Flutter align two widgets in same position on stack - flutter

Question

I have 2 widget in stack. One of them is aligned in center. And the widget which is on the top is other stack. And I want show second widget with first widget's top and left position. Here is the explain:
The yellow area is my stack. And first widget is setted like Center(child: myFirstWidget). My second widget is referenced from here it's a resizable widget so it's an another stack and it's childs are "positioned". So I need to set top and left value for initialize. But my main stack filled page So when I set my second widget's top and left to 0. It's shown as below.
But I want to show align it to centered child's top like:
My code snip:
child: Container(
color: Colors.red,
child: Stack(
children: [
Center(
child: Image.file(
File("myfilepath"),
),
),
ResizableWidget(
child: Container(
color: Colors.blue,
),
),
],
),
),

Answer 1

You can adjust the position of the widgets with the Position widget like this:
Positioned(
child: ResizableWidget(
child: Container(
color: Colors.blue,
),
),
top: 80,
right: -5,
),
The value of top and right are just random values, you should check what works for you!

Answer 2

You should make Center the parent of the Stack.
The Stack will be positioned at the center of its parent because of Center, it will get the dimensions of its biggest childs (height and width) and will position other childs according to the alignment value.
Edit : I modified the code to include a placeHolder image. Here I gave it a 6000x2000 size but you can change it to whatever value you want. Code is working as expected, see capture below.
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
body: Center(
child: Stack(
alignment: AlignmentDirectional.topStart,
children: [
Image.network('https://via.placeholder.com/6000x2000'),
SizedBox(
height: 50,
width: 50,
child: Container(
color: Colors.green,
))
],
),
),
);
}