Re: libchamplain-gtk on Windows

[Jiří Techet <techet gmail com>]

Hi,

unfortunately I'm not very familiar with the state of Windows ports of
GTK, clutter and related libraries but I really suspect it's not in a
very good state. Personally I don't use Windows and don't have it
installed anywhere so I haven't even tried to run libchamplain on it.
It appears someone in the past at least tried to build libchamplain
for Windows (see commit 7bef303) but that's about all what has been
done for the Windows port.

That said, theoretically, I don't see any reason why libchamplain
shouldn't be working under Windows as long as it's dependencies are
working correctly. The issues you describe sound rather like issues
with clutter or clutter-gtk. libchamplain uses just these libraries to
handle events, view resizing etc. and does nothing special by itself.

I'd suggest building clutter and clutter-gtk by yourself - there are
plenty of tests and demos in the source tarballs, including events,
resizing etc. which you can use to determine whether clutter is
responsible for the issues you have.

Cheers,
Jiri

On Wed, Feb 12, 2014 at 4:03 PM, M. D. <mlists line72 net> wrote:
> Hello all,
>
> I have an application [1] that I've written and am trying to port to
> Windows so that my city's transit agency can use it. My application is
> written in python with gtk+3 and libchamplain python bindings. Since
> there are no official builds of libchamplain for windows, I have tried
> two different approaches:
>
> 1. PyGObject (PyGI)
> http://opensourcepack.blogspot.com/p/pygobject-pygi-aio.html
>
> This is a fantastic project that has native builds of everything that I
> needed. However, I am having issues with libchamplain that are keeping
> it from running. Most importantly, events don't seem to be handled
> correctly. Using the default Clutter backend, no events are ever sent.
> This means that zooming and panning don't work, and mouse clicks are
> never captured. Also, this doesn't seem to resize correctly.
>
> After playing around with this for a while, I tried changing the clutter
> backend to the gdk backend by doing:
>
> Clutter.set_windowing_backend(Clutter.WINDOWING_GDK)
>
> This improved the situation for events. I can now correctly get mouse
> clicks, pan, and zoom. But resizing still doesn't work.  When I say
> resizing doesn't work, I mean that if the window changes size, the map
> doesn't resize with it. It seems to resize horizontally, but not
> vertically. But to make things worse, if the window is resized, even
> though the map doesn't resize, when the user clicks on the map, the
> coordinates are now incorrect!
>
> But changing to the GDK backend had additional drawbacks. This seemed to
> change the font rendering and completely broke it under Windows. I now
> get a bunch of errors stating:
>
> Pango-WARNING **: failed to choose a font, expect ugly output.
> engine-type='PangoRenderWin32', script='latin'
>
> and all the fonts show up as empty or symbols.
>
> 2. I then took a second approach and tried using cygwin.
>
> I had even more trouble with cygwin. It too had the issues with events,
> but it also constantly and randomly segfaulted. Changing the windowing
> backend also help with the mouse events, but it still had the same
> resize issues. But it crashed so often under cygwin, that it wasn't
> useful.
>
> I don't know if these are issues in libchamplain, or if it is a deeper
> issue in clutter. I'm suspecting it might be clutter since changing the
> backend made some things work, but I wanted to check here first.
>
> Any help would be much appreciated! Thanks in advance.
> -m
>
>
> [1] http://line72.net/index.php/software/subte/
>
>
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