GtkBuilder: Add private _gtk_builder_extend_with_template()

This adds the definition of the <template> tag with some documentation
on the variant of the format.

_gtk_builder_extend_with_template() is to be used while GtkContainer
builds from composite templates. A couple of error codes are also added
to handle a few new possible failure cases.

DTD Files gtkbuilder.rnc and gtkbuilder.rng have been updated to include
the new <template> tag and it's attributes.

1 files changed, 8 insertions, 2 deletions

diff --git a/gtk/gtkbuilder.rnc b/gtk/gtkbuilder.rnc
index a2b40320b9..635fd4f289 100644
--- a/gtk/gtkbuilder.rnc
+++ b/gtk/gtkbuilder.rnc
@@ -1,6 +1,6 @@
 start = element interface {
   attribute domain { text } ?,
-  ( requires | object | menu ) *
+  ( requires | object | template | menu ) *
 }
 
 requires = element requires {
@@ -16,6 +16,12 @@ object = element object {
   (property | signal | child | ANY) *
 }
 
+template = element template {
+  attribute class { text },
+  attribute parent { text },
+  (property | signal | child | ANY) *
+}
+
 property = element property {
   attribute name { text },
   attribute translatable { "yes" | "no" } ?,
@@ -76,7 +82,7 @@ section = element section {
   (attribute_ | item | submenu | section) *
 }
 
-ANY = element * - (interface | requires | object | property | signal | child | menu | item | attribute | link | submenu | section) {
+ANY = element * - (interface | requires | object | template | property | signal | child | menu | item | attribute | link | submenu | section) {
   attribute * { text } *,
   (ALL * & text ?)
 }