Class Item
- Direct Known Subclasses:
CoolItem
,CTabItem
,ExpandItem
,MenuItem
,TabItem
,TableColumn
,TableItem
,TaskItem
,ToolItem
,TrayItem
,TreeColumn
,TreeItem
- Styles:
- (none)
- Events:
- (none)
- See Also:
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Field Summary
Fields inherited from class org.eclipse.swt.widgets.Widget
nativeZoom
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Constructor Summary
ConstructorDescriptionConstructs a new instance of this class given its parent and a style value describing its behavior and appearance.Constructs a new instance of this class given its parent and 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 TypeMethodDescriptionprotected void
Checks that this class can be subclassed.getImage()
Returns the receiver's image if it has one, or null if it does not.getText()
Returns the receiver's text, which will be an empty string if it has never been set.void
Sets the receiver's image to the argument, which may be null indicating that no image should be displayed.void
Sets the receiver's text.Methods inherited from class org.eclipse.swt.widgets.Widget
addDisposeListener, addListener, addTypedListener, checkWidget, dispose, getData, getData, getDisplay, getListeners, getStyle, getTypedListeners, isAutoDirection, isDisposed, isListening, notifyListeners, removeDisposeListener, removeListener, removeListener, removeTypedListener, reskin, setData, setData, toString
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Constructor Details
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Item
Constructs a new instance of this class given its parent 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 widget which will be the parent of the new instance (cannot be null)style
- the style of item 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
- See Also:
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Item
Constructs a new instance of this class given its parent and 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 widget which will be the parent of the new instance (cannot be null)style
- the style of item to constructindex
- the zero-relative index at which 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
- See Also:
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Method Details
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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
andCanvas
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 classWidget
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getImage
Returns the receiver's image if it has one, or null if it does not.- Returns:
- the receiver's image
- 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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getText
Returns the receiver's text, which will be an empty string if it has never been set.- Returns:
- the receiver's text
- 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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setImage
Sets the receiver's image to the argument, which may be null indicating that no image should be displayed.- Parameters:
image
- the image to display on the receiver (may be null)- Throws:
IllegalArgumentException
-- ERROR_INVALID_ARGUMENT - if the image has been disposed
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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setText
Sets the receiver's text.Note: If control characters like '\n', '\t' etc. are used in the string, then the behavior is platform dependent.
- Parameters:
string
- the new text- Throws:
IllegalArgumentException
-- ERROR_NULL_ARGUMENT - if the text 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
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