page number indicator: migrate to new Javascript pagination API (see iOS launcher app)

[danielweck]

[danielweck]

see "pageDidChange" event:

https://github.com/readium/SDKLauncher-iOS/blob/develop/Classes/EPubViewController.m#L656

see updateToolbar:

https://github.com/readium/SDKLauncher-iOS/blob/develop/Classes/EPubViewController.m#L420

[danielweck]

Current Android code:

onPaginationChanged callback:
https://github.com/readium/SDKLauncher-Android/blob/develop/SDKLauncher-Android/src/org/readium/sdk/android/launcher/WebViewActivity.java#L497

PaginationInfo:
https://github.com/readium/SDKLauncher-Android/blob/develop/SDKLauncher-Android/src/org/readium/sdk/android/launcher/model/PaginationInfo.java#L41

Page:
https://github.com/readium/SDKLauncher-Android/blob/develop/SDKLauncher-Android/src/org/readium/sdk/android/launcher/model/Page.java#L35

[danielweck]

Addressed in this Pull Request: #40
(pending peer review...)

[balaji24]

@jccr @danielweck I had a couple of questions regarding page numbers:

1. Immediately after loading the book, how do I get the number of pages in each chapter?

• I see it in the onPaginationChanged callback, but that gives me only for that chapter and there is no easy way to access that data for all chapters or is there?

2. Is there a way to get the total number of pages in the book? I know this question is a little on the harder side because of the whole reflowable and fixed layout types but I was just wondering if there is a simple way to calculate it.

The basic situation is to be able to have a scrubber at the bottom of the book reader and being able to go through the book quickly.

[danielweck]

See how the PAGINATION_CHANGED event is captured in host_app_feedback.js:
https://github.com/readium/SDKLauncher-iOS/blob/develop/Resources/host_app_feedback.js#L137
This serialises the data into a JSON payload that can be consumed on the native application side:
https://github.com/readium/readium-shared-js/blob/develop/js/models/current_pages_info.js#L38
See for example how the iOS launcher app consumes / stores the data in native form:
https://github.com/readium/SDKLauncher-iOS/blob/develop/Classes/EPubViewController.m#L665
And see the updateToolbar function uses that information to display meaningful page context:
https://github.com/readium/SDKLauncher-iOS/blob/develop/Classes/EPubViewController.m#L429

Now, there is a Pull Request to adopt a similar design pattern in Android, but as you can see there are pending issues:
#40
We need to get back to this PR, adjust and merge. It shouldn't be very hard.