extensions-tool: Add template metadata

When we allow users to choose between different templates, we should
provide some context for each template to facilitate that choice.

Add that metadata in the form of a .desktop file, which allows us to
specify name and description, and is well supported by our translation
infrastructure.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/812

po/POTFILES.in

@@ -94,5 +94,6 @@ subprojects/extensions-tool/src/command-prefs.c
 subprojects/extensions-tool/src/command-reset.c
 subprojects/extensions-tool/src/command-uninstall.c
 subprojects/extensions-tool/src/main.c
+subprojects/extensions-tool/src/templates/00-plain.desktop.in
 # Please do not remove this file from POTFILES.in. Run "git submodule init && git submodule update" to get it.
 subprojects/gvc/gvc-mixer-control.c

subprojects/extensions-tool/meson.build

@@ -35,6 +35,8 @@ cc = meson.get_compiler('c')
 
 bash_completion = dependency('bash-completion', required: get_option('bash_completion'))
 
+po_dir = meson.source_root() + '/po'
+
 subdir('src')
 
 if bash_completion.found()

subprojects/extensions-tool/src/gnome-extensions-tool.gresource.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <gresources>
   <gresource prefix="/org/gnome/extensions-tool">
+    <file>templates/00-plain.desktop</file>
     <file>templates/plain/extension.js</file>
     <file>templates/plain/stylesheet.css</file>
   </gresource>

subprojects/extensions-tool/src/meson.build

@@ -22,9 +22,12 @@ sources = [
   'main.c'
 ]
 
+subdir('templates')
+
 resources = gnome.compile_resources('resources',
   'gnome-extensions-tool.gresource.xml',
-  source_dir: '.'
+  source_dir: ['.', meson.current_build_dir()],
+  dependencies: template_deps,
 )
 
 executable('gnome-extensions',

subprojects/extensions-tool/src/templates/00-plain.desktop.in

@@ -0,0 +1,5 @@
+[Desktop Entry]
+Type=Application
+Name=Plain
+Comment=An empty extension
+Path=plain

subprojects/extensions-tool/src/templates/meson.build

@@ -0,0 +1,12 @@
+template_metas = [
+  '00-plain.desktop',
+]
+template_deps = []
+foreach template : template_metas
+  template_deps += i18n.merge_file(template,
+    input: template + '.in',
+    output: template,
+    po_dir: po_dir,
+    type: 'desktop',
+  )
+endforeach