PDFlib Cookbook

cookbook

interactive/link_annotations

On images and text lines, create links to open PDF files or Web pages, or to execute JavaScript.

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/*
 * Link annotations:
 * On images and text lines, create links to open PDF files or Web pages or
 * execute a JavaScript.
 *
 * On an image, create a Link annotation to open a URL.
 * On a text line, create a Link annotation to open a URL.
 * On a text line, create a Link annotation to jump to another PDF file.
 * On a text line, create a Link annotation to execute a JavaScript which
 * brings up a message box.
 *
 * Required software: PDFlib/PDFlib+PDI/PPS 10
 * Required data: none
 */
package com.pdflib.cookbook.pdflib.interactive;

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

public class link_annotations
{
    public static void main (String argv[])
    {
        /* This is where the data files are. Adjust as necessary */
        String searchpath = "../input";
        String outfile = "link_annotations.pdf";
        String title = "Link Annotations";
        
        pdflib p = null;
        int exitcode = 0;

        /* PDF file to be referenced by the link */
        String pdffile = "../input/PLOP-datasheet.pdf";

        /* URL to be referenced by the link */
        String url = "http://www.pdflib.com";

        /* Image to load that will also get a link */
        String imagefile = "websurfer.jpg";

        String optlist;
        int action, image, x = 20, y = 400;

        try {
            p = new pdflib();

            /* This means we must check return values of load_font() etc. */
            p.set_option("errorpolicy=return");

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

            if (p.begin_document(outfile, "") == -1)
                throw new Exception("Error: " + p.get_errmsg());

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

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


            /* --- On an image, create a link to open a URL --- */

            /* Place an image and determine the image dimensions via the
             * "image_matchbox" matchbox
             */
            optlist =
                "boxsize={50 50} fitmethod=meet matchbox={name=image_matchbox}";

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

            p.fit_image(image, x, y, optlist);
            p.close_image(image);

            /* Create a "URI" action for opening the URL */
            optlist = "url={" + url + "}";
            action = p.create_action("URI", optlist);

            /* Using the matchbox "image_matchbox", create a Link annotation with
             * the "URI" action. 0 rectangle coordinates will be replaced with
             * matchbox coordinates.
             */
            optlist = "action={activate " + action + "} linewidth=0 " +
                      "usematchbox={image_matchbox}";
            p.create_annotation(0, 0, 0, 0, "Link", optlist);


            /* --- On a text line, create a link to open a URL --- */

            /* Place a text line and determine the text dimensions via the
             * "text_matchbox" matchbox */
            optlist =
                "fontname=NotoSerif-Regular fontsize=20 " + 
                "matchbox={name=text_matchbox} " +
                "fillcolor={rgb 0 0.6 0.6} strokecolor={rgb 0 0.6 0.6} underline";
            p.fit_textline("Go to " + url, x, y-=60, optlist);

            /* Create a "URI" action for opening the URL */
            optlist = "url={" + url + "}";
            action = p.create_action("URI", optlist);

            /* Using the matchbox "text_matchbox", create a Link annotation with
             * the "URI" action. 0 rectangle coordinates will be replaced with
             * matchbox coordinates.
             */
            optlist = "action={activate " + action + "} linewidth=0 " +
                      "usematchbox={text_matchbox}";
            p.create_annotation(0, 0, 0, 0, "Link", optlist);


            /* --- On a text line, create a link to jump to another PDF file --- */

            /* Place a text line and determine the text dimensions via the
             * "goto_matchbox" matchbox
             */
            optlist =
                "fontname=NotoSerif-Regular fontsize=20 " +
                "matchbox={name=goto_matchbox} " +
                "fillcolor={rgb 0.6 0.6 0} strokecolor={rgb 0.6 0.6 0} underline";
            p.fit_textline("Jump to file \"" + pdffile + "\"", x, y-=100, optlist);

            /* Create a "GoToR" action for jumping to another PDF file */
            optlist = "filename={" + pdffile + "}" +
                " destination {page 1 type fitwindow} newwindow";
            action = p.create_action("GoToR", optlist);

            /* Using the matchbox "text_matchbox", create a Link annotation with
             * the "GoToR" action. 0 rectangle coordinates will be replaced with
             * matchbox coordinates.
             */
            optlist = "action={activate " + action + "} linewidth=0 " +
                "usematchbox={goto_matchbox}";
            p.create_annotation(0, 0, 0, 0, "Link", optlist);


            /* --- On a text line, create a link to execute a --- *
             * --- JavaScript which brings up a message box   --- */

            /* Place a text line and determine the text dimensions via the
             * "js_matchbox" matchbox
             */
            optlist = "fontname=NotoSerif-Regular fontsize=16 " +
                "matchbox={name=js_matchbox} " +
                "fillcolor={rgb 0.6 0 0.6} strokecolor={rgb 0.6 0 0.6} underline";
            p.fit_textline("Launch JavaScript", x, y-=100, optlist);

            /* Create a "JavaScript" action with a script which brings up
             * a message box.
             */
            optlist = "script={app.alert(\"JavaScript works!\")}";
            int js_action = p.create_action("JavaScript", optlist);

            /* Using the matchbox "text_matchbox", create a Link annotation with the
             * "JavaScript" action. 0 rectangle coordinates will be replaced with
             * matchbox coordinates.
             */
            optlist = "action={activate " + js_action + "} linewidth=0 " +
                "usematchbox={js_matchbox}";
            p.create_annotation(0, 0, 0, 0, "Link", optlist);

            p.end_page_ext("");

            p.end_document("");

        } catch (PDFlibException e) {
            System.err.println("PDFlib exception occurred:");
            System.err.println("[" + e.get_errnum() + "] " + e.get_apiname()
                + ": " + e.get_errmsg());
            exitcode = 1;
        } catch (Exception e) {
            System.err.println(e);
            exitcode = 1;
        } finally {
            if (p != null) {
                p.delete();
            }
            System.exit(exitcode);
        }
    }
}