[gtksourceview] SpaceDrawer: add function to bind matrix property to GSettings key

[Sébastien Wilmet <swilmet src gnome org>]

commit 800ae1646b7d273302e611be8b79cefdfb8d3991
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Wed Oct 5 19:42:45 2016 +0200

    SpaceDrawer: add function to bind matrix property to GSettings key

 docs/reference/gtksourceview-3.0-sections.txt |    1 +
 gtksourceview/gtksourcespacedrawer.c          |   66 +++++++++++++++++++++++++
 gtksourceview/gtksourcespacedrawer.h          |    6 ++
 3 files changed, 73 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gtksourceview-3.0-sections.txt b/docs/reference/gtksourceview-3.0-sections.txt
index cbd63cf..2a04388 100644
--- a/docs/reference/gtksourceview-3.0-sections.txt
+++ b/docs/reference/gtksourceview-3.0-sections.txt
@@ -752,6 +752,7 @@ gtk_source_space_drawer_set_matrix
 gtk_source_space_drawer_get_matrix
 gtk_source_space_drawer_set_enable_matrix
 gtk_source_space_drawer_get_enable_matrix
+gtk_source_space_drawer_bind_matrix_setting
 <SUBSECTION Standard>
 GTK_SOURCE_IS_SPACE_DRAWER
 GTK_SOURCE_IS_SPACE_DRAWER_CLASS
diff --git a/gtksourceview/gtksourcespacedrawer.c b/gtksourceview/gtksourcespacedrawer.c
index ddf28fd..b392be8 100644
--- a/gtksourceview/gtksourcespacedrawer.c
+++ b/gtksourceview/gtksourcespacedrawer.c
@@ -766,6 +766,72 @@ gtk_source_space_drawer_set_enable_matrix (GtkSourceSpaceDrawer *drawer,
        }
 }
 
+static gboolean
+matrix_get_mapping (GValue   *value,
+                   GVariant *variant,
+                   gpointer  user_data)
+{
+       g_value_set_variant (value, variant);
+       return TRUE;
+}
+
+static GVariant *
+matrix_set_mapping (const GValue       *value,
+                   const GVariantType *expected_type,
+                   gpointer            user_data)
+{
+       return g_value_dup_variant (value);
+}
+
+/**
+ * gtk_source_space_drawer_bind_matrix_setting:
+ * @drawer: a #GtkSourceSpaceDrawer object.
+ * @settings: a #GSettings object.
+ * @key: the @settings key to bind.
+ * @flags: flags for the binding.
+ *
+ * Binds the #GtkSourceSpaceDrawer:matrix property to a #GSettings key.
+ *
+ * The #GSettings key must be of the same type as the
+ * #GtkSourceSpaceDrawer:matrix property, that is, `"au"`.
+ *
+ * The g_settings_bind() function cannot be used, because the default GIO
+ * mapping functions don't support #GVariant properties (maybe it will be
+ * supported by a future GIO version, in which case this function can be
+ * deprecated).
+ *
+ * Since: 3.24
+ */
+void
+gtk_source_space_drawer_bind_matrix_setting (GtkSourceSpaceDrawer *drawer,
+                                            GSettings            *settings,
+                                            const gchar          *key,
+                                            GSettingsBindFlags    flags)
+{
+       GVariant *value;
+
+       g_return_if_fail (GTK_SOURCE_IS_SPACE_DRAWER (drawer));
+       g_return_if_fail (G_IS_SETTINGS (settings));
+       g_return_if_fail (key != NULL);
+       g_return_if_fail ((flags & G_SETTINGS_BIND_INVERT_BOOLEAN) == 0);
+
+       value = g_settings_get_value (settings, key);
+       if (!g_variant_is_of_type (value, G_VARIANT_TYPE ("au")))
+       {
+               g_warning ("%s(): the GSettings key must be of type \"au\".", G_STRFUNC);
+               g_variant_unref (value);
+               return;
+       }
+       g_variant_unref (value);
+
+       g_settings_bind_with_mapping (settings, key,
+                                     drawer, "matrix",
+                                     flags,
+                                     matrix_get_mapping,
+                                     matrix_set_mapping,
+                                     NULL, NULL);
+}
+
 void
 _gtk_source_space_drawer_update_color (GtkSourceSpaceDrawer *drawer,
                                       GtkSourceView        *view)
diff --git a/gtksourceview/gtksourcespacedrawer.h b/gtksourceview/gtksourcespacedrawer.h
index 3454901..c97e5db 100644
--- a/gtksourceview/gtksourcespacedrawer.h
+++ b/gtksourceview/gtksourcespacedrawer.h
@@ -136,6 +136,12 @@ GTK_SOURCE_AVAILABLE_IN_3_24
 void                   gtk_source_space_drawer_set_enable_matrix       (GtkSourceSpaceDrawer *drawer,
                                                                         gboolean              enable_matrix);
 
+GTK_SOURCE_AVAILABLE_IN_3_24
+void                   gtk_source_space_drawer_bind_matrix_setting     (GtkSourceSpaceDrawer *drawer,
+                                                                        GSettings            *settings,
+                                                                        const gchar          *key,
+                                                                        GSettingsBindFlags    flags);
+
 G_END_DECLS
 
 #endif /* GTK_SOURCE_SPACE_DRAWER_H */