fop/fop-core/src/main/java/org/apache/fop/pdf/PDFColor.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id$ */

package org.apache.fop.pdf;

import java.awt.color.ColorSpace;
import java.util.ArrayList;
import java.util.List;

import org.apache.xmlgraphics.java2d.color.DeviceCMYKColorSpace;

/**
 * PDF Color object. It is currently only used to hold the transparent color of a masked bitmap
 * image. And in this context, only RGB and Gray values are used.
 * <p>
 * Use of this class is discouraged. {@link PDFColorHandler} is now used for in-content color
 * selection. For masked bitmaps, it may be wiser to switch to {@link java.awt.Color} in the long run.
 */
public class PDFColor extends PDFPathPaint {
    // could be 3.0 as well.
    private static double blackFactor = 2.0;
    private double red = -1.0;
    private double green = -1.0;
    private double blue = -1.0;

    private double cyan = -1.0;
    private double magenta = -1.0;
    private double yellow = -1.0;
    private double black = -1.0;

    /**
     * Create a PDF color with double values ranging from 0 to 1.
     *
     * @param theRed the red double value
     * @param theGreen the green double value
     * @param theBlue the blue double value
     */
    public PDFColor(double theRed, double theGreen, double theBlue) {
        // super(theNumber);
        this.colorSpace = new PDFDeviceColorSpace(PDFDeviceColorSpace.DEVICE_RGB);

        this.red = theRed;
        this.green = theGreen;
        this.blue = theBlue;
    }

    /**
     * Create a PDF color from a java.awt.Color object.
     *
     * Different Color objects are handled differently. Cases recognized are.
     *
     * 1. CMYK color
     * 3. 'Normal' java.awt.Color (RGB case assumed or implicit conversion to sRGB)
     *
     * @param col the java.awt.Color object for which to create a PDFColor object
     */
    public PDFColor(java.awt.Color col) {
        ColorSpace cs = col.getColorSpace();
        if (cs != null && cs instanceof DeviceCMYKColorSpace) {
            // CMYK case
            this.colorSpace = new PDFDeviceColorSpace(PDFDeviceColorSpace.DEVICE_CMYK);
            float[] cmyk = col.getColorComponents(null);
            this.cyan = cmyk[0];
            this.magenta = cmyk[1];
            this.yellow = cmyk[2];
            this.black = cmyk[3];
        } else {
            // Default (RGB) Color (ICC Colors are converted to sRGB, too)
            this.colorSpace = new PDFDeviceColorSpace(PDFDeviceColorSpace.DEVICE_RGB);
            float[] comps = new float[3];
            comps = col.getColorComponents(comps);
            this.red = comps[0];
            this.green = comps[1];
            this.blue = comps[2];
        }
    }

    /**
     * Create a PDF color with int values ranging from 0 to 255
     *
     * @param theRed the red integer value
     * @param theGreen the green integer value
     * @param theBlue the blue integer value
     */
    public PDFColor(int theRed, int theGreen, int theBlue) {
        this(((double)theRed) / 255d, ((double)theGreen) / 255d,
             ((double)theBlue) / 255d);
    }

    /**
     * Create a PDF color with CMYK values.
     *
     * @param theCyan the cyan value
     * @param theMagenta the magenta value
     * @param theYellow the yellow value
     * @param theBlack the black value
     */
    public PDFColor(double theCyan, double theMagenta, double theYellow,
                    double theBlack) {
        this.colorSpace = new PDFDeviceColorSpace(PDFDeviceColorSpace.DEVICE_CMYK);

        this.cyan = theCyan;
        this.magenta = theMagenta;
        this.yellow = theYellow;
        this.black = theBlack;
    }

    /**
     * Return a vector representation of the color
     * in the appropriate colorspace.
     *
     * @return a list containing the Double values of the color
     */
    public List getVector() {
        List theColorVector = new ArrayList();
        if (this.colorSpace.getColorSpace() == PDFDeviceColorSpace.DEVICE_RGB) {
            // RGB
            theColorVector.add(this.red);
            theColorVector.add(this.green);
            theColorVector.add(this.blue);
        } else if (this.colorSpace.getColorSpace()
                   == PDFDeviceColorSpace.DEVICE_CMYK) {
            // CMYK
            theColorVector.add(this.cyan);
            theColorVector.add(this.magenta);
            theColorVector.add(this.yellow);
            theColorVector.add(this.black);
        } else {
            // GRAY
            theColorVector.add(this.black);
        }
        return (theColorVector);
    }

    /**
     * Get the red component.
     *
     * @return the red double value
     */
    public double red() {
        return (this.red);
    }

    /**
     * Get the green component.
     *
     * @return the green double value
     */
    public double green() {
        return (this.green);
    }

    /**
     * Get the blue component.
     *
     * @return the blue double value
     */
    public double blue() {
        return (this.blue);
    }

    /**
     * Get the red integer component.
     *
     * @return the red integer value
     */
    public int red255() {
        return (int)(this.red * 255d);
    }

    /**
     * Get the green integer component.
     *
     * @return the green integer value
     */
    public int green255() {
        return (int)(this.green * 255d);
    }

    /**
     * Get the blue integer component.
     *
     * @return the blue integer value
     */
    public int blue255() {
        return (int)(this.blue * 255d);
    }

    /**
     * Get the cyan component.
     *
     * @return the cyan double value
     */
    public double cyan() {
        return (this.cyan);
    }

    /**
     * Get the magenta component.
     *
     * @return the magenta double value
     */
    public double magenta() {
        return (this.magenta);
    }

    /**
     * Get the yellow component.
     *
     * @return the yellow double value
     */
    public double yellow() {
        return (this.yellow);
    }

    /**
     * Get the black component.
     *
     * @return the black double value
     */
    public double black() {
        return (this.black);
    }

    /**
     * Set the color space for this color.
     * If the new color space is different the values are converted
     * to the new color space.
     *
     * @param theColorSpace the new color space
     */
    public void setColorSpace(int theColorSpace) {
        int theOldColorSpace = this.colorSpace.getColorSpace();
        if (theOldColorSpace != theColorSpace) {
            if (theOldColorSpace == PDFDeviceColorSpace.DEVICE_RGB) {
                if (theColorSpace == PDFDeviceColorSpace.DEVICE_CMYK) {
                    this.convertRGBtoCMYK();
                } else  {
                    // convert to Gray?
                    this.convertRGBtoGRAY();
                }
            } else if (theOldColorSpace == PDFDeviceColorSpace.DEVICE_CMYK) {
                if (theColorSpace == PDFDeviceColorSpace.DEVICE_RGB) {
                    this.convertCMYKtoRGB();
                } else {
                    // convert to Gray?
                    this.convertCMYKtoGRAY();
                }
            } else {
                // used to be Gray
                if (theColorSpace == PDFDeviceColorSpace.DEVICE_RGB) {
                    this.convertGRAYtoRGB();
                } else {
                    // convert to CMYK?
                    this.convertGRAYtoCMYK();
                }
            }
            this.colorSpace.setColorSpace(theColorSpace);
        }
    }

    /**
     * Get the PDF output string for this color.
     * This returns the string to be inserted into PDF for setting
     * the current color.
     *
     * @param fillNotStroke whether to return fill or stroke command
     * @return the PDF string for setting the fill/stroke color
     */
    public String getColorSpaceOut(boolean fillNotStroke) {
        StringBuffer p = new StringBuffer("");

        if (this.colorSpace.getColorSpace()
                == PDFDeviceColorSpace.DEVICE_RGB) {       // colorspace is RGB
            // according to pdfspec 12.1 p.399
            // if the colors are the same then just use the g or G operator
            boolean same = false;
            if (this.red == this.green && this.red == this.blue) {
                same = true;
            }
            // output RGB
            if (fillNotStroke) {
                // fill
                if (same) {
                    p.append(PDFNumber.doubleOut(this.red) + " g\n");
                } else {
                    p.append(PDFNumber.doubleOut(this.red) + " "
                             + PDFNumber.doubleOut(this.green) + " "
                             + PDFNumber.doubleOut(this.blue)
                             + " rg\n");
                }
            } else {
                // stroke/border
                if (same) {
                    p.append(PDFNumber.doubleOut(this.red) + " G\n");
                } else {
                    p.append(PDFNumber.doubleOut(this.red) + " "
                             + PDFNumber.doubleOut(this.green) + " "
                             + PDFNumber.doubleOut(this.blue)
                             + " RG\n");
                }
            }
        } else if (this.colorSpace.getColorSpace()
                  == PDFDeviceColorSpace.DEVICE_CMYK) {
            // colorspace is CMYK

            if (fillNotStroke) {
                // fill
                p.append(PDFNumber.doubleOut(this.cyan) + " "
                         + PDFNumber.doubleOut(this.magenta) + " "
                         + PDFNumber.doubleOut(this.yellow) + " "
                         + PDFNumber.doubleOut(this.black) + " k\n");
            } else {
                // stroke
                p.append(PDFNumber.doubleOut(this.cyan) + " "
                         + PDFNumber.doubleOut(this.magenta) + " "
                         + PDFNumber.doubleOut(this.yellow) + " "
                         + PDFNumber.doubleOut(this.black) + " K\n");
            }

        } else {
            // means we're in DeviceGray or Unknown.
            // assume we're in DeviceGray, because otherwise we're screwed.

            if (fillNotStroke) {
                p.append(PDFNumber.doubleOut(this.black) + " g\n");
            } else {
                p.append(PDFNumber.doubleOut(this.black) + " G\n");
            }

        }
        return (p.toString());
    }

    /**
     * Convert the color from CMYK to RGB.
     */
    protected void convertCMYKtoRGB() {
        // convert CMYK to RGB
        this.red = 1.0 - this.cyan;
        this.green = 1.0 - this.green;
        this.blue = 1.0 - this.yellow;

        this.red = (this.black / PDFColor.blackFactor) + this.red;
        this.green = (this.black / PDFColor.blackFactor) + this.green;
        this.blue = (this.black / PDFColor.blackFactor) + this.blue;

    }

    /**
     * Convert the color from RGB to CMYK.
     */
    protected void convertRGBtoCMYK() {
        // convert RGB to CMYK
        this.cyan = 1.0 - this.red;
        this.magenta = 1.0 - this.green;
        this.yellow = 1.0 - this.blue;

        this.black = 0.0;
        /*
         * If you want to calculate black, uncomment this
         * //pick the lowest color
         * tempDouble = this.red;
         *
         * if (this.green < tempDouble)
         * tempDouble = this.green;
         *
         * if (this.blue < tempDouble)
         * tempDouble = this.blue;
         *
         * this.black = tempDouble / this.blackFactor;
         */
    }

    /**
     * Convert the color from Gray to RGB.
     */
    protected void convertGRAYtoRGB() {
        this.red = 1.0 - this.black;
        this.green = 1.0 - this.black;
        this.blue = 1.0 - this.black;
    }

    /**
     * Convert the color from Gray to CMYK.
     */
    protected void convertGRAYtoCMYK() {
        this.cyan = this.black;
        this.magenta = this.black;
        this.yellow = this.black;
        // this.black=0.0;//?
    }

    /**
     * Convert the color from CMYK to Gray.
     */
    protected void convertCMYKtoGRAY() {
        double tempDouble = 0.0;

        // pick the lowest color
        tempDouble = this.cyan;

        if (this.magenta < tempDouble) {
            tempDouble = this.magenta;
        }

        if (this.yellow < tempDouble) {
            tempDouble = this.yellow;
        }

        this.black = (tempDouble / PDFColor.blackFactor);

    }

    /**
     * Convert the color from RGB to Gray.
     */
    protected void convertRGBtoGRAY() {
        double tempDouble = 0.0;

        // pick the lowest color
        tempDouble = this.red;

        if (this.green < tempDouble) {
            tempDouble = this.green;
        }

        if (this.blue < tempDouble) {
            tempDouble = this.blue;
        }

        this.black = 1.0 - (tempDouble / PDFColor.blackFactor);
    }

    /**
     * Create pdf.
     * Not used for this object.
     *
     * @return the bytes for the pdf
     */
    public byte[] toPDF() {
        return (new byte[0]);
    }

    /** {@inheritDoc} */
    protected boolean contentEquals(PDFObject obj) {
        if (!(obj instanceof PDFColor)) {
            return false;
        }
        PDFColor color = (PDFColor)obj;

        if (color.red == this.red
                && color.green == this.green
                && color.blue == this.blue) {
            return true;
        }
        return false;
    }

}