/* $Id: pdfimpose.java,v 1.6 2013/01/15 10:12:02 stm Exp $
 * PDF impose:
 * Import all pages from one more existing PDFs, and place c x r pages on each
 * sheet of the output PDF (imposition).
 * 
 * Required software: PDFlib+PDI/PPS 9
 * Required data: PDF documents
 */
import com.pdflib.pdflib;
import com.pdflib.PDFlibException;

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

    pdflib p = null;
    String pdffiles[] =
    {
        "PDFlib-real-world.pdf",
        "PDFlib-datasheet.pdf",
        "TET-datasheet.pdf",
        "PLOP-datasheet.pdf",
        "pCOS-datasheet.pdf"
    };
    int i, c = 0, r = 0;
    String optlist;
    double scale = 1;          // scaling factor of a page
    double rowheight = 0;      // row height for the page to be placed
    double colwidth = 0;       // column width for the page to be placed
    double sheetwidth = 595;   // width of the sheet
    double sheetheight = 842;  // height of the sheet
    int cols = 3, rows = 4;    // cols x rows pages will be placed on one sheet

    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: 1.6 $");
        
        /* ---------------------------------------------------------------------
         * Define the sheet width and height, and the number of rows and columns
         * and calculate the scaling factor and cell dimensions for the 
         * multi-page imposition
         * ---------------------------------------------------------------------
         */
        if (rows > cols)
            scale = 1.0 / rows;
        else
            scale = 1.0 / cols;

        rowheight = sheetheight * scale;
        colwidth = sheetwidth * scale;

        boolean pageopen = false; // is a page open that must still be closed?
        
        /* Loop over all input documents */
        for (i=0; i < pdffiles.length; i++) {
            int indoc, endpage, pageno, page;

            /* Open the input PDF */
            indoc = p.open_pdi_document(pdffiles[i], "");
            if (indoc == -1){
                System.err.println("Error: " + p.get_errmsg());
                continue;
            }
   
            endpage = (int) p.pcos_get_number(indoc, "length:pages");
            
            /* Loop over all pages of the input document */
            for (pageno = 1; pageno <= endpage; pageno++) {
                page = p.open_pdi_page(indoc, pageno, "");

                if (page == -1) {
                    System.err.println("Error: " + p.get_errmsg());
                    continue;
                }
                
                /* Start a new page */
                if (r == 0 && c == 0) {
                    p.begin_page_ext(sheetwidth, sheetheight, "");
                    pageopen = true;
                }
                
                /* The save/restore pair is required to get the clipping
                 * right, and helps PostScript printing manage its memory
                 * efficiently.
                 */
                p.save();
                p.rect(c * colwidth, sheetheight - (r + 1) * rowheight,
                    colwidth, rowheight);
                p.clip();

                optlist = "boxsize {" + colwidth + " " + rowheight + "}" +
                    " position 0 fitmethod meet";
                    
                p.fit_pdi_page(page, c * colwidth, 
                    sheetheight - (r + 1) * rowheight, optlist);

                p.close_pdi_page(page);
                
                /* Draw a frame around the mini page */ 
                p.setlinewidth(scale);
                p.rect(c * colwidth, sheetheight - (r + 1) * rowheight,
                    colwidth, rowheight);
                p.stroke();
               
                p.restore();

                c++;
                if (c == cols) {
                    c = 0;
                    r++;
                }
                if (r == rows) {
                    r = 0;
                    p.end_page_ext("");
                    pageopen = false;
                }
            }
            p.close_pdi_document(indoc);
        }
        
        if (pageopen) {
            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();
            }
        }
    }
}