[seed] Fix Bug #609508 - Support Out args as return object if possible

[Alan Knowles <alank src gnome org>]

commit 52839cb9e8993c1cfa90286f2526cb1db845d3e1
Author: alan <alan alanfast akbkhome com>
Date:   Wed Feb 24 13:07:39 2010 +0800

    Fix Bug #609508 - Support Out args as return object if possible
    
    Fixes issues with in/out arguments
    Better debug message (names the argument)
    For calls that have 'out' arguments
    a) If return is VOID - the return is an object, with properties set to the out values
    b) If the first out argument is an object, then all the out values are set as properties on that.
    c) still supports out_argument.value setting (previous way of doing this)

 libseed/seed-engine.c |   95 ++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 78 insertions(+), 17 deletions(-)
---
diff --git a/libseed/seed-engine.c b/libseed/seed-engine.c
index b1b083f..ac89f98 100644
--- a/libseed/seed-engine.c
+++ b/libseed/seed-engine.c
@@ -461,7 +461,9 @@ seed_gobject_method_invoked (JSContextRef ctx,
   GArgument *in_args;
   GArgument *out_args;
   GArgument *out_values;
-  guint n_args, n_in_args, n_out_args, i;
+  gint first_out = -1;
+  guint use_return_as_out = 0;
+  guint n_args, n_in_args, n_out_args, i; 
   guint in_args_pos, out_args_pos;
   GIArgInfo *arg_info;
   GITypeInfo *type_info;
@@ -489,15 +491,29 @@ seed_gobject_method_invoked (JSContextRef ctx,
 
   for (i = 0; (i < (n_args)); i++)
     {
-      SEED_NOTE (INVOCATION,
-		 "Converting arg: %d of function %s, exception is %p", i,
-		 g_base_info_get_name (info), exception);
+
       arg_info = g_callable_info_get_arg ((GICallableInfo *) info, i);
       dir = g_arg_info_get_direction (arg_info);
       type_info = g_arg_info_get_type (arg_info);
+
+      SEED_NOTE (INVOCATION,
+                "Converting arg: %s (%d) of function %s, exception is %p",  
+                 g_base_info_get_name ((GIBaseInfo *)arg_info),  i,
+                 g_base_info_get_name (info), exception);
+
+
+
       if (i + 1 > argumentCount)
-	{
-	  in_args[n_in_args++].v_pointer = 0;
+        {
+
+          if (dir == GI_DIRECTION_OUT)
+            {
+              GArgument *out_value = &out_values[n_out_args];
+              out_args[n_out_args++].v_pointer = out_value;
+            } 
+          else
+              in_args[n_in_args++].v_pointer = 0;   
+
 	}
       else if (dir == GI_DIRECTION_IN || dir == GI_DIRECTION_INOUT)
 	{
@@ -547,13 +563,15 @@ seed_gobject_method_invoked (JSContextRef ctx,
 	{
 	  GArgument *out_value = &out_values[n_out_args];
 	  out_args[n_out_args++].v_pointer = out_value;
+	  first_out = first_out > -1 ? first_out : i;
+
 	}
 
       g_base_info_unref ((GIBaseInfo *) type_info);
       g_base_info_unref ((GIBaseInfo *) arg_info);
     }
-  SEED_NOTE (INVOCATION, "Invoking method: %s with %d in arguments"
-	     " and %d out arguments",
+  SEED_NOTE (INVOCATION, "Invoking method: %s with %d 'in' arguments"
+	     " and %d 'out' arguments",
 	     g_base_info_get_name (info), n_in_args, n_out_args);
   if (g_function_info_invoke ((GIFunctionInfo *) info,
 			      in_args,
@@ -564,8 +582,23 @@ seed_gobject_method_invoked (JSContextRef ctx,
 
       type_info = g_callable_info_get_return_type ((GICallableInfo *) info);
       tag = g_type_info_get_tag (type_info);
-      if (tag == GI_TYPE_TAG_VOID)
-	retval_ref = JSValueMakeUndefined (ctx);
+
+      // might need to add g_type_info_is_pointer (type_info) check here..
+      
+      if (tag == GI_TYPE_TAG_VOID) 
+        {
+          // if we have no out args - returns undefined
+          // otherwise we return an object, and put the return values into that
+          // along with supporting the old object.value way
+          if (n_out_args < 1) 
+              retval_ref = JSValueMakeUndefined (ctx);
+          else 
+            {
+            
+             retval_ref = JSObjectMake (ctx, NULL, NULL);      
+             use_return_as_out = 1;
+            }
+        }
       else
 	{
 	  GIBaseInfo *interface;
@@ -624,7 +657,7 @@ seed_gobject_method_invoked (JSContextRef ctx,
       dir = g_arg_info_get_direction (arg_info);
       type_info = g_arg_info_get_type (arg_info);
 
-      if (dir == GI_DIRECTION_IN)
+      if (dir == GI_DIRECTION_IN || dir == GI_DIRECTION_INOUT) 
 	{
 	  seed_gi_release_in_arg (g_arg_info_get_ownership_transfer
 				  (arg_info), type_info,
@@ -636,15 +669,43 @@ seed_gobject_method_invoked (JSContextRef ctx,
 	  g_base_info_unref ((GIBaseInfo *) arg_info);
 	  continue;
 	}
+      
+      // we are now only dealing with out arguments.
       jsout_val = seed_gi_argument_make_js (ctx, &out_values[out_args_pos],
 					    type_info, exception);
       out_args_pos++;
-      if (!JSValueIsNull (ctx, arguments[i]) &&
-	  JSValueIsObject (ctx, arguments[i]))
-	{
-	  seed_object_set_property (ctx, (JSObjectRef) arguments[i],
-				    "value", jsout_val);
-	}
+
+
+
+      // old ? depreciated ? way to handle out args -> set 'value' on object that was send through.
+       
+      if ( (i < argumentCount) && 
+          !JSValueIsNull (ctx, arguments[i]) &&
+          JSValueIsObject (ctx, arguments[i]))
+        {
+          seed_object_set_property (ctx, (JSObjectRef) arguments[i],
+                                   "value", jsout_val);
+        }
+
+
+      // if we add it to the return argument and/or the first out arguement
+
+      if (use_return_as_out) 
+        {
+           seed_object_set_property (ctx, (JSObjectRef) retval_ref,
+                 g_base_info_get_name((GIBaseInfo*) arg_info) , jsout_val);
+        }
+       
+
+      if ( (first_out > -1) &&  
+          !JSValueIsNull (ctx, arguments[first_out]) &&
+          JSValueIsObject (ctx, arguments[first_out]) )
+       
+        {
+          seed_object_set_property (ctx, (JSObjectRef) arguments[first_out],
+                 g_base_info_get_name((GIBaseInfo*) arg_info) , jsout_val);
+        }
+
 
       g_base_info_unref ((GIBaseInfo *) arg_info);
       g_base_info_unref ((GIBaseInfo *) type_info);