Guidance on Implementing User-Friendly Incremental Page Numbers

[FumikaKodama]

Dear Readium Team,

We are currently developing an EPUB reading application using Readium, and we’re aiming to implement a user-friendly pagination system. Specifically, we would like to display a simple, incremental page number to users — increasing by one with each pagination gesture (e.g., swiping or tapping to turn the page).

We are ultimately looking to provide a consistent and intuitive page number display for users across both reflowable and fixed-layout EPUBs.

Could you advise us on the recommended approach for calculating and tracking these incremental page numbers in both layout types?

Thank you for your support and for your continued work on the Readium project.

Fumika

[mickael-menu]

For fixed-layout, this is already possible as one resource = one page. You can use the locations.position value in the current locator.

However for reflowable it is not possible, because the number of screen pages changes every time you apply different user preferences (e.g. font size) or rotate the screen. This would require rendering in the background all the resources every time there are layout changes, which is not possible with Readium. You can still use locations.position with reflowable EPUBs, but it is more akin to Kindle's locations, not actual screen pages.

[FumikaKodama]

Thank you for your explanation regarding the use of locations.position for fixed-layout EPUBs, and the limitations with reflowable layouts.

We now have a clear direction based on your guidance and will proceed accordingly.
We appreciate your support and the great work you continue to do with Readium.