Support custom to native conversions.

lib/dom/scripts/systemnative.py

Index: lib/dom/scripts/systemnative.py
diff --git a/lib/dom/scripts/systemnative.py b/lib/dom/scripts/systemnative.py
index a1de7b5b35683a6d4e8a94ee4de3b18c90c479f2..48d78d44580468130067f7ce1f5046d6747d768f 100644
--- a/lib/dom/scripts/systemnative.py
+++ b/lib/dom/scripts/systemnative.py
@@ -380,35 +380,43 @@ class NativeImplementationGenerator(systemwrapping.WrappingInterfaceGenerator):
         RESOLVER=self._cpp_resolver_emitter.Fragments())
 
   def _GenerateCppHeader(self):
-    webcore_includes = _GenerateCPPIncludes(self._interface_type_info.webcore_includes())
+    to_native_template = '    static PassRefPtr<NativeType> toNative(Dart_Handle handle, Dart_Handle& exception)'
+    if self._interface_type_info.custom_to_native():
+      to_native_template += ';\n'
+    else:
+      to_native_template += (
+          '\n'
+          '    {\n'
+          '        return DartDOMWrapper::unwrapDartWrapper<Dart$INTERFACE>(handle, exception);\n'
+          '    }\n')
 
     if ('CustomToJS' in self._interface.ext_attrs or
         'CustomToJSObject' in self._interface.ext_attrs or
         'PureInterface' in self._interface.ext_attrs or
         'CPPPureInterface' in self._interface.ext_attrs or
         self._interface_type_info.custom_to_dart()):
-      to_dart_value_template = (
+      to_dart_template = (
           'Dart_Handle toDartValue($(WEBCORE_CLASS_NAME)* value);\n')
     else:
-      to_dart_value_template = (
+      to_dart_template = (
           'inline Dart_Handle toDartValue($(WEBCORE_CLASS_NAME)* value)\n'
           '{\n'
           '    return DartDOMWrapper::toDart<Dart$(INTERFACE)>(value);\n'
           '}\n')
-    to_dart_value_emitter = emitter.Emitter()
-    to_dart_value_emitter.Emit(
-        to_dart_value_template,
-        INTERFACE=self._interface.id,
-        WEBCORE_CLASS_NAME=self._interface_type_info.native_type())
 
+    intermediate_emitter = emitter.Emitter()

[Anton Muhin, 2012/04/24 14:05:51]

this two level emitting might be too much.  Maybe generate full fragments higher
as it was a case before?

[podivilov, 2012/04/24 14:30:33]

Done.

+    intermediate_emitter.Emit(
+        self._templates.Load('cpp_header.template'),
+        TO_NATIVE=to_native_template,
+        TO_DART=to_dart_template)
 
+    webcore_includes = _GenerateCPPIncludes(self._interface_type_info.webcore_includes())
     wrapper_type = _DOMWrapperType(self._system._database, self._interface)
     self._cpp_header_emitter.Emit(
-        self._templates.Load('cpp_header.template'),
+        ''.join(intermediate_emitter.Fragments()),
         INTERFACE=self._interface.id,
         WEBCORE_INCLUDES=webcore_includes,
         WEBCORE_CLASS_NAME=self._interface_type_info.native_type(),
-        TO_DART_VALUE=to_dart_value_emitter.Fragments(),
         DECLARATIONS=self._cpp_declarations_emitter.Fragments(),
         NATIVE_TRAITS_TYPE='DartDOMWrapper::%sTraits' % wrapper_type)