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 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.
removeContext({required BuildContext context}) → void
removeContexts(int letRemain) → void
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.