#786 Allow to download content from the Android library

[Emmanuel Engelhart]

This should be implemented one time https://sourceforge.net/p/kiwix/feature-requests/785/ is completed.

The library allows to get quickly an overview of the ZIM files available on the mobile device. To get new content, people need to go online with a web browser to download them. This is not user friendly and generates many problems. For this reason, it would be better to be able to download these content in Kiwix itself.

This library download feature should work in a similar way like for the PC version but does not require to use aria2c, the whole should be implemented using Android native download primitives.

Here is a list of sub-tasks:
- Download "automatically" the online catalog from http://www.kiwix.org/library.xml
- Create an option to desactivate this
- Add a security to warn user if he uses mobile data
- Parse the XML file and store results in the local sqlite library
- Create a primitive Metalink parser to be able to extract HTTP links
- Create a solution download the content to a specific location
- Modify the library UI to allow download/stop/pauve and progressbar
- Add filtering options in the library UI to be able to find out the content you need
- Modify the UI to quickly be able to identify content on the device/online content/content downloading

[Alexey Baturin]

I would vote for that feature. Downloading ZIM files is the most annoying thing on Android devices now. I'm an experienced user, but still got stuck for a while on this initial unobvious step.

[the_redburn]

This should be the top priority. And the files should be split into 4 GB chunks.
Based on the publics stats on the Kiwix Google download page, it was installed more than 100 000 times but there's less than 3000 users.
How many frustrated users tried it and then uninstalled it because it didn't work?

[Emmanuel Engelhart]

implemented, will be available in Kiwix 2.0.