[glib: 16/24] GAppInfo: Add async API to get default Application for content type

[Philip Withnall <pwithnall src gnome org>]

commit 44dbd4317083dcb0f989d8e03e36a4694eacef5b
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Wed Jun 1 21:45:58 2022 +0200

    GAppInfo: Add async API to get default Application for content type
    
    Make possible to fetch the Application for default content type in a
    thread without using blocking I/O.

 docs/reference/gio/gio-sections-common.txt |   2 +
 gio/gappinfo.c                             | 100 +++++++++++++++++++++++++
 gio/gappinfo.h                             |   9 +++
 gio/tests/desktop-app-info.c               | 114 +++++++++++++++++++++++++++++
 4 files changed, 225 insertions(+)
---
diff --git a/docs/reference/gio/gio-sections-common.txt b/docs/reference/gio/gio-sections-common.txt
index 5f45a66f42..be4311701e 100644
--- a/docs/reference/gio/gio-sections-common.txt
+++ b/docs/reference/gio/gio-sections-common.txt
@@ -1442,6 +1442,8 @@ g_app_info_get_supported_types
 g_app_info_get_all
 g_app_info_get_all_for_type
 g_app_info_get_default_for_type
+g_app_info_get_default_for_type_async
+g_app_info_get_default_for_type_finish
 g_app_info_get_default_for_uri_scheme
 g_app_info_get_fallback_for_type
 g_app_info_get_recommended_for_type
diff --git a/gio/gappinfo.c b/gio/gappinfo.c
index 8f64974c24..cced4d0220 100644
--- a/gio/gappinfo.c
+++ b/gio/gappinfo.c
@@ -778,6 +778,106 @@ g_app_info_should_show (GAppInfo *appinfo)
   return (* iface->should_show) (appinfo);
 }
 
+typedef struct {
+  char *content_type;
+  gboolean must_support_uris;
+} DefaultForTypeData;
+
+static void
+default_for_type_data_free (DefaultForTypeData *data)
+{
+  g_free (data->content_type);
+  g_free (data);
+}
+
+static void
+get_default_for_type_thread (GTask         *task,
+                             gpointer       object,
+                             gpointer       task_data,
+                             GCancellable  *cancellable)
+{
+  DefaultForTypeData *data = task_data;
+  GAppInfo *info;
+
+  info = g_app_info_get_default_for_type (data->content_type,
+                                          data->must_support_uris);
+
+  if (!info)
+    {
+      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_FOUND,
+                               _("Failed to find default application for "
+                                 "content type ‘%s’"), data->content_type);
+      return;
+    }
+
+  g_task_return_pointer (task, g_steal_pointer (&info), g_object_unref);
+}
+
+/**
+ * g_app_info_get_default_for_type_async:
+ * @content_type: the content type to find a #GAppInfo for
+ * @must_support_uris: if %TRUE, the #GAppInfo is expected to
+ *     support URIs
+ * @cancellable: optional #GCancellable object, %NULL to ignore
+ * @callback: (nullable): a #GAsyncReadyCallback to call when the request is done
+ * @user_data: (nullable): data to pass to @callback
+ *
+ * Asynchronously gets the default #GAppInfo for a given content type.
+ *
+ * Since: 2.74
+ */
+void
+g_app_info_get_default_for_type_async  (const char          *content_type,
+                                        gboolean             must_support_uris,
+                                        GCancellable        *cancellable,
+                                        GAsyncReadyCallback  callback,
+                                        gpointer             user_data)
+{
+  GTask *task;
+  DefaultForTypeData *data;
+
+  g_return_if_fail (content_type != NULL && *content_type != '\0');
+  g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
+
+  data = g_new0 (DefaultForTypeData, 1);
+  data->content_type = g_strdup (content_type);
+  data->must_support_uris = must_support_uris;
+
+  task = g_task_new (NULL, cancellable, callback, user_data);
+  g_task_set_source_tag (task, g_app_info_get_default_for_type_async);
+  g_task_set_task_data (task, data, (GDestroyNotify) default_for_type_data_free);
+  g_task_set_check_cancellable (task, TRUE);
+  g_task_run_in_thread (task, get_default_for_type_thread);
+  g_object_unref (task);
+}
+
+/**
+ * g_app_info_get_default_for_type_finish:
+ * @result: a #GAsyncResult
+ * @error: (nullable): a #GError
+ *
+ * Finishes a default #GAppInfo lookup started by
+ * g_app_info_get_default_for_type_async().
+ *
+ * If no #GAppInfo is found, then @error will be set to %G_IO_ERROR_NOT_FOUND.
+ *
+ * Returns: (transfer full): #GAppInfo for given @content_type or
+ *     %NULL on error.
+ *
+ * Since: 2.74
+ */
+GAppInfo *
+g_app_info_get_default_for_type_finish (GAsyncResult  *result,
+                                        GError       **error)
+{
+  g_return_val_if_fail (g_task_is_valid (result, NULL), NULL);
+  g_return_val_if_fail (g_task_get_source_tag (G_TASK (result)) ==
+                        g_app_info_get_default_for_type_async, NULL);
+  g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+  return g_task_propagate_pointer (G_TASK (result), error);
+}
+
 /**
  * g_app_info_launch_default_for_uri:
  * @uri: the uri to show
diff --git a/gio/gappinfo.h b/gio/gappinfo.h
index 8a49ab42c1..722e8b36d4 100644
--- a/gio/gappinfo.h
+++ b/gio/gappinfo.h
@@ -246,6 +246,15 @@ void      g_app_info_reset_type_associations     (const char  *content_type);
 GLIB_AVAILABLE_IN_ALL
 GAppInfo *g_app_info_get_default_for_type        (const char  *content_type,
                                                   gboolean     must_support_uris);
+GLIB_AVAILABLE_IN_2_74
+void      g_app_info_get_default_for_type_async  (const char          *content_type,
+                                                  gboolean             must_support_uris,
+                                                  GCancellable        *cancellable,
+                                                  GAsyncReadyCallback  callback,
+                                                  gpointer             user_data);
+GLIB_AVAILABLE_IN_2_74
+GAppInfo *g_app_info_get_default_for_type_finish (GAsyncResult         *result,
+                                                  GError              **error);
 GLIB_AVAILABLE_IN_ALL
 GAppInfo *g_app_info_get_default_for_uri_scheme  (const char  *uri_scheme);
 
diff --git a/gio/tests/desktop-app-info.c b/gio/tests/desktop-app-info.c
index 65815fe70a..75bf6c557f 100644
--- a/gio/tests/desktop-app-info.c
+++ b/gio/tests/desktop-app-info.c
@@ -154,6 +154,119 @@ test_default (void)
   g_object_unref (info3);
 }
 
+typedef struct
+{
+  GAppInfo *expected_info;
+  GMainLoop *loop;
+} DefaultForTypeData;
+
+static void
+on_default_for_type_cb (GObject      *object,
+                        GAsyncResult *result,
+                        gpointer      user_data)
+{
+  GAppInfo *info;
+  GError *error = NULL;
+  DefaultForTypeData *data = user_data;
+
+  g_assert_null (object);
+
+  info = g_app_info_get_default_for_type_finish (result, &error);
+
+  if (data->expected_info)
+    {
+      g_assert_nonnull (info);
+      g_assert_no_error (error);
+      g_assert_true (g_app_info_equal (info, data->expected_info));
+    }
+  else
+    {
+      g_assert_null (info);
+      g_assert_error (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND);
+    }
+
+  g_main_loop_quit (data->loop);
+  g_clear_object (&info);
+  g_clear_error (&error);
+}
+
+static void
+test_default_async (void)
+{
+  DefaultForTypeData data;
+  GAppInfo *info1, *info2, *info3;
+  GList *list;
+  GError *error = NULL;
+
+  data.loop = g_main_loop_new (NULL, TRUE);
+
+  info1 = create_app_info ("Blah1");
+  info2 = create_app_info ("Blah2");
+  info3 = create_app_info ("Blah3");
+
+  g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL,
+                         "*assertion*content_type*failed*");
+  g_app_info_get_default_for_type_async (NULL, FALSE, NULL, NULL, NULL);
+  g_test_assert_expected_messages ();
+
+  g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL,
+                         "*assertion*content_type*failed*");
+  g_app_info_get_default_for_type_async ("", FALSE, NULL, NULL, NULL);
+  g_test_assert_expected_messages ();
+
+  g_app_info_set_as_default_for_type (info1, "application/x-test", &error);
+  g_assert_no_error (error);
+
+  g_app_info_set_as_default_for_type (info2, "application/x-test", &error);
+  g_assert_no_error (error);
+
+  data.expected_info = info2;
+  g_app_info_get_default_for_type_async ("application/x-test", FALSE,
+                                         NULL, on_default_for_type_cb, &data);
+  g_main_loop_run (data.loop);
+
+  /* now try adding something, but not setting as default */
+  g_app_info_add_supports_type (info3, "application/x-test", &error);
+  g_assert_no_error (error);
+
+  /* check that info2 is still default */
+  data.expected_info = info2;
+  g_app_info_get_default_for_type_async ("application/x-test", FALSE,
+                                         NULL, on_default_for_type_cb, &data);
+  g_main_loop_run (data.loop);
+
+  /* now remove info1 again */
+  g_app_info_remove_supports_type (info1, "application/x-test", &error);
+  g_assert_no_error (error);
+
+  /* and make sure info2 is still default */
+  data.expected_info = info2;
+  g_app_info_get_default_for_type_async ("application/x-test", FALSE,
+                                         NULL, on_default_for_type_cb, &data);
+  g_main_loop_run (data.loop);
+
+  /* now clean it all up */
+  g_app_info_reset_type_associations ("application/x-test");
+
+  data.expected_info = NULL;
+  g_app_info_get_default_for_type_async ("application/x-test", FALSE,
+                                         NULL, on_default_for_type_cb, &data);
+  g_main_loop_run (data.loop);
+
+  list = g_app_info_get_all_for_type ("application/x-test");
+  g_assert_null (list);
+
+  g_app_info_delete (info1);
+  g_app_info_delete (info2);
+  g_app_info_delete (info3);
+
+  g_object_unref (info1);
+  g_object_unref (info2);
+  g_object_unref (info3);
+
+  g_main_loop_unref (data.loop);
+}
+
 static void
 test_fallback (void)
 {
@@ -824,6 +937,7 @@ main (int   argc,
 
   g_test_add_func ("/desktop-app-info/delete", test_delete);
   g_test_add_func ("/desktop-app-info/default", test_default);
+  g_test_add_func ("/desktop-app-info/default-async", test_default_async);
   g_test_add_func ("/desktop-app-info/fallback", test_fallback);
   g_test_add_func ("/desktop-app-info/lastused", test_last_used);
   g_test_add_func ("/desktop-app-info/extra-getters", test_extra_getters);