Generate java bindings for constants.

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

Index: mojo/public/tools/bindings/generators/mojom_java_generator.py
diff --git a/mojo/public/tools/bindings/generators/mojom_java_generator.py b/mojo/public/tools/bindings/generators/mojom_java_generator.py
new file mode 100644
index 0000000000000000000000000000000000000000..0b381270122f982c512769990be54e1f27a7f985
--- /dev/null
+++ b/mojo/public/tools/bindings/generators/mojom_java_generator.py
@@ -0,0 +1,182 @@
+# Copyright 2014 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 java source files from a mojom.Module."""
+
+import argparse
+import os
+import re
+
+import mojom.generate.generator as generator
+import mojom.generate.module as mojom
+from mojom.generate.template_expander import UseJinja
+
+
+GENERATOR_PREFIX = 'java'
+
+_spec_to_java_type = {
+  'b':     'boolean',
+  'd':     'double',
+  'f':     'float',
+  'h:d:c': 'org.chromium.mojo.system.DataPipe.ConsumerHandle',
+  'h:d:p': 'org.chromium.mojo.system.DataPipe.ProducerHandle',
+  'h:m':   'org.chromium.mojo.system.MessagePipeHandle',
+  'h':     'org.chromium.mojo.system.UntypedHandle',
+  'h:s':   'org.chromium.mojo.system.SharedBufferHandle',
+  'i16':   'short',
+  'i32':   'int',
+  'i64':   'long',
+  'i8':    'byte',
+  's':     'String',
+  'u16':   'short',
+  'u32':   'int',
+  'u64':   'long',
+  'u8':    'byte',
+}
+
+
+def NameToComponent(name):
+  # insert '_' between anything and a Title name (e.g, HTTPEntry2FooBar ->
+  # HTTP_Entry2_FooBar)
+  name = re.sub('([^_])([A-Z][^A-Z_]+)', r'\1_\2', name)
+  # insert '_' between non upper and start of upper blocks (e.g.,
+  # HTTP_Entry2_FooBar -> HTTP_Entry2_Foo_Bar)
+  name = re.sub('([^A-Z_])([A-Z])', r'\1_\2', name)
+  return [x.lower() for x in name.split('_')]
+
+def CapitalizeFirst(string):
+  return string[0].upper() + string[1:]
+
+def UpperCamelCase(name):
+  return ''.join([CapitalizeFirst(x) for x in NameToComponent(name)])
+
+def CamelCase(name):
+  uccc = UpperCamelCase(name)
+  return uccc[0].lower() + uccc[1:]
+
+def ConstantStyle(name):
+  components = NameToComponent(name)
+  if components[0] == 'k':
+    components = components[1:]
+  return '_'.join([x.upper() for x in components])
+
+def GetNameForElement(element):
+  if (isinstance(element, mojom.Enum) or
+      isinstance(element, mojom.Interface) or
+      isinstance(element, mojom.Struct)):
+    return UpperCamelCase(element.name)
+  if (isinstance(element, mojom.Method) or
+      isinstance(element, mojom.Parameter) or
+      isinstance(element, mojom.Field)):
+    return CamelCase(element.name)
+  if isinstance(element,  mojom.EnumValue):
+    return (UpperCamelCase(element.enum_name) + '.' +
+            ConstantStyle(element.name))
+  if (isinstance(element, mojom.NamedValue) or
+      isinstance(element, mojom.Constant)):
+    return ConstantStyle(element.name)
+  raise Exception("Unexpected element: " % element)
+
+def GetPackage(module):
+  if 'JavaPackage' in module.attributes:
+    package = module.attributes['JavaPackage']
+    if isinstance(package, basestring):
+      return package
+    assert package[0] == 'EXPRESSION'
+    assert len(package[1]) == 1
+    return package[1][0][1:-1].encode('string_escape')
+  # Default package.
+  return "org.chromium.mojom." + module.namespace
+
+def GetNameForKind(kind):
+  def _GetNameHierachy(kind):
+    hierachy = []
+    if kind.parent_kind:
+      hierachy = _GetNameHierachy(kind.parent_kind)
+    hierachy.append(kind.name)
+    return hierachy
+
+  elements = [GetPackage(kind.module)]
+  elements += _GetNameHierachy(kind)
+  return '.'.join(elements)
+
+def GetJavaType(kind):
+  if isinstance(kind, (mojom.Struct, mojom.Interface)):
+    return GetNameForKind(kind)
+  if isinstance(kind, mojom.Array):
+    return "%s[]" % GetJavaType(kind.kind)
+  if isinstance(kind, mojom.Enum):
+    return "int"
+  return _spec_to_java_type[kind.spec]
+
+def TranslateConstants(token, module):
+  def _TranslateNamedValue(named_value):
+    entity_name = GetNameForElement(named_value)
+    if named_value.parent_kind:
+      return GetJavaType(named_value.parent_kind) + '.' + entity_name
+    # Handle the case where named_value is a module level constant:
+    if not isinstance(named_value, mojom.EnumValue):
+      entity_name = (GetConstantsMainEntityName(named_value.module) + '.' +
+                      entity_name)
+    return GetPackage(named_value.module) + '.' + entity_name
+
+  if isinstance(token, mojom.NamedValue):
+    return _TranslateNamedValue(token)
+  # Add Long suffix to all number literals.
+  if re.match('^[0-9]+$', token):
+    return token + 'L'
+  return token
+
+def ExpressionToText(value, module):
+  if value[0] != "EXPRESSION":
+    raise Exception("Expected EXPRESSION, got" + value)
+  return "".join(generator.ExpressionMapper(value,
+      lambda token: TranslateConstants(token, module)))
+
+def GetConstantsMainEntityName(module):
+  # This constructs the name of the embedding classes for module level constants
+  # by extracting the mojom's filename and prepending it to Constants.
+  return (UpperCamelCase(module.path.split('/')[-1].rsplit('.', 1)[0]) +
+          'Constants')
+
+class Generator(generator.Generator):
+
+  java_filters = {
+    "expression_to_text": ExpressionToText,
+    "java_type": GetJavaType,
+    "name": GetNameForElement,
+    "verify_token_type": generator.VerifyTokenType,
+  }
+
+  def GetJinjaExports(self):
+    return {
+      "module": self.module,
+      "package": GetPackage(self.module),
+    }
+
+  @UseJinja("java_templates/constants.java.tmpl", filters=java_filters,
+            lstrip_blocks=True, trim_blocks=True)
+  def GenerateConstantsSource(self, module):
+    exports = self.GetJinjaExports()
+    exports.update({"main_entity": GetConstantsMainEntityName(module),
+                    "constants": module.constants})
+    return exports
+
+  def GenerateFiles(self, unparsed_args):
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--java_output_directory", dest="java_output_directory")
+    args = parser.parse_args(unparsed_args)
+    if self.output_dir and args.java_output_directory:
+      self.output_dir = os.path.join(args.java_output_directory,
+                                     GetPackage(self.module).replace('.', '/'))
+      if not os.path.exists(self.output_dir):
+        try:
+          os.makedirs(self.output_dir)
+        except:
+          # Ignore errors on directory creation.
+          pass
+
+    if self.module.constants:
+      self.Write(self.GenerateConstantsSource(self.module),
+                 "%s.java" % GetConstantsMainEntityName(self.module))