replace deprecated classes, update code, fix errors, add missing stuff

resources/meson.build

@@ -1,10 +1,4 @@
-blueprints = custom_target('blueprints',
-  input: files(
-    'window.blp'
-  ),
-  output: '.',
-  command: [find_program('blueprint-compiler'), 'batch-compile', '@OUTPUT@', '@CURRENT_SOURCE_DIR@', '@INPUT@'],
-)
+subdir('ui')
 
 resources = gnome.compile_resources('resources',
   'flashcards.gresource.xml',
@@ -12,4 +6,27 @@ resources = gnome.compile_resources('resources',
   c_name: 'flashcards'
 )
 
-schemas = gnome.compile_schemas()
+compile_schemas = find_program('glib-compile-schemas', required: false, disabler: true)
+test('Validate schema file',
+     compile_schemas,
+     args: ['--strict', '--dry-run', meson.current_source_dir()])
+
+install_data('li.sopht.Flashcards.gschema.xml',
+   install_dir: get_option('datadir') / 'glib-2.0/schemas',
+)
+
+desktop_file = i18n.merge_file(
+        input: 'li.sopht.Flashcards.desktop.in',
+       output: 'li.sopht.Flashcards.desktop',
+         type: 'desktop',
+       po_dir: '../po',
+      install: true,
+  install_dir: get_option('datadir') / 'applications'
+)
+
+desktop_utils = find_program('desktop-file-validate', required: false)
+if desktop_utils.found()
+  test('Validate desktop file', desktop_utils, args: [desktop_file])
+endif
+
+subdir('icons')