Block the focus, focusin, visibilitychange, and blur events

[boehs]

No description provided.

[boehs]

window.onblur = null;
window.blurred = false;

document.hasFocus = function () {return true;};
window.onFocus = function () {return true;};

Object.defineProperty(document, "hidden", { value : false});
Object.defineProperty(document, "mozHidden", { value : false});
Object.defineProperty(document, "msHidden", { value : false});
Object.defineProperty(document, "webkitHidden", { value : false});
Object.defineProperty(document, 'visibilityState', { get: function () { return "visible"; } });

document.onvisibilitychange = undefined;

for (event_name of ["visibilitychange",
                    "webkitvisibilitychange",
                    "blur", // may cause issues on some websites
                    "mozvisibilitychange",
                    "msvisibilitychange"]) {
  window.addEventListener(event_name, function(event) {
        event.stopImmediatePropagation();
    }, true);
}

[polcak]

Hello,

Do I understand correctly that these are proposed wrappers?

[boehs]

Yes. The code in the comment is my description if you will. It's not designed for a extension, it's close to untested (ran on holdd.netlify.app and it disabled the relevant bit), there may be a better way, etc, But a picture is worth a thousand words and this effectively describe what I am going for

I don't have much data on how it could be exploited, but the obvious thing that comes to mind is analytics, and targeted content based on attention span, and I can't figure out how the browser api would be useful to a website

[boehs]

• https://developer.mozilla.org/en-US/docs/Web/API/Document/visibilityState
• https://developer.mozilla.org/en-US/docs/Web/API/Document/hidden
• https://developer.mozilla.org/en-US/docs/Web/API/Document/onvisibilitychange
• https://developer.mozilla.org/en-US/docs/Web/API/Document/visibilitychange_event
• https://developer.mozilla.org/en-US/docs/Web/API/Window/blur_event (This one should probably be removed from the default)
• https://w3c.github.io/page-visibility/#extensions-to-the-document-interface

[polcak]

I explicitely mentioned this issue in https://pagure.io/JShelter/webextension/issue/66. We do not modify/filter events, yet. But I think that we should explore the possibilities.

[boehs]

Thank you for taking care to crosslink, it means lots to me

[AWKohler]

some websites might also use mouse in mouse out events as a workaround