[virt-manager PATCH v3 4/8] Handle desktop files using gettext

[Pino Toscano]

Starting from version 0.19, gettext has native capabilities to extract
from, and merge back translations in desktop files.

Hence, use xgettext to extract messages, and msgfmt to create a desktop
file with translations; this requires two changes:
- the keys in desktop files do not need to be prefixed with underscore
  anymore
- add a LINGUAS file in the meta-po subdirectory (empty for now), as
  otherwise msgfmt does not recognize the directory as containing
  translations

Update the gettext required version in INSTALL.md.

Signed-off-by: Pino Toscano <ptoscano at redhat.com>
---
 INSTALL.md                   |  2 +-
 data/virt-manager.desktop.in |  4 ++--
 meta-po/LINGUAS              |  0
 setup.py                     | 42 +++++++++++++++++++++++++++++++++---
 4 files changed, 42 insertions(+), 6 deletions(-)
 create mode 100644 meta-po/LINGUAS

diff --git a/INSTALL.md b/INSTALL.md
index 7080fce8..dbc3ebde 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -30,7 +30,7 @@ A detailed dependency list can be found in
 
 Minimum version requirements of major components:
 
-   - gettext
+   - gettext >= 0.19
    - python >= 3.4
    - gtk3 >= 3.22
    - libvirt-python >= 0.6.0
diff --git a/data/virt-manager.desktop.in b/data/virt-manager.desktop.in
index 33765ec3..41cc26a1 100644
--- a/data/virt-manager.desktop.in
+++ b/data/virt-manager.desktop.in
@@ -1,6 +1,6 @@
 [Desktop Entry]
-_Name=Virtual Machine Manager
-_Comment=Manage virtual machines
+Name=Virtual Machine Manager
+Comment=Manage virtual machines
 Icon=virt-manager
 Exec=virt-manager
 Type=Application
diff --git a/meta-po/LINGUAS b/meta-po/LINGUAS
new file mode 100644
index 00000000..e69de29b
diff --git a/setup.py b/setup.py
index d1202c68..95e7b16e 100755
--- a/setup.py
+++ b/setup.py
@@ -62,7 +62,7 @@ _appdata_files = [
 
 def _generate_meta_potfiles_in():
     potfiles = ""
-    for ignore, filelist in _desktop_files + _appdata_files:
+    for ignore, filelist in _appdata_files:
         potfiles += "\n".join(filelist) + "\n"
     return potfiles
 
@@ -118,9 +118,35 @@ class my_build_i18n(distutils.command.build.build):
             if po_mtime > max_po_mtime:
                 max_po_mtime = po_mtime
 
+        # merge .in with translations using gettext
+        for (file_set, switch) in [(_desktop_files, "--desktop")]:
+            for (target, files) in file_set:
+                build_target = os.path.join("build", target)
+                if not os.path.exists(build_target):
+                    os.makedirs(build_target)
+
+                files_merged = []
+                for f in files:
+                    if f.endswith(".in"):
+                        file_merged = os.path.basename(f[:-3])
+                    else:
+                        file_merged = os.path.basename(f)
+
+                    file_merged = os.path.join(build_target, file_merged)
+                    cmd = ["msgfmt", switch, "--template", f, "-d", po_dir,
+                           "-o", file_merged]
+                    mtime_merged = (os.path.exists(file_merged) and
+                                    os.path.getmtime(file_merged)) or 0
+                    mtime_file = os.path.getmtime(f)
+                    if (mtime_merged < max_po_mtime or
+                        mtime_merged < mtime_file):
+                        # Only build if output is older than input (.po,.in)
+                        self.spawn(cmd)
+                    files_merged.append(file_merged)
+                self.distribution.data_files.append((target, files_merged))
+
         # merge .in with translation
-        for (file_set, switch) in [(_desktop_files, "-d"),
-                                   (_appdata_files, "-x")]:
+        for (file_set, switch) in [(_appdata_files, "-x")]:
             for (target, files) in file_set:
                 build_target = os.path.join("build", target)
                 if not os.path.exists(build_target):
@@ -703,7 +729,12 @@ class ExtractMessages(distutils.core.Command):
         po_dir = "meta-po"
         potfiles = _generate_meta_potfiles_in()
         potpath = "meta-po/POTFILES.in"
+        pot_file = os.path.join(po_dir, "virt-manager-meta.pot")
+
+        xgettext_args = self.common_xgettext_args + \
+                        ["-o", pot_file, "--package-name=virt-manager-meta"]
 
+        # First extract the messages from the AppStream sources
         try:
             open(potpath, "w").write(potfiles)
             cmd = ["intltool-update", "-p", "-g", "virt-manager-meta"]
@@ -714,6 +745,11 @@ class ExtractMessages(distutils.core.Command):
         finally:
             os.unlink(potpath)
 
+        # Then extract the messages from the desktop files
+        desktop_files = [f for sublist in _desktop_files for f in sublist[1]]
+        cmd = xgettext_args + ["-j", "-L", "Desktop"] + desktop_files
+        self.spawn(cmd)
+
     def run(self):
         self._extract_main()
         self._extract_meta()
-- 
2.26.2