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text_output/transparent_part_of_text

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/* $Id: transparent_part_of_text.java,v 1.8 2013/01/15 10:12:08 stm Exp $
 * Transparent part of text:
 * Create transparent text and highlight it with transparent rectangles
 * 
 * Use the "opacityfill" and "opacitystroke" options of create_gstate() to 
 * create an explicit graphics state with transparency settings. 
 * Place a transparent text line in two different ways. 
 * First use set_gstate() to set the explicit graphics state before placing the
 * text line. 
 * Second use the "gstate" option of fit_textline(). 
 * Output a Textflow with one word highlighted with a transparent rectangle
 * using the "gstate" suboption of the "matchbox" option of add_textflow().
 * Output a transparent Textflow with one word surrounded by the transparent
 * borders of a rectangle using the "gstate" suboption of the "matchbox" option
 * and the "gstate" option of add_textflow().
 *
 * Required software: PDFlib/PDFlib+PDI/PPS 9
 * Required data: image file
 */
package com.pdflib.cookbook.pdflib.text_output;

import com.pdflib.pdflib;
import com.pdflib.PDFlibException;

public class transparent_part_of_text
{
    public static void main (String argv[])
    {
    /* This is where the data files are. Adjust as necessary. */
    String searchpath = "../input";
    String outfile = "transparent_part_of_text.pdf";
    String title = "Transparent Part of Text";

    pdflib p = null;
    
    String imagefile = "nesrin.jpg";
    
    String text, optlist, mopts, gopts, result;
    int image, gstate, font, tf = -1;
    
    try {
        p = new pdflib();

        p.set_option("searchpath={" + searchpath + "}");

        /* 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: 1.8 $");
        
        /* Load image */
        image = p.load_image("auto", imagefile, "");
        if (image == -1)
            throw new Exception("Error: " + p.get_errmsg());

        /* Load the font. */
        font = p.load_font("Helvetica-Bold", "unicode", "");
        if (font == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Start page */
        p.begin_page_ext(842, 595, "");
        
        /* Draw a yellow background rectangle */
        p.setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
        p.rect(0, 0, 842, 595);
        p.fill(); 
        
        /* Output a background image */
        p.fit_image(image, 50, 50, "");
        
        /* Save the current graphics state. The save/restore of the current
         * state is not necessarily required, but it will help you get back to
         * a graphics state without any transparency.
         */
        p.save();
        
        /* Create an extended graphics state with transparency set to 50%, using
         * create_gstate() with the "opacityfill" option set to 0.5.
         */
        gstate = p.create_gstate("opacityfill=.5");
        
        /* Apply the extended graphics state */
        p.set_gstate(gstate);
        
        /* Display some text which will be transparent according to the
         * graphics state set
         */
        p.setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
        p.fit_textline("Page 1: My favorite holiday photo", 100, 100, 
            "font=" + font + " fontsize=40");
        
        /* Restore the current graphics state */
        p.restore();
        
        p.end_page_ext("");
        
        /* Start page */
        p.begin_page_ext(842, 595, "");
        
        /* Draw a yellow background rectangle */
        p.setcolor("fill", "rgb", 1, 0.9, 0.58, 0);
        p.rect(0, 0, 842, 595);
        p.fill(); 
        
        /* Output a background image */
        p.fit_image(image, 50, 50, "");
        
        
        /* ------------------------------
         * Output a transparent text line
         * ------------------------------
         */
        
        /* Create an explicit graphics state with the transparency for fill 
         * operations set to 40%
         */
        gstate = p.create_gstate("opacityfill=0.4");
        
        /* Display a text line with the explicit graphics state applied. The
         * text will appear transparent. 
         */
        optlist = 
            "font=" + font + " fontsize=40 " + 
            "fillcolor={rgb 1 0.9 0.58} " +
            "gstate=" + gstate;
        
        p.fit_textline("Page 2: My favorite holiday photo", 100, 470, 
            optlist);
        
        
        /* --------------------------------------------------------
         * Output a Textflow with the word "favorite" filled with a 
         * transparent rectangle
         * --------------------------------------------------------
         */
        
        /* Create an explicit graphics state with the transparency for fill
         * operations set to 40%
         */
        gstate = p.create_gstate("opacityfill=0.4");
        
        /* Define the general Textflow options */
        optlist =
            "fontname=Helvetica-Bold fontsize=30 encoding=unicode " +
            "leading=120% charref fillcolor={rgb 1 0.9 0.58} ";
        
        /* Add parts of the Textflow */
        text = "Here you can see my ";  
        tf = p.add_textflow(tf, text, optlist);
        if (tf == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Use the "matchbox" option to define a matchbox rectangle to be 
         * filled on parts of the Textflow. To fill the rectangle 
         * transparently the matchbox is provided with the graphics state
         * created above.
         */
        mopts = "matchbox={name=mymatchbox boxheight={ascender descender}" +
            " fillcolor={rgb 1 0.9 0.58} gstate=" + gstate +
            " offsetleft=-4 offsetright=4 offsettop=4} ";
        
        /* Use the "gstate" option to apply the explicit graphics state
         * defined above
         */
        gopts = "gstate=" + gstate;
        
        /* Add a part of the Textflow with the "matchbox" and "gstate" 
         * options. That part of the text will be filled with a transparent
         * rectangle and will appear transparent.
         */
        text = "favorite";   
        tf = p.add_textflow(tf, text, optlist + mopts + gopts);
        if (tf == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Define the "matchbox=end" option to end the matchbox */
        mopts = "matchbox=end ";
        
        /* Create another explicit graphics state with no transparency */
        gstate = p.create_gstate("opacityfill=1");
        
        /* Use the "gstate" option to apply the explicit graphics state
         * defined above
         */
        gopts = "gstate=" + gstate;
        
        /* Add parts of the text with the "matchbox=end" option applied.
         * The matchbox rectangle will end before the text to be added.
         * The text will not appear transparent any more.
         */
        text = " holiday photo.";
        tf = p.add_textflow(tf, text, optlist + mopts + gopts);
        if (tf == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        result = p.fit_textflow(tf, 100, 200, 300, 400, "");
        if (!result.equals("_stop"))
        {
            /* Check for errors or more text to be placed */
        }
        p.delete_textflow(tf);
        
        
        /* -----------------------------------------------------------------
         * Output a transparent Textflow with the word "favorite" surrounded
         * by the transparent borders of a rectangle.
         * -----------------------------------------------------------------
         */
        tf = -1;
        
        /* Create an explicit graphics state with transparency for stroking
         * and filling set to 40%
         */
        gstate = p.create_gstate("opacitystroke=0.4 opacityfill=0.4");
        
        /* Define the general Textflow options including the graphics state
         * defined above
         */
        optlist =
            "fontname=Helvetica-Bold fontsize=30 encoding=unicode " +
            "leading=120% charref fillcolor={rgb 1 0.9 0.58} " +
            "gstate=" + gstate;
        
        /* Add parts of the Textflow */
        text = "This is my ";  
        tf = p.add_textflow(tf, text, optlist);
        if (tf == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Use the "matchbox" option for defining a matchbox rectangle to be 
         * stroked around parts of the Textflow. To stroke the rectangle 
         * transparently the matchbox is provided with the graphics state 
         * created above.
         */
        mopts = " matchbox={name=mymatchbox gstate=" + gstate + 
            " boxheight={ascender descender} linecap=projecting" +
        	" borderwidth=3 strokecolor={rgb 1 0.9 0.58}" +
            " offsetleft=-4 offsetright=4 offsettop=4}";
        
        /* Add a part of the Textflow with the matchbox option */
        text = "favorite";   
        tf = p.add_textflow(tf, text, optlist + mopts);
        if (tf == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Define the "matchbox=end" option to end the matchbox */
        mopts = " matchbox=end";
        
        /* Add parts of the text with the "matchbox=end" option.
         * The matchbox rectangle will end before the text to be added.
         */
        text = " holiday photo.";
        tf = p.add_textflow(tf, text, optlist + mopts);
        if (tf == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        result = p.fit_textflow(tf, 650, 100, 780, 280, "");
        if (!result.equals("_stop"))
        {
            /* Check for errors or more text to be placed */
        }
        p.delete_textflow(tf);
 
        p.end_page_ext("");

        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");
        } catch (Exception e) {
            System.err.println(e.toString());
        } finally {
            if (p != null) {
                p.delete();
            }
        }
    }
}