java.awt.image.renderable
Class RenderContext

java.lang.Object
  java.awt.image.renderable.RenderContext

All Implemented Interfaces:

Cloneable

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.

Field Summary

(package private) Shape	aoi The area of interest.
(package private) RenderingHints	hints Table of hints.
(package private) AffineTransform	usr2dev Transform to convert user coordinates to device coordinates.

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	concatenateTransform(AffineTransform modTransform) Modifies the current user-to-device transform by appending another transform.
void	concetenateTransform(AffineTransform modTransform) Deprecated. replaced by concatenateTransform(AffineTransform).
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	preConcatenateTransform(AffineTransform modTransform) Modifies the current user-to-device transform by prepending another transform.
void	preConcetenateTransform(AffineTransform modTransform) Deprecated. replaced by preConcatenateTransform(AffineTransform).
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

Field Detail

hints

RenderingHints hints

Table of hints. May be null.

usr2dev

AffineTransform usr2dev

Transform to convert user coordinates to device coordinates.

aoi

Shape aoi

The area of interest. May be null.

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.

See Also:

setRenderingHints(RenderingHints)

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.

See Also:

getRenderingHints()

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.

See Also:

getTransform()

preConcatenateTransform

public void preConcatenateTransform(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.

preConcetenateTransform

public void preConcetenateTransform(AffineTransform modTransform)

Deprecated. replaced by preConcatenateTransform(AffineTransform).

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

 [this] = [modTransform] x [this]
 

This method does the same thing as the preConcatenateTransform method. It is here for backward compatibility with previous releases which misspelled the method name.

Parameters:

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

concatenateTransform

public void concatenateTransform(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.

concetenateTransform

public void concetenateTransform(AffineTransform modTransform)

Deprecated. replaced by concatenateTransform(AffineTransform).

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

 [this] = [this] x [modTransform]
 

This method does the same thing as the concatenateTransform method. It is here for backward compatibility with previous releases which misspelled the method name.

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.

See Also:

setTransform(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.

See Also:

getAreaOfInterest()

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.

See Also:

setAreaOfInterest(Shape)

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.

Overrides:

clone in class Object

Returns:

the new cloned RenderContext.

See Also:

Cloneable