Eclipse Platform
Release 3.7

org.eclipse.swt.widgets
Class ExpandBar

java.lang.Object
  extended by org.eclipse.swt.widgets.Widget
      extended by org.eclipse.swt.widgets.Control
          extended by org.eclipse.swt.widgets.Scrollable
              extended by org.eclipse.swt.widgets.Composite
                  extended by org.eclipse.swt.widgets.ExpandBar
All Implemented Interfaces:
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:
3.2
See Also:
ExpandItem, ExpandEvent, ExpandListener, ExpandAdapter, ExpandBar snippets, SWT Example: ControlExample, Sample code and further information
Restriction:
This class is not intended to be subclassed by clients.

Field Summary
 
Fields inherited from class org.eclipse.swt.widgets.Control
handle
 
Constructor Summary
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
 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.
 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 setFont(Font font)
          Sets the font that the receiver will use to paint textual information to the font specified by the argument, or to the default font for that kind of control if the argument is null.
 void setSpacing(int spacing)
          Sets the receiver's spacing.
 
Methods inherited from class org.eclipse.swt.widgets.Composite
changed, drawBackground, 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, addMouseMoveListener, addMouseTrackListener, addMouseWheelListener, addPaintListener, addTouchListener, addTraverseListener, computeSize, dragDetect, dragDetect, forceFocus, getAccessible, getBackground, getBackgroundImage, getBorderWidth, getBounds, getCursor, getDragDetect, getEnabled, getFont, getForeground, getLayoutData, getLocation, getMenu, getMonitor, getOrientation, getParent, getRegion, getShell, getSize, getToolTipText, getTouchEnabled, getVisible, internal_dispose_GC, internal_new_GC, isEnabled, isFocusControl, isReparentable, isVisible, moveAbove, moveBelow, pack, pack, print, redraw, redraw, removeControlListener, removeDragDetectListener, removeFocusListener, removeGestureListener, removeHelpListener, removeKeyListener, removeMenuDetectListener, removeMouseListener, removeMouseMoveListener, removeMouseTrackListener, removeMouseWheelListener, removePaintListener, removeTouchListener, removeTraverseListener, setBackground, setBackgroundImage, setBounds, setBounds, setCapture, setCursor, setDragDetect, setEnabled, setForeground, setLayoutData, setLocation, setLocation, setMenu, setOrientation, setParent, setRedraw, setRegion, setSize, setSize, setToolTipText, setTouchEnabled, setVisible, toControl, toControl, toDisplay, toDisplay, traverse, traverse, traverse, 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, setData, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

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:
SWT.V_SCROLL, Widget.checkSubclass(), Widget.getStyle()
Method Detail

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)

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 Composite

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

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)

setFont

public void setFont(Font font)
Description copied from class: Control
Sets the font that the receiver will use to paint textual information to the font specified by the argument, or to the default font for that kind of control if the argument is null.

Overrides:
setFont in class Control
Parameters:
font - the new font (or null)

setSpacing

public void setSpacing(int spacing)
Sets the receiver's spacing. Spacing specifies the number of pixels allocated around each item.

Parameters:
spacing - the spacing 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

Eclipse Platform
Release 3.7

Guidelines for using Eclipse APIs.

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