add meson build system

After switching to meson, calling the `g-ir-scanner` command with the
`--warn-all` parameter in the generated `build.ninja` file will display these warnings:

```
Warning: MateMenu: symbol="DesktopEntryType": unknown namespace for identifier "DesktopEntryType"
Warning: MateMenu: symbol='desktop_entry_new': Unknown namespace for symbol 'desktop_entry_new'
Warning: MateMenu: symbol='EntryDirectory': Unknown namespace for identifier 'EntryDirectory'
```

The reason for these warnings is that we use `MateMenu` as `identifier_prefix`
and `matemenu` as `symbol_prefix`, but the symbols that report warnings do not
start with these prefixes.

1 files changed, 72 insertions, 0 deletions

diff --git a/libmenu/meson.build b/libmenu/meson.build
new file mode 100644
index 0000000..5fbc93e
--- /dev/null
+++ b/libmenu/meson.build
@@ -0,0 +1,72 @@
+source_h = [
+  'matemenu-tree.h',
+]
+
+install_headers(source_h, subdir : 'mate-menus')
+
+sources = [
+  'desktop-entries.h',
+  'entry-directories.h',
+  'menu-layout.h',
+  'menu-monitor.h',
+  'menu-util.h',
+  'desktop-entries.c',
+  'entry-directories.c',
+  'matemenu-tree.c',
+  'menu-layout.c',
+  'menu-monitor.c',
+  'menu-util.c',
+]
+
+gnome = import('gnome')
+pkg = import('pkgconfig')
+
+libmate_menu = shared_library('mate-menu',
+  sources,
+  dependencies: [gio_unix_dep],
+  soversion: soversion,
+  version: libversion,
+  include_directories: top_srcdir,
+  install : true,
+  install_dir : get_option('libdir')
+  )
+
+libmate_menu_deps = declare_dependency(sources: source_h,
+                                include_directories: [top_srcdir, include_directories('.')],
+                                dependencies: [gio_unix_dep],
+                                link_with: libmate_menu)
+
+pkg.generate(
+  name: 'mate-menu',
+  version: meson.project_version(),
+  description: 'Desktop Menu Specification Implementation',
+  requires_private: 'gio-unix-2.0',
+  filebase: 'libmate-menu',
+  libraries: '-lmate-menu',
+  subdirs: 'mate-menus',
+  )
+
+if get_option('introspection')
+  libmate_menu_gir = gnome.generate_gir(libmate_menu,
+    sources: [source_h, sources],
+    nsversion : api_version,
+    namespace : 'MateMenu',
+    symbol_prefix : 'matemenu',
+    export_packages: 'libmatemenu',
+    identifier_prefix : 'MateMenu',
+    link_with: libmate_menu,
+    includes : ['Gio-2.0'],
+    install : true,
+    install_dir_gir: girdir,
+    install_dir_typelib: typelibdir,
+    extra_args: [ '--c-include=mate-menus/matemenu-tree.h' ],
+    )
+  if get_option('vapi')
+    mate_menu_vapi = gnome.generate_vapi('libmate-menu',
+      sources: libmate_menu_gir.get(0),
+      packages: 'gio-unix-2.0',
+      install: true,
+      install_dir: vapidir,
+      )
+  endif
+endif