org.eclipse.swt.widgets

Class TaskItem

java.lang.Object

org.eclipse.swt.widgets.Widget

org.eclipse.swt.widgets.Item

org.eclipse.swt.widgets.TaskItem

public class TaskItem
extends Item

Instances of this class represent a task item.

Styles:

(none)

Events:

(none)

Since:

3.6

See Also:

Sample code and further information

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) Menu	menu
(package private) Image	overlayImage
(package private) java.lang.String	overlayText
(package private) TaskBar	parent
(package private) int	progress
(package private) static int	PROGRESS_MAX
(package private) int	progressState
(package private) Shell	shell
(package private) boolean	showingText

Fields inherited from class org.eclipse.swt.widgets.Item

image, text

Fields inherited from class org.eclipse.swt.widgets.Widget

CANVAS, data, DEFAULT_HEIGHT, DEFAULT_WIDTH, DISABLED, display, DISPOSE_SENT, DISPOSED, DRAG_DETECT, DRAW_BACKGROUND, eventTable, FOREIGN_HANDLE, HIDDEN, IGNORE_WM_CHANGEUISTATE, KEYED_DATA, LAYOUT_CHANGED, LAYOUT_CHILD, LAYOUT_NEEDED, MAJOR, MINOR, MOVE_DEFERRED, MOVE_OCCURRED, PARENT_BACKGROUND, RELEASED, RESIZE_DEFERRED, RESIZE_OCCURRED, SKIN_NEEDED, state, style, THEME_BACKGROUND, TRACK_MOUSE

Constructor Summary

Constructors

Constructor and Description
TaskItem(TaskBar parent, int style) Constructs a new instance of this class given its parent (which must be a Tray) and a style value describing its behavior and appearance.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	checkSubclass() Checks that this class can be subclassed.
(package private) void	destroyWidget() Destroys the widget in the operating system and releases the widget's handle.
Menu	getMenu() Returns the receiver's pop up menu if it has one, or null if it does not.
Image	getOverlayImage() Returns the receiver's overlay image if it has one, or null if it does not.
java.lang.String	getOverlayText() Returns the receiver's overlay text, which will be an empty string if it has never been set.
TaskBar	getParent() Returns the receiver's parent, which must be a TaskBar.
int	getProgress() Returns the receiver's progress.
int	getProgressState() Returns the receiver's progress state.
(package private) void	recreate()
(package private) void	releaseHandle()
(package private) void	releaseWidget()
void	setMenu(Menu menu) Sets the receiver's pop up menu to the argument.
void	setOverlayImage(Image overlayImage) Sets the receiver's overlay image, which may be null indicating that no image should be displayed.
void	setOverlayText(java.lang.String overlayText) Sets the receiver's overlay text.
void	setProgress(int progress) Sets the receiver's progress, the progress represents a percentage and should be in range from 0 to 100.
void	setProgressState(int progressState) Sets the receiver's progress state, the state can be one of the following: SWT.DEFAULT SWT.NORMAL SWT.PAUSED SWT.ERROR SWT.INDETERMINATE The percentage of progress shown by the states SWT#NORMAL, SWT#PAUSED, SWT#ERROR is set with setProgress().
(package private) void	setShell(Shell shell)
(package private) void	updateImage()
(package private) void	updateProgress()
(package private) void	updateProgressState()
(package private) void	updateText()

Methods inherited from class org.eclipse.swt.widgets.Item

getImage, getNameText, getText, setImage, setText

Methods inherited from class org.eclipse.swt.widgets.Widget

_addListener, addDisposeListener, addListener, callWindowProc, checkBits, checkOpened, checkOrientation, checkParent, checkWidget, DeferWindowPos, dispose, dragDetect, error, filters, findItem, fixMnemonic, fixMnemonic, getData, getData, getDisplay, getListeners, getName, getStyle, hooks, isDisposed, isListening, isValidSubclass, isValidThread, mapEvent, new_GC, notifyListeners, postEvent, postEvent, release, releaseChildren, releaseParent, removeDisposeListener, removeListener, removeListener, reskin, reskinChildren, reskinWidget, sendDragEvent, sendDragEvent, sendEvent, sendEvent, sendEvent, sendEvent, sendFocusEvent, sendKeyEvent, sendKeyEvent, sendMouseEvent, sendMouseEvent, sendMouseWheelEvent, sendSelectionEvent, sendSelectionEvent, setData, setData, setInputState, setKeyState, setLocationMask, setTabGroupFocus, setTabItemFocus, SetWindowPos, showMenu, showMenu, toString, updateMenuLocation, wmCaptureChanged, wmChar, wmContextMenu, wmIMEChar, wmKeyDown, wmKeyUp, wmKillFocus, wmLButtonDblClk, wmLButtonDown, wmLButtonUp, wmMButtonDblClk, wmMButtonDown, wmMButtonUp, wmMouseHover, wmMouseHWheel, wmMouseLeave, wmMouseMove, wmMouseWheel, wmNCPaint, wmPaint, wmPrint, wmRButtonDblClk, wmRButtonDown, wmRButtonUp, wmSetFocus, wmSysChar, wmSysKeyDown, wmSysKeyUp, wmXButtonDblClk, wmXButtonDown, wmXButtonUp

Methods inherited from class java.lang.Object

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

Field Detail

parent

TaskBar parent

shell

Shell shell

progress

int progress

progressState

int progressState

overlayImage

Image overlayImage

overlayText

java.lang.String overlayText

showingText

boolean showingText

menu

Menu menu

PROGRESS_MAX

static final int PROGRESS_MAX

See Also:

Constant Field Values

Constructor Detail

TaskItem

TaskItem(TaskBar parent,
        int style)

Constructs a new instance of this class given its parent (which must be a Tray) 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 composite 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, Widget.checkSubclass(), Widget.getStyle()

Method Detail

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

destroyWidget

void destroyWidget()

Description copied from class: Widget

Destroys the widget in the operating system and releases the widget's handle. If the widget does not have a handle, this method may hide the widget, mark the widget as destroyed or do nothing, depending on the widget.

When a widget is destroyed in the operating system, its descendants are also destroyed by the operating system. This means that it is only necessary to call destroyWidget on the root of the widget tree.

This method is called after releaseWidget().

See also releaseChild(), releaseWidget() and releaseHandle().

Overrides:

destroyWidget in class Widget

See Also:

Widget.dispose()

getMenu

public Menu getMenu()

Returns the receiver's pop up menu if it has one, or null if it does not.

Overrides:

getMenu in class Widget

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

getOverlayImage

public Image getOverlayImage()

Returns the receiver's overlay image if it has one, or null if it does not.

Returns:

the receiver's overlay 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

getOverlayText

public java.lang.String getOverlayText()

Returns the receiver's overlay text, which will be an empty string if it has never been set.

Returns:

the receiver's overlay 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

getParent

public TaskBar getParent()

Returns the receiver's parent, which must be a TaskBar.

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

getProgress

public int getProgress()

Returns the receiver's progress.

Returns:

the receiver's progress

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

getProgressState

public int getProgressState()

Returns the receiver's progress state.

Returns:

the receiver's progress 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

recreate

void recreate()

releaseHandle

void releaseHandle()

Overrides:

releaseHandle in class Widget

releaseWidget

void releaseWidget()

Overrides:

releaseWidget in class Item

setMenu

public void setMenu(Menu menu)

Sets the receiver's pop up menu to the argument. The way the menu is shown is platform specific.

This feature might not be available for the receiver on all platforms. The application code can check if it is supported by calling the respective get method. When the feature is not available, the get method will always return the NULL.

For better cross platform support, the application code should set this feature on the TaskItem for application.
On Windows, this feature will only work on RCP applications.

The menu should be fully created before this method is called. Dynamic changes to the menu after the method is called will not be reflected in the native menu.

Parameters:

menu - the new pop up menu

Throws:

java.lang.IllegalArgumentException -

• ERROR_MENU_NOT_POP_UP - the menu is not a pop up menu
• ERROR_INVALID_ARGUMENT - if the menu 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

setOverlayImage

public void setOverlayImage(Image overlayImage)

Sets the receiver's overlay image, which may be null indicating that no image should be displayed. The bounds for the overlay image is determined by the platform and in general it should be a small image.

This feature might not be available for the receiver on all platforms. The application code can check if it is supported by calling the respective get method. When the feature is not available, the get method will always return the NULL.

For better cross platform support, the application code should first try to set this feature on the TaskItem for the main shell then on the TaskItem for the application.

Parameters:

overlayImage - the new overlay image (may be null)

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_ARGUMENT - if the overlayImage 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

setOverlayText

public void setOverlayText(java.lang.String overlayText)

Sets the receiver's overlay text. The space available to display the overlay text is platform dependent and in general it should be no longer than a few characters.

This feature might not be available for the receiver on all platforms. The application code can check if it is supported by calling the respective get method. When the feature is not available, the get method will always return an empty string.

For better cross platform support, the application code should first try to set this feature on the TaskItem for the main shell then on the TaskItem for the application.

Parameters:

overlayText - the new overlay text

Throws:

java.lang.IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the overlayText 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

setProgress

public void setProgress(int progress)

Sets the receiver's progress, the progress represents a percentage and should be in range from 0 to 100. The progress is only shown when the progress state is different than SWT#DEFAULT.

This feature might not be available for the receiver on all platforms. The application code can check if it is supported by calling the respective get method. When the feature is not available, the get method will always return zero.

For better cross platform support, the application code should first try to set this feature on the TaskItem for the main shell then on the TaskItem for the application.

Parameters:

progress - the new progress

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 setProgressState(int)

setProgressState

public void setProgressState(int progressState)

Sets the receiver's progress state, the state can be one of the following:

• SWT.DEFAULT
• SWT.NORMAL
• SWT.PAUSED
• SWT.ERROR
• SWT.INDETERMINATE

The percentage of progress shown by the states SWT#NORMAL, SWT#PAUSED, SWT#ERROR is set with setProgress().
The state SWT#DEFAULT indicates that no progress should be shown.

This feature might not be available for the receiver on all platforms. The application code can check if it is supported by calling the respective get method. When the feature is not available, the get method will always return SWT#DEFAULT.

For better cross platform support, the application code should first try to set this feature on the TaskItem for the main shell then on the TaskItem for the application.

Parameters:

progressState - the new progress 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 setProgress(int)

setShell

void setShell(Shell shell)

updateImage

void updateImage()

updateProgress

void updateProgress()

updateProgressState

void updateProgressState()

updateText

void updateText()