packages/go_router/lib/src/delegate.dart - mirrors/packages - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:async';

 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';

 import 'builder.dart';
 import 'configuration.dart';
 import 'match.dart';
 import 'matching.dart';
 import 'misc/errors.dart';
 import 'typedefs.dart';

 /// GoRouter implementation of [RouterDelegate].
 class GoRouterDelegate extends RouterDelegate<RouteMatchList>
     with ChangeNotifier {
   /// Constructor for GoRouter's implementation of the RouterDelegate base
   /// class.
   GoRouterDelegate({
     required RouteConfiguration configuration,
     required GoRouterBuilderWithNav builderWithNav,
     required GoRouterPageBuilder? errorPageBuilder,
     required GoRouterWidgetBuilder? errorBuilder,
     required List<NavigatorObserver> observers,
     required this.routerNeglect,
     String? restorationScopeId,
   })  : _configuration = configuration,
         builder = RouteBuilder(
           configuration: configuration,
           builderWithNav: builderWithNav,
           errorPageBuilder: errorPageBuilder,
           errorBuilder: errorBuilder,
           restorationScopeId: restorationScopeId,
           observers: observers,
         );

   /// Builds the top-level Navigator given a configuration and location.
   @visibleForTesting
   final RouteBuilder builder;

   /// Set to true to disable creating history entries on the web.
   final bool routerNeglect;

   RouteMatchList _matchList = RouteMatchList.empty;

   /// Stores the number of times each route route has been pushed.
   ///
   /// This is used to generate a unique key for each route.
   ///
   /// For example, it could be equal to:
   /// ```dart
   /// {
   ///   'family': 1,
   ///   'family/:fid': 2,
   /// }
   /// ```
   final Map<String, int> _pushCounts = <String, int>{};
   final RouteConfiguration _configuration;

   _NavigatorStateIterator _createNavigatorStateIterator() =>
       _NavigatorStateIterator(_matchList, navigatorKey.currentState!);

   @override
   Future<bool> popRoute() async {
     final _NavigatorStateIterator iterator = _createNavigatorStateIterator();
     while (iterator.moveNext()) {
       final bool didPop = await iterator.current.maybePop();
       if (didPop) {
         return true;
       }
     }
     return false;
   }

   ValueKey<String> _getNewKeyForPath(String path) {
     // Remap the pageKey to allow any number of the same page on the stack
     final int count = (_pushCounts[path] ?? -1) + 1;
     _pushCounts[path] = count;
     return ValueKey<String>('$path-p$count');
   }

   Future<T?> _push<T extends Object?>(
       RouteMatchList matches, ValueKey<String> pageKey) async {
     final ImperativeRouteMatch<T> newPageKeyMatch = ImperativeRouteMatch<T>(
       route: matches.last.route,
       matchedLocation: matches.last.matchedLocation,
       extra: matches.last.extra,
       error: matches.last.error,
       pageKey: pageKey,
       matches: matches,
     );

     _matchList = _matchList.push(newPageKeyMatch);
     return newPageKeyMatch.future;
   }

   void _remove(RouteMatch match) {
     _matchList = _matchList.remove(match);
   }

   /// Pushes the given location onto the page stack.
   ///
   /// See also:
   /// * [pushReplacement] which replaces the top-most page of the page stack and
   ///   always use a new page key.
   /// * [replace] which replaces the top-most page of the page stack but treats
   ///   it as the same page. The page key will be reused. This will preserve the
   ///   state and not run any page animation.
   Future<T?> push<T extends Object?>(RouteMatchList matches) async {
     assert(matches.last.route is! ShellRoute);

     final ValueKey<String> pageKey = _getNewKeyForPath(matches.fullPath);
     final Future<T?> future = _push(matches, pageKey);
     notifyListeners();
     return future;
   }

   /// Returns `true` if the active Navigator can pop.
   bool canPop() {
     final _NavigatorStateIterator iterator = _createNavigatorStateIterator();
     while (iterator.moveNext()) {
       if (iterator.current.canPop()) {
         return true;
       }
     }
     return false;
   }

   /// Pops the top-most route.
   void pop<T extends Object?>([T? result]) {
     final _NavigatorStateIterator iterator = _createNavigatorStateIterator();
     while (iterator.moveNext()) {
       if (iterator.current.canPop()) {
         iterator.current.pop<T>(result);
         return;
       }
     }
     throw GoError('There is nothing to pop');
   }

   void _debugAssertMatchListNotEmpty() {
     assert(
       _matchList.isNotEmpty,
       'You have popped the last page off of the stack,'
       ' there are no pages left to show',
     );
   }

   bool _onPopPage(Route<Object?> route, Object? result) {
     if (!route.didPop(result)) {
       return false;
     }
     final Page<Object?> page = route.settings as Page<Object?>;
     final RouteMatch? match = builder.getRouteMatchForPage(page);
     assert(match != null);
     if (match is ImperativeRouteMatch) {
       match.complete(result);
     }
     _remove(match!);
     notifyListeners();
     assert(() {
       _debugAssertMatchListNotEmpty();
       return true;
     }());
     return true;
   }

   /// Replaces the top-most page of the page stack with the given one.
   ///
   /// The page key of the new page will always be different from the old one.
   ///
   /// See also:
   /// * [push] which pushes the given location onto the page stack.
   /// * [replace] which replaces the top-most page of the page stack but treats
   ///   it as the same page. The page key will be reused. This will preserve the
   ///   state and not run any page animation.
   void pushReplacement(RouteMatchList matches) {
     assert(matches.last.route is! ShellRoute);
     _remove(_matchList.last);
     push(matches); // [push] will notify the listeners.
   }

   /// Replaces the top-most page of the page stack with the given one but treats
   /// it as the same page.
   ///
   /// The page key will be reused. This will preserve the state and not run any
   /// page animation.
   ///
   /// See also:
   /// * [push] which pushes the given location onto the page stack.
   /// * [pushReplacement] which replaces the top-most page of the page stack but
   ///   always uses a new page key.
   void replace(RouteMatchList matches) {
     assert(matches.last.route is! ShellRoute);
     final RouteMatch routeMatch = _matchList.last;
     final ValueKey<String> pageKey = routeMatch.pageKey;
     _remove(routeMatch);
     _push(matches, pageKey);
     notifyListeners();
   }

   /// For internal use; visible for testing only.
   @visibleForTesting
   RouteMatchList get matches => _matchList;

   /// For use by the Router architecture as part of the RouterDelegate.
   GlobalKey<NavigatorState> get navigatorKey => _configuration.navigatorKey;

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   RouteMatchList get currentConfiguration => _matchList;

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   Widget build(BuildContext context) {
     return builder.build(
       context,
       _matchList,
       _onPopPage,
       routerNeglect,
     );
   }

   /// For use by the Router architecture as part of the RouterDelegate.
   @override
   Future<void> setNewRoutePath(RouteMatchList configuration) {
     _matchList = configuration;
     assert(_matchList.isNotEmpty);
     notifyListeners();
     // Use [SynchronousFuture] so that the initial url is processed
     // synchronously and remove unwanted initial animations on deep-linking
     return SynchronousFuture<void>(null);
   }
 }

 /// An iterator that iterates through navigators that [GoRouterDelegate]
 /// created from the inner to outer.
 ///
 /// The iterator starts with the navigator that hosts the top-most route. This
 /// navigator may not be the inner-most navigator if the top-most route is a
 /// pageless route, such as a dialog or bottom sheet.
 class _NavigatorStateIterator extends Iterator<NavigatorState> {
   _NavigatorStateIterator(this.matchList, this.root)
       : index = matchList.matches.length;

   final RouteMatchList matchList;
   int index = 0;
   final NavigatorState root;
   @override
   late NavigatorState current;

   @override
   bool moveNext() {
     if (index < 0) {
       return false;
     }
     for (index -= 1; index >= 0; index -= 1) {
       final RouteMatch match = matchList.matches[index];
       final RouteBase route = match.route;
       if (route is GoRoute && route.parentNavigatorKey != null) {
         final GlobalKey<NavigatorState> parentNavigatorKey =
             route.parentNavigatorKey!;
         final ModalRoute<Object?>? parentModalRoute =
             ModalRoute.of(parentNavigatorKey.currentContext!);
         // The ModalRoute can be null if the parentNavigatorKey references the
         // root navigator.
         if (parentModalRoute == null) {
           index = -1;
           assert(root == parentNavigatorKey.currentState);
           current = root;
           return true;
         }
         // It must be a ShellRoute that holds this parentNavigatorKey;
         // otherwise, parentModalRoute would have been null. Updates the index
         // to the ShellRoute
         for (index -= 1; index >= 0; index -= 1) {
           final RouteBase route = matchList.matches[index].route;
           if (route is ShellRoute) {
             if (route.navigatorKey == parentNavigatorKey) {
               break;
             }
           }
         }
         // There may be a pageless route on top of ModalRoute that the
         // NavigatorState of parentNavigatorKey is in. For example, an open
         // dialog. In that case we want to find the navigator that host the
         // pageless route.
         if (parentModalRoute.isCurrent == false) {
           continue;
         }

         current = parentNavigatorKey.currentState!;
         return true;
       } else if (route is ShellRoute) {
         // Must have a ModalRoute parent because the navigator ShellRoute
         // created must not be the root navigator.
         final ModalRoute<Object?> parentModalRoute =
             ModalRoute.of(route.navigatorKey.currentContext!)!;
         // There may be pageless route on top of ModalRoute that the
         // parentNavigatorKey is in. For example an open dialog.
         if (parentModalRoute.isCurrent == false) {
           continue;
         }
         current = route.navigatorKey.currentState!;
         return true;
       }
     }
     assert(index == -1);
     current = root;
     return true;
   }
 }
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:async';

	import 'package:flutter/foundation.dart';
	import 'package:flutter/widgets.dart';

	import 'builder.dart';
	import 'configuration.dart';
	import 'match.dart';
	import 'matching.dart';
	import 'misc/errors.dart';
	import 'typedefs.dart';

	/// GoRouter implementation of [RouterDelegate].
	class GoRouterDelegate extends RouterDelegate<RouteMatchList>
	with ChangeNotifier {
	/// Constructor for GoRouter's implementation of the RouterDelegate base
	/// class.
	GoRouterDelegate({
	required RouteConfiguration configuration,
	required GoRouterBuilderWithNav builderWithNav,
	required GoRouterPageBuilder? errorPageBuilder,
	required GoRouterWidgetBuilder? errorBuilder,
	required List<NavigatorObserver> observers,
	required this.routerNeglect,
	String? restorationScopeId,
	}) : _configuration = configuration,
	builder = RouteBuilder(
	configuration: configuration,
	builderWithNav: builderWithNav,
	errorPageBuilder: errorPageBuilder,
	errorBuilder: errorBuilder,
	restorationScopeId: restorationScopeId,
	observers: observers,
	);

	/// Builds the top-level Navigator given a configuration and location.
	@visibleForTesting
	final RouteBuilder builder;

	/// Set to true to disable creating history entries on the web.
	final bool routerNeglect;

	RouteMatchList _matchList = RouteMatchList.empty;

	/// Stores the number of times each route route has been pushed.
	///
	/// This is used to generate a unique key for each route.
	///
	/// For example, it could be equal to:
	/// ```dart
	/// {
	/// 'family': 1,
	/// 'family/:fid': 2,
	/// }
	/// ```
	final Map<String, int> _pushCounts = <String, int>{};
	final RouteConfiguration _configuration;

	_NavigatorStateIterator _createNavigatorStateIterator() =>
	_NavigatorStateIterator(_matchList, navigatorKey.currentState!);

	@override
	Future<bool> popRoute() async {
	final _NavigatorStateIterator iterator = _createNavigatorStateIterator();
	while (iterator.moveNext()) {
	final bool didPop = await iterator.current.maybePop();
	if (didPop) {
	return true;
	}
	}
	return false;
	}

	ValueKey<String> _getNewKeyForPath(String path) {
	// Remap the pageKey to allow any number of the same page on the stack
	final int count = (_pushCounts[path] ?? -1) + 1;
	_pushCounts[path] = count;
	return ValueKey<String>('$path-p$count');
	}

	Future<T?> _push<T extends Object?>(
	RouteMatchList matches, ValueKey<String> pageKey) async {
	final ImperativeRouteMatch<T> newPageKeyMatch = ImperativeRouteMatch<T>(
	route: matches.last.route,
	matchedLocation: matches.last.matchedLocation,
	extra: matches.last.extra,
	error: matches.last.error,
	pageKey: pageKey,
	matches: matches,
	);

	_matchList = _matchList.push(newPageKeyMatch);
	return newPageKeyMatch.future;
	}

	void _remove(RouteMatch match) {
	_matchList = _matchList.remove(match);
	}

	/// Pushes the given location onto the page stack.
	///
	/// See also:
	/// * [pushReplacement] which replaces the top-most page of the page stack and
	/// always use a new page key.
	/// * [replace] which replaces the top-most page of the page stack but treats
	/// it as the same page. The page key will be reused. This will preserve the
	/// state and not run any page animation.
	Future<T?> push<T extends Object?>(RouteMatchList matches) async {
	assert(matches.last.route is! ShellRoute);

	final ValueKey<String> pageKey = _getNewKeyForPath(matches.fullPath);
	final Future<T?> future = _push(matches, pageKey);
	notifyListeners();
	return future;
	}

	/// Returns `true` if the active Navigator can pop.
	bool canPop() {
	final _NavigatorStateIterator iterator = _createNavigatorStateIterator();
	while (iterator.moveNext()) {
	if (iterator.current.canPop()) {
	return true;
	}
	}
	return false;
	}

	/// Pops the top-most route.
	void pop<T extends Object?>([T? result]) {
	final _NavigatorStateIterator iterator = _createNavigatorStateIterator();
	while (iterator.moveNext()) {
	if (iterator.current.canPop()) {
	iterator.current.pop<T>(result);
	return;
	}
	}
	throw GoError('There is nothing to pop');
	}

	void _debugAssertMatchListNotEmpty() {
	assert(
	_matchList.isNotEmpty,
	'You have popped the last page off of the stack,'
	' there are no pages left to show',
	);
	}

	bool _onPopPage(Route<Object?> route, Object? result) {
	if (!route.didPop(result)) {
	return false;
	}
	final Page<Object?> page = route.settings as Page<Object?>;
	final RouteMatch? match = builder.getRouteMatchForPage(page);
	assert(match != null);
	if (match is ImperativeRouteMatch) {
	match.complete(result);
	}
	_remove(match!);
	notifyListeners();
	assert(() {
	_debugAssertMatchListNotEmpty();
	return true;
	}());
	return true;
	}

	/// Replaces the top-most page of the page stack with the given one.
	///
	/// The page key of the new page will always be different from the old one.
	///
	/// See also:
	/// * [push] which pushes the given location onto the page stack.
	/// * [replace] which replaces the top-most page of the page stack but treats
	/// it as the same page. The page key will be reused. This will preserve the
	/// state and not run any page animation.
	void pushReplacement(RouteMatchList matches) {
	assert(matches.last.route is! ShellRoute);
	_remove(_matchList.last);
	push(matches); // [push] will notify the listeners.
	}

	/// Replaces the top-most page of the page stack with the given one but treats
	/// it as the same page.
	///
	/// The page key will be reused. This will preserve the state and not run any
	/// page animation.
	///
	/// See also:
	/// * [push] which pushes the given location onto the page stack.
	/// * [pushReplacement] which replaces the top-most page of the page stack but
	/// always uses a new page key.
	void replace(RouteMatchList matches) {
	assert(matches.last.route is! ShellRoute);
	final RouteMatch routeMatch = _matchList.last;
	final ValueKey<String> pageKey = routeMatch.pageKey;
	_remove(routeMatch);
	_push(matches, pageKey);
	notifyListeners();
	}

	/// For internal use; visible for testing only.
	@visibleForTesting
	RouteMatchList get matches => _matchList;

	/// For use by the Router architecture as part of the RouterDelegate.
	GlobalKey<NavigatorState> get navigatorKey => _configuration.navigatorKey;

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	RouteMatchList get currentConfiguration => _matchList;

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	Widget build(BuildContext context) {
	return builder.build(
	context,
	_matchList,
	_onPopPage,
	routerNeglect,
	);
	}

	/// For use by the Router architecture as part of the RouterDelegate.
	@override
	Future<void> setNewRoutePath(RouteMatchList configuration) {
	_matchList = configuration;
	assert(_matchList.isNotEmpty);
	notifyListeners();
	// Use [SynchronousFuture] so that the initial url is processed
	// synchronously and remove unwanted initial animations on deep-linking
	return SynchronousFuture<void>(null);
	}
	}

	/// An iterator that iterates through navigators that [GoRouterDelegate]
	/// created from the inner to outer.
	///
	/// The iterator starts with the navigator that hosts the top-most route. This
	/// navigator may not be the inner-most navigator if the top-most route is a
	/// pageless route, such as a dialog or bottom sheet.
	class _NavigatorStateIterator extends Iterator<NavigatorState> {
	_NavigatorStateIterator(this.matchList, this.root)
	: index = matchList.matches.length;

	final RouteMatchList matchList;
	int index = 0;
	final NavigatorState root;
	@override
	late NavigatorState current;

	@override
	bool moveNext() {
	if (index < 0) {
	return false;
	}
	for (index -= 1; index >= 0; index -= 1) {
	final RouteMatch match = matchList.matches[index];
	final RouteBase route = match.route;
	if (route is GoRoute && route.parentNavigatorKey != null) {
	final GlobalKey<NavigatorState> parentNavigatorKey =
	route.parentNavigatorKey!;
	final ModalRoute<Object?>? parentModalRoute =
	ModalRoute.of(parentNavigatorKey.currentContext!);
	// The ModalRoute can be null if the parentNavigatorKey references the
	// root navigator.
	if (parentModalRoute == null) {
	index = -1;
	assert(root == parentNavigatorKey.currentState);
	current = root;
	return true;
	}
	// It must be a ShellRoute that holds this parentNavigatorKey;
	// otherwise, parentModalRoute would have been null. Updates the index
	// to the ShellRoute
	for (index -= 1; index >= 0; index -= 1) {
	final RouteBase route = matchList.matches[index].route;
	if (route is ShellRoute) {
	if (route.navigatorKey == parentNavigatorKey) {
	break;
	}
	}
	}
	// There may be a pageless route on top of ModalRoute that the
	// NavigatorState of parentNavigatorKey is in. For example, an open
	// dialog. In that case we want to find the navigator that host the
	// pageless route.
	if (parentModalRoute.isCurrent == false) {
	continue;
	}

	current = parentNavigatorKey.currentState!;
	return true;
	} else if (route is ShellRoute) {
	// Must have a ModalRoute parent because the navigator ShellRoute
	// created must not be the root navigator.
	final ModalRoute<Object?> parentModalRoute =
	ModalRoute.of(route.navigatorKey.currentContext!)!;
	// There may be pageless route on top of ModalRoute that the
	// parentNavigatorKey is in. For example an open dialog.
	if (parentModalRoute.isCurrent == false) {
	continue;
	}
	current = route.navigatorKey.currentState!;
	return true;
	}
	}
	assert(index == -1);
	current = root;
	return true;
	}
	}