[template-glib] gi: allow accessing namespace children

[Christian Hergert <chergert src gnome org>]

commit 93c5477fdf0858fd5ab8f1c660ae9c37dfefcda8
Author: Christian Hergert <chergert redhat com>
Date:   Mon Oct 23 15:24:35 2017 -0700

    gi: allow accessing namespace children
    
    This allows you to access items within a namespace such as
    "Gio.File". Further work is needed to be able to call methods
    and such on the GIBaseInfo data.

 src/tmpl-expr-eval.c  |   32 ++++++++++++++++++++++++++++++++
 src/tmpl-gi-private.h |    4 +++-
 src/tmpl-gi.c         |    3 ++-
 3 files changed, 37 insertions(+), 2 deletions(-)
---
diff --git a/src/tmpl-expr-eval.c b/src/tmpl-expr-eval.c
index 46d9c5e..78d9918 100644
--- a/src/tmpl-expr-eval.c
+++ b/src/tmpl-expr-eval.c
@@ -484,6 +484,38 @@ tmpl_expr_getattr_eval (TmplExprGetattr  *node,
   if (!tmpl_expr_eval_internal (node->left, scope, &left, error))
     goto cleanup;
 
+  if (G_VALUE_HOLDS (&left, TMPL_TYPE_TYPELIB) &&
+      g_value_get_pointer (&left) != NULL)
+    {
+      GIRepository *repository = g_irepository_get_default ();
+      GITypelib *typelib = g_value_get_pointer (&left);
+      const gchar *ns = g_typelib_get_namespace (typelib);
+      GIBaseInfo *base_info;
+
+      /* Maybe we can resolve this dot accessor (.foo) using GObject
+       * Introspection from the first object.
+       */
+
+      base_info = g_irepository_find_by_name (repository, ns, node->attr);
+
+      if (base_info == NULL)
+        {
+          g_set_error (error,
+                       TMPL_ERROR,
+                       TMPL_ERROR_GI_FAILURE,
+                       "Failed to locate %s within %s",
+                       node->attr, ns);
+          goto cleanup;
+        }
+
+      g_value_init (return_value, TMPL_TYPE_BASE_INFO);
+      g_value_set_pointer (return_value, base_info);
+
+      ret = TRUE;
+
+      goto cleanup;
+    }
+
   if (!G_VALUE_HOLDS_OBJECT (&left))
     {
       g_set_error (error,
diff --git a/src/tmpl-gi-private.h b/src/tmpl-gi-private.h
index d7cd8b1..7dbc311 100644
--- a/src/tmpl-gi-private.h
+++ b/src/tmpl-gi-private.h
@@ -21,9 +21,11 @@
 
 G_BEGIN_DECLS
 
-#define TMPL_TYPE_TYPELIB (tmpl_typelib_get_type())
+#define TMPL_TYPE_TYPELIB   (tmpl_typelib_get_type())
+#define TMPL_TYPE_BASE_INFO (tmpl_base_info_get_type())
 
 GType    tmpl_typelib_get_type         (void);
+GType    tmpl_base_info_get_type       (void);
 gboolean tmpl_gi_argument_from_g_value (const GValue  *value,
                                         GITypeInfo    *type_info,
                                         GIArgument    *arg,
diff --git a/src/tmpl-gi.c b/src/tmpl-gi.c
index 35d8b5c..092fff1 100644
--- a/src/tmpl-gi.c
+++ b/src/tmpl-gi.c
@@ -20,7 +20,8 @@
 #include "tmpl-error.h"
 #include "tmpl-gi-private.h"
 
-G_DEFINE_POINTER_TYPE (GisTypelib, tmpl_typelib)
+G_DEFINE_POINTER_TYPE (TmplTypelib, tmpl_typelib)
+G_DEFINE_POINTER_TYPE (TmplBaseInfo, tmpl_base_info)
 
 #define return_type_mismatch(value, type)                          \
   G_STMT_START {                                                   \