javax.swing.border

Class AbstractBorder

public abstract class AbstractBorder extends Object implements Border, Serializable

An invisible zero-width border, serving as a base class for implementing more interesting borders.

Constructor Summary
	AbstractBorder() Constructs a new AbstractBorder.

Method Summary
Insets	getBorderInsets(Component c) Returns the insets required for drawing this border around the specified component.
Insets	getBorderInsets(Component c, Insets insets) Returns the insets required for drawing this border around the specified component.
Rectangle	getInteriorRectangle(Component c, int x, int y, int width, int height) Returns a rectangle that covers the specified area minus the insets required to draw this border.
static Rectangle	getInteriorRectangle(Component c, Border b, int x, int y, int width, int height) Returns a rectangle that covers the specified area minus the insets required to draw the specified border (if the border is `null`, zero insets are assumed).
boolean	isBorderOpaque() Determines whether or not this border is opaque.
void	paintBorder(Component c, Graphics g, int x, int y, int width, int height) Performs nothing, because the default implementation provided by this class is an invisible, zero-width border.

Constructor Detail

AbstractBorder

public AbstractBorder()

Constructs a new AbstractBorder.

Method Detail

getBorderInsets

public Insets getBorderInsets(Component c)

Returns the insets required for drawing this border around the specified component.

Parameters: c the component that the border applies to (ignored here, subclasses may use it).

Returns: an Insets object whose left, right, top and bottom fields indicate the width of the border at the respective edge, which is zero for the default implementation provided by AbstractButton.

getBorderInsets

public Insets getBorderInsets(Component c, Insets insets)

Returns the insets required for drawing this border around the specified component. The default implementation provided here sets the left, right, top and bottom fields of the passed insets parameter to zero.

Parameters: c the component that the border applies to (ignored here, subclasses may use it). insets an instance that will be overwritten and returned as the result (null not permitted).

Returns: The border insets (the same object that was passed as the insets argument).

Throws: NullPointerException if insets is null.

getInteriorRectangle

public Rectangle getInteriorRectangle(Component c, int x, int y, int width, int height)

Returns a rectangle that covers the specified area minus the insets required to draw this border. Components that wish to determine an area into which they can safely draw without intersecting with a border might want to use this helper method.

Parameters: c the component in the center of this border. x the horizontal position of the border. y the vertical position of the border. width the width of the available area for the border. height the height of the available area for the border.

Returns: The interior rectangle.

getInteriorRectangle

public static Rectangle getInteriorRectangle(Component c, Border b, int x, int y, int width, int height)

Returns a rectangle that covers the specified area minus the insets required to draw the specified border (if the border is null, zero insets are assumed). Components that wish to determine an area into which they can safely draw without intersecting with a border might want to use this helper method.

Parameters: c the component in the center of this border. b the border (null permitted). x the horizontal position of the border. y the vertical position of the border. width the width of the available area for the border. height the height of the available area for the border.

Returns: The interior rectangle.

isBorderOpaque

public boolean isBorderOpaque()

Determines whether or not this border is opaque. An opaque border fills every pixel in its area when painting. Partially translucent borders must return false, or ugly artifacts can appear on screen. The default implementation provided here always returns false.

Returns: false.

paintBorder

public void paintBorder(Component c, Graphics g, int x, int y, int width, int height)

Performs nothing, because the default implementation provided by this class is an invisible, zero-width border. Subclasses will likely want to override this method, but they are not required to do so.

Parameters: c the component whose border is to be painted. g the graphics for painting. x the horizontal position for painting the border. y the vertical position for painting the border. width the width of the available area for painting the border. height the height of the available area for painting the border.