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text_output/textflow_with_shading

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/*

 * $Id: textflow_with_shading.java,v 1.4 2017/01/25 14:56:49 stm Exp $

 *

 * Textflow with shading:

 * Create multi-column text output which may span multiple pages.

 * The text columns are colorized with a shading which matches the

 * geometry of each column. To emphasize the effect we create a radial

 * shading which starts in the middle of the fitbox.

 *

 * Required software: PDFlib/PDFlib+PDI/PPS 9

 * Required data: none

 */

package com.pdflib.cookbook.pdflib.text_output;


import com.pdflib.pdflib;

import com.pdflib.PDFlibException;


public class textflow_with_shading {

   

    static int create_shading(pdflib p, int tf) throws PDFlibException {

        /*

         * Query formatting results of the Textflow (coordinates of the placed

         * text)

         */

        double llx = p.info_textflow(tf, "x1");

        double lly = p.info_textflow(tf, "y1");

        double urx = p.info_textflow(tf, "x3");

        double ury = p.info_textflow(tf, "y3");


        /*

         * Create axial shading from red to blue. The start and end circles have

         * their centers in the center of the fitbox. The radius of the start

         * circle is zero, the radius of the end circle is chosen so that the

         * full fitbox is covered (half of the diagonal). PDFlib 9.1 supports

         * the simpler "endcolor=blue" instead of RGB values as function

         * parameters.

         */

        int sh = p.shading("radial", (llx + urx) / 2, (lly + ury) / 2,

            (llx + urx) / 2, (lly + ury) / 2, 0, 0, 1, 0,

            "startcolor=red r0=0 r1=" + 0.5

                * Math.sqrt(Math.pow(ury - lly, 2) + Math.pow(urx - llx, 2)));


        return p.shading_pattern(sh, "");

    }


    public static void main(String argv[]) {


        String outfile = "textflow_with_shading.pdf";

        String title = "Starter Textflow";

        int i, tf = -1;

        String result;

        final double llx1 = 50, lly1 = 50, urx1 = 250, ury1 = 800;

        final double llx2 = 300, lly2 = 50, urx2 = 500, ury2 = 800;

        int exitcode = 0;


        /* Repeat the dummy text to produce more contents */

        final int count = 50;


        final String optlist1 = "fontname=Helvetica fontsize=10.5 encoding=unicode "

            + "fillcolor={gray 0} alignment=justify hyphenchar=U+002D";


        /*

         * Dummy text for filling the columns. Soft hyphens are marked with the

         * character reference "­" (character references are enabled by the

         * charref option).

         */

        final String text = "Lorem ipsum dolor sit amet, consectetur adi­pi­sicing elit, "

            + "sed do eius­mod tempor incidi­dunt ut labore et dolore "

            + "magna ali­qua. Ut enim ad minim ve­niam, quis nostrud "

            + "exer­citation ull­amco la­bo­ris nisi ut "

            + "ali­quip ex ea commodo con­sequat. Duis aute irure dolor "

            + "in repre­henderit in voluptate velit esse cillum dolore eu "

            + "fugiat nulla pari­atur. Excep­teur sint occae­cat "

            + "cupi­datat non proident, sunt in culpa qui officia "

            + "dese­runt mollit anim id est laborum. ";


        pdflib p = null;

       

        try {

            p = new pdflib();


            /* This means we must check return values of load_font() etc. */

            p.set_option("errorpolicy=return");


            if (p.begin_document(outfile, "") == -1)

                throw new Exception("Error: " + p.get_errmsg());


            p.set_info("Creator", "PDFlib Cookbook");

            p.set_info("Title", title + " $Revision: 1.4 $");


            final String optlist2 = "fontname=Helvetica-Bold fontsize=14 encoding=unicode "

                + "charref hyphenchar=U+002D";


            /*

             * Create some amount of dummy text and feed it to a Textflow object

             * with alternating options.

             */

            for (i = 1; i <= count; i++) {

                String num = i + " ";


                tf = p.add_textflow(tf, num, optlist2);

                if (tf == -1)

                    throw new Exception("Error: " + p.get_errmsg());


                tf = p.add_textflow(tf, text, optlist1);

                if (tf == -1)

                    throw new Exception("Error: " + p.get_errmsg());

            }


            /*

             * Loop until all of the text is placed; create new pages as long as

             * more text needs to be placed. Two columns will be created on all

             * pages.

             */

            do {

                /* Add "showborder" to visualize the fitbox borders */

                String optlist = "verticalalign=justify linespreadlimit=120% ";


                p.begin_page_ext(0, 0, "width=a4.width height=a4.height");


                /* Place the first column in blind mode (for formatting only) */

                result = p.fit_textflow(tf, llx1, lly1, urx1, ury1,

                    optlist + " blind");

               

                /* handle for shading pattern */

                int shp = create_shading(p, tf);


                /*

                 * Place the first column in real mode and replace the gray fill

                 * color with the shading pattern. We must rewind the Textflow

                 * to undo the result of the "blind" formatting.

                 */

                result = p.fit_textflow(tf, llx1, lly1, urx1, ury1,

                    optlist + "rewind=-1 exchangefillcolors={{gray 0} {pattern "

                        + shp + "}}");


                /* Process the second column if we have more text */

                if (!result.equals("_stop")) {

                    /* Place second column in "blind" mode */

                    result = p.fit_textflow(tf, llx2, lly2, urx2, ury2,

                        optlist + " blind");


                    shp = create_shading(p, tf);


                    /*

                     * Place second column in real mode and replace the gray

                     * fill color with the shading pattern.

                     */

                    result = p.fit_textflow(tf, llx2, lly2, urx2, ury2,

                        optlist

                            + "rewind=-1 exchangefillcolors={{gray 0} {pattern "

                            + shp + "}}");

                }


                p.end_page_ext("");


                /*

                 * "_boxfull" means we must continue because there is more text;

                 * "_nextpage" is interpreted as "start new column"

                 */

            }

            while (result.equals("_boxfull") || result.equals("_nextpage"));


            /* Check for errors */

            if (!result.equals("_stop")) {

                /*

                 * "_boxempty" happens if the box is very small and doesn't hold

                 * any text at all.

                 */

                if (result.equals("_boxempty"))

                    throw new Exception("Error: Textflow box too small");

                else {

                    /*

                     * Any other return value is a user exit caused by the

                     * "return" option; this requires dedicated code to deal

                     * with.

                     */

                    throw new Exception(

                        "User return '" + result + "' found in Textflow");

                }

            }


            p.delete_textflow(tf);


            p.end_document("");

        }

        catch (PDFlibException e) {

            System.err.print("PDFlib exception occurred:\n");

            System.err.print("[" + e.get_errnum() + "] " + e.get_apiname()

                + ": " + e.get_errmsg() + "\n");

            exitcode = 1;

        }

        catch (Exception e) {

            System.err.println(e.getMessage());

            exitcode = 1;

        }

        finally {

            if (p != null) {

                p.delete();

            }

            System.exit(exitcode);

        }

    }

}