Add icon update tool (#6201)

dev/tools/update_icons.dart

+// 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.
+
+// Regenerates the material icons file.
+// See https://github.com/flutter/flutter/wiki/Updating-Material-Design-Fonts
+
+import 'dart:convert' show LineSplitter;
+import 'dart:io';
+
+import 'package:args/args.dart';
+import 'package:path/path.dart' as path;
+
+const String kOptionCodepointsPath = 'codepoints';
+const String kOptionIconsPath = 'icons';
+const String kOptionDryRun = 'dry-run';
+
+const String kDefaultCodepointsPath = 'bin/cache/artifacts/material_fonts/codepoints';
+const String kDefaultIconsPath = 'packages/flutter/lib/src/material/icons.dart';
+
+const String kBeginGeneratedMark = '// BEGIN GENERATED';
+const String kEndGeneratedMark = '// END GENERATED';
+
+const Map<String, String> kIdentifierRewrites = const <String, String>{
+  '360': 'threesixty',
+  '3d_rotation': 'threed_rotation',
+  '4k': 'four_k',
+  'class': 'class_',
+};
+
+void main(List<String> args) {
+  // If we're run from the `tools` dir, set the cwd to the repo root.
+  if (path.basename(Directory.current.path) == 'tools')
+    Directory.current = Directory.current.parent.parent;
+
+  ArgParser argParser = new ArgParser();
+  argParser.addOption(kOptionCodepointsPath, defaultsTo: kDefaultCodepointsPath);
+  argParser.addOption(kOptionIconsPath, defaultsTo: kDefaultIconsPath);
+  argParser.addFlag(kOptionDryRun, defaultsTo: false);
+  ArgResults argResults = argParser.parse(args);
+
+  File iconFile = new File(path.absolute(argResults[kOptionIconsPath]));
+  if (!iconFile.existsSync()) {
+    stderr.writeln('Icons file not found: ${iconFile.path}');
+    exit(1);
+  }
+  File codepointsFile = new File(path.absolute(argResults[kOptionCodepointsPath]));
+  if (!codepointsFile.existsSync()) {
+    stderr.writeln('Codepoints file not found: ${codepointsFile.path}');
+    exit(1);
+  }
+
+  String iconData = iconFile.readAsStringSync();
+  String codepointData = codepointsFile.readAsStringSync();
+  String newIconData = regenerateIconsFile(iconData, codepointData);
+
+  if (argResults[kOptionDryRun])
+    stdout.writeln(newIconData);
+  else
+    iconFile.writeAsStringSync(newIconData);
+}
+
+String regenerateIconsFile(String iconData, String codepointData) {
+  StringBuffer buf = new StringBuffer();
+  bool generating = false;
+  for (String line in LineSplitter.split(iconData)) {
+    if (!generating)
+      buf.writeln(line);
+    if (line.contains(kBeginGeneratedMark)) {
+      generating = true;
+      String iconDeclarations = generateIconDeclarations(codepointData);
+      buf.write(iconDeclarations);
+    } else if (line.contains(kEndGeneratedMark)) {
+      generating = false;
+      buf.writeln(line);
+    }
+  }
+  return buf.toString();
+}
+
+String generateIconDeclarations(String codepointData) {
+  return LineSplitter.split(codepointData)
+      .map((String l) => l.trim())
+      .where((String l) => l.isNotEmpty)
+      .map(getIconDeclaration)
+      .join();
+}
+
+String getIconDeclaration(String line) {
+  List<String> tokens = line.split(' ');
+  if (tokens.length != 2)
+    throw new FormatException('Unexpected codepoint data: $line');
+  String name = tokens[0];
+  String codepoint = tokens[1];
+  String identifier = kIdentifierRewrites[name] ?? name;
+  String description = name.replaceAll('_', ' ');
+  return '''
+
+  /// <p><i class="material-icons md-36">$name</i> &#x2014; material icon named "$description".</p>
+  static const IconData $identifier = const IconData(0x$codepoint);
+''';
+}

packages/flutter/lib/src/material/icons.dart

@@ -42,11 +42,15 @@ class IconData {
 class Icons {
   Icons._();
 
+  // Generated code: do not hand-edit.
+  // See https://github.com/flutter/flutter/wiki/Updating-Material-Design-Fonts
+  // BEGIN GENERATED
+
   /// <p><i class="material-icons md-36">360</i> &#x2014; material icon named "360".</p>
   static const IconData threesixty = const IconData(0xe577);
 
   /// <p><i class="material-icons md-36">3d_rotation</i> &#x2014; material icon named "3d rotation".</p>
-  static const IconData threed_rotation = const IconData(0xe84d); // 3d_rotation isn't a valid identifier.
+  static const IconData threed_rotation = const IconData(0xe84d);
 
   /// <p><i class="material-icons md-36">4k</i> &#x2014; material icon named "4k".</p>
   static const IconData four_k = const IconData(0xe072);
@@ -589,7 +593,7 @@ class Icons {
   static const IconData chrome_reader_mode = const IconData(0xe86d);
 
   /// <p><i class="material-icons md-36">class</i> &#x2014; material icon named "class".</p>
-  static const IconData class_ = const IconData(0xe86e); // class is a reserved word in Dart.
+  static const IconData class_ = const IconData(0xe86e);
 
   /// <p><i class="material-icons md-36">clear</i> &#x2014; material icon named "clear".</p>
   static const IconData clear = const IconData(0xe14c);
@@ -2996,4 +3000,5 @@ class Icons {
 
   /// <p><i class="material-icons md-36">zoom_out_map</i> &#x2014; material icon named "zoom out map".</p>
   static const IconData zoom_out_map = const IconData(0xe56b);
+  // END GENERATED
 }