java.awt.image.renderable
Class RenderContext

java.lang.Object
  |
  +--java.awt.image.renderable.RenderContext

public class RenderContext

extends Object

implements Cloneable

A RenderContext encapsulates the information needed to produce a specific rendering from a RenderableImage. It contains the area to be rendered specified in rendering-independent terms, the resolution at which the rendering is to be performed, and hints used to control the rendering process.

Users create RenderContexts and pass them to the RenderableImage via the createRendering method. Most of the methods of RenderContexts are not meant to be used directly by applications, but by the RenderableImage and operator classes to which it is passed.

The AffineTransform parameter passed into and out of this class are cloned. The RenderingHints and Shape parameters are not necessarily cloneable and are therefore only reference copied. Altering RenderingHints or Shape instances that are in use by instances of RenderContext may have undesired side effects.

Constructor Summary

RenderContext(AffineTransform usr2dev)
Constructs a RenderContext with a given transform.

RenderContext(AffineTransform usr2dev, RenderingHints hints)
Constructs a RenderContext with a given transform and rendering hints.

RenderContext(AffineTransform usr2dev, Shape aoi)
Constructs a RenderContext with a given transform and area of interest.

RenderContext(AffineTransform usr2dev, Shape aoi, RenderingHints hints)
Constructs a RenderContext with a given transform.

Method Summary

Object	clone() Makes a copy of a RenderContext.
void	concetenateTransform(AffineTransform modTransform) Modifies the current user-to-device transform by appending another transform.
Shape	getAreaOfInterest() Gets the ares of interest currently contained in the RenderContext.
RenderingHints	getRenderingHints() Gets the rendering hints of this RenderContext.
AffineTransform	getTransform() Gets the current user-to-device AffineTransform.
void	preConcetenateTransform(AffineTransform modTransform) Modifies the current user-to-device transform by prepending another transform.
void	setAreaOfInterest(Shape newAoi) Sets the current area of interest.
void	setRenderingHints(RenderingHints hints) Sets the rendering hints of this RenderContext.
void	setTransform(AffineTransform newTransform) Sets the current user-to-device AffineTransform contained in the RenderContext to a given transform.

Methods inherited from class java.lang.Object

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

Constructor Detail

RenderContext

public RenderContext(AffineTransform usr2dev,
                     Shape aoi,
                     RenderingHints hints)

Constructs a RenderContext with a given transform. The area of interest is supplied as a Shape, and the rendering hints are supplied as a RenderingHints object.

Parameters:

usr2dev - an AffineTransform.

aoi - a Shape representing the area of interest.

hints - a RenderingHints object containing rendering hints.

RenderContext

public RenderContext(AffineTransform usr2dev)

Constructs a RenderContext with a given transform. The area of interest is taken to be the entire renderable area. No rendering hints are used.

Parameters:

usr2dev - an AffineTransform.

RenderContext

public RenderContext(AffineTransform usr2dev,
                     RenderingHints hints)

Constructs a RenderContext with a given transform and rendering hints. The area of interest is taken to be the entire renderable area.

Parameters:

usr2dev - an AffineTransform.

hints - a RenderingHints object containing rendering hints.

RenderContext

public RenderContext(AffineTransform usr2dev,
                     Shape aoi)

Constructs a RenderContext with a given transform and area of interest. The area of interest is supplied as a Shape. No rendering hints are used.

Parameters:

usr2dev - an AffineTransform.

aoi - a Shape representing the area of interest.

Method Detail

getRenderingHints

public RenderingHints getRenderingHints()

Gets the rendering hints of this RenderContext.

Returns:

a RenderingHints object that represents the rendering hints of this RenderContext.

setRenderingHints

public void setRenderingHints(RenderingHints hints)

Sets the rendering hints of this RenderContext.

Parameters:

hints - a RenderingHints object that represents the rendering hints to assign to this RenderContext.

setTransform

public void setTransform(AffineTransform newTransform)

Sets the current user-to-device AffineTransform contained in the RenderContext to a given transform.

Parameters:

newTransform - the new AffineTransform.

preConcetenateTransform

public void preConcetenateTransform(AffineTransform modTransform)

Modifies the current user-to-device transform by prepending another transform. In matrix notation the operation is:

 [this] = [modTransform] x [this]
 

Parameters:

modTransform - the AffineTransform to prepend to the current usr2dev transform.

concetenateTransform

public void concetenateTransform(AffineTransform modTransform)

Modifies the current user-to-device transform by appending another transform. In matrix notation the operation is:

 [this] = [this] x [modTransform]
 

Parameters:

modTransform - the AffineTransform to append to the current usr2dev transform.

getTransform

public AffineTransform getTransform()

Gets the current user-to-device AffineTransform.

Returns:

a reference to the current AffineTransform.

setAreaOfInterest

public void setAreaOfInterest(Shape newAoi)

Sets the current area of interest. The old area is discarded.

Parameters:

newAoi - The new area of interest.

getAreaOfInterest

public Shape getAreaOfInterest()

Gets the ares of interest currently contained in the RenderContext.

Returns:

a reference to the area of interest of the RenderContext, or null if none is specified.

clone

public Object clone()

Makes a copy of a RenderContext. The area of interest is copied by reference. The usr2dev AffineTransform and hints are cloned, while the area of interest is copied by reference.

Returns:

the new cloned RenderContext.

Overrides:

clone in class Object