[pointer_interceptor_web] Update package APIs and tests. (flutter#5785)

## Changes:

* Updates the web implementation of the `pointer_interceptor` to `package:web`, and the latest `HtmlElementView` APIs available on Flutter.
* Resolves a timing issue in integration tests by waiting a few frames before doing any assertions from the DOM of a Flutter Web app, that should fix flutter rolls.

## Issues:

* Fixes flutter/flutter#140834
* Fixes flutter/flutter#139753
* Closes flutter#5673 (Credit to @balvinderz!)

## Tests

* Tested manually. All integration tests pass locally.

---

Co-authored-by: balvinderz <balvindersi2@gmail.com>

packages/pointer_interceptor/pointer_interceptor_web/CHANGELOG.md

@@ -1,4 +1,9 @@
+## 0.10.1
+
+* Uses `HtmlElementView.fromTagName` instead of custom factories.
+* Migrates package and tests to `platform:web`.
+* Updates minimum supported SDK version to Flutter 3.16.0/Dart 3.2.0.
+
 ## 0.10.0
 
 * Moves web implementation to its own package.
-

packages/pointer_interceptor/pointer_interceptor_web/example/integration_test/widget_test.dart

@@ -4,22 +4,19 @@
 
 // ignore_for_file: avoid_print
 
-import 'dart:html' as html;
-
 // Imports the Flutter Driver API.
 import 'package:flutter/src/widgets/framework.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
-
 import 'package:pointer_interceptor_web_example/main.dart' as app;
+import 'package:web/web.dart' as web;
 
 final Finder nonClickableButtonFinder =
     find.byKey(const Key('transparent-button'));
 final Finder clickableWrappedButtonFinder =
     find.byKey(const Key('wrapped-transparent-button'));
 final Finder clickableButtonFinder = find.byKey(const Key('clickable-button'));
-final Finder backgroundFinder =
-    find.byKey(const ValueKey<String>('background-widget'));
+final Finder backgroundFinder = find.byKey(const Key('background-widget'));
 
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
@@ -28,10 +25,9 @@ void main() {
     testWidgets(
         'on wrapped elements, the browser does not hit the background-html-view',
         (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAtCenter(clickableButtonFinder, tester);
 
       expect(element.id, isNot('background-html-view'));
@@ -40,10 +36,9 @@ void main() {
     testWidgets(
         'on wrapped elements with intercepting set to false, the browser hits the background-html-view',
         (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAtCenter(clickableWrappedButtonFinder, tester);
 
       expect(element.id, 'background-html-view');
@@ -52,20 +47,18 @@ void main() {
     testWidgets(
         'on unwrapped elements, the browser hits the background-html-view',
         (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAtCenter(nonClickableButtonFinder, tester);
 
       expect(element.id, 'background-html-view');
     }, semanticsEnabled: false);
 
     testWidgets('on background directly', (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAt(tester.getTopLeft(backgroundFinder));
 
       expect(element.id, 'background-html-view');
@@ -75,15 +68,9 @@ void main() {
   group('With semantics', () {
     testWidgets('finds semantics of wrapped widgets',
         (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      if (!_newSemanticsAvailable()) {
-        print('Skipping test: Needs flutter > 2.10');
-        return;
-      }
-
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAtCenter(clickableButtonFinder, tester);
 
       expect(element.tagName.toLowerCase(), 'flt-semantics');
@@ -93,15 +80,9 @@ void main() {
     testWidgets(
         'finds semantics of wrapped widgets with intercepting set to false',
         (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
-
-      if (!_newSemanticsAvailable()) {
-        print('Skipping test: Needs flutter > 2.10');
-        return;
-      }
+      await _fullyRenderApp(tester);
 
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAtCenter(clickableWrappedButtonFinder, tester);
 
       expect(element.tagName.toLowerCase(), 'flt-semantics');
@@ -111,15 +92,9 @@ void main() {
 
     testWidgets('finds semantics of unwrapped elements',
         (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      if (!_newSemanticsAvailable()) {
-        print('Skipping test: Needs flutter > 2.10');
-        return;
-      }
-
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAtCenter(nonClickableButtonFinder, tester);
 
       expect(element.tagName.toLowerCase(), 'flt-semantics');
@@ -134,20 +109,26 @@ void main() {
     // simply allows the hit test to land on the platform view by making itself
     // hit test transparent.
     testWidgets('on background directly', (WidgetTester tester) async {
-      app.main();
-      await tester.pumpAndSettle();
+      await _fullyRenderApp(tester);
 
-      final html.Element element =
+      final web.Element element =
           _getHtmlElementAt(tester.getTopLeft(backgroundFinder));
 
       expect(element.id, 'background-html-view');
     });
   });
 }
 
+Future<void> _fullyRenderApp(WidgetTester tester) async {
+  await tester.pumpWidget(const app.MyApp());
+  // Pump 2 frames so the framework injects the platform view into the DOM.
+  await tester.pump();
+  await tester.pump();
+}
+
 // Calls [_getHtmlElementAt] passing it the center of the widget identified by
 // the `finder`.
-html.Element _getHtmlElementAtCenter(Finder finder, WidgetTester tester) {
+web.Element _getHtmlElementAtCenter(Finder finder, WidgetTester tester) {
   final Offset point = tester.getCenter(finder);
   return _getHtmlElementAt(point);
 }
@@ -158,22 +139,20 @@ html.Element _getHtmlElementAtCenter(Finder finder, WidgetTester tester) {
 // sensitive to the presence of shadow roots and browser quirks (not all
 // browsers agree on what it should return in all situations). Since this test
 // runs only in Chromium, it relies on Chromium's behavior.
-html.Element _getHtmlElementAt(Offset point) {
+web.Element _getHtmlElementAt(Offset point) {
   // Probe at the shadow so the browser reports semantics nodes in addition to
   // platform view elements. If probed from `html.document` the browser hides
   // the contents of <flt-glass-name> as an implementation detail.
-  final html.ShadowRoot glassPaneShadow =
-      html.document.querySelector('flt-glass-pane')!.shadowRoot!;
-  return glassPaneShadow.elementFromPoint(point.dx.toInt(), point.dy.toInt())!;
+  final web.ShadowRoot glassPaneShadow =
+      web.document.querySelector('flt-glass-pane')!.shadowRoot!;
+  // Use `round` below to ensure clicks always fall *inside* the located
+  // element, rather than truncating the decimals.
+  // Truncating decimals makes some tests fail when a centered element (in high
+  // DPI) is not exactly aligned to the pixel grid (because the browser *rounds*)
+  return glassPaneShadow.elementFromPoint(point.dx.round(), point.dy.round());
 }
 
-// TODO(dit): Remove this after flutter master (2.13) lands into stable.
-// This detects that we can do new semantics assertions by looking at the 'id'
-// attribute on flt-semantics elements (it is now set in 2.13 and up).
-bool _newSemanticsAvailable() {
-  final html.ShadowRoot glassPaneShadow =
-      html.document.querySelector('flt-glass-pane')!.shadowRoot!;
-  final List<html.Element> elements =
-      glassPaneShadow.querySelectorAll('flt-semantics[id]');
-  return elements.isNotEmpty;
+/// Shady API: https://github.com/w3c/csswg-drafts/issues/556
+extension ElementFromPointInShadowRoot on web.ShadowRoot {
+  external web.Element elementFromPoint(int x, int y);
 }

packages/pointer_interceptor/pointer_interceptor_web/example/lib/main.dart

@@ -2,50 +2,51 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// ignore: avoid_web_libraries_in_flutter
-import 'dart:html' as html;
+import 'dart:js_interop';
 import 'dart:ui_web' as ui_web;
 
 import 'package:flutter/material.dart';
 import 'package:pointer_interceptor_platform_interface/pointer_interceptor_platform_interface.dart';
 import 'package:pointer_interceptor_web/pointer_interceptor_web.dart';
+import 'package:web/web.dart' as web;
 
 const String _htmlElementViewType = '_htmlElementViewType';
-const double _videoWidth = 640;
-const double _videoHeight = 480;
+const double _containerWidth = 640;
+const double _containerHeight = 480;
 
 /// The html.Element that will be rendered underneath the flutter UI.
-html.Element htmlElement = html.DivElement()
-  ..style.width = '100%'
-  ..style.height = '100%'
-  ..style.backgroundColor = '#fabada'
-  ..style.cursor = 'auto'
-  ..id = 'background-html-view';
+final web.Element _htmlElement =
+    (web.document.createElement('div') as web.HTMLDivElement)
+      ..style.width = '100%'
+      ..style.height = '100%'
+      ..style.backgroundColor = '#fabada'
+      ..style.cursor = 'auto'
+      ..id = 'background-html-view';
 
 // See other examples commented out below...
 
-// html.Element htmlElement = html.VideoElement()
-//   ..style.width = '100%'
-//   ..style.height = '100%'
-//   ..style.cursor = 'auto'
-//   ..style.backgroundColor = 'black'
-//   ..id = 'background-html-view'
-//   ..src = 'https://archive.org/download/BigBuckBunny_124/Content/big_buck_bunny_720p_surround.mp4'
-//   ..poster = 'https://peach.blender.org/wp-content/uploads/title_anouncement.jpg?x11217'
-//   ..controls = true;
-
-// html.Element htmlElement = html.IFrameElement()
+// final web.Element _htmlElement =
+//     (web.document.createElement('video') as web.HTMLVideoElement)
+//       ..style.width = '100%'
+//       ..style.height = '100%'
+//       ..style.cursor = 'auto'
+//       ..style.backgroundColor = 'black'
+//       ..id = 'background-html-view'
+//       ..src =
+//           'https://archive.org/download/BigBuckBunny_124/Content/big_buck_bunny_720p_surround.mp4'
+//       ..poster =
+//           'https://peach.blender.org/wp-content/uploads/title_anouncement.jpg?x11217'
+//       ..controls = true;
+
+// final web.Element _htmlElement =
+//     (web.document.createElement('video') as web.HTMLIFrameElement)
 //       ..width = '100%'
 //       ..height = '100%'
 //       ..id = 'background-html-view'
 //       ..src = 'https://www.youtube.com/embed/IyFZznAk69U'
 //       ..style.border = 'none';
 
 void main() {
-  ui_web.platformViewRegistry.registerViewFactory(
-    _htmlElementViewType,
-    (int viewId) => htmlElement,
-  );
   runApp(const MyApp());
 }
 
@@ -81,6 +82,15 @@ class _MyHomePageState extends State<MyHomePage> {
     });
   }
 
+  @override
+  void initState() {
+    super.initState();
+    ui_web.platformViewRegistry.registerViewFactory(
+      _htmlElementViewType,
+      (int viewId) => _htmlElement,
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -109,13 +119,13 @@ class _MyHomePageState extends State<MyHomePage> {
             ),
             Container(
               color: Colors.black,
-              width: _videoWidth,
-              height: _videoHeight,
+              width: _containerWidth,
+              height: _containerHeight,
               child: Stack(
                 alignment: Alignment.center,
                 children: <Widget>[
                   HtmlElement(
-                    key: const ValueKey<String>('background-widget'),
+                    key: const Key('background-widget'),
                     onClick: () {
                       _clickedOn('html-element');
                     },
@@ -207,9 +217,12 @@ class HtmlElement extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    htmlElement.onClick.listen((_) {
-      onClick();
-    });
+    _htmlElement.addEventListener(
+      'click',
+      (JSAny? _) {
+        onClick();
+      }.toJS,
+    );
 
     return const HtmlElementView(
       viewType: _htmlElementViewType,

packages/pointer_interceptor/pointer_interceptor_web/example/pubspec.yaml

@@ -3,8 +3,8 @@ description: "Demonstrates how to use the pointer_interceptor_web plugin."
 publish_to: 'none'
 
 environment:
-  sdk: ">=3.1.0 <4.0.0"
-  flutter: ">=3.13.0"
+  sdk: ^3.2.0
+  flutter: '>=3.16.0'
 
 dependencies:
   cupertino_icons: ^1.0.2
@@ -13,6 +13,7 @@ dependencies:
   pointer_interceptor_platform_interface: ^0.10.0
   pointer_interceptor_web:
     path: ../../pointer_interceptor_web
+  web: '>=0.3.0 <0.5.0'
 
 dev_dependencies:
   flutter_test:

packages/pointer_interceptor/pointer_interceptor_web/example/web/index.html

@@ -11,10 +11,13 @@
     The path provided below has to start and end with a slash "/" in order for
     it to work correctly.
 
-    Fore more details:
+    For more details:
     * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
+
+    This is a placeholder for base href that will be replaced by the value of
+    the `--base-href` argument provided to `flutter build`.
   -->
-  <base href="/">
+  <base href="$FLUTTER_BASE_HREF">
 
   <meta charset="UTF-8">
   <meta content="IE=Edge" http-equiv="X-UA-Compatible">
@@ -31,18 +34,21 @@
 
   <title>example</title>
   <link rel="manifest" href="manifest.json">
+
+  <!-- This script adds the flutter initialization JS code -->
+  <script src="flutter.js" defer></script>
 </head>
 <body>
-  <!-- This script installs service_worker.js to provide PWA functionality to
-       application. For more information, see:
-       https://developers.google.com/web/fundamentals/primers/service-workers -->
   <script>
-    if ('serviceWorker' in navigator) {
-      window.addEventListener('flutter-first-frame', function () {
-        navigator.serviceWorker.register('flutter_service_worker.js');
+    window.addEventListener('load', function(ev) {
+      // Download main.dart.js
+      _flutter.loader.loadEntrypoint({
+        onEntrypointLoaded: async function(engineInitializer) {
+          let appRunner = await engineInitializer.initializeEngine();
+          appRunner.runApp();
+        }
       });
-    }
+    });
   </script>
-  <script src="main.dart.js" type="application/javascript"></script>
 </body>
 </html>