app, libgimp*, plug-ins: int32 array arguments don't need a size argument anymore.

GimpArray (and therefore the int32 array typedef) contains its own size.
We don't need to store the array size in a preceding argument.

Also adding gimp_int32_array_get_values() and gimp_int32_array_set_values()
to edit an existing GimpArray.
This comes with the fact we should start making the GimpArray type more
explicit, because clearly by trying to hide this type so much, it was
too much looking like the int32 array param spec was expecting a C array
(as was visible in the file-ico plug-in where we were getting a C array,
which was a bug only made invisible by the fact we were not setting the
C array back in the config object in the end).

Last but not least, I finally implemented int32 array (de)serialization.

As a side fix, the "images" arg in file-pdf-export-multi procedure is
now a proper image array (not an int32 array), and of course the "count"
arg was removed.

libgimpbase/gimpbase.def

@@ -85,6 +85,8 @@ EXPORTS
 	gimp_installation_directory
 	gimp_installation_directory_file
 	gimp_int32_array_get_type
+	gimp_int32_array_get_values
+	gimp_int32_array_set_values
 	gimp_interpolation_type_get_type
 	gimp_is_canonical_identifier
 	gimp_join_style_get_type

libgimpbase/gimpparamspecs.c

@@ -452,6 +452,49 @@ gimp_value_take_array (GValue *value,
 typedef GimpArray GimpInt32Array;
 G_DEFINE_BOXED_TYPE (GimpInt32Array, gimp_int32_array, gimp_array_copy, gimp_array_free)
 
+/**
+ * gimp_int32_array_get_values:
+ * @array: the #GimpArray representing #int32 values.
+ * @length: the number of #int32 values in the returned array.
+ *
+ * Returns: (array length=length) (transfer none): a C-array of #gint32.
+ */
+const gint32 *
+gimp_int32_array_get_values (GimpArray *array,
+                             gsize     *length)
+{
+  g_return_val_if_fail (array->length % sizeof (gint32) == 0, NULL);
+
+  if (length)
+    *length = array->length / sizeof (gint32);
+
+  return (const gint32 *) array->data;
+}
+
+/**
+ * gimp_int32_array_set_values:
+ * @array: the array to modify.
+ * @values: (array length=length): the C-array.
+ * @length: the number of #int32 values in @data.
+ * @static_data: whether @data is a static rather than allocated array.
+ */
+void
+gimp_int32_array_set_values (GimpArray    *array,
+                             const gint32 *values,
+                             gsize         length,
+                             gboolean      static_data)
+{
+  g_return_if_fail ((values == NULL && length == 0) || (values != NULL && length  > 0));
+
+  if (! array->static_data)
+    g_free (array->data);
+
+  array->length      = length * sizeof (gint32);
+  array->data        = static_data ? (guint8 *) values : g_memdup2 (values, array->length);
+  array->static_data = static_data;
+}
+
+
 /*
  * GIMP_TYPE_PARAM_INT32_ARRAY
  */

libgimpbase/gimpparamspecs.h

@@ -211,10 +211,17 @@ GParamSpec * gimp_param_spec_array     (const gchar  *name,
  * GIMP_TYPE_INT32_ARRAY
  */
 
-#define GIMP_TYPE_INT32_ARRAY               (gimp_int32_array_get_type ())
-#define GIMP_VALUE_HOLDS_INT32_ARRAY(value) (G_TYPE_CHECK_VALUE_TYPE ((value), GIMP_TYPE_INT32_ARRAY))
+#define        GIMP_TYPE_INT32_ARRAY               (gimp_int32_array_get_type ())
+#define        GIMP_VALUE_HOLDS_INT32_ARRAY(value) (G_TYPE_CHECK_VALUE_TYPE ((value), GIMP_TYPE_INT32_ARRAY))
 
-GType   gimp_int32_array_get_type           (void) G_GNUC_CONST;
+GType          gimp_int32_array_get_type           (void) G_GNUC_CONST;
+
+const gint32 * gimp_int32_array_get_values         (GimpArray    *array,
+                                                    gsize        *length);
+void           gimp_int32_array_set_values         (GimpArray    *array,
+                                                    const gint32 *values,
+                                                    gsize         length,
+                                                    gboolean      static_data);
 
 
 /*