/* $Id: invisible_text.java,v 1.4 2007/09/28 16:48:11 katja Exp $
 * Invisible text:
 * Output invisible text on top of an image 
 *  
 * Place an image and create invisible text on top of it with the
 * "textrendering" parameter set to 3.  The most common scenario for this is
 * "scanned page with invisible OCR text (which has been retrieved from the
 * scanned page in an earlier step with OCR).

 * Required software: PDFlib Lite/PDFlib/PDFlib+PDI/PPS 7
 * Required data: image file
 */
package com.pdflib.cookbook.pdflib.text_output;

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

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

    pdflib p = null;
    
    String imagefile = "multi_page.tif";
    int font, image;
 
    try {
        p = new pdflib();

        p.set_parameter("SearchPath", searchpath);

        /* This means we must check return values of load_font() etc. */
        p.set_parameter("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 $");

        /* Load the font; for PDFlib Lite: change "unicode" to "winansi" */
        font = p.load_font("Helvetica", "unicode", "");
        if (font == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Load the  image */
        image = p.load_image("auto", imagefile, "page=1");
        if (image == -1)
            throw new Exception("Error: " + p.get_errmsg());

        /* Start page */
        p.begin_page_ext(0, 0, "width=a4.width height=a4.height");
        
        /* Place the image */
        p.fit_image(image, 0, 0, "boxsize={595 842} fitmethod=meet");
        p.close_image(image);
        
        /* Save the current graphics state */
        p.save();
        
        /* Set the text rendering mode to "invisible text" */
        p.set_value("textrendering", 3);
              
        /* Output the text invisibly on top of the image with the rendering
         * mode set to "invisible text" above. (The text can be output
         * on top of the image or below the image.) The following text 
         * resembles text retrieved from the scanned page via OCR.
         */
        p.setfont(font, 21);
        p.show_xy("PDFlib GmbH München, Germany", 130, 750);
        p.show_xy("www.pdflib.com", 215, 710);
        
        p.setfont(font, 28);
        p.show_xy("Tutorial for", 120, 480);
        p.show_xy("PDFlib, PDI, and PPS", 120, 445);
        
        p.setfont(font, 21);
        p.show_xy("General Edition for", 195, 125);
        p.show_xy("Cobol, C, C++, Java, Perl", 165, 95);
        p.show_xy("PHP, Phyton, RPG, Ruby, and Tcl", 140, 70);
        
        /* Restore the current graphics state */
        p.restore();
        
        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.getMessage());
        } finally {
            if (p != null) {
                p.delete();
            }
        }
    }
}