A presentation you can steer without a mouse

The presentation player got a keymap: space and k to play or pause, left and right to seek, up and down for volume, m for mute, c for captions, f for fullscreen, Home and End for the ends.

The commit that added it opens with the plain version of why: a presentation could only be steered with the pointer. Everything else was there. Multiple languages, subtitles, a chosen poster frame, lazy media, an accessible tree. And no spacebar, which is the first thing anyone tries.

The work is not the listener, it is deciding which player a key belongs to. A page can hold several embeds. So the document keymap picks in order: a player in fullscreen owns the keyboard, otherwise the focused one, otherwise the only one on the page, and if there are several and none is focused, nothing happens rather than something surprising. The player root became focusable, with a focus ring shown for keyboard focus only, so tabbing to a film tells you it is now listening.

One detail that separates a keymap that helps from one that fights you: typing in a field elsewhere on the page must never steer a video. But the player's own sliders are not typing, so they keep their arrow keys. Those two rules look similar and are opposite.

It came with a test suite of its own and the version bump to 1.0.

Phlo Presentation 1.0. See the Presentation handbook.