[SailfishDevel] Map applications in Harbour

[rinigus]

Hi,

reading through this week community meeting, I saw that Jolla is planning
to have internal discussions regarding map apps and the open-source
predictive keyboard. While keyboard is somewhat simpler case (in terms of
dependencies), I would like to save Jolla's time and list the dependencies
required for inclusion of such mapping applications as WhoGo Maps. This
internal discussion is very much welcome and I would like to stress that
such incorporation is actually relatively simple.

1: It may sound surprising, but we need ability to use QtPositioning and
QtLocation. In this sense, application developers have much faster response
time than Jolla and I am sure we'll be able to adapt to transition from
QtPositioning/QtLocation 5.2 to 5.6 in a blink of an eye, comparing to
soon^TM.

2: WhoGo Maps (and sports app Laufhelden) use Mapbox GL for showing maps.
This is done via QML plugin https://github.com/rinigus/mapbox-gl-qml . The
plugin is based on recent QtLocation code and my own development on the
basis of it. Its API has been designed to make it simple to access Mapbox
GL functionality from pure QML applications and was shaped while I was
porting Poor Maps to this widget. Since API is in our own hands, we could
keep it as stable as we please. To compile the plugin, Mapbox GL branch
specifically developed for QtLocation inclusion is used. This requires
newer gcc; SFOS version is compiled with gcc 6.4 (
https://build.merproject.org/package/show/home:rinigus:toolbox/opt-gcc).
Plugin license is LGPLv3 since some of the code comes from newer
QtLocation. Plugin and corresponding QMapboxGL are packaged and compiled at
OBS. I don't know Mer's licensing policy and who is deciding it (community
or Jolla), but it seems to me that this QML maybe incorporated into it.
Alternative would be to have it in some separate repository.

3: For voice instructions, we need TTS engines. Two of them (mimic, flite
based; picoTTS) are available and packaged at OBS. I would suggest to
incorporate them into Mer

Finally, regarding online/offline maps and EU network charges. The privacy,
network coverage redundancy, and requirements for OSM Scout Server have
been addressed during the meeting by community members. However, while
network access is much cheaper in EU, don't forget that online maps require
a server on the other side. There are few commercial solutions, but, they
are not cheap. @otsaloma had to install his own server to go around these
costs. So, with incorporation of maps software and distribution of it among
many users (many is relative) may lead to a requirement of setting up the
server(s) or paying for it. Offline maps are cheaper due to the local
processing of requests, but may require larger network bandwidth to get
maps on devices. So far, @MartinK and  @bomo are distributing maps prepared
by me via their servers (thank you!).

I hope that I didn't forget anything.

Have a nice weekend,

Rinigus
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.sailfishos.org/pipermail/devel/attachments/20180407/6f289066/attachment.html>