Gen types file

third_party/web_keyboard_layouts/lib/definitions.g.dart

@@ -15,7 +15,7 @@
 
 part of web_keyboard_layouts;
 
-const String kCompressedBody =
+final LayoutStore kCompressedBody = unmarshallStoreCompressed(
   'H4sIAAAAAAAAE+1c+XdUVba+51ShdPf7IwTbdgAEBRnUVpzneRaliRolgoAh2N2K'
   'rCSEDBBkFEgCARJCGAIkjEkgsFbdKn/o1Hqv+A+e+Af4L7z9ffucW7cqlQHa99S3'
   'WIuz7qnKpVK1v29/ezi7MjP5Qvk/HzOP4fK4eRyXJ8wTuDxpnsTlKfMULk+bp3F5'
@@ -140,4 +140,4 @@ const String kCompressedBody =
   'OV5wP/4AVyeFebEb4p7mZVm/9zRBVb5HVZkpGEbg0vttut3NRkBgKMziWxwezOy3'
   'mXb9Yye0hVyn4vz24QLV9hWUqvStXy+dsbRsxYgh3psdjDE6GImfL9VMoIehR/Sl'
   'mhjB+Kev8jsaoyaGPGjKtzGCkl2MxE/VW2U1R5mUPNgma3OUbMqDmqifIS/ZJqu1'
-  'xHGs/M7Ez0PtPJGVW5rl/230nQ3Z18ralO9uyB37XX/jfwDr7kubSFEAAA=='; // 7996 bytes
+  'xHGs/M7Ez0PtPJGVW5rl/230nQ3Z18ralO9uyB37XX/jfwDr7kubSFEAAA=='); // 7996 bytes

third_party/web_keyboard_layouts/lib/types.g.dart

@@ -0,0 +1,200 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
+// DO NOT EDIT -- DO NOT EDIT -- DO NOT EDIT
+//
+// This file is auto generated by flutter/engine:flutter/tools/gen_web_keyboard_layouts based on
+// layout_types.dart in the same pacakge.
+//
+// Edit the following files instead:
+//
+//  - Script: lib/main.dart
+//  - Templates: data/*.tmpl
+//
+// See flutter/engine:flutter/tools/gen_web_keyboard_layouts/README.md for more information.
+
+part of web_keyboard_layouts;
+
+/// The platform that the browser is running on.
+enum LayoutPlatform {
+  /// Windows.
+  win,
+  /// Linux.
+  linux,
+  /// MacOS or iOS.
+  darwin,
+}
+
+// The length of [LayoutEntry.printable].
+const int _kPrintableLength = 4;
+
+/// Describes the characters that a physical keyboard key will be mapped to
+/// under different modifier states, for a given language on a given
+/// platform.
+class LayoutEntry {
+  /// Create a layout entry.
+  LayoutEntry(this.printables, this.deadMasks)
+    : assert(printables.length == _kPrintableLength);
+
+  /// The printable characters that a key should be mapped to under different
+  /// modifier states.
+  ///
+  /// The [printables] always have a length of 4, corresponding to "without any
+  /// modifiers", "with Shift", "with AltGr", and "with Shift and AltGr"
+  /// respectively. Some values might be empty, or be dead keys that are
+  /// indiecated by [deadMasks].
+  final List<String> printables;
+
+  /// Whether the outcome of a key is a dead key under different modifier
+  /// states.
+  ///
+  /// The four LSB [deadMasks] correspond to the four conditions of
+  /// [printables]: 0x1 for "without any modifiers", 0x2 for "with Shift",
+  /// 0x4 for "with AltGr", and 0x8 for "with Shift and AltGr". A set bit means
+  /// the character is a dead key.
+  final int deadMasks;
+
+  /// An empty [LayoutEntry] that produces dead keys under all conditions.
+  static final LayoutEntry empty = LayoutEntry(
+    const <String>['', '', '', ''], 0xf);
+}
+
+/// Describes the characters that all goal keys will be mapped to for a given
+/// language on a given platform.
+class Layout {
+  /// Create a [Layout].
+  const Layout(this.language, this.platform, this.entries);
+
+  /// The language being used.
+  final String language;
+
+  /// The platform that the browser is running on.
+  final LayoutPlatform platform;
+
+  /// Maps from DOM `KeyboardKey.key`s to the characters they produce.
+  final Map<String, LayoutEntry> entries;
+}
+
+/// Describes all information needed to detect keyboard layout for any languages
+/// on any platforms.
+class LayoutStore {
+  /// Create a [LayoutStore].
+  const LayoutStore(this.goals, this.layouts);
+
+  /// The list of goals, mapping from DOM `KeyboardKey.key` to their mandatory
+  /// goal characters, or null if this goal is optional.
+  ///
+  /// Mandatory goals are characters that must be fulfilled during keyboard
+  /// layout detection. If the character of a mandatory goal is not assigned in
+  /// earlier stages, this character (the value of this map) will be assigned
+  /// to its corresponding key (the key of this map).
+  ///
+  /// Optional goals are keys that will be tested to see if they can be mapped
+  /// to mandatory goal characters.
+  final Map<String, String?> goals;
+
+  /// The layout information for different languages on different platforms.
+  final List<Layout> layouts;
+}
+
+// A [ByteBuffer] that records a offset for the convenience of reading
+// sequentially.
+class _ByteStream {
+  _ByteStream(this.buffer)
+    : _data = buffer.asByteData(), _offset = 0;
+
+  final ByteBuffer buffer;
+  final ByteData _data;
+
+  // The current offset.
+  //
+  // The next read will start from this byte (inclusive).
+  int get offest => _offset;
+  int _offset;
+
+  // Read the next byte as an 8-bit unsigned integer, and increase [offset] by
+  // 1.
+  int readUint8() {
+    final int result = _data.getUint8(_offset);
+    _offset += 1;
+    return result;
+  }
+
+  // Read the next few bytes as a UTF-8 string, and increase [offset]
+  // accordingly.
+  //
+  // The first byte will be a uint8, `length`, the number of bytes of the UTF-8
+  // sequence. Following that is the UTF-8 sequence. Therefore, the total
+  // increment for [offset] is `length + 1`.
+  //
+  // If the `length` is 0, then an empty string is returned.
+  String readString() {
+    final int length = _data.getUint8(_offset);
+    if (length == 0) {
+      _offset += 1;
+      return '';
+    }
+    final Uint8List bytes = buffer.asUint8List(_offset + 1, length);
+    final String result = utf8.decode(bytes);
+    _offset += 1 + length;
+    return result;
+  }
+
+  // Read the next few bytes as a nullable UTF-8 string, and increase [offset]
+  // accordingly.
+  //
+  // It is the same as [readString], except that if the `length` is 0, a null is
+  // returned.
+  String? readNullableString() {
+    final int length = _data.getUint8(_offset);
+    if (length == 0) {
+      _offset += 1;
+      return null;
+    }
+    return readString();
+  }
+}
+
+/// Decode a [LayoutStore] out of the compressed binary data.
+LayoutStore unmarshallStoreCompressed(String compressed) {
+  final Uint8List bytes = Uint8List.fromList(gzip.decode(base64.decode(compressed)));
+  return _unmarshallStore(bytes.buffer);
+}
+
+LayoutStore _unmarshallStore(ByteBuffer buffer) {
+  final _ByteStream stream = _ByteStream(buffer);
+  final Map<String, String?> goals = _unmarshallGoals(stream);
+  final List<String> goalKeys = goals.keys.toList();
+  final int layoutNum = stream.readUint8();
+  final List<Layout> layouts = List<Layout>.generate(layoutNum, (_) {
+    return _unmarshallLayout(stream, goalKeys);
+  });
+  return LayoutStore(goals, layouts);
+}
+
+Map<String, String?> _unmarshallGoals(_ByteStream stream) {
+  final int goalsLength = stream.readUint8();
+  return Map<String, String?>.fromEntries((() sync* {
+    for (int goalIndex = 0; goalIndex < goalsLength; goalIndex += 1) {
+      yield MapEntry<String, String?>(stream.readString(), stream.readNullableString());
+    }
+  })());
+}
+
+Layout _unmarshallLayout(_ByteStream stream, List<String> goalKeys) {
+  final String language = stream.readString();
+  final LayoutPlatform platform = LayoutPlatform.values[stream.readUint8()];
+  final Map<String, LayoutEntry> entries = Map<String, LayoutEntry>.fromIterables(
+    goalKeys,
+    goalKeys.map((_) => _unmarshallLayoutEntry(stream)),
+  );
+  return Layout(language, platform, entries);
+}
+
+LayoutEntry _unmarshallLayoutEntry(_ByteStream stream) {
+  final List<String> printables = List<String>.generate(_kPrintableLength,
+    (_) => stream.readString());
+  final int deadMasks = stream.readUint8();
+  return LayoutEntry(printables, deadMasks);
+}
+;

third_party/web_keyboard_layouts/lib/web_keyboard_layouts.dart

@@ -3,5 +3,9 @@
 
 library web_keyboard_layouts;
 
-part 'base.dart';
+import 'dart:convert' show base64, utf8;
+import 'dart:io' hide BytesBuilder;
+import 'dart:typed_data';
+
+part 'types.g.dart';
 part 'definitions.g.dart';

tools/gen_web_keyboard_layouts/bin/gen_web_keyboard_layouts.dart

@@ -62,6 +62,7 @@ Future<void> main(List<String> rawArguments) async {
     githubToken: envGithubToken,
     cacheRoot: path.join(packageRoot.path, '.cache'),
     dataRoot: path.join(packageRoot.path, 'data'),
+    libRoot: path.join(packageRoot.path, 'lib'),
     force: parsedArguments['force'] as bool,
     outputRoot: path.join(packageRoot.parent.parent.path,
         'third_party', 'web_keyboard_layouts', 'lib'),

tools/gen_web_keyboard_layouts/data/definitions.dart.tmpl

@@ -15,5 +15,5 @@
 
 part of web_keyboard_layouts;
 
-const String kCompressedBody =
-@@@BODY@@@; // @@@BODY_LENGTH@@@ bytes
+final LayoutStore kCompressedBody = unmarshallStoreCompressed(
+@@@BODY@@@); // @@@BODY_LENGTH@@@ bytes

tools/gen_web_keyboard_layouts/data/types.dart.tmpl

@@ -0,0 +1,17 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
+// DO NOT EDIT -- DO NOT EDIT -- DO NOT EDIT
+//
+// This file is auto generated by flutter/engine:flutter/tools/gen_web_keyboard_layouts based on
+// layout_types.dart in the same pacakge.
+//
+// Edit the following files instead:
+//
+//  - Script: lib/main.dart
+//  - Templates: data/*.tmpl
+//
+// See flutter/engine:flutter/tools/gen_web_keyboard_layouts/README.md for more information.
+
+part of web_keyboard_layouts;
+@@@BODY@@@;

tools/gen_web_keyboard_layouts/lib/layout_types.dart

@@ -6,6 +6,17 @@ import 'dart:convert' show base64, utf8;
 import 'dart:io' hide BytesBuilder;
 import 'dart:typed_data';
 
+// Changing the structure of layouting classes must change the following places
+// as well:
+//
+//  * Marshalling,
+//  * Unmarshalling,
+//  * Verification.
+
+// The following segment is not only used in the generating script, but also
+// copied to the generated package.
+/*@@@ SHARED SEGMENT START @@@*/
+
 /// The platform that the browser is running on.
 enum LayoutPlatform {
   /// Windows.
@@ -189,7 +200,14 @@ LayoutEntry _unmarshallLayoutEntry(_ByteStream stream) {
   return LayoutEntry(printables, deadMasks);
 }
 
+/*@@@ SHARED SEGMENT END @@@*/
+
 /// Compress a [LayoutStore] into the compressed binary data.
+///
+/// See [unmarshallStoreCompressed] for decompression.
+///
+/// The corretness of compression and decompression is checked by
+/// [verifyLayoutStoreEqual], which is run at the end of every generation.
 String marshallStoreCompressed(LayoutStore store) {
   final BytesBuilder bodyBuilder = BytesBuilder();
   _marshallStore(bodyBuilder, store);