feat: Add option to automatically play on load, or when page url ends in #autoplay

[W-Floyd]

Fixes #159

[W-Floyd]

Ah, I'd added a log during testing but forgot to remove the import. @badaix you want a debug log on autoplay?

[badaix]

Ah, I'd added a log during testing but forgot to remove the import. @badaix you want a debug log on autoplay?

yes, why not, I think a debug log won't hurt

[badaix]

I tried it and I'm running into the problem that the browser does not start playing audio, but throws this error:

(index):1 Uncaught (in promise) NotAllowedError: play() failed because the user didn't interact with the document first. https://goo.gl/xX8pDD

[W-Floyd]

If the browser has allowed the site to autoplay, it works. Eg, Firefox setting:

That is to say, the browser must either allow sites to autoplay, or the user will need to manually set it to be allowed. Maybe we could do a check and notify the user (if nothing else, in the console) if autoplay not being allowed?

[badaix]

Yes, I think we need a check and notify the user if autoplay is not working. Snapweb is already using "Alert Snackbars" if the server can't be reached, such a snackbar could be used to inform the user that autoplay is not allowed.

[W-Floyd]

See https://caniuse.com/mdn-api_navigator_getautoplaypolicy. I'm using this check, but falling back to trying directly if it's unknown. Currently only Firefox supports reading this directly, so we rely on fallback in all other cases.

Safari:

Firefox: