Android PhoneGap gets yaw, step, roll, relative to ground coordinates

Question

I have the following script on a web page:

window.addEventListener('deviceorientation', function(event) { // Get Euler angles from device var alpha = 360 - event.alpha; var beta = event.beta; var gamma = event.gamma; // Display Euler angles document.getElementById("alpha").innerHTML = alpha; document.getElementById("beta").innerHTML = beta; document.getElementById("gamma").innerHTML = gamma; }, false); 

This works great in a browser like mobile Firefox for Android. It displays my title, step and roll in relation to the coordinates of the Earth (alpha is always 0 when pointing to the north, beta is always 90 when keeping the device vertical, etc.).

Now I load the same script into the PhoneGap application using WebView and it does not display anything. How to get these values ​​in PhoneGap without having to completely recreate the merge from scratch?