[gnome-builder] dspy: provide method invocation signature from DspyArgInfo

[Christian Hergert <chergert src gnome org>]

commit 963f1b4a95002b33a0b01f6a1bf00d10d02e9814
Author: Christian Hergert <chergert redhat com>
Date:   Wed Apr 24 15:53:24 2019 -0700

    dspy: provide method invocation signature from DspyArgInfo

 src/plugins/dspy/libdspy/dspy-tree-view.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)
---
diff --git a/src/plugins/dspy/libdspy/dspy-tree-view.c b/src/plugins/dspy/libdspy/dspy-tree-view.c
index 5db96b566..677f655d6 100644
--- a/src/plugins/dspy/libdspy/dspy-tree-view.c
+++ b/src/plugins/dspy/libdspy/dspy-tree-view.c
@@ -85,7 +85,23 @@ dspy_tree_view_selection_changed (DspyTreeView     *self,
           dspy_method_invocation_set_method (invocation, node->method.name);
 
           if (node->method.in_args.length == 0)
-            dspy_method_invocation_set_parameters (invocation, g_variant_new ("()"));
+            {
+              dspy_method_invocation_set_parameters (invocation, g_variant_new ("()"));
+            }
+          else
+            {
+              g_autoptr(GString) str = g_string_new ("(");
+
+              for (const GList *list = node->method.in_args.head; list; list = list->next)
+                {
+                  DspyArgInfo *info = list->data;
+                  g_string_append (str, info->signature);
+                }
+
+              g_string_append_c (str, ')');
+
+              dspy_method_invocation_set_signature (invocation, str->str);
+            }
         }
       else if (node->any.kind == DSPY_NODE_KIND_PROPERTY)
         {