Publication might be too big to be sent through an Intent to the Navigator

[mickael-menu]

Intent extra data is limited in size, but Publication is not. This can produce a TransactionTooLargeException for big publications when starting the Navigator's Activity.

The PR readium/r2-testapp-kotlin#285 attempts to fix this problem with a global variable in the Navigator, but this strategy has some issues described in the PR's comments.

Possible alternatives are raised in readium/r2-testapp-kotlin#285 (comment).

[mickael-menu]

I think using Fragment instead of Activity, as described in this issue, would fix the problem.

With this solution, the test-app would be responsible to propagate how they see fit the Publication in their own navigator Activity (if they choose to have one). In the navigator, we would expose a FragmentFactory to do proper dependency injection and get the Publication, as well as any non-serializable objects we might need (e.g. DRMContext for LCP rights management).

[mickael-menu]

@Bolling88 reported that the issue occurs with this book: https://www.gutenberg.org/ebooks/61253.epub

He's using the positionList feature which increases the problem because the whole list is serialized, thus increasing the size of Publication.

[mickael-menu]

While the aforelinked PRs quickly fix the problem with an ad-hoc API, the proper way to fix that if we still need to expose an Activity in r2-navigator-kotlin could be to use an AppComponentFactory to inject the Publication object.