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Java(TM) 2 Platform, Standard Edition, v1.2.2 API Specification: Class Box - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

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javax.swing
Class Box

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--javax.swing.Box
public class Box
extends Container
implements Accessible

A lightweight container that uses a BoxLayout object as its layout manager. Box provides several class methods that are useful for containers using BoxLayout -- even non-Box containers.

The Box class can create several kinds of invisible components that affect layout: glue, struts, and rigid areas. If all the components your Box contains have a fixed size, you might want to use a glue component (returned by createGlue) to control the components' positions. If you need a fixed amount of space between two components, try using a strut (createHorizontalStrut or createVerticalStrut). If you need an invisible component that always takes up the same amount of space, get it by invoking createRigidArea.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. A future release of Swing will provide support for long term persistence.

See Also:
BoxLayout, Serialized Form

Inner Class Summary
protected  class Box.AccessibleBox
           
static class Box.Filler
          An implementation of a lightweight component that participates in layout but has no view.
 
Field Summary
protected  AccessibleContext accessibleContext
          The currently set AccessibleContext object.
 
Fields inherited from class java.awt.Component
BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
 
Constructor Summary
Box(int axis)
          Creates a Box that displays its components along the the specified axis.
 
Method Summary
static Component createGlue()
          Creates an invisible "glue" component that can be useful in a Box whose visible components have a maximum width (for a horizontal box) or height (for a vertical box).
static Box createHorizontalBox()
          Creates a Box that displays its components from left to right.
static Component createHorizontalGlue()
          Creates a horizontal glue component.
static Component createHorizontalStrut(int width)
          Creates an invisible, fixed-width component.
static Component createRigidArea(Dimension d)
          Creates an invisible component that's always the specified size.
static Box createVerticalBox()
          Creates a Box that displays its components from top to bottom.
static Component createVerticalGlue()
          Creates a vertical glue component.
static Component createVerticalStrut(int height)
          Creates an invisible, fixed-height component.
 AccessibleContext getAccessibleContext()
          Get the AccessibleContext associated with this JComponent.
 void setLayout(LayoutManager l)
          Throws an AWTError, since a Box can use only a BoxLayout.
 
Methods inherited from class java.awt.Container
add, add, add, add, add, addContainerListener, addImpl, addNotify, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getInsets, getLayout, getMaximumSize, getMinimumSize, getPreferredSize, insets, invalidate, isAncestorOf, layout, list, list, locate, minimumSize, paint, paintComponents, paramString, preferredSize, print, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setCursor, setFont, update, validate, validateTree
 
Methods inherited from class java.awt.Component
action, add, addComponentListener, addFocusListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addPropertyChangeListener, addPropertyChangeListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, getBackground, getBounds, getBounds, getColorModel, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getGraphics, getHeight, getInputContext, getInputMethodRequests, getLocale, getLocation, getLocation, getLocationOnScreen, getName, getParent, getPeer, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isDisplayable, isDoubleBuffered, isEnabled, isFocusTraversable, isLightweight, isOpaque, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, remove, removeComponentListener, removeFocusListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setDropTarget, setEnabled, setForeground, setLocale, setLocation, setLocation, setName, setSize, setSize, setVisible, show, show, size, toString, transferFocus
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

accessibleContext

protected AccessibleContext accessibleContext
The currently set AccessibleContext object.
Constructor Detail

Box

public Box(int axis)
Creates a Box that displays its components along the the specified axis.
Parameters:
axis - can be either BoxLayout.X_AXIS (to display components from left to right) or BoxLayout.Y_AXIS (to display them from top to bottom)
See Also:
createHorizontalBox(), createVerticalBox()
Method Detail

createHorizontalBox

public static Box createHorizontalBox()
Creates a Box that displays its components from left to right.
Returns:
the box

createVerticalBox

public static Box createVerticalBox()
Creates a Box that displays its components from top to bottom.
Returns:
the box

createRigidArea

public static Component createRigidArea(Dimension d)
Creates an invisible component that's always the specified size.
Parameters:
d - the dimensions of the invisible component
Returns:
the component
See Also:
createGlue(), createHorizontalStrut(int), createVerticalStrut(int)

createHorizontalStrut

public static Component createHorizontalStrut(int width)
Creates an invisible, fixed-width component. In a horizontal box, you typically use this method to force a certain amount of space between two components. In a vertical box, you might use this method to force the box to be at least the specified width. The invisible component has no height unless excess space is available, in which case it takes its share of available space, just like any other component that has no maximum height.
Parameters:
width - the width of the invisible component, in pixels >= 0
Returns:
the component
See Also:
createVerticalStrut(int), createGlue(), createRigidArea(java.awt.Dimension)

createVerticalStrut

public static Component createVerticalStrut(int height)
Creates an invisible, fixed-height component. In a vertical box, you typically use this method to force a certain amount of space between two components. In a horizontal box, you might use this method to force the box to be at least the specified height. The invisible component has no width unless excess space is available, in which case it takes its share of available space, just like any other component that has no maximum width.
Parameters:
height - the height of the invisible component, in pixels >= 0
Returns:
the component
See Also:
createHorizontalStrut(int), createGlue(), createRigidArea(java.awt.Dimension)

createGlue

public static Component createGlue()
Creates an invisible "glue" component that can be useful in a Box whose visible components have a maximum width (for a horizontal box) or height (for a vertical box). You can think of the glue component as being a gooey substance that expands as much as necessary to fill the space between its neighboring components.

For example, suppose you have a horizontal box that contains two fixed-size components. If the box gets extra space, the fixed-size components won't become larger, so where does the extra space go? Without glue, the extra space goes to the right of the second component. If you put glue between the fixed-size components, then the extra space goes there. If you put glue before the first fixed-size component, the extra space goes there, and the fixed-size components are shoved against the right edge of the box. If you put glue before the first fixed-size component and after the second fixed-size component, the fixed-size components are centered in the box.

To use glue, call Box.createGlue and add the returned component to a container. The glue component has no minimum or preferred size, so it takes no space unless excess space is available. If excess space is available, then the glue component takes its share of available horizontal or vertical space, just like any other component that has no maximum width or height.

Returns:
the component

createHorizontalGlue

public static Component createHorizontalGlue()
Creates a horizontal glue component.
Returns:
the component

createVerticalGlue

public static Component createVerticalGlue()
Creates a vertical glue component.
Returns:
the component

setLayout

public void setLayout(LayoutManager l)
Throws an AWTError, since a Box can use only a BoxLayout.
Overrides:
setLayout in class Container
Parameters:
l - the layout manager to use

getAccessibleContext

public AccessibleContext getAccessibleContext()
Get the AccessibleContext associated with this JComponent. Creates a new context if necessary.
Specified by:
getAccessibleContext in interface Accessible
Returns:
the AccessibleContext of this JComponent
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