Routing in Flutter

[ericltw]

https://medium.com/@kpbird/flutter-introduction-of-routing-and-navigation-49738dbd6abe

[ericltw]

組成

• Navigator

  為Widget，透過Overlay與Route管理child widgets。

• Overlay

  為Widget，本質上為Stack，被Navigator所引用。

• Route

  被Navigator所管理的抽象，Route管理Overlay所呈現的內容與過度的動畫效果。

關係

• Navigator引用Overlay

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/navigator.dart#L2187

• Navigator給予Route Overlay的控制權

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/navigator.dart#L1741

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/navigator.dart#L1565

• Navigator紀錄歷史Route

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/navigator.dart#L1743

• Route不會控制Overlay widget的initialEntries

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/navigator.dart#L2189

• Route新增initialEntries以外的Overlay entry

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/routes.dart#L43

Route

• 類型

  • Route

  被Navigator widget所管理的抽象。

  • OverlayRoute

  OverlayRoute賦予Route能新增Overlay entry的能力。

  • TransitionRoute

  帶入入口和出口過渡動畫。

  • ModalRoute

  禁止與前一個Route交互的Route，每一ModalRoute新增兩層OverlayEntry於Overlay。

  https://github.com/flutter/flutter/blob/stable/packages/flutter/lib/src/widgets/routes.dart#L1259

  • PageRoute

  替換整個screen的ModalRoute。

  • MaterialPageRoute

  用平台(iOS / Android)自適應過渡效果，替換整個screen的ModalRoute。

• 各類Route覆寫class成員情況

  MaterialPageRute	PageRoute	ModalRoute	TransitionRoute	OverlayRoute	Route
  RouteSettings settings, bool fullscreenDialog WidgetBuilder builder bool maintainState	RouteSettings settings, bool fullscreenDialog	RouteSettings settings	RouteSettings settings	RouteSettings settings	RouteSettings settings
  					NavigatorState get navigator
  				List get overlayEntries	List get overlayEntries
  		void install(OverlayEntry insertionPoint)	void install(OverlayEntry insertionPoint)	void install(OverlayEntry insertionPoint)	void install(OverlayEntry insertionPoint)
  		TickerFuture didPush()	TickerFuture didPush()		TickerFuture didPush()
  			void didReplace(Route oldRoute)		void didReplace(Route oldRoute)
  		Future willPop()			Future willPop()
  					bool get willHandlePopInternally
  					T get currentResult
  					Future get popped
  			bool didPop(T result)	bool didPop(T result)	bool didPop(T result)
  					void didComplete(T result)
  			void didPopNext(Route nextRoute)		void didPopNext(Route nextRoute)
  			void didChangeNext(Route nextRoute)		void didChangeNext(Route nextRoute)
  		void didChangePrevious(Route previousRoute)			void didChangePrevious(Route previousRoute)
  		void changedInternalState()			void changedInternalState()
  		void changedExternalState()			void changedExternalState()
  		void dispose()	void dispose()	void dispose()	void dispose()
  					bool get isCurrent
  					bool get isFirst
  					bool get isActive
  		Iterable createOverlayEntries()		Iterable createOverlayEntries()
  			bool get finishedWhenPopped	bool get finishedWhenPopped
  			Future get completed
  Duration get transitionDuration			Duration get transitionDuration;
  	bool get opaque		bool get opaque;
  		Animation get animation	Animation get animation
  			AnimationController get controller
  		Animation get secondaryAnimation	Animation get secondaryAnimation
  	AnimationController createAnimationController()		AnimationController createAnimationController(
  			Animation createAnimation()
  			T _result
  			void _handleStatusChanged(AnimationStatus status)
  			void _updateSecondaryAnimation(Route nextRoute)
  bool canTransitionTo(TransitionRoute nextRoute)	bool canTransitionTo(TransitionRoute nextRoute)		bool canTransitionTo(TransitionRoute nextRoute)
  bool canTransitionFrom(TransitionRoute previousRoute)	bool canTransitionFrom(TransitionRoute previousRoute)		bool canTransitionFrom(TransitionRoute previousRoute)
  String get debugLabel			String get debugLabel
  		String toString()	String toString()
  Widget buildPage( BuildContext context, Animation animation, Animation secondaryAnimation, )		Widget buildPage(BuildContext context, Animation animation, Animation secondaryAnimation)
  Widget buildTransitions(BuildContext context, Animation animation, Animation secondaryAnimation, Widget child)		Widget buildTransitions( BuildContext context, Animation animation, Animation secondaryAnimation, Widget child, )
  		final FocusScopeNode focusScopeNode
  	bool get barrierDismissible	bool get barrierDismissible
  		bool get semanticsDismissible
  Color get barrierColor		Color get barrierColor
  String get barrierLabel		String get barrierLabel
  		bool get maintainState
  		bool get offstage
  		BuildContext get subtreeContext
  		void addScopedWillPopCallback(WillPopCallback callback)
  		void removeScopedWillPopCallback(WillPopCallback callback)
  		bool get hasScopedWillPopCallback
  		bool get canPop
  		OverlayEntry _modalBarrier;
  		Widget _buildModalBarrier(BuildContext context)
  		Widget _modalScopeCache;
  		Widget _buildModalScope(BuildContext context)
  	Widget _defaultTransitionsBuilder(BuildContext context, Animation animation, Animation secondaryAnimation, Widget child)