Generate the proto JSON converter for DOM distiller

third_party/dom_distiller_js/protoc_plugins/util/writer.py

+# Copyright 2016 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.
+
+import contextlib
+
+class CodeWriter(object):
+  """Helper class for code indentation."""
+  def __init__(self):
+    self.indent = 0
+    self.value = []
+    self.errors = []
+
+  def GetErrors(self):
+    return self.errors
+
+  @contextlib.contextmanager
+  def AddIndent(self, indent=2):
+    self.indent += indent
+    yield 0
+    self.indent -= indent
+
+  def IncreaseIndent(self, indent=2):
+    self.indent += indent
+
+  def DecreaseIndent(self, indent=2):
+    self.indent -= indent
+
+  def Output(self, fmt, **kwargs):
+    s = fmt.format(**kwargs)
+    s = s.rstrip('\n')
+    lines = s.split('\n')
+    lines = map(lambda s: (' ' * self.indent + s).rstrip(), lines)
+    self.value.extend(lines)
+
+  def AddError(self, fmt, **kwargs):
+    self.errors.append(fmt.format(**kwargs))
+
+  def GetValue(self):
+    return '\n'.join(self.value) + '\n'
+
+  def WriteCStyleHeader(self):
+    self.Output("// GENERATED FILE")
+    self.Output("// This file generated by DomDistillerJs protoc plugin.")