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.
*/
public class RenderContext implements Cloneable {
/** Table of hints. May be null. */
RenderingHints hints;
/** Transform to convert user coordinates to device coordinates. */
AffineTransform usr2dev;
/** The area of interest. May be null. */
Shape aoi;
// Various constructors that allow different levels of
// specificity. If the Shape is missing the whole renderable area
// is assumed. If hints is missing no hints are assumed.
/**
* 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.
*
* @param usr2dev an AffineTransform.
* @param aoi a Shape representing the area of interest.
* @param hints a RenderingHints object containing rendering hints.
*/
public RenderContext(AffineTransform usr2dev,
Shape aoi,
RenderingHints hints) {
this.hints = hints;
this.aoi = aoi;
this.usr2dev = (AffineTransform)usr2dev.clone();
}
/**
* Constructs a RenderContext with a given transform.
* The area of interest is taken to be the entire renderable area.
* No rendering hints are used.
*
* @param usr2dev an AffineTransform.
*/
public RenderContext(AffineTransform usr2dev) {
this(usr2dev, null, null);
}
/**
* Constructs a RenderContext with a given transform and rendering hints.
* The area of interest is taken to be the entire renderable area.
*
* @param usr2dev an AffineTransform.
* @param hints a RenderingHints object containing rendering hints.
*/
public RenderContext(AffineTransform usr2dev, RenderingHints hints) {
this(usr2dev, null, hints);
}
/**
* 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.
*
* @param usr2dev an AffineTransform.
* @param aoi a Shape representing the area of interest.
*/
public RenderContext(AffineTransform usr2dev, Shape aoi) {
this(usr2dev, aoi, null);
}
/**
* Gets the rendering hints of this RenderContext.
* @return a RenderingHints object that represents
* the rendering hints of this RenderContext.
* @see #setRenderingHints(RenderingHints)
*/
public RenderingHints getRenderingHints() {
return hints;
}
/**
* Sets the rendering hints of this RenderContext.
* @param hints a RenderingHints object that represents
* the rendering hints to assign to this RenderContext.
* @see #getRenderingHints
*/
public void setRenderingHints(RenderingHints hints) {
this.hints = hints;
}
/**
* Sets the current user-to-device AffineTransform contained
* in the RenderContext to a given transform.
*
* @param newTransform the new AffineTransform.
* @see #getTransform
*/
public void setTransform(AffineTransform newTransform) {
usr2dev = (AffineTransform)newTransform.clone();
}
/**
* Modifies the current user-to-device transform by prepending another
* transform. In matrix notation the operation is:
*
* [this] = [modTransform] x [this]
*
*
* @param modTransform the AffineTransform to prepend to the
* current usr2dev transform.
* @since 1.3
*/
public void preConcatenateTransform(AffineTransform modTransform) {
this.preConcetenateTransform(modTransform);
}
/**
* 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.
*
* @param modTransform the AffineTransform to prepend to the
* current usr2dev transform.
* @deprecated replaced by
* preConcatenateTransform(AffineTransform).
*/
@Deprecated
public void preConcetenateTransform(AffineTransform modTransform) {
usr2dev.preConcatenate(modTransform);
}
/**
* Modifies the current user-to-device transform by appending another
* transform. In matrix notation the operation is:
*
* [this] = [this] x [modTransform]
*
*
* @param modTransform the AffineTransform to append to the
* current usr2dev transform.
* @since 1.3
*/
public void concatenateTransform(AffineTransform modTransform) {
this.concetenateTransform(modTransform);
}
/**
* 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.
*
* @param modTransform the AffineTransform to append to the
* current usr2dev transform.
* @deprecated replaced by
* concatenateTransform(AffineTransform).
*/
@Deprecated
public void concetenateTransform(AffineTransform modTransform) {
usr2dev.concatenate(modTransform);
}
/**
* Gets the current user-to-device AffineTransform.
*
* @return a reference to the current AffineTransform.
* @see #setTransform(AffineTransform)
*/
public AffineTransform getTransform() {
return (AffineTransform)usr2dev.clone();
}
/**
* Sets the current area of interest. The old area is discarded.
*
* @param newAoi The new area of interest.
* @see #getAreaOfInterest
*/
public void setAreaOfInterest(Shape newAoi) {
aoi = newAoi;
}
/**
* Gets the ares of interest currently contained in the
* RenderContext.
*
* @return a reference to the area of interest of the RenderContext,
* or null if none is specified.
* @see #setAreaOfInterest(Shape)
*/
public Shape getAreaOfInterest() {
return aoi;
}
/**
* 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.
*
* @return the new cloned RenderContext.
*/
public Object clone() {
RenderContext newRenderContext = new RenderContext(usr2dev,
aoi, hints);
return newRenderContext;
}
}