[gtksourceview/wip/metadata] FileLoader: add load_metadata(), sync and async versions

[Sébastien Wilmet <swilmet src gnome org>]

commit fb1c90f30abda6e45a33186f098d23054f52a625
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Apr 30 15:00:37 2016 +0200

    FileLoader: add load_metadata(), sync and async versions

 docs/reference/gtksourceview-3.0-sections.txt |    3 +
 gtksourceview/gtksourcefileloader.c           |  148 ++++++++++++++++++++++++-
 gtksourceview/gtksourcefileloader.h           |   21 ++++-
 3 files changed, 170 insertions(+), 2 deletions(-)
---
diff --git a/docs/reference/gtksourceview-3.0-sections.txt b/docs/reference/gtksourceview-3.0-sections.txt
index 03fea7e..6bfacb1 100644
--- a/docs/reference/gtksourceview-3.0-sections.txt
+++ b/docs/reference/gtksourceview-3.0-sections.txt
@@ -291,6 +291,9 @@ gtk_source_file_loader_get_location
 gtk_source_file_loader_get_input_stream
 gtk_source_file_loader_load_async
 gtk_source_file_loader_load_finish
+gtk_source_file_loader_load_metadata
+gtk_source_file_loader_load_metadata_async
+gtk_source_file_loader_load_metadata_finish
 gtk_source_file_loader_get_encoding
 gtk_source_file_loader_get_newline_type
 gtk_source_file_loader_get_compression_type
diff --git a/gtksourceview/gtksourcefileloader.c b/gtksourceview/gtksourcefileloader.c
index d409b57..32370b6 100644
--- a/gtksourceview/gtksourcefileloader.c
+++ b/gtksourceview/gtksourcefileloader.c
@@ -77,6 +77,7 @@ enum
 };
 
 #define READ_CHUNK_SIZE 8192
+#define METADATA_QUERY_ATTRIBUTES "metadata::*"
 #define LOADER_QUERY_ATTRIBUTES G_FILE_ATTRIBUTE_STANDARD_CONTENT_TYPE "," \
                                G_FILE_ATTRIBUTE_STANDARD_TYPE "," \
                                G_FILE_ATTRIBUTE_TIME_MODIFIED "," \
@@ -751,7 +752,7 @@ query_info_cb (GFile               *file,
        }
 
        g_file_query_info_async (file,
-                                "metadata::*",
+                                METADATA_QUERY_ATTRIBUTES,
                                 G_FILE_QUERY_INFO_NONE,
                                 g_task_get_priority (loader->priv->task),
                                 g_task_get_cancellable (loader->priv->task),
@@ -1225,6 +1226,151 @@ gtk_source_file_loader_load_finish (GtkSourceFileLoader  *loader,
 }
 
 /**
+ * gtk_source_file_loader_load_metadata:
+ * @loader: a #GtkSourceFileLoader.
+ * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
+ * @error: location to a %NULL #GError, or %NULL.
+ *
+ * Loads synchronously the metadata.
+ *
+ * Returns: whether the metadata was loaded successfully.
+ * Since: 3.22
+ */
+gboolean
+gtk_source_file_loader_load_metadata (GtkSourceFileLoader  *loader,
+                                     GCancellable         *cancellable,
+                                     GError              **error)
+{
+       GFileInfo *metadata;
+       gboolean ok;
+
+       g_return_val_if_fail (GTK_SOURCE_IS_FILE_LOADER (loader), FALSE);
+       g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), FALSE);
+       g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+       if (loader->priv->file == NULL ||
+           loader->priv->location == NULL)
+       {
+               return FALSE;
+       }
+
+       metadata = g_file_query_info (loader->priv->location,
+                                     METADATA_QUERY_ATTRIBUTES,
+                                     G_FILE_QUERY_INFO_NONE,
+                                     cancellable,
+                                     error);
+
+       ok = metadata != NULL;
+
+       _gtk_source_file_set_metadata_info (loader->priv->file, metadata);
+       g_clear_object (&metadata);
+
+       return ok;
+}
+
+static void
+load_metadata_async_cb (GFile        *location,
+                       GAsyncResult *result,
+                       GTask        *task)
+{
+       GtkSourceFileLoader *loader;
+       GFileInfo *metadata;
+       GError *error = NULL;
+
+       DEBUG ({
+              g_print ("%s\n", G_STRFUNC);
+       });
+
+       metadata = g_file_query_info_finish (location, result, &error);
+
+       if (error != NULL)
+       {
+               g_task_return_error (task, error);
+               g_object_unref (task);
+               g_clear_object (&metadata);
+               return;
+       }
+
+       loader = g_task_get_source_object (task);
+       if (loader->priv->file != NULL)
+       {
+               _gtk_source_file_set_metadata_info (loader->priv->file, metadata);
+       }
+
+       g_task_return_boolean (task, TRUE);
+       g_object_unref (task);
+       g_clear_object (&metadata);
+}
+
+/**
+ * gtk_source_file_loader_load_metadata_async:
+ * @loader: a #GtkSourceFileLoader.
+ * @io_priority: the I/O priority of the request. E.g. %G_PRIORITY_LOW,
+ *   %G_PRIORITY_DEFAULT or %G_PRIORITY_HIGH.
+ * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
+ * @callback: (scope async): a #GAsyncReadyCallback to call when the request is
+ *   satisfied.
+ * @user_data: user data to pass to @callback.
+ *
+ * Loads asynchronously the metadata. See the #GAsyncResult documentation to
+ * know how to use this function.
+ *
+ * Since: 3.22
+ */
+void
+gtk_source_file_loader_load_metadata_async (GtkSourceFileLoader *loader,
+                                           gint                 io_priority,
+                                           GCancellable        *cancellable,
+                                           GAsyncReadyCallback  callback,
+                                           gpointer             user_data)
+{
+       GTask *task;
+
+       g_return_if_fail (GTK_SOURCE_IS_FILE_LOADER (loader));
+       g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable));
+
+       if (loader->priv->file == NULL ||
+           loader->priv->location == NULL)
+       {
+               return;
+       }
+
+       task = g_task_new (loader, cancellable, callback, user_data);
+
+       g_file_query_info_async (loader->priv->location,
+                                METADATA_QUERY_ATTRIBUTES,
+                                G_FILE_QUERY_INFO_NONE,
+                                io_priority,
+                                cancellable,
+                                (GAsyncReadyCallback) load_metadata_async_cb,
+                                task);
+}
+
+/**
+ * gtk_source_file_loader_load_metadata_finish:
+ * @loader: a #GtkSourceFileLoader.
+ * @result: a #GAsyncResult.
+ * @error: location to a %NULL #GError, or %NULL.
+ *
+ * Finishes the metadata loading started with
+ * gtk_source_file_loader_load_metadata_async().
+ *
+ * Returns: whether the metadata was loaded successfully.
+ * Since: 3.22
+ */
+gboolean
+gtk_source_file_loader_load_metadata_finish (GtkSourceFileLoader  *loader,
+                                            GAsyncResult         *result,
+                                            GError              **error)
+{
+       g_return_val_if_fail (GTK_SOURCE_IS_FILE_LOADER (loader), FALSE);
+       g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+       g_return_val_if_fail (g_task_is_valid (result, loader), FALSE);
+
+       return g_task_propagate_boolean (G_TASK (result), error);
+}
+
+/**
  * gtk_source_file_loader_get_encoding:
  * @loader: a #GtkSourceFileLoader.
  *
diff --git a/gtksourceview/gtksourcefileloader.h b/gtksourceview/gtksourcefileloader.h
index 3ff4851..fc139b6 100644
--- a/gtksourceview/gtksourcefileloader.h
+++ b/gtksourceview/gtksourcefileloader.h
@@ -5,7 +5,7 @@
  * Copyright (C) 2005 - Paolo Maggi
  * Copyright (C) 2007 - Paolo Maggi, Steve Frécinaux
  * Copyright (C) 2008 - Jesse van den Kieboom
- * Copyright (C) 2014 - Sébastien Wilmet
+ * Copyright (C) 2014, 2016 - Sébastien Wilmet
  *
  * GtkSourceView is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -121,6 +121,25 @@ gboolean            gtk_source_file_loader_load_finish     (GtkSourceFileLoader     
*loader,
                                                                 GAsyncResult            *result,
                                                                 GError                 **error);
 
+GTK_SOURCE_AVAILABLE_IN_3_22
+gboolean                gtk_source_file_loader_load_metadata   (GtkSourceFileLoader     *loader,
+                                                                GCancellable            *cancellable,
+                                                                GError                 **error);
+
+GTK_SOURCE_AVAILABLE_IN_3_22
+void                    gtk_source_file_loader_load_metadata_async
+                                                               (GtkSourceFileLoader     *loader,
+                                                                gint                     io_priority,
+                                                                GCancellable            *cancellable,
+                                                                GAsyncReadyCallback      callback,
+                                                                gpointer                 user_data);
+
+GTK_SOURCE_AVAILABLE_IN_3_22
+gboolean                gtk_source_file_loader_load_metadata_finish
+                                                               (GtkSourceFileLoader     *loader,
+                                                                GAsyncResult            *result,
+                                                                GError                 **error);
+
 GTK_SOURCE_AVAILABLE_IN_3_14
 const GtkSourceEncoding        *gtk_source_file_loader_get_encoding    (GtkSourceFileLoader     *loader);