Protocol Buffer runtime library and 'protoc' plugin

lib/protobuf/plugin/EnumGenerator.dart

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class EnumAlias {
+  EnumAlias(GoogleProtobuf_EnumValueDescriptorProto this.value,
+      GoogleProtobuf_EnumValueDescriptorProto this.canonicalValue);
+  GoogleProtobuf_EnumValueDescriptorProto value;
+  GoogleProtobuf_EnumValueDescriptorProto canonicalValue;
+}
+
+class EnumGenerator implements ProtobufContainer {
+
+  // Whitespace
+  static final String sp = MessageGenerator.sp;
+
+  EnumGenerator(GoogleProtobuf_EnumDescriptorProto this._descriptor,
+      ProtobufContainer this._parent, GenerationContext this._context)
+    : _canonicalValues = [], _aliases = [] {
+    _classname = _parent === null ?
+        _descriptor.name :
+        "${_parent.classname}_${_descriptor.name}";
+    _fqname = _parent === null ?
+        _descriptor.name :
+        "${_parent.fqname}.${_descriptor.name}";
+    _optimizeFor = _parent != null ? _parent.optimizeFor : null;
+
+    for (GoogleProtobuf_EnumValueDescriptorProto value in _descriptor.value) {
+      GoogleProtobuf_EnumValueDescriptorProto canonicalValue =
+          findValueByNumber(value.number);
+      if (value === canonicalValue) {
+        _canonicalValues.add(value);
+      } else {
+        _aliases.add(new EnumAlias(value, canonicalValue));
+      }
+    }
+    _context.register(this);
+  }
+
+  GoogleProtobuf_EnumValueDescriptorProto findValueByNumber(int number) {
+    for (GoogleProtobuf_EnumValueDescriptorProto value in _descriptor.value) {
+      if (value.number == number) return value;
+    }
+    return null;
+  }
+
+  /*
+   * Not clear on the Reflection-labeled section.
+   */
+  void generate(IndentingWriter out) {
+    out.addBlock("class ${_classname} extends ProtobufEnum "
+        "implements Hashable {", "}\n", () {
+      // -----------------------------------------------------------------
+      // define enum types
+      int index = 0;
+      for (GoogleProtobuf_EnumValueDescriptorProto val in _canonicalValues) {
+        out.println("static ${_classname} get ${val.name}()${sp}=>"
+            "${sp}values[${index++}];");
+      }
+      out.println("static List<${_classname}> _byIndex;");
+      out.println("static Map<int, ${_classname}> _byValue;");
+      out.blankLine();
+      out.println("static void _init()${sp}{");
+      out.println("${sp}${sp}_byIndex${sp}=${sp}const${sp}[");
+      index = 0;
+      for (GoogleProtobuf_EnumValueDescriptorProto val in _canonicalValues) {
+        out.println("${sp}${sp}${sp}${sp}const ${_classname}._(${index++},"
+            "${sp}${val.number},${sp}'${val.name}'),");
+      }
+      out.println("${sp}${sp}];");
+      out.println("${sp}${sp}_byValue = "
+          "ProtobufEnum.initByValue(_byIndex);");
+      out.println("}");
+      out.blankLine();
+      out.println("static List<${_classname}> get values()${sp}{");
+      out.println("${sp}${sp}if (null${sp}==${sp}_byIndex)${sp}_init();");
+      out.println("${sp}${sp}return${sp}_byIndex;");
+      out.println("}");
+      out.blankLine();
+      out.println("static ${_classname} valueOf(int value)${sp}{");
+      out.println("${sp}${sp}if (null${sp}==${sp}_byValue)${sp}_init();");
+      out.println("${sp}${sp}return _byValue[value];");
+      out.println("}");
+
+      // -----------------------------------------------------------------
+      // define aliases and _VALUE fields
+      if (!_aliases.isEmpty()) {
+        out.blankLine();
+      }
+      for (EnumAlias alias in _aliases) {
+        out.println("static final ${_classname} ${alias.value.name} ="
+            " ${alias.canonicalValue.name};");
+      }
+      out.blankLine();
+
+      // -----------------------------------------------------------------
+      // define equals operator
+      out.addBlock("bool operator ==(Object o) {", "}", () {
+        out.println("if (o is ${_classname}) {");
+        out.println("  ${_classname} p = o;");
+        out.println("  return value == p.value;");
+        out.println("} else {");
+        out.println("  return false;");
+        out.println("}");
+      });
+      out.blankLine();
+
+      // -----------------------------------------------------------------
+      // constructor
+      out.println("const ${_classname}._(int i,${sp}int v,${sp}String n)${sp}"
+          ":${sp}super(i,${sp}v,${sp}n);");
+    });
+  }
+
+  String get classname() => _classname;
+  String get fqname() => _fqname;
+  GoogleProtobuf_FileOptions_OptimizeMode get optimizeFor() => _optimizeFor;
+
+  GoogleProtobuf_EnumDescriptorProto _descriptor;
+  ProtobufContainer _parent;
+  GenerationContext _context;
+  String _classname;
+  String _fqname;
+  List<GoogleProtobuf_EnumValueDescriptorProto> _canonicalValues;
+  List<EnumAlias> _aliases;
+  GoogleProtobuf_FileOptions_OptimizeMode _optimizeFor;
+}