Userscript won't un-focus the text input on some pages

Question

I have a small Greasemonkey script which is meant to unfocus everything and just return the focus to the top level of the webpage.
The code looks like this:

document.addEventListener('keydown', function(event) {
    if (event.ctrlKey && event.keyCode === 32) {
        document.activeElement.blur()
    }
}, true);

It works fine on all the web pages I use, except for WhatsApp Web. It immediately refocuses the message typing box.
I have turned autofocus off in Firefox.

How can one ensure that truly nothing is left in focus? Not even the WhatsApp Web message input box.

Answer 1

Are there any errors or messages in the browser console? And what browser version are you using?

Anyway, without creating a WhatsApp account, or you posting an MCVE, here some possibilities:

• The page uses JS to reset focus -- triggered by keydown.
• The page uses JS to reset focus -- triggered by something else.
• The page has reset the default active element ( (Used to be) possible on some browsers).
• The page has overridden document.activeElement.blur()

This code might work:

document.addEventListener ('keydown', zEvent => {
    if (zEvent.ctrlKey && zEvent.keyCode === 32) {
        let actElem     = document.activeElement;
        if (actElem)    actElem.blur ();
        else            console.error ("document.activeElement is unset");

        zEvent.preventDefault ();
        zEvent.stopImmediatePropagation ();
    }
}, true);

If it doesn't and there are no relevant messages in the browser console, run this from the console:

console.log (document.activeElement.blur.toSource() );

And see if it's not the native function.

Another thing you can try is to find or create a different input and .focus() it. (document.body.focus() will often not work, alas.)

---

Otherwise, you'll have to find the javascript that's resetting focus and block that. How to do such a thing depends on exactly what the page code is. It's something for a different question but various mechanisms have all been covered on other Stack Overflow questions already.