What if I want to present an X button that the user can click to exit fullscreen? How would I do that without a programmable API?
Also, especially for video, the browser should be able to play it full screen without any distractions.
Of course, there are optional enhancements (subtitles, or different audio tracks) driven via JS. And for those the controls have to go somewhere.
Ideally, if there were a standard for those, the browser could handle it. (But then we're at the problem of an ever bloating browser.)
I think you're overreacting to one bad-actor. Inevitably your suggestion here leads to good-actor pages having much less power to present good UI to its users. The browser has to think of all use-cases and have options for that, rather than defining lower-level hooks that pages can do what they want with.
Would it make you feel better that there already many other ways that pages can do user-hostile things? Have you ever visited a page that blocks right-click? Would you want to forbid Mouse Events because of this?
No, the left mouse button is for interaction with the webpage, the right mouse button is mine. Just don't send any events for the right mouse button.
> You're asking that the browser define its own UI for an exit button.
Yes. Currently firefox puts a "to exit full screen press esc" OSD already on videos, that also interferes with visual presentation of sites/directors. So ... directors already don't put shit there.
The same thing goes for walled gardens (like Apple's - they don't allow some things), the problem is not that it's curated, the problem is that there are insufficient tools available for users to put their walls where they want.
Yes, by default I don't want to allow blocking right click. (You might be familiar with the saga of this bug https://bugzilla.mozilla.org/show_bug.cgi?id=78414 . )