func<T, S> static method

StatefulSheetDelegate<T> func<T, S>(StatefulFunctionDelegate<T, S> function)

Creates a StatefulSheetDelegate using a custom function that takes a MultiStateSheetController and returns an optional value of type T. This allows for dynamic control of the sheet's behavior based on the controller's state.

⚠️ Important: You should create this delegate outside the widget's build method — ideally as a final field in a State class, or within a view model or other persistent scope. Avoid constructing it inline within build() to ensure consistency and performance.

The function parameter is a callback that receives the current MultiStateSheetController and returns a value of type T or null.

Implementation

static StatefulSheetDelegate<T> func<T, S>(
        StatefulFunctionDelegate<T, S> function) =>
    StatefulSheetDelegateFunction<T, S>(function: function);