Package org.eclipse.swt.widgets

Class ExpandBar

java.lang.Object

org.eclipse.swt.widgets.Widget

org.eclipse.swt.widgets.Control

org.eclipse.swt.widgets.Scrollable

org.eclipse.swt.widgets.Composite

org.eclipse.swt.widgets.ExpandBar

All Implemented Interfaces:

Adaptable, Drawable

public class ExpandBar
extends Composite

Instances of this class support the layout of selectable expand bar items.

The item children that may be added to instances of this class must be of type ExpandItem.

Styles:

V_SCROLL

Events:

Expand, Collapse

IMPORTANT: This class is not intended to be subclassed.

Since:

1.2

See Also:

• ExpandItem
• ExpandEvent
• ExpandListener
• ExpandAdapter

Constructor Summary

Constructors

Constructor	Description
ExpandBar(Composite parent, int style)	Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

Method Summary

Modifier and Type	Method	Description
void	addExpandListener(ExpandListener listener)	Adds the listener to the collection of listeners who will be notified when an item in the receiver is expanded or collapsed by sending it one of the messages defined in the ExpandListener interface.
protected void	checkSubclass()	Checks that this class can be subclassed.
Point	computeSize(int wHint, int hHint, boolean changed)	Returns the preferred size of the receiver.
<T> T	getAdapter(Class<T> adapter)	Implementation of the Adaptable interface.
ExpandItem	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.
ExpandItem[]	getItems()	Returns an array of ExpandItems which are the items in the receiver.
int	getSpacing()	Returns the receiver's spacing.
int	indexOf(ExpandItem 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.
void	removeExpandListener(ExpandListener listener)	Removes the listener from the collection of listeners who will be notified when items in the receiver are expanded or collapsed.
void	setData(String key, Object value)	Sets the application defined property of the receiver with the specified name to the given value.
void	setOrientation(int orientation)	Sets the orientation of the receiver, which must be one of the constants SWT.LEFT_TO_RIGHT or SWT.RIGHT_TO_LEFT.
void	setSpacing(int spacing)	Sets the receiver's spacing.

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

changed, getBackgroundMode, getChildren, getLayout, getLayoutDeferred, getTabList, isLayoutDeferred, layout, layout, layout, layout, layout, setBackgroundMode, setFocus, setLayout, setLayoutDeferred, setTabList

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

computeTrim, getClientArea, getHorizontalBar, getVerticalBar

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

addControlListener, addDragDetectListener, addFocusListener, addGestureListener, addHelpListener, addKeyListener, addMenuDetectListener, addMouseListener, addTouchListener, addTraverseListener, computeSize, forceFocus, getAccessible, getBackground, getBackgroundImage, getBorderWidth, getBounds, getCursor, getEnabled, getFont, getForeground, getLayoutData, getLocation, getMenu, getMonitor, getOrientation, getParent, getShell, getSize, getToolTipText, getTouchEnabled, getVisible, isEnabled, isFocusControl, isReparentable, isVisible, moveAbove, moveBelow, pack, pack, redraw, redraw, removeControlListener, removeDragDetectListener, removeFocusListener, removeGestureListener, removeHelpListener, removeKeyListener, removeMenuDetectListener, removeMouseListener, removeTouchListener, removeTraverseListener, requestLayout, setBackground, setBackgroundImage, setBounds, setBounds, setCursor, setEnabled, setFont, setForeground, setLayoutData, setLocation, setLocation, setMenu, setParent, setRedraw, setSize, setSize, setToolTipText, setTouchEnabled, setVisible, toControl, toControl, toDisplay, toDisplay, update

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

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

Methods inherited from class java.lang.Object

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

Constructor Details

ExpandBar

public ExpandBar(Composite parent,
 int style)

Constructs a new instance of this class given its parent 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.

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:

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:

• Widget.checkSubclass()
• Widget.getStyle()

Method Details

addExpandListener

public void addExpandListener(ExpandListener listener)

Adds the listener to the collection of listeners who will be notified when an item in the receiver is expanded or collapsed by sending it one of the messages defined in the ExpandListener 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:

• ExpandListener
• removeExpandListener(org.eclipse.swt.events.ExpandListener)

removeExpandListener

public void removeExpandListener(ExpandListener listener)

Removes the listener from the collection of listeners who will be notified when items in the receiver are expanded or collapsed.

Parameters:

listener - the listener which should no longer 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:

• ExpandListener
• addExpandListener(org.eclipse.swt.events.ExpandListener)

computeSize

public Point computeSize(int wHint,
 int hHint,
 boolean changed)

Description copied from class: Control

Returns the preferred size of the receiver.

The preferred size of a control is the size that it would best be displayed at. The width hint and height hint arguments allow the caller to ask a control questions such as "Given a particular width, how high does the control need to be to show all of the contents?" To indicate that the caller does not wish to constrain a particular dimension, the constant SWT.DEFAULT is passed for the hint.

If the changed flag is true, it indicates that the receiver's contents have changed, therefore any caches that a layout manager containing the control may have been keeping need to be flushed. When the control is resized, the changed flag will be false, so layout manager caches can be retained.

Overrides:

computeSize in class Composite

Parameters:

wHint - the width hint (can be SWT.DEFAULT)

hHint - the height hint (can be SWT.DEFAULT)

changed - true if the control's contents have changed, and false otherwise

Returns:

the preferred size of the control.

See Also:

• Layout
• Control.getBorderWidth()
• Control.getBounds()
• Control.getSize()
• Control.pack(boolean)
• "computeTrim, getClientArea for controls that implement them"

getItem

public ExpandItem 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.

Parameters:

index - the index of the item to return

Returns:

the item at the given index

Throws:

IllegalArgumentException -

• ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)

SWTException -

• 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.

Returns:

the number of items

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

getItems

public ExpandItem[] getItems()

Returns an array of ExpandItems 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.

Returns:

the items in 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

getSpacing

public int getSpacing()

Returns the receiver's spacing.

Returns:

the spacing

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

indexOf

public int indexOf(ExpandItem 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.

Parameters:

item - the search item

Returns:

the index of the item

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the item is null
• ERROR_INVALID_ARGUMENT - if the item 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

setSpacing

public void setSpacing(int spacing)

Sets the receiver's spacing. Spacing specifies the number of pixels allocated around each item.

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

setOrientation

public void setOrientation(int orientation)

Description copied from class: Control

Sets the orientation of the receiver, which must be one of the constants SWT.LEFT_TO_RIGHT or SWT.RIGHT_TO_LEFT.

Overrides:

setOrientation in class Control

Parameters:

orientation - new orientation style

setData

public void setData(String key,
 Object value)

Description copied from class: Widget

Sets the application defined property of the receiver with the specified name to the given value.

Applications may associate arbitrary objects with the receiver in this fashion. If the objects stored in the properties need to be notified when the widget is disposed of, it is the application's responsibility to hook the Dispose event on the widget and do so.

Overrides:

setData in class Control

Parameters:

key - the name of the property

value - the new value for the property

See Also:

• Widget.getData(String)

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 Widget

getAdapter

public <T> T getAdapter(Class<T> adapter)

Description copied from class: Widget

Implementation of the Adaptable 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 interface Adaptable

Overrides:

getAdapter in class Composite

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.