Return AnimatedContainer in Build Widget When Icon is Pressed

at first let me tell you my question. I want to add an Animation to a Build Widget. When I test both code in a single way it is working fine. If i want to add the Animation to the Build Widget it is not working. I am Flutter beginner but i hope you can help me. I do not found a working way or stackoverflow-page that has a soloution for this problem.

Here is the Code of the Build Widget:

@override

Widget build(BuildContext context) {

return Scaffold(

  backgroundColor: Colors.white,

  appBar: AppBar(

    backgroundColor: Colors.white,

    title: Text(

      "Title",

      style: TextStyle(

        color: Colors.black,

        fontSize: 16,

      ),

    ),

    leading: IconButton(

      icon: Icon(

        Icons.arrow_back,

        color: Colors.black,

      ),

      onPressed: () {

        Navigator.of(context).pop();

      },

    ),

  ),

  body: FutureBuilder(

    builder: (context, snapshot) {

      if (snapshot.hasData) {

        return _buildNews(snapshot.data);

      }



      if (snapshot.hasError) {

        return ErrorView();

      }



      return Center(

        child: SizedBox(

          width: 40,

          height: 40,

          child: CircularProgressIndicator(),

        ),

      );

    },

    future: Repository.getNews(),

  ),

);

}

I want to add the following code like appbar. if the icon is pressed, the animation should rotate the entire page.

Widget build(BuildContext context) {
return AnimatedContainer(
    transform: Matrix4Transform()
        .translate(x: xoffSet, y: yoffSet)
        .rotate(angle)
        .matrix4,
    duration: Duration(milliseconds: 250),
    child: Container(
        height: MediaQuery.of(context).size.height,
        width: MediaQuery.of(context).size.width,
        decoration: BoxDecoration(
            color: Colors.blue[200],
            borderRadius: isOpen
                ? BorderRadius.circular(10)
                : BorderRadius.circular(0)),
        child: SafeArea(
          child: Stack(
            children: [
              !isOpen
                  ? IconButton(
                      icon: Icon(
                        Icons.menu,
                        color: Color(0xFF1f186f),
                      ),
                      onPressed: () {
                        setState(() {
                          xoffSet = 150;
                          yoffSet = 80;
                          angle = -0.2;
                          isOpen = true;
                        });

                        secondLayerState.setState(() {
                          secondLayerState.xoffSet = 122;
                          secondLayerState.yoffSet = 110;
                          secondLayerState.angle = -0.275;
                        });
                      })
                  : IconButton(
                      icon: Icon(Icons.arrow_back_ios,
                          color: Color(0xFF1f186f)),
                      onPressed: () {
                        if (isOpen == true) {
                          setState(() {
                            xoffSet = 0;
                            yoffSet = 0;
                            angle = 0;
                            isOpen = false;
                          });

                          secondLayerState.setState(() {
                            secondLayerState.xoffSet = 0;
                            secondLayerState.yoffSet = 0;
                            secondLayerState.angle = 0;
                          });
                        }
                      }),
              Center(
                child: Image.asset(
                  "assets/avatar.png",
                  height: MediaQuery.of(context).size.height / 2,
                ),
              ),
            ],
          ),
        )));

}

Thank you very much for your help!!!

@JustCodeNinja Do give this a look, I think you can help him!