structure: Add get/set_array/list using GValueArray

This adds a binding friendly interface to get and set arrays
and list into GstStructure.

New API:
 - gst_structure_set_array
 - gst_structure_set_list
 - gst_structure_get_array
 - gst_structure_get_list

https://bugzilla.gnome.org/show_bug.cgi?id=753754

docs/gst/gstreamer-sections.txt

@@ -2771,6 +2771,8 @@ gst_structure_get
 gst_structure_get_valist
 gst_structure_get_value
 gst_structure_set_value
+gst_structure_set_array
+gst_structure_set_list
 gst_structure_take_value
 gst_structure_set
 gst_structure_set_valist
@@ -2802,6 +2804,8 @@ gst_structure_get_date_time
 gst_structure_get_clock_time
 gst_structure_get_enum
 gst_structure_get_fraction
+gst_structure_get_array
+gst_structure_get_list
 gst_structure_foreach
 gst_structure_map_in_place
 gst_structure_filter_and_map_in_place

gst/gststructure.c

@@ -65,6 +65,10 @@
 #include "config.h"
 #endif
 
+/* FIXME 2.0: suppress warnings for deprecated API such as GValueArray
+ * with newer GLib versions (>= 2.31.0) */
+#define GLIB_DISABLE_DEPRECATION_WARNINGS
+
 #include <string.h>
 
 #include "gst_private.h"
@@ -2989,3 +2993,145 @@ gst_structure_fixate (GstStructure * structure)
 
   gst_structure_foreach (structure, default_fixate, structure);
 }
+
+static gboolean
+_gst_structure_get_any_list (GstStructure * structure, GType type,
+    const gchar * fieldname, GValueArray ** array)
+{
+  GstStructureField *field;
+  GValue val = G_VALUE_INIT;
+
+  g_return_val_if_fail (structure != NULL, FALSE);
+  g_return_val_if_fail (fieldname != NULL, FALSE);
+  g_return_val_if_fail (array != NULL, FALSE);
+
+  field = gst_structure_get_field (structure, fieldname);
+
+  if (field == NULL || G_VALUE_TYPE (&field->value) != type)
+    return FALSE;
+
+  g_value_init (&val, G_TYPE_VALUE_ARRAY);
+
+  if (g_value_transform (&field->value, &val)) {
+    *array = g_value_get_boxed (&val);
+    return TRUE;
+  }
+
+  g_value_unset (&val);
+  return FALSE;
+}
+
+/**
+ * gst_structure_get_array:
+ * @structure: a #GstStructure
+ * @fieldname: the name of a field
+ * @array: (out): a pointer to a #GValueArray
+ *
+ * This is useful in language bindings where unknown #GValue types are not
+ * supported. This function will convert the %GST_TYPE_ARRAY and
+ * %GST_TYPE_LIST into a newly allocated #GValueArray and return it through
+ * @array. Be aware that this is slower then getting the #GValue directly.
+ *
+ * Returns: %TRUE if the value could be set correctly. If there was no field
+ * with @fieldname or the existing field did not contain an int, this function
+ * returns %FALSE.
+ */
+gboolean
+gst_structure_get_array (GstStructure * structure, const gchar * fieldname,
+    GValueArray ** array)
+{
+  return _gst_structure_get_any_list (structure, GST_TYPE_ARRAY, fieldname,
+      array);
+}
+
+/**
+ * gst_structure_get_list:
+ * @structure: a #GstStructure
+ * @fieldname: the name of a field
+ * @array: (out): a pointer to a #GValueArray
+ *
+ * This is useful in language bindings where unknown #GValue types are not
+ * supported. This function will convert the %GST_TYPE_ARRAY and
+ * %GST_TYPE_LIST into a newly allocated GValueArray and return it through
+ * @array. Be aware that this is slower then getting the #GValue directly.
+ *
+ * Returns: %TRUE if the value could be set correctly. If there was no field
+ * with @fieldname or the existing field did not contain an int, this function
+ * returns %FALSE.
+ *
+ * Since 1.12
+ */
+gboolean
+gst_structure_get_list (GstStructure * structure, const gchar * fieldname,
+    GValueArray ** array)
+{
+  return _gst_structure_get_any_list (structure, GST_TYPE_LIST, fieldname,
+      array);
+}
+
+static void
+_gst_structure_set_any_list (GstStructure * structure, GType type,
+    const gchar * fieldname, const GValueArray * array)
+{
+  GValue arval = G_VALUE_INIT;
+  GValue value = G_VALUE_INIT;
+
+  g_return_if_fail (structure != NULL);
+  g_return_if_fail (fieldname != NULL);
+  g_return_if_fail (array != NULL);
+  g_return_if_fail (IS_MUTABLE (structure));
+
+  g_value_init (&value, type);
+  g_value_init (&arval, G_TYPE_VALUE_ARRAY);
+  g_value_set_static_boxed (&arval, array);
+
+  if (g_value_transform (&arval, &value)) {
+    gst_structure_id_set_value_internal (structure,
+        g_quark_from_string (fieldname), &value);
+  } else {
+    g_warning ("Failed to convert a GValueArray");
+  }
+
+  g_value_unset (&arval);
+  g_value_unset (&value);
+}
+
+/**
+ * gst_structure_set_array:
+ * @structure: a #GstStructure
+ * @fieldname: the name of a field
+ * @array: a pointer to a #GValueArray
+ *
+ * This is useful in language bindings where unknown GValue types are not
+ * supported. This function will convert a @array to %GST_TYPE_ARRAY and set
+ * the field specified by @fieldname.  Be aware that this is slower then using
+ * %GST_TYPE_ARRAY in a #GValue directly.
+ *
+ * Since 1.12
+ */
+void
+gst_structure_set_array (GstStructure * structure, const gchar * fieldname,
+    const GValueArray * array)
+{
+  _gst_structure_set_any_list (structure, GST_TYPE_ARRAY, fieldname, array);
+}
+
+/**
+ * gst_structure_set_list:
+ * @structure: a #GstStructure
+ * @fieldname: the name of a field
+ * @array: a pointer to a #GValueArray
+ *
+ * This is useful in language bindings where unknown GValue types are not
+ * supported. This function will convert a @array to %GST_TYPE_ARRAY and set
+ * the field specified by @fieldname. Be aware that this is slower then using
+ * %GST_TYPE_ARRAY in a #GValue directly.
+ *
+ * Since 1.12
+ */
+void
+gst_structure_set_list (GstStructure * structure, const gchar * fieldname,
+    const GValueArray * array)
+{
+  _gst_structure_set_any_list (structure, GST_TYPE_LIST, fieldname, array);
+}

gst/gststructure.h

@@ -145,6 +145,14 @@ void                  gst_structure_set_value            (GstStructure        *
                                                           const gchar         * fieldname,
                                                           const GValue        * value);
 
+void                  gst_structure_set_array            (GstStructure        * structure,
+                                                          const gchar         * fieldname,
+                                                          const GValueArray   * array);
+
+void                  gst_structure_set_list             (GstStructure        * structure,
+                                                          const gchar         * fieldname,
+                                                          const GValueArray   * array);
+
 void                  gst_structure_id_take_value        (GstStructure        * structure,
                                                           GQuark                field,
                                                           GValue              * value);
@@ -293,6 +301,14 @@ gboolean              gst_structure_get_flagset          (const GstStructure  *
                                                           guint               * value_flags,
                                                           guint               * value_mask);
 
+gboolean              gst_structure_get_array            (GstStructure        * structure,
+                                                          const gchar         * fieldname,
+                                                          GValueArray        ** array);
+
+gboolean              gst_structure_get_list             (GstStructure        * structure,
+                                                          const gchar         * fieldname,
+                                                          GValueArray        ** array);
+
 gchar *               gst_structure_to_string    (const GstStructure * structure) G_GNUC_MALLOC;
 
 GstStructure *        gst_structure_from_string  (const gchar * string,

win32/common/libgstreamer.def

@@ -1277,6 +1277,7 @@ EXPORTS
 	gst_structure_free
 	gst_structure_from_string
 	gst_structure_get
+	gst_structure_get_array
 	gst_structure_get_boolean
 	gst_structure_get_clock_time
 	gst_structure_get_date
@@ -1288,6 +1289,7 @@ EXPORTS
 	gst_structure_get_fraction
 	gst_structure_get_int
 	gst_structure_get_int64
+	gst_structure_get_list
 	gst_structure_get_name
 	gst_structure_get_name_id
 	gst_structure_get_string
@@ -1325,6 +1327,8 @@ EXPORTS
 	gst_structure_remove_fields
 	gst_structure_remove_fields_valist
 	gst_structure_set
+	gst_structure_set_array
+	gst_structure_set_list
 	gst_structure_set_name
 	gst_structure_set_parent_refcount
 	gst_structure_set_valist