1. /*

  2.  * @(#)RenderContext.java	1.11 00/02/02

  3.  *

  4.  * Copyright 1998-2000 Sun Microsystems, Inc. All Rights Reserved.

  5.  * 

  6.  * This software is the proprietary information of Sun Microsystems, Inc.  

  7.  * Use is subject to license terms.

  8.  * 

  9.  */

  10. 

  11. /* ********************************************************************

  12.  **********************************************************************

  13.  **********************************************************************

  14.  *** COPYRIGHT (c) Eastman Kodak Company, 1997                      ***

  15.  *** As  an unpublished  work pursuant to Title 17 of the United    ***

  16.  *** States Code.  All rights reserved.                             ***

  17.  **********************************************************************

  18.  **********************************************************************

  19.  **********************************************************************/

  20. 

  21. package java.awt.image.renderable;

  22. import java.util.*;

  23. import java.awt.geom.*;

  24. import java.awt.*;

  25. import java.awt.image.*;

  26. 

  27. /**

  28.  * A RenderContext encapsulates the information needed to produce a

  29.  * specific rendering from a RenderableImage.  It contains the area to

  30.  * be rendered specified in rendering-independent terms, the

  31.  * resolution at which the rendering is to be performed, and hints

  32.  * used to control the rendering process.

  33.  * 

  34.  * <p> Users create RenderContexts and pass them to the

  35.  * RenderableImage via the createRendering method.  Most of the methods of

  36.  * RenderContexts are not meant to be used directly by applications,

  37.  * but by the RenderableImage and operator classes to which it is

  38.  * passed.

  39.  *

  40.  * <p> The AffineTransform parameter passed into and out of this class

  41.  * are cloned.  The RenderingHints and Shape parameters are not

  42.  * necessarily cloneable and are therefore only reference copied.

  43.  * Altering RenderingHints or Shape instances that are in use by

  44.  * instances of RenderContext may have undesired side effects.

  45.  */

  46. public class RenderContext implements Cloneable {

  47.     

  48.     /** Table of hints. May be null. */

  49.     RenderingHints hints;

  50.     

  51.     /** Transform to convert user coordinates to device coordinates.  */

  52.     AffineTransform usr2dev;

  53.     

  54.     /** The area of interest.  May be null. */

  55.     Shape aoi;

  56.     

  57.     // Various constructors that allow different levels of

  58.     // specificity. If the Shape is missing the whole renderable area

  59.     // is assumed. If hints is missing no hints are assumed.  

  60. 

  61.     /**

  62.      * Constructs a RenderContext with a given transform.

  63.      * The area of interest is supplied as a Shape,

  64.      * and the rendering hints are supplied as a RenderingHints object.

  65.      *

  66.      * @param usr2dev an AffineTransform.

  67.      * @param aoi a Shape representing the area of interest.

  68.      * @param hints a RenderingHints object containing rendering hints.

  69.      */

  70.     public RenderContext(AffineTransform usr2dev,

  71.                          Shape aoi,

  72.                          RenderingHints hints) {

  73.         this.hints = hints;

  74.         this.aoi = aoi;

  75.         this.usr2dev = (AffineTransform)usr2dev.clone();

  76.     }

  77.     

  78.     /**

  79.      * Constructs a RenderContext with a given transform.

  80.      * The area of interest is taken to be the entire renderable area.

  81.      * No rendering hints are used.

  82.      *

  83.      * @param usr2dev an AffineTransform.

  84.      */

  85.     public RenderContext(AffineTransform usr2dev) {

  86.         this(usr2dev, null, null);

  87.     }

  88.     

  89.     /**

  90.      * Constructs a RenderContext with a given transform and rendering hints.

  91.      * The area of interest is taken to be the entire renderable area.

  92.      *

  93.      * @param usr2dev an AffineTransform.

  94.      * @param hints a RenderingHints object containing rendering hints.

  95.      */

  96.     public RenderContext(AffineTransform usr2dev, RenderingHints hints) {

  97.         this(usr2dev, null, hints);

  98.     }

  99.     

  100.     /**

  101.      * Constructs a RenderContext with a given transform and area of interest.

  102.      * The area of interest is supplied as a Shape.

  103.      * No rendering hints are used.

  104.      *

  105.      * @param usr2dev an AffineTransform.

  106.      * @param aoi a Shape representing the area of interest.

  107.      */

  108.     public RenderContext(AffineTransform usr2dev, Shape aoi) {

  109.         this(usr2dev, aoi, null);

  110.     }

  111. 

  112.     /**

  113.      * Gets the rendering hints of this <code>RenderContext</code>.

  114.      * @return a <code>RenderingHints</code> object that represents

  115.      * the rendering hints of this <code>RenderContext</code>.

  116.      */

  117.     public RenderingHints getRenderingHints() {

  118.         return hints;

  119.     }

  120. 

  121.     /**

  122.      * Sets the rendering hints of this <code>RenderContext</code>.

  123.      * @param hints a <code>RenderingHints</code> object that represents

  124.      * the rendering hints to assign to this <code>RenderContext</code>.

  125.      */

  126.     public void setRenderingHints(RenderingHints hints) {

  127.         this.hints = hints;

  128.     }

  129.     

  130.     /**

  131.      * Sets the current user-to-device AffineTransform contained

  132.      * in the RenderContext to a given transform.

  133.      *

  134.      * @param newTransform the new AffineTransform.

  135.      */

  136.     public void setTransform(AffineTransform newTransform) {

  137.         usr2dev = (AffineTransform)newTransform.clone();

  138.     }

  139.         

  140.     /**

  141.      * Modifies the current user-to-device transform by prepending another

  142.      * transform.  In matrix notation the operation is:

  143.      * <pre>

  144.      * [this] = [modTransform] x [this]

  145.      * </pre>

  146.      *

  147.      * @param modTransform the AffineTransform to prepend to the

  148.      *        current usr2dev transform.

  149.      */

  150.     public void preConcatenateTransform(AffineTransform modTransform) {

  151.         this.preConcetenateTransform(modTransform);                

  152.     }

  153.     

  154.     /**

  155.      * Modifies the current user-to-device transform by prepending another

  156.      * transform.  In matrix notation the operation is:

  157.      * <pre>

  158.      * [this] = [modTransform] x [this]

  159.      * </pre>

  160.      * This method does the same thing as the preConcatenateTransform

  161.      * method.  It is here for backward compatibility with previous releases

  162.      * which misspelled the method name.

  163.      *

  164.      * @param modTransform the AffineTransform to prepend to the

  165.      *        current usr2dev transform.

  166.      * @deprecated     replaced by

  167.      *                 <code>preConcatenateTransform(AffineTransform)</code>.

  168.      */

  169.     public void preConcetenateTransform(AffineTransform modTransform) {

  170.         usr2dev.preConcatenate(modTransform);                

  171.     }

  172. 

  173.     /**

  174.      * Modifies the current user-to-device transform by appending another

  175.      * transform.  In matrix notation the operation is:

  176.      * <pre>

  177.      * [this] = [this] x [modTransform]

  178.      * </pre>

  179.      *

  180.      * @param modTransform the AffineTransform to append to the

  181.      *        current usr2dev transform.

  182.      */

  183.     public void concatenateTransform(AffineTransform modTransform) {

  184.         this.concetenateTransform(modTransform);                

  185.     }

  186.     

  187.     /**

  188.      * Modifies the current user-to-device transform by appending another

  189.      * transform.  In matrix notation the operation is:

  190.      * <pre>

  191.      * [this] = [this] x [modTransform]

  192.      * </pre>

  193.      * This method does the same thing as the concatenateTransform

  194.      * method.  It is here for backward compatibility with previous releases

  195.      * which misspelled the method name.

  196.      *

  197.      * @param modTransform the AffineTransform to append to the

  198.      *        current usr2dev transform.

  199.      * @deprecated     replaced by

  200.      *                 <code>concatenateTransform(AffineTransform)</code>.

  201.      */

  202.     public void concetenateTransform(AffineTransform modTransform) {

  203.         usr2dev.concatenate(modTransform);                

  204.     }

  205.     

  206.     /**

  207.      * Gets the current user-to-device AffineTransform.

  208.      *

  209.      * @return a reference to the current AffineTransform.

  210.      */

  211.     public AffineTransform getTransform() {

  212.         return (AffineTransform)usr2dev.clone();

  213.     }

  214. 

  215.     /**

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

  217.      *

  218.      * @param newAoi The new area of interest.

  219.      */

  220.     public void setAreaOfInterest(Shape newAoi) {

  221.         aoi = newAoi;

  222.     }

  223. 

  224.     /**

  225.      * Gets the ares of interest currently contained in the

  226.      * RenderContext.

  227.      * 

  228.      * @return a reference to the area of interest of the RenderContext, 

  229.      *         or null if none is specified.

  230.      */

  231.     public Shape getAreaOfInterest() {

  232.         return aoi;

  233.     }

  234. 

  235.     /**

  236.      * Makes a copy of a RenderContext. The area of interest is copied

  237.      * by reference.  The usr2dev AffineTransform and hints are cloned,

  238.      * while the area of interest is copied by reference.

  239.      *

  240.      * @return the new cloned RenderContext.

  241.      */

  242.     public Object clone() {

  243.         RenderContext newRenderContext = new RenderContext(usr2dev,

  244.                                                            aoi, hints);

  245.         return newRenderContext;

  246.     }

  247. }