Mobile

Release Note · Kotlin Toolkit Version 3.2.0

We are pleased to announce version 3.2.0 of the Readium Kotlin Toolkit. This release brings animated page transitions to EPUB, adds support for fetching remote EPUB resources, and includes a number of fixes and housekeeping improvements.

Browse the full release on Github.

Smooth page transitions in EPUB

EPUB paginated mode now supports animated page turns, giving users a more natural reading experience when flipping between pages.

To enable animations when navigating programmatically, pass animated = true to any of the go() APIs on the navigator. If you are using DirectionalNavigationAdapter for swipe or button navigation, set animatedTransition = true when initializing it.

Remote resources in EPUB publications

The EpubParser constructor now accepts an httpClient parameter, enabling the toolkit to fetch remote resources referenced in a Publication object. This is useful for EPUBs that load content from remote URLs.

Along with this change, the navigator now correctly resolves resources with absolute href values, which previously failed to load.

Technical updates and fixes

LCP custom device identifier: A new initializer parameter lets you supply your own device identifier for LCP licensing. If you use this option, make sure the identifier is unique and stable across app launches — generating an app-scoped UUID and storing it securely is the recommended approach.
Deprecations: The Presentation Hints properties have been deprecated from the Readium Web Publication Manifest models, in line with the official EPUB profile specification. Additionally, title inference based on folder names inside image and audio archives has been removed — the archive's filename is now used instead.
Bug fixes: A typo in the accessibility metadata has been corrected (describeMath is now describedMath). The audio navigator now correctly handles decimal time fragment values in locators (e.g., t=1.5), which previously caused playback to restart from the beginning.