flutter · yjbanov · Jun 16, 2020 · Jun 12, 2020 · Jun 12, 2020 · Jun 12, 2020
diff --git a/.cirrus.yml b/.cirrus.yml
@@ -127,7 +127,7 @@ task:
       script:
         - cd $ENGINE_PATH/src/flutter/lib/web_ui
         - $ENGINE_PATH/src/out/host_debug_unopt/dart-sdk/bin/pub get
-        - $ENGINE_PATH/src/out/host_debug_unopt/dart-sdk/bin/dartanalyzer --fatal-warnings --fatal-hints dev/ lib/ test/ tool/
+        - $ENGINE_PATH/src/out/host_debug_unopt/dart-sdk/bin/dartanalyzer --enable-experiment=non-nullable --fatal-warnings --fatal-hints dev/ lib/ test/ tool/
 
     - name: format_and_dart_test
       format_script: |

diff --git a/lib/web_ui/analysis_options.yaml b/lib/web_ui/analysis_options.yaml
@@ -3,6 +3,8 @@
 # uncommented, we'll delete this file and simply inherit the root options.
 
 analyzer:
+  enable-experiment:
+    - non-nullable
   strong-mode:
     # TODO(uncomment) implicit-casts: false
     implicit-dynamic: false

diff --git a/lib/web_ui/build.canvaskit.yaml b/lib/web_ui/build.canvaskit.yaml
@@ -11,6 +11,8 @@ targets:
           dart2js_args:
             - --no-minify
             - --enable-asserts
+            - --enable-experiment=non-nullable
+            - --no-sound-null-safety
             - -DFLUTTER_WEB_USE_SKIA=true
         generate_for:
           include:

diff --git a/lib/web_ui/build.html.yaml b/lib/web_ui/build.html.yaml
@@ -10,6 +10,8 @@ targets:
           dart2js_args:
             - --no-minify
             - --enable-asserts
+            - --enable-experiment=non-nullable
+            - --no-sound-null-safety
         generate_for:
           include:
             - test/**.dart

diff --git a/lib/web_ui/dev/integration_tests_manager.dart b/lib/web_ui/dev/integration_tests_manager.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// @dart = 2.6
+
 import 'dart:io' as io;
 import 'package:path/path.dart' as pathlib;
 import 'package:web_driver_installer/chrome_driver_installer.dart';
@@ -51,7 +53,7 @@ class IntegrationTestsManager {
         // LUCI installs driver from CIPD, so we skip installing it on LUCI.
         await _prepareDriver();
       } else {
-        await _verifyDriverForLUCI();
+        _verifyDriverForLUCI();
       }
       await _startDriver(_browserDriverDir.path);
       // TODO(nurhan): https://github.com/flutter/flutter/issues/52987
@@ -109,13 +111,13 @@ class IntegrationTestsManager {
     }
   }
 
-  void _startDriver(String workingDirectory) async {
+  Future<void> _startDriver(String workingDirectory) async {
     await startProcess('./chromedriver/chromedriver', ['--port=4444'],
         workingDirectory: workingDirectory);
     print('INFO: Driver started');
   }
 
-  void _prepareDriver() async {
+  Future<void> _prepareDriver() async {
     if (_browserDriverDir.existsSync()) {
       _browserDriverDir.deleteSync(recursive: true);
     }
@@ -130,7 +132,10 @@ class IntegrationTestsManager {
     final String chromeDriverVersion = await queryChromeDriverVersion();
     ChromeDriverInstaller chromeDriverInstaller =
         ChromeDriverInstaller.withVersion(chromeDriverVersion);
-    await chromeDriverInstaller.install(alwaysInstall: true);
+    // TODO(yjbanov): remove this dynamic hack when chromeDriverInstaller.install returns Future<void>
+    //                https://github.com/flutter/flutter/issues/59376
+    final dynamic installationFuture = chromeDriverInstaller.install(alwaysInstall: true) as dynamic;
+    await installationFuture;
     io.Directory.current = temp;
   }
 
@@ -172,7 +177,7 @@ class IntegrationTestsManager {
         .whereType<io.File>()
         .toList();
 
-    final List<String> e2eTestsToRun = List<String>();
+    final List<String> e2eTestsToRun = <String>[];
     final List<String> blockedTests =
         blockedTestsListsMap[getBlockedTestsListMapKey(_browser)] ?? <String>[];
 
@@ -265,7 +270,7 @@ class IntegrationTestsManager {
     // Whether the project has the pubspec.yaml file.
     bool pubSpecFound = false;
     // The test directory 'test_driver'.
-    io.Directory testDirectory = null;
+    io.Directory testDirectory;
 
     for (io.FileSystemEntity e in entities) {
       // The tests should be under this directories.

diff --git a/lib/web_ui/dev/test_runner.dart b/lib/web_ui/dev/test_runner.dart
@@ -446,6 +446,7 @@ class TestCommand extends Command<bool> with ArgUtils {
       'run',
       'build_runner',
       'build',
+      '--enable-experiment=non-nullable',
       'test',
       '-o',
       forCanvasKit ? canvasKitOutputRelativePath : 'build',

diff --git a/lib/web_ui/dev/utils.dart b/lib/web_ui/dev/utils.dart
@@ -67,7 +67,7 @@ Future<int> runProcess(
 }
 
 /// Runs [executable]. Do not follow the exit code or the output.
-void startProcess(
+Future<void> startProcess(
   String executable,
   List<String> arguments, {
   String workingDirectory,

diff --git a/lib/web_ui/lib/src/engine.dart b/lib/web_ui/lib/src/engine.dart
@@ -152,7 +152,7 @@ void registerHotRestartListener(ui.VoidCallback listener) {
 /// environment in the native embedder.
 // TODO(yjbanov): we should refactor the code such that the framework does not
 //                call this method directly.
-void webOnlyInitializeEngine() {
+void initializeEngine() {
   if (_engineInitialized) {
     return;
   }

diff --git a/lib/web_ui/lib/src/engine/compositor/embedded_views.dart b/lib/web_ui/lib/src/engine/compositor/embedded_views.dart
@@ -93,8 +93,8 @@ class HtmlViewEmbedder {
       return;
     }
 
-    final PlatformViewFactory factory =
-        platformViewRegistry.registeredFactories[viewType];
+    final ui.PlatformViewFactory factory =
+        ui.platformViewRegistry.registeredFactories[viewType];
     if (factory == null) {
       callback(codec.encodeErrorEnvelope(
         code: 'unregistered_view_type',

diff --git a/lib/web_ui/lib/src/engine/compositor/initialization.dart b/lib/web_ui/lib/src/engine/compositor/initialization.dart
@@ -51,5 +51,10 @@ js.JsObject canvasKit;
 /// The Skia font collection.
 SkiaFontCollection skiaFontCollection;
 
+/// Initializes [skiaFontCollection].
+void ensureSkiaFontCollectionInitialized() {
+  skiaFontCollection ??= SkiaFontCollection();
+}
+
 /// The scene host, where the root canvas and overlay canvases are added to.
 html.Element skiaSceneHost;
diff --git a/lib/web_ui/lib/src/engine/platform_views.dart b/lib/web_ui/lib/src/engine/platform_views.dart
@@ -5,90 +5,7 @@
 // @dart = 2.6
 part of engine;
 
-/// A registry for factories that create platform views.
-class PlatformViewRegistry {
-  final Map<String, PlatformViewFactory> registeredFactories =
-      <String, PlatformViewFactory>{};
-
-  final Map<int, html.Element> _createdViews = <int, html.Element>{};
-
-  /// Private constructor so this class can be a singleton.
-  PlatformViewRegistry._();
-
-  /// Register [viewTypeId] as being creating by the given [factory].
-  bool registerViewFactory(String viewTypeId, PlatformViewFactory factory) {
-    if (registeredFactories.containsKey(viewTypeId)) {
-      return false;
-    }
-    registeredFactories[viewTypeId] = factory;
-    return true;
-  }
-
-  /// Returns the view that has been created with the given [id], or `null` if
-  /// no such view exists.
-  html.Element getCreatedView(int id) {
-    return _createdViews[id];
-  }
-}
-
-/// A function which takes a unique [id] and creates an HTML element.
-typedef PlatformViewFactory = html.Element Function(int viewId);
-
-/// The platform view registry for this app.
-final PlatformViewRegistry platformViewRegistry = PlatformViewRegistry._();
-
-/// Handles a platform call to `flutter/platform_views`.
-///
-/// Used to create platform views.
-void handlePlatformViewCall(
-  ByteData data,
-  ui.PlatformMessageResponseCallback callback,
-) {
-  const MethodCodec codec = StandardMethodCodec();
-  final MethodCall decoded = codec.decodeMethodCall(data);
-
-  switch (decoded.method) {
-    case 'create':
-      _createPlatformView(decoded, callback);
-      return;
-    case 'dispose':
-      _disposePlatformView(decoded, callback);
-      return;
-  }
-  callback(null);
-}
-
-void _createPlatformView(
-    MethodCall methodCall, ui.PlatformMessageResponseCallback callback) {
-  final Map<dynamic, dynamic> args = methodCall.arguments;
-  final int id = args['id'];
-  final String viewType = args['viewType'];
-  const MethodCodec codec = StandardMethodCodec();
-
-  // TODO(het): Use 'direction', 'width', and 'height'.
-  if (!platformViewRegistry.registeredFactories.containsKey(viewType)) {
-    callback(codec.encodeErrorEnvelope(
-      code: 'Unregistered factory',
-      message: "No factory registered for viewtype '$viewType'",
-    ));
-    return;
-  }
-  // TODO(het): Use creation parameters.
-  final html.Element element =
-      platformViewRegistry.registeredFactories[viewType](id);
-
-  platformViewRegistry._createdViews[id] = element;
-  callback(codec.encodeSuccessEnvelope(null));
-}
-
-void _disposePlatformView(
-    MethodCall methodCall, ui.PlatformMessageResponseCallback callback) {
-  final int id = methodCall.arguments;
-  const MethodCodec codec = StandardMethodCodec();
-
-  // Remove the root element of the view from the DOM.
-  platformViewRegistry._createdViews[id]?.remove();
-  platformViewRegistry._createdViews.remove(id);
-
-  callback(codec.encodeSuccessEnvelope(null));
-}
+// TODO(yjbanov): The code in this file was temporarily moved to lib/web_ui/lib/ui.dart
+//                during the NNBD migration so that `dart:ui` does not have to export
+//                `dart:_engine`. NNBD does not allow exported non-migrated libraries
+//                from migrated libraries.
diff --git a/lib/web_ui/lib/src/engine/plugins.dart b/lib/web_ui/lib/src/engine/plugins.dart
@@ -6,7 +6,3 @@
 part of engine;
 
 Future<void> Function(String, ByteData, ui.PlatformMessageResponseCallback) pluginMessageCallHandler;
-
-void webOnlySetPluginHandler(Future<void> Function(String, ByteData, ui.PlatformMessageResponseCallback) handler) {
-  pluginMessageCallHandler = handler;
-}
diff --git a/lib/web_ui/lib/src/engine/semantics/incrementable.dart b/lib/web_ui/lib/src/engine/semantics/incrementable.dart
@@ -110,13 +110,13 @@ class Incrementable extends RoleManager {
     _element.setAttribute('aria-valuenow', surrogateTextValue);
     _element.setAttribute('aria-valuetext', semanticsObject.value);
 
-    final bool canIncrease = semanticsObject.increasedValue != null;
+    final bool canIncrease = semanticsObject.increasedValue.isNotEmpty;
     final String surrogateMaxTextValue =
         canIncrease ? '${_currentSurrogateValue + 1}' : surrogateTextValue;
     _element.max = surrogateMaxTextValue;
     _element.setAttribute('aria-valuemax', surrogateMaxTextValue);
 
-    final bool canDecrease = semanticsObject.decreasedValue != null;
+    final bool canDecrease = semanticsObject.decreasedValue.isNotEmpty;
     final String surrogateMinTextValue =
         canDecrease ? '${_currentSurrogateValue - 1}' : surrogateTextValue;
     _element.min = surrogateMinTextValue;

diff --git a/lib/web_ui/lib/src/engine/surface/canvas.dart b/lib/web_ui/lib/src/engine/surface/canvas.dart
@@ -87,7 +87,7 @@ class SurfaceCanvas implements ui.Canvas {
 
   @override
   void clipRect(ui.Rect/*!*/ rect,
-      {ui.ClipOp clipOp/*!*/ = ui.ClipOp.intersect, bool/*!*/ doAntiAlias = true}) {
+      {ui.ClipOp/*!*/ clipOp = ui.ClipOp.intersect, bool/*!*/ doAntiAlias = true}) {
     assert(rectIsValid(rect));
     assert(clipOp != null);
     assert(doAntiAlias != null);

diff --git a/lib/web_ui/lib/src/engine/surface/platform_view.dart b/lib/web_ui/lib/src/engine/surface/platform_view.dart
@@ -47,7 +47,7 @@ class PersistedPlatformView extends PersistedLeafSurface {
       }''';
     _shadowRoot.append(_styleReset);
     final html.Element platformView =
-        platformViewRegistry.getCreatedView(viewId);
+        ui.platformViewRegistry.getCreatedView(viewId);
     if (platformView != null) {
       _shadowRoot.append(platformView);
     } else {
@@ -67,7 +67,7 @@ class PersistedPlatformView extends PersistedLeafSurface {
       ..height = '${height}px';
     // Set size of the root element created by the PlatformView.
     final html.Element platformView =
-        platformViewRegistry.getCreatedView(viewId);
+        ui.platformViewRegistry.getCreatedView(viewId);
     if (platformView != null) {
       platformView.style
         ..width = '${width}px'

diff --git a/lib/web_ui/lib/src/engine/util.dart b/lib/web_ui/lib/src/engine/util.dart
@@ -12,7 +12,7 @@ typedef Callback<T> = void Function(T result);
 ///
 /// Return value should be null on success, and a string error message on
 /// failure.
-typedef Callbacker<T> = String Function(Callback<T> callback);
+typedef Callbacker<T> = String/*?*/ Function(Callback<T> callback);
 
 /// Converts a method that receives a value-returning callback to a method that
 /// returns a Future.

diff --git a/lib/web_ui/lib/src/engine/window.dart b/lib/web_ui/lib/src/engine/window.dart
@@ -582,7 +582,7 @@ class EngineWindow extends ui.Window {
         if (experimentalUseSkia) {
           rasterizer.viewEmbedder.handlePlatformViewCall(data, callback);
         } else {
-          handlePlatformViewCall(data, callback);
+          ui.handlePlatformViewCall(data, callback);
         }
         return;
 

diff --git a/lib/web_ui/lib/src/ui/annotations.dart b/lib/web_ui/lib/src/ui/annotations.dart
@@ -4,7 +4,7 @@
 
 // TODO(dnfield): Remove unused_import ignores when https://github.com/dart-lang/sdk/issues/35164 is resolved.
 
-// @dart = 2.6
+// @dart = 2.9
 part of ui;
 
 // TODO(dnfield): Update this if/when we default this to on in the tool,
@@ -39,7 +39,7 @@ part of ui;
 ///   }
 /// }
 /// ```
-const _KeepToString/*!*/ keepToString = _KeepToString();
+const _KeepToString keepToString = _KeepToString();
 
 class _KeepToString {
   const _KeepToString();