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 'dart:math' as math;

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

 import 'builder.dart';
 import 'configuration.dart';
 import 'match.dart';
 import 'misc/errors.dart';
 import 'route.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,
     bool requestFocus = true,
   }) : _configuration = configuration {
     builder = RouteBuilder(
       configuration: configuration,
       builderWithNav: builderWithNav,
       errorPageBuilder: errorPageBuilder,
       errorBuilder: errorBuilder,
       restorationScopeId: restorationScopeId,
       observers: observers,
       onPopPageWithRouteMatch: _handlePopPageWithRouteMatch,
       requestFocus: requestFocus,
     );
   }

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

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

   final RouteConfiguration _configuration;

   _NavigatorStateIterator _createNavigatorStateIterator() =>
       _NavigatorStateIterator(currentConfiguration, 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;
   }

   /// 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(
       currentConfiguration.isNotEmpty,
       'You have popped the last page off of the stack,'
       ' there are no pages left to show',
     );
   }

   bool _handlePopPageWithRouteMatch(
       Route<Object?> route, Object? result, RouteMatch? match) {
     if (route.willHandlePopInternally) {
       final bool popped = route.didPop(result);
       assert(!popped);
       return popped;
     }
     assert(match != null);
     final RouteBase routeBase = match!.route;
     if (routeBase is! GoRoute || routeBase.onExit == null) {
       route.didPop(result);
       _completeRouteMatch(result, match);
       return true;
     }

     // The _handlePopPageWithRouteMatch is called during draw frame, schedule
     // a microtask in case the onExit callback want to launch dialog or other
     // navigator operations.
     scheduleMicrotask(() async {
       final bool onExitResult =
           await routeBase.onExit!(navigatorKey.currentContext!);
       if (onExitResult) {
         _completeRouteMatch(result, match);
       }
     });
     return false;
   }

   void _completeRouteMatch(Object? result, RouteMatch match) {
     if (match is ImperativeRouteMatch) {
       match.complete(result);
     }
     currentConfiguration = currentConfiguration.remove(match);
     notifyListeners();
     assert(() {
       _debugAssertMatchListNotEmpty();
       return true;
     }());
   }

   /// 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 currentConfiguration = RouteMatchList.empty;

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

   /// For use by the Router architecture as part of the RouterDelegate.
   // This class avoids using async to make sure the route is processed
   // synchronously if possible.
   @override
   Future<void> setNewRoutePath(RouteMatchList configuration) {
     if (currentConfiguration == configuration) {
       return SynchronousFuture<void>(null);
     }

     assert(configuration.isNotEmpty || configuration.isError);

     final BuildContext? navigatorContext = navigatorKey.currentContext;
     // If navigator is not built or disposed, the GoRoute.onExit is irrelevant.
     if (navigatorContext != null) {
       final int compareUntil = math.min(
         currentConfiguration.matches.length,
         configuration.matches.length,
       );
       int indexOfFirstDiff = 0;
       for (; indexOfFirstDiff < compareUntil; indexOfFirstDiff++) {
         if (currentConfiguration.matches[indexOfFirstDiff] !=
             configuration.matches[indexOfFirstDiff]) {
           break;
         }
       }
       if (indexOfFirstDiff < currentConfiguration.matches.length) {
         final List<GoRoute> exitingGoRoutes = currentConfiguration.matches
             .sublist(indexOfFirstDiff)
             .map<RouteBase>((RouteMatch match) => match.route)
             .whereType<GoRoute>()
             .toList();
         return _callOnExitStartsAt(exitingGoRoutes.length - 1,
                 navigatorContext: navigatorContext, routes: exitingGoRoutes)
             .then<void>((bool exit) {
           if (!exit) {
             return SynchronousFuture<void>(null);
           }
           return _setCurrentConfiguration(configuration);
         });
       }
     }

     return _setCurrentConfiguration(configuration);
   }

   /// Calls [GoRoute.onExit] starting from the index
   ///
   /// The returned future resolves to true if all routes below the index all
   /// return true. Otherwise, the returned future resolves to false.
   static Future<bool> _callOnExitStartsAt(int index,
       {required BuildContext navigatorContext, required List<GoRoute> routes}) {
     if (index < 0) {
       return SynchronousFuture<bool>(true);
     }
     final GoRoute goRoute = routes[index];
     if (goRoute.onExit == null) {
       return _callOnExitStartsAt(index - 1,
           navigatorContext: navigatorContext, routes: routes);
     }

     Future<bool> handleOnExitResult(bool exit) {
       if (exit) {
         return _callOnExitStartsAt(index - 1,
             navigatorContext: navigatorContext, routes: routes);
       }
       return SynchronousFuture<bool>(false);
     }

     final FutureOr<bool> exitFuture = goRoute.onExit!(navigatorContext);
     if (exitFuture is bool) {
       return handleOnExitResult(exitFuture);
     }
     return exitFuture.then<bool>(handleOnExitResult);
   }

   Future<void> _setCurrentConfiguration(RouteMatchList configuration) {
     currentConfiguration = configuration;
     notifyListeners();
     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 - 1;

   final RouteMatchList matchList;
   int index;

   final NavigatorState root;
   @override
   late NavigatorState current;

   RouteBase _getRouteAtIndex(int index) => matchList.matches[index].route;

   void _findsNextIndex() {
     final GlobalKey<NavigatorState>? parentNavigatorKey =
         _getRouteAtIndex(index).parentNavigatorKey;
     if (parentNavigatorKey == null) {
       index -= 1;
       return;
     }

     for (index -= 1; index >= 0; index -= 1) {
       final RouteBase route = _getRouteAtIndex(index);
       if (route is ShellRouteBase) {
         if (route.navigatorKeyForSubRoute(_getRouteAtIndex(index + 1)) ==
             parentNavigatorKey) {
           return;
         }
       }
     }
     assert(root == parentNavigatorKey.currentState);
   }

   @override
   bool moveNext() {
     if (index < 0) {
       return false;
     }
     _findsNextIndex();

     while (index >= 0) {
       final RouteBase route = _getRouteAtIndex(index);
       if (route is ShellRouteBase) {
         final GlobalKey<NavigatorState> navigatorKey =
             route.navigatorKeyForSubRoute(_getRouteAtIndex(index + 1));
         // Must have a ModalRoute parent because the navigator ShellRoute
         // created must not be the root navigator.
         final ModalRoute<Object?> parentModalRoute =
             ModalRoute.of(navigatorKey.currentContext!)!;
         // There may be pageless route on top of ModalRoute that the
         // parentNavigatorKey is in. For example an open dialog.
         if (parentModalRoute.isCurrent) {
           current = navigatorKey.currentState!;
           return true;
         }
       }
       _findsNextIndex();
     }
     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 'dart:math' as math;

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

	import 'builder.dart';
	import 'configuration.dart';
	import 'match.dart';
	import 'misc/errors.dart';
	import 'route.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,
	bool requestFocus = true,
	}) : _configuration = configuration {
	builder = RouteBuilder(
	configuration: configuration,
	builderWithNav: builderWithNav,
	errorPageBuilder: errorPageBuilder,
	errorBuilder: errorBuilder,
	restorationScopeId: restorationScopeId,
	observers: observers,
	onPopPageWithRouteMatch: _handlePopPageWithRouteMatch,
	requestFocus: requestFocus,
	);
	}

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

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

	final RouteConfiguration _configuration;

	_NavigatorStateIterator _createNavigatorStateIterator() =>
	_NavigatorStateIterator(currentConfiguration, 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;
	}

	/// 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(
	currentConfiguration.isNotEmpty,
	'You have popped the last page off of the stack,'
	' there are no pages left to show',
	);
	}

	bool _handlePopPageWithRouteMatch(
	Route<Object?> route, Object? result, RouteMatch? match) {
	if (route.willHandlePopInternally) {
	final bool popped = route.didPop(result);
	assert(!popped);
	return popped;
	}
	assert(match != null);
	final RouteBase routeBase = match!.route;
	if (routeBase is! GoRoute \|\| routeBase.onExit == null) {
	route.didPop(result);
	_completeRouteMatch(result, match);
	return true;
	}

	// The _handlePopPageWithRouteMatch is called during draw frame, schedule
	// a microtask in case the onExit callback want to launch dialog or other
	// navigator operations.
	scheduleMicrotask(() async {
	final bool onExitResult =
	await routeBase.onExit!(navigatorKey.currentContext!);
	if (onExitResult) {
	_completeRouteMatch(result, match);
	}
	});
	return false;
	}

	void _completeRouteMatch(Object? result, RouteMatch match) {
	if (match is ImperativeRouteMatch) {
	match.complete(result);
	}
	currentConfiguration = currentConfiguration.remove(match);
	notifyListeners();
	assert(() {
	_debugAssertMatchListNotEmpty();
	return true;
	}());
	}

	/// 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 currentConfiguration = RouteMatchList.empty;

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

	/// For use by the Router architecture as part of the RouterDelegate.
	// This class avoids using async to make sure the route is processed
	// synchronously if possible.
	@override
	Future<void> setNewRoutePath(RouteMatchList configuration) {
	if (currentConfiguration == configuration) {
	return SynchronousFuture<void>(null);
	}

	assert(configuration.isNotEmpty \|\| configuration.isError);

	final BuildContext? navigatorContext = navigatorKey.currentContext;
	// If navigator is not built or disposed, the GoRoute.onExit is irrelevant.
	if (navigatorContext != null) {
	final int compareUntil = math.min(
	currentConfiguration.matches.length,
	configuration.matches.length,
	);
	int indexOfFirstDiff = 0;
	for (; indexOfFirstDiff < compareUntil; indexOfFirstDiff++) {
	if (currentConfiguration.matches[indexOfFirstDiff] !=
	configuration.matches[indexOfFirstDiff]) {
	break;
	}
	}
	if (indexOfFirstDiff < currentConfiguration.matches.length) {
	final List<GoRoute> exitingGoRoutes = currentConfiguration.matches
	.sublist(indexOfFirstDiff)
	.map<RouteBase>((RouteMatch match) => match.route)
	.whereType<GoRoute>()
	.toList();
	return _callOnExitStartsAt(exitingGoRoutes.length - 1,
	navigatorContext: navigatorContext, routes: exitingGoRoutes)
	.then<void>((bool exit) {
	if (!exit) {
	return SynchronousFuture<void>(null);
	}
	return _setCurrentConfiguration(configuration);
	});
	}
	}

	return _setCurrentConfiguration(configuration);
	}

	/// Calls [GoRoute.onExit] starting from the index
	///
	/// The returned future resolves to true if all routes below the index all
	/// return true. Otherwise, the returned future resolves to false.
	static Future<bool> _callOnExitStartsAt(int index,
	{required BuildContext navigatorContext, required List<GoRoute> routes}) {
	if (index < 0) {
	return SynchronousFuture<bool>(true);
	}
	final GoRoute goRoute = routes[index];
	if (goRoute.onExit == null) {
	return _callOnExitStartsAt(index - 1,
	navigatorContext: navigatorContext, routes: routes);
	}

	Future<bool> handleOnExitResult(bool exit) {
	if (exit) {
	return _callOnExitStartsAt(index - 1,
	navigatorContext: navigatorContext, routes: routes);
	}
	return SynchronousFuture<bool>(false);
	}

	final FutureOr<bool> exitFuture = goRoute.onExit!(navigatorContext);
	if (exitFuture is bool) {
	return handleOnExitResult(exitFuture);
	}
	return exitFuture.then<bool>(handleOnExitResult);
	}

	Future<void> _setCurrentConfiguration(RouteMatchList configuration) {
	currentConfiguration = configuration;
	notifyListeners();
	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 - 1;

	final RouteMatchList matchList;
	int index;

	final NavigatorState root;
	@override
	late NavigatorState current;

	RouteBase _getRouteAtIndex(int index) => matchList.matches[index].route;

	void _findsNextIndex() {
	final GlobalKey<NavigatorState>? parentNavigatorKey =
	_getRouteAtIndex(index).parentNavigatorKey;
	if (parentNavigatorKey == null) {
	index -= 1;
	return;
	}

	for (index -= 1; index >= 0; index -= 1) {
	final RouteBase route = _getRouteAtIndex(index);
	if (route is ShellRouteBase) {
	if (route.navigatorKeyForSubRoute(_getRouteAtIndex(index + 1)) ==
	parentNavigatorKey) {
	return;
	}
	}
	}
	assert(root == parentNavigatorKey.currentState);
	}

	@override
	bool moveNext() {
	if (index < 0) {
	return false;
	}
	_findsNextIndex();

	while (index >= 0) {
	final RouteBase route = _getRouteAtIndex(index);
	if (route is ShellRouteBase) {
	final GlobalKey<NavigatorState> navigatorKey =
	route.navigatorKeyForSubRoute(_getRouteAtIndex(index + 1));
	// Must have a ModalRoute parent because the navigator ShellRoute
	// created must not be the root navigator.
	final ModalRoute<Object?> parentModalRoute =
	ModalRoute.of(navigatorKey.currentContext!)!;
	// There may be pageless route on top of ModalRoute that the
	// parentNavigatorKey is in. For example an open dialog.
	if (parentModalRoute.isCurrent) {
	current = navigatorKey.currentState!;
	return true;
	}
	}
	_findsNextIndex();
	}
	assert(index == -1);
	current = root;
	return true;
	}
	}