Since gettext 0.19, gettext itself has been able to extract strings from
and merge translations to .desktop files. As a result, there is no need
to use intltool. More details are available on
https://wiki.gnome.org/MigratingFromIntltoolToGettext, though that page
assumes a project using Autotools, which this project does not.
One advantage of using xgettext rather than intltool is that there is no
need to prefix translatable keys in the .desktop.in file with _. This
patch adjusts tuxpaint.desktop.in accordingly, which makes the input
file itself a valid desktop file.
The LINGUAS file contains the list of supported languages. This could
in principle be generated automatically from one of the other places in
the source tree that has a manually-maintained list of languages; but in
my experience it is generally maintained by hand and checked into the
source tree.
POTFILES.in.in must be updated to remove the intltool-specific file
encoding annotation; instead this is passed to xgettext.
Finally, update-po.sh is rewritten to invoke xgettext and msgfmt rather
than intltool commands.
The mangling of POTFILES.in.in to prefix all filenames with '../' is
only necessary to minimize the churn when updating the .pot and .po
files, to simplify review of this change. The alternative is to pass
--directory=.. to xgettext. This would cause all .po files to be updated
as follows when regenerated:
#. Response to Black (0, 0, 0) color selected
-#: ../colors.h:86
+#: colors.h:86
msgid "Black!"
msgstr "Noir !"
