WIP: Guided Navigation

[HadrienGardeur]

This is a WIP for a new take on Media Overlay with an updated scope to cover more media.

Some of our design goals include:

• support for image references, video references and text in addition to audio and text references
• synchronized media is essentially an alternate reading order, not necessarily following the "normal" reading order of a publication
• instead of an EPUB-specific approach, this is meant to be generic enough to work on audiobooks and comics (Divina) as well

Preview link: https://github.com/readium/architecture/tree/sync-media/models/guided

[mickael-menu]

This has the advantage of being more compact in the manifest, and allow to specify multiple sync media in a single publication (maybe with rel or additional metadata).

[qnga]

I may not get the point, but I would expect a simple and natural way to define multiple synchronized reading orders.

[mickael-menu]

What's the purpose of the xrefs in grouping elements? Does it limit the children to a given scope?

[mickael-menu]

I'm concerned that we can't synchronize two media of the same type, which would be useful for parallel texts.

[danielweck]

Also see: readium/webpub-manifest#83

[HadrienGardeur]

I'm thinking of moving this work to its own repo/project, probably guided-navigation.

I expect that there will be enough material to warrant this, just like we did with webpub-manifest. There's not much overall in this PR, so rewriting this into more of a spec sounds like a good idea anyway.

[HadrienGardeur]

I've merged this PR but all of the work dedicated to the Guided Navigation document is now handled in its own separate repo: https://github.com/readium/guided-navigation/