Reverts "[pointer_interceptor] Add ios implementation and move web im…

…plementation to federated structure" (#5591)

Reverts #5500
Initiated by: stuartmorgan
This change reverts the following previous change:
Original Description:
Addresses flutter/flutter#30143 by adding an iOS implementation 

This PR is Part 2 of #5233

packages/pointer_interceptor/pointer_interceptor/CHANGELOG.md

@@ -1,7 +1,3 @@
-## NEXT
-
-* Adds iOS implementation.
-
 ## 0.9.3+7
 
 * Updates metadata to point to new source folder

packages/pointer_interceptor/pointer_interceptor/README.md

@@ -1,25 +1,24 @@
 # pointer_interceptor
 
-|             | iOS     | Web |
-|-------------|---------|-----|
-| **Support** | iOS 11+ | Any |
+`PointerInterceptor` is a widget that prevents mouse events (in web) from being captured by an underlying [`HtmlElementView`](https://api.flutter.dev/flutter/widgets/HtmlElementView-class.html).
 
-`PointerInterceptor` is a widget that prevents mouse events from being captured by an underlying [`HtmlElementView`](https://api.flutter.dev/flutter/widgets/HtmlElementView-class.html) in web, or an underlying [`PlatformView`](https://api.flutter.dev/flutter/widgets/PlatformViewLink-class.html) on iOS.
+You can use this widget in a cross-platform app freely. In mobile, where the issue that this plugin fixes does not exist, the widget acts as a pass-through of its `children`, without adding anything to the render tree.
 
 ## What is the problem?
 
-When overlaying Flutter widgets on top of `HtmlElementView`/`PlatformView` widgets that respond to mouse gestures (handle clicks, for example), the clicks will be consumed by the `HtmlElementView`/`PlatformView`, and not relayed to Flutter.
+When overlaying Flutter widgets on top of `HtmlElementView` widgets that respond to mouse gestures (handle clicks, for example), the clicks will be consumed by the `HtmlElementView`, and not relayed to Flutter.
 
-The result is that Flutter widget's `onTap` (and other) handlers won't fire as expected, but they'll affect the underlying native platform view.
+The result is that Flutter widget's `onTap` (and other) handlers won't fire as expected, but they'll affect the underlying webview.
 
 |The problem...|
 |:-:|
 |![Depiction of problematic areas](https://raw.githubusercontent.com/flutter/packages/main/packages/pointer_interceptor/doc/img/affected-areas.png)|
 |_In the dashed areas, mouse events won't work as expected. The `HtmlElementView` will consume them before Flutter sees them._|
 
+
 ## How does this work?
 
-In web, `PointerInterceptor` creates a platform view consisting of an empty HTML element, while on iOS it creates an empty `UIView` instead. The element has the size of its `child` widget, and is inserted in the layer tree _behind_ its child in paint order.
+`PointerInterceptor` creates a platform view consisting of an empty HTML element. The element has the size of its `child` widget, and is inserted in the layer tree _behind_ its child in paint order.
 
 This empty platform view doesn't do anything with mouse events, other than preventing them from reaching other platform views underneath it.
 

packages/pointer_interceptor/pointer_interceptor/example/.gitignore

@@ -32,6 +32,7 @@
 /build/
 
 # Web related
+lib/generated_plugin_registrant.dart
 
 # Symbolication related
 app.*.symbols

packages/pointer_interceptor/pointer_interceptor/example/.metadata

@@ -4,27 +4,7 @@
 # This file should be version controlled and should not be manually edited.
 
 version:
-  revision: "969911d1d09d6c4f145e9ce27c08093e8c285561"
-  channel: "main"
+  revision: e6bd95bc5caa5e34c5b0285a559673984374b7ea
+  channel: master
 
 project_type: app
-
-# Tracks metadata for the flutter migrate command
-migration:
-  platforms:
-    - platform: root
-      create_revision: 969911d1d09d6c4f145e9ce27c08093e8c285561
-      base_revision: 969911d1d09d6c4f145e9ce27c08093e8c285561
-    - platform: ios
-      create_revision: 969911d1d09d6c4f145e9ce27c08093e8c285561
-      base_revision: 969911d1d09d6c4f145e9ce27c08093e8c285561
-
-  # User provided section
-
-  # List of Local paths (relative to this file) that should be
-  # ignored by the migrate tool.
-  #
-  # Files that are not part of the templates will be ignored by default.
-  unmanaged_files:
-    - 'lib/main.dart'
-    - 'ios/Runner.xcodeproj/project.pbxproj'

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

@@ -4,13 +4,176 @@
 
 // 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_example/main.dart' as app;
+
+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'));
+
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
-  // TODO(louisehsu): given the difficulty of making the same integration tests
-  // work for both web and ios implementations, please find tests in their respective
-  // platform implementation packages.
-  testWidgets('placeholder test', (WidgetTester tester) async {});
+
+  group('Without semantics', () {
+    testWidgets(
+        'on wrapped elements, the browser does not hit the background-html-view',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableButtonFinder, tester);
+
+      expect(element.id, isNot('background-html-view'));
+    }, semanticsEnabled: false);
+
+    testWidgets(
+        'on wrapped elements with intercepting set to false, the browser hits the background-html-view',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableWrappedButtonFinder, tester);
+
+      expect(element.id, 'background-html-view');
+    }, semanticsEnabled: false);
+
+    testWidgets(
+        'on unwrapped elements, the browser hits the background-html-view',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      final html.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();
+
+      final html.Element element =
+          _getHtmlElementAt(tester.getTopLeft(backgroundFinder));
+
+      expect(element.id, 'background-html-view');
+    }, semanticsEnabled: false);
+  });
+
+  group('With semantics', () {
+    testWidgets('finds semantics of wrapped widgets',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      if (!_newSemanticsAvailable()) {
+        print('Skipping test: Needs flutter > 2.10');
+        return;
+      }
+
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableButtonFinder, tester);
+
+      expect(element.tagName.toLowerCase(), 'flt-semantics');
+      expect(element.getAttribute('aria-label'), 'Works As Expected');
+    });
+
+    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;
+      }
+
+      final html.Element element =
+          _getHtmlElementAtCenter(clickableWrappedButtonFinder, tester);
+
+      expect(element.tagName.toLowerCase(), 'flt-semantics');
+      expect(element.getAttribute('aria-label'),
+          'Never calls onPressed transparent');
+    });
+
+    testWidgets('finds semantics of unwrapped elements',
+        (WidgetTester tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+
+      if (!_newSemanticsAvailable()) {
+        print('Skipping test: Needs flutter > 2.10');
+        return;
+      }
+
+      final html.Element element =
+          _getHtmlElementAtCenter(nonClickableButtonFinder, tester);
+
+      expect(element.tagName.toLowerCase(), 'flt-semantics');
+      expect(element.getAttribute('aria-label'), 'Never calls onPressed');
+    });
+
+    // Notice that, when hit-testing the background platform view, instead of
+    // finding a semantics node, the platform view itself is found. This is
+    // because the platform view does not add interactive semantics nodes into
+    // the framework's semantics tree. Instead, its semantics is determined by
+    // the HTML content of the platform view itself. Flutter's semantics tree
+    // 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();
+
+      final html.Element element =
+          _getHtmlElementAt(tester.getTopLeft(backgroundFinder));
+
+      expect(element.id, 'background-html-view');
+    });
+  });
+}
+
+// Calls [_getHtmlElementAt] passing it the center of the widget identified by
+// the `finder`.
+html.Element _getHtmlElementAtCenter(Finder finder, WidgetTester tester) {
+  final Offset point = tester.getCenter(finder);
+  return _getHtmlElementAt(point);
+}
+
+// Locates the DOM element at the given `point` using `elementFromPoint`.
+//
+// `elementFromPoint` is an approximate proxy for a hit test, although it's
+// 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) {
+  // 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())!;
+}
+
+// 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;
 }