIGHT, RIGHT_TO_LEFT
-
Events:
- Help, Hide, Show
Note: Only one of BAR, DROP_DOWN and POP_UP may be specified.
Only one of LEFT_TO_RIGHT or RIGHT_TO_LEFT may be specified.
IMPORTANT: This class is not intended to be subclassed.
-
See Also:
-
Menu snippets,
SWT Example: ControlExample,
Sample code and further information
-
Restriction:
- This class is not intended to be subclassed by clients.
Field Summary
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int
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handle
the handle to the OS resource
(Warning: This field is platform dependent)
IMPORTANT: This field is not part of the SWT
public API. |
Constructor Summary
|
Menu
(
Control parent)
Constructs a new instance of this class given its parent,
and sets the style for the instance so that the instance
will be a popup menu on the given parent's shell. |
Menu
(
Decorations parent,
int style)
Constructs a new instance of this class given its parent
(which must be a Decorations ) and a style value
describing its behavior and appearance. |
Menu
(
Menu parentMenu)
Constructs a new instance of this class given its parent
(which must be a Menu ) and sets the style
for the instance so that the instance will be a drop-down
menu on the given parent's parent. |
Menu
(
MenuItem parentItem)
Constructs a new instance of this class given its parent
(which must be a MenuItem ) and sets the style
for the instance so that the instance will be a drop-down
menu on the given parent's parent menu. |
Method Summary
|
void
|
addHelpListener
(
HelpListener listener)
Adds the listener to the collection of listeners who will
be notified when help events are generated for the control,
by sending it one of the messages defined in the
HelpListener interface. |
void
|
addMenuListener
(
MenuListener listener)
Adds the listener to the collection of listeners who will
be notified when menus are hidden or shown, by sending it
one of the messages defined in the MenuListener
interface. |
MenuItem
|
getDefaultItem
()
Returns the default menu item or null if none has
been previously set. |
boolean
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getEnabled
()
Returns true if the receiver is enabled, and
false otherwise. |
MenuItem
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getItem
(int index)
Returns the item at the given, zero-relative index in the
receiver. |
int
|
getItemCount
()
Returns the number of items contained in the receiver. |
MenuItem[]
|
getItems
()
Returns a (possibly empty) array of MenuItem s which
are the items in the receiver. |
Decorations
|
getParent
()
Returns the receiver's parent, which must be a Decorations . |
MenuItem
|
getParentItem
()
Returns the receiver's parent item, which must be a
MenuItem or null when the receiver is a
root. |
Menu
|
getParentMenu
()
Returns the receiver's parent item, which must be a
Menu or null when the receiver is a
root. |
Shell
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getShell
()
Returns the receiver's shell. |
boolean
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getVisible
()
Returns true if the receiver is visible, and
false otherwise. |
int
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indexOf
(
MenuItem item)
Searches the receiver's list starting at the first item
(index 0) until an item is found that is equal to the
argument, and returns the index of that item. |
boolean
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isEnabled
()
Returns true if the receiver is enabled and all
of the receiver's ancestors are enabled, and false
otherwise. |
boolean
|
isVisible
()
Returns true if the receiver is visible and all
of the receiver's ancestors are visible and false
otherwise. |
void
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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
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removeMenuListener
(
MenuListener listener)
Removes the listener from the collection of listeners who will
be notified when the menu events are generated for the control. |
void
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setDefaultItem
(
MenuItem item)
Sets the default menu item to the argument or removes
the default emphasis when the argument is null . |
void
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setEnabled
(boolean enabled)
Enables the receiver if the argument is true ,
and disables it otherwise. |
void
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setLocation
(int x,
int y)
Sets the location of the receiver, which must be a popup,
to the point specified by the arguments which are relative
to the display. |
void
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setLocation
(
Point location)
Sets the location of the receiver, which must be a popup,
to the point specified by the argument which is relative
to the display. |
void
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setVisible
(boolean visible)
Marks the receiver as visible if the argument is true ,
and marks it invisible otherwise. |
Methods inherited from class org.eclipse.swt.widgets.
Widget
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addDisposeListener,
addListener,
checkSubclass,
checkWidget,
dispose,
getData,
getData,
getDisplay,
getListeners,
getStyle,
isDisposed,
isListening,
notifyListeners,
removeDisposeListener,
removeListener,
removeListener,
setData,
setData,
toString
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handle
public int handle
- the handle to the OS resource
(Warning: This field is platform dependent)
IMPORTANT: This field is not part of the SWT
public API. It is marked public only so that it can be shared
within the packages provided by SWT. It is not available on all
platforms and should never be accessed from application code.
Menu
public Menu(
Control parent)
- Constructs a new instance of this class given its parent,
and sets the style for the instance so that the instance
will be a popup menu on the given parent's shell.
After constructing a menu, it can be set into its parent
using parent.setMenu(menu) . In this case, the parent may
be any control in the same widget tree as the parent.
-
Parameters:
-
parent - a control which will be the parent of the new instance (cannot be null)
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the parent is null
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SWTException
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- 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
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See Also:
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SWT.POP_UP ,
Widget.checkSubclass() ,
Widget.getStyle()
Menu
public Menu(
Decorations parent,
int style)
- Constructs a new instance of this class given its parent
(which must be a
Decorations ) and a style value
describing its behavior and appearance.
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.
After constructing a menu or menuBar, it can be set into its parent
using parent.setMenu(menu) or parent.setMenuBar(menuBar) .
-
Parameters:
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parent - a decorations control which will be the parent of the new instance (cannot be null) -
style - the style of menu to construct
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the parent is null
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SWTException
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- 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
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See Also:
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SWT.BAR ,
SWT.DROP_DOWN ,
SWT.POP_UP ,
SWT.NO_RADIO_GROUP ,
SWT.LEFT_TO_RIGHT ,
SWT.RIGHT_TO_LEFT ,
Widget.checkSubclass() ,
Widget.getStyle()
Menu
public Menu(
Menu parentMenu)
- Constructs a new instance of this class given its parent
(which must be a
Menu ) and sets the style
for the instance so that the instance will be a drop-down
menu on the given parent's parent.
After constructing a drop-down menu, it can be set into its parentMenu
using parentMenu.setMenu(menu) .
-
Parameters:
-
parentMenu - a menu which will be the parent of the new instance (cannot be null)
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the parent is null
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SWTException
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- 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
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See Also:
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SWT.DROP_DOWN ,
Widget.checkSubclass() ,
Widget.getStyle()
Menu
public Menu(
MenuItem parentItem)
- Constructs a new instance of this class given its parent
(which must be a
MenuItem ) and sets the style
for the instance so that the instance will be a drop-down
menu on the given parent's parent menu.
After constructing a drop-down menu, it can be set into its parentItem
using parentItem.setMenu(menu) .
-
Parameters:
-
parentItem - a menu item which will be the parent of the new instance (cannot be null)
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the parent is null
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SWTException
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- 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
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See Also:
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SWT.DROP_DOWN ,
Widget.checkSubclass() ,
Widget.getStyle()
addHelpListener
public void addHelpListener(
HelpListener listener)
- Adds the listener to the collection of listeners who will
be notified when help events are generated for the control,
by sending it one of the messages defined in the
HelpListener interface.
-
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Parameters:
-
listener - the listener which should be notified
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the listener is null
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SWTException
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- 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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See Also:
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HelpListener ,
removeHelpListener(org.eclipse.swt.events.HelpListener)
addMenuListener
public void addMenuListener(
MenuListener listener)
- Adds the listener to the collection of listeners who will
be notified when menus are hidden or shown, by sending it
one of the messages defined in the
MenuListener
interface.
-
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Parameters:
-
listener - the listener which should be notified
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the listener is null
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SWTException
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- 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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See Also:
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MenuListener ,
removeMenuListener(org.eclipse.swt.events.MenuListener)
getDefaultItem
public
MenuItem getDefaultItem()
- Returns the default menu item or null if none has
been previously set.
-
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Returns:
- the default menu item.
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Throws:
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
getEnabled
public boolean getEnabled()
- Returns
true if the receiver is enabled, and
false otherwise. A disabled menu 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
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See Also:
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isEnabled()
getItem
public
MenuItem getItem(int index)
- Returns the item at the given, zero-relative index in the
receiver. Throws an exception if the index is out of range.
-
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Parameters:
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index - the index of the item to return
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Returns:
- the item at the given index
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Throws:
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IllegalArgumentException
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- ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
getItemCount
public int getItemCount()
- Returns the number of items contained in the receiver.
-
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Returns:
- the number of items
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Throws:
-
SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
getItems
public
MenuItem[] getItems()
- Returns a (possibly empty) array of
MenuItem s which
are the items in the receiver.
Note: This is not the actual structure used by the receiver
to maintain its list of items, so modifying the array will
not affect the receiver.
-
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Returns:
- the items in the receiver
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Throws:
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
getParent
public
Decorations getParent()
- Returns the receiver's parent, which must be a
Decorations .
-
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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
getParentItem
public
MenuItem getParentItem()
- Returns the receiver's parent item, which must be a
MenuItem or null when the receiver is a
root.
-
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Returns:
- the receiver's parent item
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Throws:
-
SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
getParentMenu
public
Menu getParentMenu()
- Returns the receiver's parent item, which must be a
Menu or null when the receiver is a
root.
-
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Returns:
- the receiver's parent item
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Throws:
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
getShell
public
Shell getShell()
- Returns the receiver's shell. For all controls other than
shells, this simply returns the control's nearest ancestor
shell. Shells return themselves, even if they are children
of other shells.
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Returns:
- the receiver's shell
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Throws:
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SWTException
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- 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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See Also:
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getParent()
getVisible
public boolean getVisible()
- Returns
true if the receiver is visible, and
false otherwise.
If one of the receiver's ancestors is not visible or some
other condition makes the receiver not visible, this method
may still indicate that it is considered visible even though
it may not actually be showing.
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Returns:
- the receiver's visibility state
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Throws:
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
indexOf
public int indexOf(
MenuItem item)
- Searches the receiver's list starting at the first item
(index 0) until an item is found that is equal to the
argument, and returns the index of that item. If no item
is found, returns -1.
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Parameters:
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item - the search item
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Returns:
- the index of the item
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Throws:
-
IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the item is null
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
isEnabled
public boolean isEnabled()
- Returns
true if the receiver is enabled and all
of the receiver's ancestors are enabled, and false
otherwise. A disabled menu is typically not selectable from the
user interface and draws with an inactive or "grayed" look.
-
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Returns:
- the receiver's enabled state
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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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See Also:
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getEnabled()
isVisible
public boolean isVisible()
- Returns
true if the receiver is visible and all
of the receiver's ancestors are visible and false
otherwise.
-
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Returns:
- the receiver's visibility state
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Throws:
-
SWTException
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- 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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See Also:
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getVisible()
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.
-
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Parameters:
-
listener - the listener which should no longer be notified
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the listener is null
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SWTException
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- 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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See Also:
-
HelpListener ,
addHelpListener(org.eclipse.swt.events.HelpListener)
removeMenuListener
public void removeMenuListener(
MenuListener listener)
- Removes the listener from the collection of listeners who will
be notified when the menu events are generated for the control.
-
-
Parameters:
-
listener - the listener which should no longer be notified
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Throws:
-
IllegalArgumentException
-
- ERROR_NULL_ARGUMENT - if the listener is null
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SWTException
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- 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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See Also:
-
MenuListener ,
addMenuListener(org.eclipse.swt.events.MenuListener)
setDefaultItem
public void setDefaultItem(
MenuItem item)
- Sets the default menu item to the argument or removes
the default emphasis when the argument is
null .
-
-
Parameters:
-
item - the default menu item or null
-
Throws:
-
IllegalArgumentException
-
- ERROR_INVALID_ARGUMENT - if the menu item has been disposed
-
SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
setEnabled
public void setEnabled(boolean enabled)
- Enables the receiver if the argument is
true ,
and disables it otherwise. A disabled menu is typically
not selectable from the user interface and draws with an
inactive or "grayed" look.
-
-
Parameters:
-
enabled - the new enabled state
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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
setLocation
public void setLocation(int x,
int y)
- Sets the location of the receiver, which must be a popup,
to the point specified by the arguments which are relative
to the display.
Note that this is different from most widgets where the
location of the widget is relative to the parent.
Note that the platform window manager ultimately has control
over the location of popup menus.
-
-
Parameters:
-
x - the new x coordinate for the receiver -
y - the new y coordinate for the receiver
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Throws:
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
setLocation
public void setLocation(
Point location)
- Sets the location of the receiver, which must be a popup,
to the point specified by the argument which is relative
to the display.
Note that this is different from most widgets where the
location of the widget is relative to the parent.
Note that the platform window manager ultimately has control
over the location of popup menus.
-
-
Parameters:
-
location - the new location for the receiver
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Throws:
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IllegalArgumentException
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- ERROR_NULL_ARGUMENT - if the point is null
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SWTException
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- 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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Since:
- 2.1
setVisible
public void setVisible(boolean visible)
- Marks the receiver as visible if the argument is
true ,
and marks it invisible otherwise.
If one of the receiver's ancestors is not visible or some
other condition makes the receiver not visible, marking
it visible may not actually cause it to be displayed.
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Parameters:
-
visible - the new visibility state
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Throws:
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SWTException
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- ERROR_WIDGET_DISPOSED - if the receiver has been disposed
- ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
Guidelines for using Eclipse APIs.
Copyright (c) Eclipse contributors and others 2000, 2008. All rights reserved.
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