Add .desktop file

This adds a .desktop file (without icon for now), which will automatically be installed when
`meson install` is run.

build-aux/meson_post_install.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+
+from os import environ, path
+from subprocess import call
+
+if not environ.get('DESTDIR', ''):
+    PREFIX = environ.get('MESON_INSTALL_PREFIX', '/usr/local')
+    DATA_DIR = path.join(PREFIX, 'share')
+    print('Updating icon cache...')
+    call(['gtk-update-icon-cache', '-qtf', path.join(DATA_DIR, 'icons/hicolor')])
+    print("Updating desktop database...")
+    call(["update-desktop-database", path.join(DATA_DIR, 'applications')])

data/meson.build

@@ -0,0 +1,16 @@
+desktop_file = '@0@.desktop'.format(base_id)
+
+if desktop_file_validate.found()
+  test(
+    'validate-desktop',
+    desktop_file_validate,
+    args: [
+      desktop_file
+    ],
+  )
+endif
+
+install_data(
+    desktop_file,
+    install_dir: datadir / 'applications'
+)

data/org.freedesktop.ryuukyu.Helvum.desktop

@@ -0,0 +1,8 @@
+[Desktop Entry]
+Name=Helvum
+GenericName=Patchbay
+Comment=A patchbay for pipewire
+Type=Application
+Exec=helvum
+Terminal=false
+Categories=AudioVideo;Audio;Video;Midi;Settings;GNOME;GTK;

meson.build

@@ -6,6 +6,8 @@ project(
   meson_version: '>=0.50.0'
 )
 
+base_id = 'org.freedesktop.ryuukyu.Helvum'
+
 dependency('glib-2.0', version: '>= 2.48')
 dependency('gtk4',     version: '>= 4.0.0')
 dependency('libpipewire-0.3')
@@ -16,11 +18,13 @@ if rust_version < min_rust_version
   error('Rust version too old: Required version is ' + min_rust_version + ' but actual version is ' + rust_version)
 endif
 
+desktop_file_validate = find_program('desktop-file-validate', required: false)
 cargo = find_program('cargo', required: true)
 cargo_script = find_program('build-aux/cargo.sh')
 
 prefix = get_option('prefix')
 bindir = prefix / get_option('bindir')
+datadir = prefix / get_option('datadir')
 
 cargo_sources = files(
   'Cargo.toml',
@@ -28,3 +32,6 @@ cargo_sources = files(
 )
 
 subdir('src')
+subdir('data')
+
+meson.add_install_script('build-aux/meson_post_install.py')