[Mojo] Make javascript enums extensible.

mojo/public/tools/bindings/generators/mojom_js_generator.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates JavaScript source files from a mojom.Module."""
 
 import mojom.generate.generator as generator
 import mojom.generate.module as mojom
 import mojom.generate.pack as pack
 from mojom.generate.template_expander import UseJinja
@@ skipping 120 matching lines @@
   if mojom.IsEnumKind(kind):
     return _kind_to_codec_type[mojom.INT32]
   if mojom.IsMapKind(kind):
     map_type = "NullableMapOf" if mojom.IsNullableKind(kind) else "MapOf"
     key_type = ElementCodecType(kind.key_kind)
     value_type = ElementCodecType(kind.value_kind)
     return "new codec.%s(%s, %s)" % (map_type, key_type, value_type)
   raise Exception("No codec type for %s" % kind)
 
 
 def ElementCodecType(kind):

[mbjorge, 2016/09/30 19:10:48]

I wasn't totally sure if this was the best place for this since I don't think
the enum kind.name is really a codec type? But it kept the type lookup in
JavaScriptValidateArrayParams and JavascriptValidateMapParams cleaner. 

[Ken Rockot(use gerrit already), 2016/09/30 21:14:38]

I think it would make more sense to just add a codec type for enums in see
mojo/public/js/codec.js. It could be constructed over the generated enum type
similar to how the PointerTo codec is constructed for struct types.

-  return "codec.PackedBool" if mojom.IsBoolKind(kind) else CodecType(kind)
+  if mojom.IsBoolKind(kind):
+    return "codec.PackedBool"
+
+  if mojom.IsEnumKind(kind):
+    return kind.name
+
+  return CodecType(kind)
 
 def JavaScriptDecodeSnippet(kind):
   if (kind in mojom.PRIMITIVES or mojom.IsUnionKind(kind) or
       mojom.IsInterfaceKind(kind) or mojom.IsAssociatedKind(kind)):
     return "decodeStruct(%s)" % CodecType(kind)
   if mojom.IsStructKind(kind):
     return "decodeStructPointer(%s)" % JavaScriptType(kind)
   if mojom.IsMapKind(kind):
     return "decodeMapPointer(%s, %s)" % \
         (ElementCodecType(kind.key_kind), ElementCodecType(kind.value_kind))
@@ skipping 68 matching lines @@
   element_kind = field.kind.kind
   element_size = pack.PackedField.GetSizeForKind(element_kind)
   expected_dimension_sizes = GetArrayExpectedDimensionSizes(
       field.kind)
   element_type = ElementCodecType(element_kind)
   return "%s, %s, %s, %s, 0" % \
       (element_size, element_type, nullable,
        expected_dimension_sizes)
 
 
+def JavaScriptValidateEnumParams(field):
+  nullable = JavaScriptNullableParam(field)
+  enum_type = JavaScriptType(field.kind)
+  return "%s, %s" % (enum_type, nullable)
+
 def JavaScriptValidateStructParams(field):
   nullable = JavaScriptNullableParam(field)
   struct_type = JavaScriptType(field.kind)
   return "%s, %s" % (struct_type, nullable)
 
 def JavaScriptValidateUnionParams(field):
   nullable = JavaScriptNullableParam(field)
   union_type = JavaScriptType(field.kind)
   return "%s, %s" % (union_type, nullable)
 
@@ skipping 68 matching lines @@
 
   return token
 
 
 def ExpressionToText(value):
   return TranslateConstants(value)
 
 def IsArrayPointerField(field):
   return mojom.IsArrayKind(field.kind)
 
+def IsEnumField(field):
+  return mojom.IsEnumKind(field.kind)
+
 def IsStringPointerField(field):
   return mojom.IsStringKind(field.kind)
 
 def IsStructPointerField(field):
   return mojom.IsStructKind(field.kind)
 
 def IsMapPointerField(field):
   return mojom.IsMapKind(field.kind)
 
 def IsHandleField(field):
@@ skipping 19 matching lines @@
     "payload_size": JavaScriptPayloadSize,
     "decode_snippet": JavaScriptDecodeSnippet,
     "encode_snippet": JavaScriptEncodeSnippet,
     "union_decode_snippet": JavaScriptUnionDecodeSnippet,
     "union_encode_snippet": JavaScriptUnionEncodeSnippet,
     "expression_to_text": ExpressionToText,
     "field_offset": JavaScriptFieldOffset,
     "has_callbacks": mojom.HasCallbacks,
     "is_array_pointer_field": IsArrayPointerField,
     "is_bool_field": IsBoolField,
+    "is_enum_field": IsEnumField,
     "is_map_pointer_field": IsMapPointerField,
     "is_struct_pointer_field": IsStructPointerField,
     "is_string_pointer_field": IsStringPointerField,
     "is_union_field": IsUnionField,
     "is_handle_field": IsHandleField,
     "is_interface_field": IsInterfaceField,
     "is_interface_request_field": IsInterfaceRequestField,
     "js_type": JavaScriptType,
     "js_proxy_method_parameter_value": JavaScriptProxyMethodParameterValue,
     "js_stub_method_parameter_value": JavaScriptStubMethodParameterValue,
     "stylize_method": generator.StudlyCapsToCamel,
     "validate_array_params": JavaScriptValidateArrayParams,
+    "validate_enum_params": JavaScriptValidateEnumParams,
     "validate_handle_params": JavaScriptValidateHandleParams,
     "validate_interface_params": JavaScriptValidateInterfaceParams,
     "validate_map_params": JavaScriptValidateMapParams,
     "validate_string_params": JavaScriptValidateStringParams,
     "validate_struct_params": JavaScriptValidateStructParams,
     "validate_union_params": JavaScriptValidateUnionParams,
   }
 
   def GetParameters(self):
     return {
@@ skipping 46 matching lines @@
     return self.module.imports
 
   def GetImportedInterfaces(self):
     interface_to_import = {};
     for each_import in self.module.imports:
       for each_interface in each_import["module"].interfaces:
         name = each_interface.name
         interface_to_import[name] = each_import["unique_name"] + "." + name
     return interface_to_import;