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general/metric_topdown_coordinates

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/* $Id: metric_topdown_coordinates.java,v 1.5 2013/01/15 10:11:58 stm Exp $
 * Metric topdown coordinates:
 * Output text using metric coordinates in a topdown coordinate system
 * 
 * Use topdown coordinates starting from the top left instead from the bottom
 * left, scale the coordinate system to use metric coordinates, and place some
 * horizontal lines 1 cm from each other.
 *  
 * Required software: PDFlib/PDFlib+PDI/PPS 9
 * Required data: none
 */
package com.pdflib.cookbook.pdflib.general;

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

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

    pdflib p = null;
    int font;

    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: 1.5 $");
        
        font = p.load_font("Helvetica", "unicode", "");
        if (font == -1)
            throw new Exception("Error: " + p.get_errmsg());
        
        /* Use topdown coordinates */
        p.set_option("topdown=true");
        
        /* Start an A4 page */
        p.begin_page_ext(0, 0, "width=a4.width height=a4.height");
        
        /* Scale the coordinate system to use metric coordinates.
         * By default, PDFlib will expect incoming coordinates in DTP points 
         * which are defined as: 1 pt = 1/72 inch = 25.4/72 mm = 0.3528 mm.
         * In order to supply the coordinates in centimeters instead of points
         * we have to calculate the scaling factor as follows:
         * (72 points/inch) / (2.54 cm/inch) = 28.3465 points/cm.
         */
        p.scale(28.3465, 28.3465);
        
        /* Now, PDFlib will interpret all coordinates (except for interactive
         * features, see below) in centimeters. The scaling is only in effect
         * for the current page, and must be repeated on each page (if so
         * desired).
         */
        
        /* Interpret all coordinates for hypertext elements in the coordinates
         * defined above as well
         */
        p.set_option("usercoordinates=true");
        
        /* Place some horizontal lines 1 cm from each other. 
         * With the third line, draw a rectangle.
         */
        p.setlinewidth(0.01);
     
        for (int i = 1; i < 29; i++) {
            p.moveto(0, i);
            p.lineto(1, i);
            if (i == 3) {
                p.rect(0, i, 1, 1);
            }
        	p.fill_stroke();
        }
        
        /* Set the font size in cm */
        p.setfont(font, 0.5);
        
        p.fit_textline("Centimeters from the top left instead of points from " +
            "the bottom left:", 2, 5, "");
        p.fit_textline("The small lines on the left are placed 1 cm from " +
            "each other.", 2, 6, "");
        p.fit_textline("This text line is displayed at 7 cm from top and 2 " +
            "cm from the left.", 2, 7, "");
        
        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();
            }
        }
    }
}