Eclipse Platform
Release 4.2

org.eclipse.swt.widgets
Class Group

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.Group
All Implemented Interfaces:
Drawable

public class Group
extends Composite

Instances of this class provide an etched border with an optional title.

Shadow styles are hints and may not be honoured by the platform. To create a group with the default shadow style for the platform, do not specify a shadow style.

Styles:
SHADOW_ETCHED_IN, SHADOW_ETCHED_OUT, SHADOW_IN, SHADOW_OUT, SHADOW_NONE
Events:
(none)

Note: Only one of the above styles may be specified.

IMPORTANT: This class is not intended to be subclassed.

See Also:
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
Group(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
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.
 Rectangle computeTrim(int x, int y, int width, int height)
          Given a desired client area for the receiver (as described by the arguments), returns the bounding rectangle which would be required to produce that client area.
 Rectangle getClientArea()
          Returns a rectangle which describes the area of the receiver which is capable of displaying data (that is, not covered by the "trimmings").
 String getText()
          Returns the receiver's text, which is the string that the is used as the title.
 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 setText(String string)
          Sets the receiver's text, which is the string that will be displayed as the receiver's title, to the argument, which may not be null.
 
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
getHorizontalBar, getScrollbarsMode, 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

Group

public Group(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.SHADOW_ETCHED_IN, SWT.SHADOW_ETCHED_OUT, SWT.SHADOW_IN, SWT.SHADOW_OUT, SWT.SHADOW_NONE, 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 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"

computeTrim

public Rectangle computeTrim(int x,
                             int y,
                             int width,
                             int height)
Description copied from class: Scrollable
Given a desired client area for the receiver (as described by the arguments), returns the bounding rectangle which would be required to produce that client area.

In other words, it returns a rectangle such that, if the receiver's bounds were set to that rectangle, the area of the receiver which is capable of displaying data (that is, not covered by the "trimmings") would be the rectangle described by the arguments (relative to the receiver's parent).

Overrides:
computeTrim in class Scrollable
Parameters:
x - the desired x coordinate of the client area
y - the desired y coordinate of the client area
width - the desired width of the client area
height - the desired height of the client area
Returns:
the required bounds to produce the given client area
See Also:
Scrollable.getClientArea()

getClientArea

public Rectangle getClientArea()
Description copied from class: Scrollable
Returns a rectangle which describes the area of the receiver which is capable of displaying data (that is, not covered by the "trimmings").

Overrides:
getClientArea in class Scrollable
Returns:
the client area
See Also:
Scrollable.computeTrim(int, int, int, int)

getText

public String getText()
Returns the receiver's text, which is the string that the is used as the title. If the text has not previously been set, returns an empty string.

Returns:
the 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

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)

setText

public void setText(String string)
Sets the receiver's text, which is the string that will be displayed as the receiver's title, to the argument, which may not be null. The string may include the mnemonic character.

Mnemonics are indicated by an '&' that causes the next character to be the mnemonic. When the user presses a key sequence that matches the mnemonic, focus is assigned to the first child of the group. On most platforms, the mnemonic appears underlined but may be emphasised in a platform specific manner. The mnemonic indicator character '&' can be escaped by doubling it in the string, causing a single '&' to be displayed.

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

Eclipse Platform
Release 4.2

Guidelines for using Eclipse APIs.

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