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titleContent Freeze

As of July 25th, 2023, there is a content freeze on this page.

This section describes how to use the mobile device accelerometer to test for a shake event.  Perhaps you want to allow the user to clear the data on the screen just by shaking the device.


Code Block

document.addEventListener("deviceready", onDeviceReady, false);
function onDeviceReady() {

var watchID;
function startWatch() {
  var previousReading = {
    x: null,
    y: null,
    z: null
  var options = { frequency: 250 };  // Update acceleration every quarter second
  watchID = navigator.accelerometer.watchAcceleration(function onSuccess(acceleration) {
    var changes = {},
    bound = 4;  // this controls the sensitivity for detecting the shake event
    if (previousReading.x !== null) {
      changes.x = Math.abs(previousReading.x, acceleration.x);
      changes.y = Math.abs(previousReading.y, acceleration.y);
    if (changes.x > bound && changes.y > bound) {
      // We are relying on a hidden button with an ID of shake to be present on the Profound UI Rich Display File screen
      if (getObj("shake") != null)"shake");
      setTimeout(startWatch, 3000);
    previousReading = {
      x: acceleration.x,
      y: acceleration.y,
      z: acceleration.z
  }, function onError() {
    alert('Some problem has occurred in reading the accelerometer.');
  }, options);

function stopWatch() {
  if (watchID) {
    watchID = null;

To utilize the above in a Profound UI RPG application, simply place a hidden button on the screen.  Assign the id of "shake" to the button and bind the response property to a named indicator called Shake.  Then, in your RPG code, simply test for the Shake event as follows:

Code Block

If Shake = *On;
  // RPG logic, such as clearing screen data, would go here