Java example source code file (RenderContext.java)

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Java - Java tags/keywords

affinetransform, awt, cloneable, deprecated, geometry, image, object, rendercontext, renderinghints, shape, util

The RenderContext.java Java example source code

/*
 * Copyright (c) 1998, 2008, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
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/* ********************************************************************
 **********************************************************************
 **********************************************************************
 *** COPYRIGHT (c) Eastman Kodak Company, 1997                      ***
 *** As  an unpublished  work pursuant to Title 17 of the United    ***
 *** States Code.  All rights reserved.                             ***
 **********************************************************************
 **********************************************************************
 **********************************************************************/

package java.awt.image.renderable;
import java.util.*;
import java.awt.geom.*;
import java.awt.*;
import java.awt.image.*;

/**
 * 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.
 *
 * <p> 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.
 *
 * <p> 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 <code>RenderContext.
     * @return a <code>RenderingHints object that represents
     * the rendering hints of this <code>RenderContext.
     * @see #setRenderingHints(RenderingHints)
     */
    public RenderingHints getRenderingHints() {
        return hints;
    }

    /**
     * Sets the rendering hints of this <code>RenderContext.
     * @param hints a <code>RenderingHints object that represents
     * the rendering hints to assign to this <code>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:
     * <pre>
     * [this] = [modTransform] x [this]
     * </pre>
     *
     * @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:
     * <pre>
     * [this] = [modTransform] x [this]
     * </pre>
     * 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
     *                 <code>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:
     * <pre>
     * [this] = [this] x [modTransform]
     * </pre>
     *
     * @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:
     * <pre>
     * [this] = [this] x [modTransform]
     * </pre>
     * 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
     *                 <code>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;
    }
}