[gtk+] Document new selection apis

[Matthias Clasen <matthiasc src gnome org>]

commit 65408a0b0c5c6fb74c246b44bae891311d361130
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Oct 23 05:46:58 2017 +0200

    Document new selection apis
    
    Document the new cairo surface-based apis for GtkSelection.

 docs/reference/gtk/gtk4-sections.txt |    2 ++
 gtk/gtkselection.c                   |   28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gtk/gtk4-sections.txt b/docs/reference/gtk/gtk4-sections.txt
index f88b3bf..38591fc 100644
--- a/docs/reference/gtk/gtk4-sections.txt
+++ b/docs/reference/gtk/gtk4-sections.txt
@@ -5247,6 +5247,8 @@ gtk_selection_data_set_text
 gtk_selection_data_get_text
 gtk_selection_data_set_pixbuf
 gtk_selection_data_get_pixbuf
+gtk_selection_data_set_surface
+gtk_selection_data_get_surface
 gtk_selection_data_set_uris
 gtk_selection_data_get_uris
 gtk_selection_data_get_targets
diff --git a/gtk/gtkselection.c b/gtk/gtkselection.c
index 6590fac..611c09e 100644
--- a/gtk/gtkselection.c
+++ b/gtk/gtkselection.c
@@ -1733,6 +1733,20 @@ gtk_selection_data_set_pixbuf (GtkSelectionData *selection_data,
   return FALSE;
 }
 
+/**
+ * gtk_selection_data_set_surface:
+ * @selection_data: a #GtkSelectionData
+ * @surface: a cairo image surface
+ * 
+ * Sets the contents of the selection from a cairo image surface.
+ * The surface is converted to the form determined by
+ * @selection_data->target.
+ * 
+ * Returns: %TRUE if the selection was successfully set,
+ *   otherwise %FALSE.
+ *
+ * Since: 3.94
+ **/
 gboolean
 gtk_selection_data_set_surface (GtkSelectionData *selection_data,
                                cairo_surface_t  *surface)
@@ -1750,6 +1764,20 @@ gtk_selection_data_set_surface (GtkSelectionData *selection_data,
   return retval;
 }
 
+/**
+ * gtk_selection_data_get_surface:
+ * @selection_data: a #GtkSelectionData
+ * 
+ * Gets the contents of the selection data as a cairo surface.
+ * 
+ * Returns: (nullable) (transfer full): if the selection data
+ *   contained a recognized image type and it could be converted to a
+ *   cairo surface, a newly allocated surface is returned, otherwise
+ *   %NULL.  If the result is non-%NULL it must be freed with
+ *   g_object_unref().
+ *
+ * Since: 3.94
+ **/
 cairo_surface_t *
 gtk_selection_data_get_surface (GtkSelectionData *selection_data)
 {