颤振:如何移动、旋转和缩放容器?

我想做一个容器,可以拖动,缩放和旋转。我能实现变焦。下面是我的代码:

//variable declaration
  double _scale = 1.0;
  double _previousScale;
  var yOffset = 400.0;
  var xOffset = 50.0;
  var rotation = 0.0;
  var lastRotation = 0.0;

//生成方法

@override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Center(
          child: GestureDetector(
            onScaleStart: (scaleDetails) {
              _previousScale = _scale;
              print(' scaleStarts = ${scaleDetails.focalPoint}');
            },
            onScaleUpdate: (scaleUpdates){
              //ScaleUpdateDetails
              rotation += lastRotation - scaleUpdates.rotation;
              lastRotation = scaleUpdates.rotation;
              print("lastRotation = $lastRotation");
              print(' scaleUpdates = ${scaleUpdates.scale} rotation = ${scaleUpdates.rotation}');
              setState(() => _scale = _previousScale * scaleUpdates.scale);
            },
            onScaleEnd: (scaleEndDetails) {
              _previousScale = null;
              print(' scaleEnds = ${scaleEndDetails.velocity}');
            },
            child:
            Transform(
              transform: Matrix4.diagonal3( Vector3(_scale, _scale, _scale))..rotateZ(rotation * math.pi/180.0),
              alignment: FractionalOffset.center,
              child: Container(
                height: 200.0,
                width: 200.0,
                color: Colors.red,
              ),
            )
            ,
          ),
        ),
      ),
    );
  }

目前,没有旋转,我不能移动容器。