Safari on iPhone and iPad has picture-in-picture but never implemented
requestPictureInPicture; it exposes WebKit's older presentation-mode switch
instead, and document.pictureInPictureEnabled is undefined there. Every
capability check in the player and the feed was that one property, so they
all answered "no" and the button was hidden outright on the platform where
people most want it.
The difference is confined to customPlayer: supportsPiP, pipElement, enterPiP
and exitPiP speak for both APIs, and bindPiPEvents re-fires WebKit's
webkitpresentationmodechanged -- which does not bubble -- as the standard
enter/leave events, so the feed's delegated listeners, the pane pin and the
media-key stepping work unchanged. Capability is read from the method's
presence rather than webkitSupportsPresentationMode(), which answers false
until a video track is loaded and would hide the button on preload="none"
feed videos.
There is no iPhone here, so smoke_ios_pip.py reshapes the browser to iOS's
API surface -- deleting the standard entry points and installing WebKit's --
and drives the button through it. That covers what actually broke: which API
the code reaches for.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QBDkEXP4htyXTCZUwMLphd
191c81e55e