Re: Animated zoom and scaled tiles implemented

[Jiří Techet <techet gmail com>]

Hi Tomaž,

On Wed, Aug 17, 2011 at 18:10, Quikee <quikee gmail com> wrote:
> On Tue, Aug 16, 2011 at 01:07, Jiří Techet <techet gmail com> wrote:
>> Hi,
>>
>> this has been a really calm release cycle. First because I didn't have
>> much time to implement new features and second that there have been no
>> bugs reported. No bugs reported can have two explanations: either
>> there are really no bugs in libchamplain or nobody is using it. I'll
>> assume the first option is right :-).
>>
>> Anyway, I've just pushed a new feature which is animated zoom in and
>> out. This means that when you zoom in, you'll see the map scaled to
>> the new zoom level. The rescaled image stays in the background until
>> the new tiles are downloaded so it eliminates the blank screen moments
>> between two zooms. Basically it works similarly to Google maps. Please
>> test it and let me know if the animations should be adjusted in some
>> way. I'll also add some knob to make the animations optional.
>>
>> I plan to make the first 0.12 release the next weekend. There won't be
>> any other major features in the 0.12 release - just some cleanups and
>> documentation updates (this time I should really find some time to
>> write a libchamplain overview and tutorial).
>>
>> Cheers,
>>
>> Jiri
>> _______________________________________________
>> libchamplain-list mailing list
>> libchamplain-list gnome org
>> http://mail.gnome.org/mailman/listinfo/libchamplain-list
>>
>
> Hi,
>
> It is great that libchamplain 0.12 will materialize. Because of the
> silence I thought that there won't be any release this Gnome release
> cycle.
>
> As of bugs I have some but they may be connected with vala 0.12 gir
> support not being the best and I did not test vala 0.14 (0.13.x). The

Vala and introspection is the reason why I won't make a release this
weekend after all. I'm currently on Ubuntu Natty which still uses GTK
2 and cannot test introspection and vapi generation properly. I could
install the latest gnome using jhbuild but I'm a bit lazy to do that
so I'll rather install the development release of Ubuntu, but I won't
have time to do it until the next week.

> only thing that I have found besides this is that I think that the map
> tiles are not rechecked if they are changed. If I change or add
> something in OSM, I have to delete the cache to force to re-download
> the tiles. In the past libchamplain did re-download the tiles this is
> what I am sure.

That's strange, I've made some tests and it seems to work. It's
implemented this way: libchamplain checks the date of the tile in the
cache and if it's not older than 7 days, it uses this tile. If it's
older, it uses the stored ETag for the given tile and using the ETag
it checks whether there's a new tile on the server. If the response is
that the tile was not modified, it just sets new date for the tile (so
it won't be checked for the following 7 days) and uses the tile from
the cache. If the tile was modified or the tile doesn't exist in the
cache, it downloads the tile from the server.

>
> A good thing would also be to update the todos and ideas as I don't
> have a clue what to expect from the next versions of libchamplain. One
> thing that I am missing in libchamplain now is a continuous map from
> west to east, the ability to rotate the map would also be cool.

Both of the features are in libchamplain's bug tracker. I'd also like
to have the possibility to rotate the map but it's a bit more work.
It's not just plain rotation, also the correct tiles have to be loaded
and while e.g. paths should be rotated too, the labels should not be
rotated. So the implementation isn't just telling the clutter actor to
rotate. Regarding the continuous map, I also suspect it won't be as
easy to implement as it may seem (maybe I'm wrong). In any case,
patches are welcome :-).

Cheers,

Jiri

>
> Regards, Tomaž
>