Remote control to navigate the slideshow

[olange]

Concepts

• Head: a tuple, that reflects the active ‹slide;display› combination currently displayed on a slideshow player; specific to every slideshow player instance; either synchronized with global live head (set by the speakers) or moving freely in the slide/display deck, detached from the live head (controlled by the user of the slideshow player);
• Live head – Current slide/display of the speakers; it is a global value, synchronized thru an upstream; usually, head of every member of the audience and the other speaker is synchronized with this live head;
• Detached head – Current slide/display of a speaker or member of the audience; detached head is specific to every slideshow player instance;
• Resync – either resets the the live head to the current detached head of the slideshow player (only speakers can do this); or resets the head of a slideshow player to the global live head;
• Audience – all participants of the presentation; their slideshow is by default automatically synchronized to live head, and they can go to detached head and revisit previous slides, until they resync with live head;
• Speaker – controls the live head and can optionaly go to detached head (to look for a slide);
• Room (future use) – if there would be multiple rooms with different speakers on same presentation, live head would be different in each room; we have no such requirement, but introduced it incidentally in the Firebase database model, to serve as a key in the live document collection.

Features

Focus on moving live head first, for speakers. Note: outcome of same the keypresses is different for speakers and audience, so a boolean attribute speaker will be needed on ‹dia-show› element.

Then focus on detached head, for both speakers and audience. An additional detached boolean attribute will probably help on ‹dia-show› element.

Configuration

• Connexion to Firebase project should be configurable TODO
• User should be able to opt-in/-out of the remote controller TODO see Refactor ‹dia-controller› to allow opt-in/out of child controllers #12

Speakers

• Connect to back-end, to sync with active slide of presenters and update live head
• Cursor right ⟶ / left ⟵ moves live head to next/previous slide, all local and remote views synchronized to head (and space is alias of cursor right)
• ALT-CTRL-S goes to speaker mode
• First ESC press first goes to detached head, all local views subsequently synchronized with detached head; live head is not affected until resync
• Second ESC press displays overview of all slides & click on a slide/display sets detached head to the clicked slide/display
• SPACE leaves detached mode and resynchronizes the speaker's detached head with live head (and she·he looses the slide where she·he currently was)
• CTRL-SPACE resynchronizes the live head with the speaker's detached head (what Yves named to « re-focus »).

Audience

• Connects to back-end, to sync with live head of speakers and communicate their current head (a feedback to the speakers)
• Cursor right ⟶ / left ⟵ moves goes to detached head and moves detached head to next/previous slide; subsenquetly stays unsynchronized, until resync;
• SPACE resynchronizes the audience's detached head with live head
• ESC displays overview of all slides & click on a slide/display sets detached head to the clicked slide/display.

Note

• When the speaker sets the live head, the ‹slide;display› tuple it sends to the remote is its ‹current slide;default audience display› – the speaker indeed simultaneously sees/projects contents of all displays;
• whereas the audience actually can only see one display at a time – and they use the default audience display that the speaker sent;
• therefore, the slideshow author must determine, for each slide, which diapositive should be displayed to the audience.

See also

• Keyboard controls to navigate the slideshow #5 Keyboard controls to navigate the slideshow
• Refactor ‹dia-controller› to allow opt-in/out of child controllers #12 Refactor ‹dia-controller› to allow opt-in/out of child controllers