[web] Use PlatformLocation from ui_web (#126851)

Remove the following APIs and export them directly from `dart:ui_web`:
- `urlStrategy` getter and setter
- `HashUrlStrategy`
- `PlatformLocation` and `BrowserPlatformLocation` (keep the façades for non-web platforms)

Depends on https://github.com/flutter/engine/pull/42043
Depends on https://github.com/flutter/engine/pull/42252

Part of https://github.com/flutter/flutter/issues/126831

packages/flutter_web_plugins/lib/flutter_web_plugins.dart

@@ -17,6 +17,5 @@ library flutter_web_plugins;
 
 export 'src/navigation/url_strategy.dart';
 export 'src/navigation/utils.dart';
-export 'src/navigation_common/platform_location.dart';
 export 'src/plugin_event_channel.dart';
 export 'src/plugin_registry.dart';

packages/flutter_web_plugins/lib/src/navigation/url_strategy.dart

@@ -2,39 +2,23 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
-import 'dart:html' as html;
-import 'dart:ui' as ui;
 import 'dart:ui_web' as ui_web;
 
-import '../navigation_common/platform_location.dart';
 import 'utils.dart';
 
-export 'dart:ui_web' show UrlStrategy;
-
-/// Saves the current [UrlStrategy] to be accessed by [urlStrategy] or
-/// [setUrlStrategy].
-///
-/// This is particularly required for web plugins relying on valid URL
-/// encoding.
-//
-// Keep this in sync with the default url strategy in the web engine.
-// Find it at:
-// https://github.com/flutter/engine/blob/master/lib/web_ui/lib/src/engine/window.dart#L360
-//
-ui_web.UrlStrategy? _urlStrategy = const HashUrlStrategy();
-
-/// Returns the present [UrlStrategy] for handling the browser URL.
-///
-/// In case null is returned, the browser integration has been manually
-/// disabled by [setUrlStrategy].
-ui_web.UrlStrategy? get urlStrategy => _urlStrategy;
+export 'dart:ui_web'
+    show
+        BrowserPlatformLocation,
+        EventListener,
+        HashUrlStrategy,
+        PlatformLocation,
+        UrlStrategy,
+        urlStrategy;
 
 /// Change the strategy to use for handling browser URL.
 ///
 /// Setting this to null disables all integration with the browser history.
 void setUrlStrategy(ui_web.UrlStrategy? strategy) {
-  _urlStrategy = strategy;
   ui_web.urlStrategy = strategy;
 }
 
@@ -43,99 +27,6 @@ void usePathUrlStrategy() {
   setUrlStrategy(PathUrlStrategy());
 }
 
-/// Uses the browser URL's [hash fragments](https://en.wikipedia.org/wiki/Uniform_Resource_Locator#Syntax)
-/// to represent its state.
-///
-/// By default, this class is used as the URL strategy for the app. However,
-/// this class is still useful for apps that want to extend it.
-///
-/// In order to use [HashUrlStrategy] for an app, it needs to be set like this:
-///
-/// ```dart
-/// import 'package:flutter_web_plugins/flutter_web_plugins.dart';
-///
-/// // Somewhere before calling `runApp()` do:
-/// setUrlStrategy(const HashUrlStrategy());
-/// ```
-class HashUrlStrategy extends ui_web.UrlStrategy {
-  /// Creates an instance of [HashUrlStrategy].
-  ///
-  /// The [PlatformLocation] parameter is useful for testing to mock out browser
-  /// interactions.
-  const HashUrlStrategy(
-      [this._platformLocation = const BrowserPlatformLocation()]);
-
-  final PlatformLocation _platformLocation;
-
-  @override
-  ui.VoidCallback addPopStateListener(ui_web.PopStateListener fn) {
-    void wrappedFn(Object event) {
-      // `fn` expects `event.state`, not a `html.Event`.
-      fn((event as html.PopStateEvent).state);
-    }
-    _platformLocation.addPopStateListener(wrappedFn);
-    return () => _platformLocation.removePopStateListener(wrappedFn);
-  }
-
-  @override
-  String getPath() {
-    // the hash value is always prefixed with a `#`
-    // and if it is empty then it will stay empty
-    final String path = _platformLocation.hash;
-    assert(path.isEmpty || path.startsWith('#'));
-
-    // We don't want to return an empty string as a path. Instead we default to "/".
-    if (path.isEmpty || path == '#') {
-      return '/';
-    }
-    // At this point, we know [path] starts with "#" and isn't empty.
-    return path.substring(1);
-  }
-
-  @override
-  Object? getState() => _platformLocation.state;
-
-  @override
-  String prepareExternalUrl(String internalUrl) {
-    // It's convention that if the hash path is empty, we omit the `#`; however,
-    // if the empty URL is pushed it won't replace any existing fragment. So
-    // when the hash path is empty, we still return the location's path and
-    // query.
-    return '${_platformLocation.pathname}${_platformLocation.search}'
-        '${internalUrl.isEmpty ? '' : '#$internalUrl'}';
-  }
-
-  @override
-  void pushState(Object? state, String title, String url) {
-    _platformLocation.pushState(state, title, prepareExternalUrl(url));
-  }
-
-  @override
-  void replaceState(Object? state, String title, String url) {
-    _platformLocation.replaceState(state, title, prepareExternalUrl(url));
-  }
-
-  @override
-  Future<void> go(int count) {
-    _platformLocation.go(count);
-    return _waitForPopState();
-  }
-
-  /// Waits until the next popstate event is fired.
-  ///
-  /// This is useful, for example, to wait until the browser has handled the
-  /// `history.back` transition.
-  Future<void> _waitForPopState() {
-    final Completer<void> completer = Completer<void>();
-    late ui.VoidCallback unsubscribe;
-    unsubscribe = addPopStateListener((_) {
-      unsubscribe();
-      completer.complete();
-    });
-    return completer.future;
-  }
-}
-
 /// Uses the browser URL's pathname to represent Flutter's route name.
 ///
 /// In order to use [PathUrlStrategy] for an app, it needs to be set like this:
@@ -146,17 +37,19 @@ class HashUrlStrategy extends ui_web.UrlStrategy {
 /// // Somewhere before calling `runApp()` do:
 /// setUrlStrategy(PathUrlStrategy());
 /// ```
-class PathUrlStrategy extends HashUrlStrategy {
+class PathUrlStrategy extends ui_web.HashUrlStrategy {
   /// Creates an instance of [PathUrlStrategy].
   ///
-  /// The [PlatformLocation] parameter is useful for testing to mock out browser
+  /// The [ui_web.PlatformLocation] parameter is useful for testing to mock out browser
   /// interactions.
   PathUrlStrategy([
     super.platformLocation,
-  ])  : _basePath = stripTrailingSlash(extractPathname(checkBaseHref(
+  ])  : _platformLocation = platformLocation,
+        _basePath = stripTrailingSlash(extractPathname(checkBaseHref(
           platformLocation.getBaseHref(),
         )));
 
+  final ui_web.PlatformLocation _platformLocation;
   final String _basePath;
 
   @override
@@ -176,61 +69,3 @@ class PathUrlStrategy extends HashUrlStrategy {
     return '$_basePath$internalUrl';
   }
 }
-
-/// Delegates to real browser APIs to provide platform location functionality.
-class BrowserPlatformLocation extends PlatformLocation {
-  /// Default constructor for [BrowserPlatformLocation].
-  const BrowserPlatformLocation();
-
-  // Default value for [pathname] when it's not set in window.location.
-  // According to MDN this should be ''. Chrome seems to return '/'.
-  static const String _defaultPathname = '';
-
-  // Default value for [search] when it's not set in window.location.
-  // According to both chrome, and the MDN, this is ''.
-  static const String _defaultSearch = '';
-
-  html.Location get _location => html.window.location;
-
-  html.History get _history => html.window.history;
-
-  @override
-  void addPopStateListener(html.EventListener fn) {
-    html.window.addEventListener('popstate', fn);
-  }
-
-  @override
-  void removePopStateListener(html.EventListener fn) {
-    html.window.removeEventListener('popstate', fn);
-  }
-
-  @override
-  String get pathname => _location.pathname ?? _defaultPathname;
-
-  @override
-  String get search => _location.search ?? _defaultSearch;
-
-  @override
-  String get hash => _location.hash;
-
-  @override
-  Object? get state => _history.state;
-
-  @override
-  void pushState(Object? state, String title, String url) {
-    _history.pushState(state, title, url);
-  }
-
-  @override
-  void replaceState(Object? state, String title, String url) {
-    _history.replaceState(state, title, url);
-  }
-
-  @override
-  void go(int count) {
-    _history.go(count);
-  }
-
-  @override
-  String? getBaseHref() => getBaseElementHrefFromDom();
-}

packages/flutter_web_plugins/lib/src/navigation_common/platform_location.dart → packages/flutter_web_plugins/lib/src/navigation_non_web/platform_location.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.
 
+import 'url_strategy.dart';
+
 /// Function type that handles pop state events.
 typedef EventListener = dynamic Function(Object event);
 
@@ -10,11 +12,7 @@ typedef EventListener = dynamic Function(Object event);
 ///
 /// For convenience, the [PlatformLocation] class can be used by implementations
 /// of [UrlStrategy] to interact with DOM apis like pushState, popState, etc.
-abstract class PlatformLocation {
-  /// Abstract const constructor. This constructor enables subclasses to provide
-  /// const constructors so that they can be used in const expressions.
-  const PlatformLocation();
-
+abstract interface class PlatformLocation {
   /// Registers an event listener for the `popstate` event.
   ///
   /// See: https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onpopstate
@@ -74,3 +72,46 @@ abstract class PlatformLocation {
   /// See: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
   String? getBaseHref();
 }
+
+/// Delegates to real browser APIs to provide platform location functionality.
+class BrowserPlatformLocation implements PlatformLocation {
+  @override
+  void addPopStateListener(EventListener fn) {
+    // No-op.
+  }
+
+  @override
+  void removePopStateListener(EventListener fn) {
+    // No-op.
+  }
+
+  @override
+  String get pathname => '';
+
+  @override
+  String get search => '';
+
+  @override
+  String get hash => '';
+
+  @override
+  Object? get state => null;
+
+  @override
+  void pushState(Object? state, String title, String url) {
+    // No-op.
+  }
+
+  @override
+  void replaceState(Object? state, String title, String url) {
+    // No-op.
+  }
+
+  @override
+  void go(int count) {
+    // No-op.
+  }
+
+  @override
+  String? getBaseHref() => null;
+}

packages/flutter_web_plugins/lib/src/navigation_non_web/url_strategy.dart

@@ -5,7 +5,9 @@
 import 'dart:async';
 import 'dart:ui' as ui;
 
-import '../navigation_common/platform_location.dart';
+import 'platform_location.dart';
+
+export 'platform_location.dart';
 
 /// Callback that receives the new state of the browser history entry.
 typedef PopStateListener = void Function(Object? state);
@@ -123,5 +125,5 @@ class PathUrlStrategy extends HashUrlStrategy {
   ///
   /// The [PlatformLocation] parameter is useful for testing to mock out browser
   /// integrations.
-  PathUrlStrategy([PlatformLocation? _]);
+  const PathUrlStrategy([PlatformLocation? _]);
 }

packages/flutter_web_plugins/lib/url_strategy.dart

@@ -2,7 +2,5 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-export 'src/navigation_common/platform_location.dart';
-
 export 'src/navigation_non_web/url_strategy.dart'
     if (dart.library.ui_web) 'src/navigation/url_strategy.dart';

packages/flutter_web_plugins/test/navigation/common.dart

@@ -5,7 +5,7 @@
 import 'package:flutter_web_plugins/url_strategy.dart';
 
 /// A mock implementation of [PlatformLocation] that doesn't access the browser.
-class TestPlatformLocation extends PlatformLocation {
+class TestPlatformLocation implements PlatformLocation {
   @override
   String pathname = '';
 

packages/flutter_web_plugins/test/navigation/url_strategy_test.dart

@@ -11,60 +11,6 @@ import 'package:flutter_web_plugins/url_strategy.dart';
 import 'common.dart';
 
 void main() {
-  group('$HashUrlStrategy', () {
-    late TestPlatformLocation location;
-
-    setUp(() {
-      location = TestPlatformLocation();
-    });
-
-    test('allows null state', () {
-      final HashUrlStrategy strategy = HashUrlStrategy(location);
-      expect(() => strategy.pushState(null, '', '/'), returnsNormally);
-      expect(() => strategy.replaceState(null, '', '/'), returnsNormally);
-    });
-
-    test('leading slash is optional', () {
-      final HashUrlStrategy strategy = HashUrlStrategy(location);
-
-      location.hash = '#/';
-      expect(strategy.getPath(), '/');
-
-      location.hash = '#/foo';
-      expect(strategy.getPath(), '/foo');
-
-      location.hash = '#foo';
-      expect(strategy.getPath(), 'foo');
-    });
-
-    test('path should not be empty', () {
-      final HashUrlStrategy strategy = HashUrlStrategy(location);
-
-      location.hash = '';
-      expect(strategy.getPath(), '/');
-
-      location.hash = '#';
-      expect(strategy.getPath(), '/');
-    });
-
-    test('allows location path/search before fragment', () {
-      const String internalUrl = '/menu?foo=bar';
-      final HashUrlStrategy strategy = HashUrlStrategy(location);
-
-      location.pathname = '/';
-      expect(strategy.prepareExternalUrl(internalUrl), '/#/menu?foo=bar');
-
-      location.pathname = '/main';
-      expect(strategy.prepareExternalUrl(internalUrl), '/main#/menu?foo=bar');
-
-      location.search = '?foo=bar';
-      expect(
-        strategy.prepareExternalUrl(internalUrl),
-        '/main?foo=bar#/menu?foo=bar',
-      );
-    });
-  });
-
   group('$PathUrlStrategy', () {
     late TestPlatformLocation location;