webview-touchend-trigger.js

// In case you embed a webview in a native app and the native app has a navigation bar you may find
// swiping up from the webview to the header (and releasing your finger on the header) will not fire
// a 'touchend' event on the webview.
//
// This code fixes it in a way where we listen for 'touchmove' events and fire a 'touchend' event
// programmatically in case the user leaves the webview at the top (negative Y coordinate):

document.addEventListener("touchmove", function(e) {
    if (e.changedTouches[0].pageY < 0) {
        e.preventDefault();
        document.dispatchEvent(new Event('touchend'));
    }
}, false);