Update widget position onTap - flutter

Question

I have a stack widget that holds a background image and a textField widgets , I want the user to be able to change the position of the text onTap, I know how to get point details of the tap , but I don't know how to pass this information to textField to update its position
Edit: that's what I did so far, it works only to right or right, then it just disappears!! I think the problem in the coordinate details and use of stack and positioned widgets , but can't figure out how to fix it
Stack(children: [
SingleChildScrollView(
child: Container(
padding: EdgeInsets.all(16),
child: Card(
child: (finalsd == null)
? Image.file(File(_image.path))
: Image.file(File(finalsd!.path))))),
Positioned(
top: 25,
left: 50,
child: Visibility(
visible: caption_vis,
child: GestureDetector(
onTapDown: (details) {
setState(() {
positionHeight = details.localPosition.dx;
positionWidth = details.localPosition.dy;
print(positionWidth);
});
},
child: Container(
height: positionHeight,
width: positionWidth,
child: TextField(
controller: _controller,
focusNode: myFocusNode,
decoration: const InputDecoration(
border: InputBorder.none,
focusedBorder: InputBorder.none,
enabledBorder: InputBorder.none,
errorBorder: InputBorder.none,
disabledBorder: InputBorder.none,
),
onSubmitted: (String value) async {
//Your Code
},
),
)),
),
)
])

Answer 1

You can resize it by wrapping it with a TextField Container and updating the container height and width when the trigger you want occurs.
double? positionHeight = 0;
double? positionWidth = 0;
GestureDetector(
onTapDown: (details) {
setState(() {
positionHeight = 100;
positionWidth = 100;
});
},
child: Container(
height: positionHeight,
width: positionWidth,
child: TextField(
controller: _controller,
focusNode:myFocusNode ,
decoration: const InputDecoration(
border: InputBorder.none,
focusedBorder: InputBorder.none,
enabledBorder: InputBorder.none,
errorBorder: InputBorder.none,
disabledBorder: InputBorder.none,
),
onSubmitted: (String value) async {
//Your Code
},
),
)),
If you only want to position, not resize, you can set the Padding value this way.
EdgeInsetsGeometry textFieldPadding = EdgeInsets.all(8.0);
GestureDetector(
onTapDown: (details) {
setState(() {
textFieldPadding = const EdgeInsets.all(8.0);
textFieldPadding = EdgeInsets.zero;
textFieldPadding = EdgeInsetsGeometry.infinity;
textFieldPadding =
const EdgeInsets.symmetric(vertical: 10.0, horizontal: 10);
});
},
child: Padding(
padding: textFieldPadding,
child: TextField(
controller: _controller,
focusNode:myFocusNode ,
decoration: const InputDecoration(
border: InputBorder.none,
focusedBorder: InputBorder.none,
enabledBorder: InputBorder.none,
errorBorder: InputBorder.none,
disabledBorder: InputBorder.none,
),
onSubmitted: (String value) async {
//Your Code
},
),
),
);