PDF control inside an HTML

This document explains how to control a PDF loaded in an HTML document (PDF document declared in an iframe).

The Gekkota 4 PDF viewer listens to the following messages :

Message listening

Code sample:

window.addEventListener("message", function (event) {
            if (event.source === MyIframeWindow) {
                var type;
                if (typeof event.data === "string") {
                    type = event.data.toLowerCase();
                } else {
                    type = event.data.type.toLowerCase();
                // retrieve event detail if present
                if (event.data.detail) {


The Gekkota 4 PDF viewer can send the following messages:

Message sending

Code sample:

MyIframeWindow.postMessage("restart", "*");
var goToPageMessage = {
    type: "gotoPage",
    detail: 3
MyIframeWindow.postMessage(goToPageMessage, "*");

Entire example

Here is a entire HTML example to interact with a PDF file: