Flutter Material Modified

A few small changes to give flutter a different flavor.

Stateful Building

In flutter, a StatefulWidget is responsible for creating its associated State, then that State defines how the widget should build().

class MyWidget extends StatefulWidget {
    const MyWidget({super.key});

    @override
    State createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
    // state props and function stuff

    Widget build(BuildContext context) {
        return MyFancyWidgetTree();
    }
}

This package delegates the build() definition as a duty of the StatefulWidget instead.

class MyWidget extends StatefulWidget<_MyWidgetState> {
    const MyWidget({super.key});

    @override
    State createState() => _MyWidgetState();
    
    @override
    Widget build(BuildContext context, _MyWidgetState state) {
        return MyFancyWidgetTree();
    }
}

class _MyWidgetState extends State<MyWidget> {
    // state props and function stuff
}

This change was included since the idea behind Widgets is to recursively compose other Widgets in a way that represents how the Element tree will be structured. Defining build() in the StatefulWidget instead of its State feels like it follows this recursion idea better.

After-building

One small enhancement was added to the States of StatefulWidgets that allows them to more conveniently run arbitrary code after the widget has rebuilt.

(This example just aims to show what it looks like to use afterBuild(); this is not meant to illustrate any specific use case.)

class _MyWidgetState extends State<MyWidget> {
    int animationStage = -1;

    void startMyAnimation() {
        setState(() {
            animationStage = 0;
        });

        afterBuild(_animateStage1)
    }

    void _animateStage1() {
        setState(() {
            animationStage = 1;
        })

        afterBuild(() {
            _makeSomeApiCalls();
            _animateStage2();
        })
    }

    void _animateStage2() {
        // ...
    }

    void _makeSomeApiCalls() {
        // ...
    }
}