InViewState class Null safety

Class that stores the context's of the widgets and String id's of the widgets that are currently in-view. It notifies the listeners when the list is scrolled.



InViewState({required List<String> intialIds, bool isInViewCondition(double, double, double)?})


hashCode int
The hash code for this object. [...]
read-only, inherited
hasListeners bool
Whether any listeners are currently registered. [...]
@protected, read-only, inherited
inViewWidgetIdsLength int
Number of widgets that are currently in-view.
numberOfContextStored int
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


addContext({required BuildContext? context, required String id}) → void
Add the widget's context and an unique string id that needs to be notified.
addListener(VoidCallback listener) → void
Register a closure to be called when the object changes. [...]
dispose() → void
Discards any resources used by the object. After this is called, the object is not in a usable state and should be discarded (calls to addListener and removeListener will throw after the object is disposed). [...]
@mustCallSuper, inherited
inView(String id) bool
Checks if the widget with the id is currently in-view or not.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
notifyListeners() → void
Call all the registered listeners. [...]
onScroll(ScrollNotification notification) → void
The listener that is called when the list view is scrolled.
removeContexts(int letRemain) → void
Keeps the number of widget's contexts the InViewNotifier should stored/cached for the calculations thats needed to be done to check if the widgets are inView or not. Defaults to 10 and should be greater than 1. This is done to reduce the number of calculations being performed.
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that are notified when the object changes. [...]
toString() String
A string representation of this object. [...]


operator ==(Object other) bool
The equality operator. [...]