After doing some more research I think I can point you in the right direction and I wrote a small demonstration app that should help you so I found a good article explaining why I was having issues nesting widgets that both receive touch input. It is slightly complex but the gist of it is. If multiple touch inputs are detected they are handled in what is called the GestureArena and the child widget always wins. You can define your own GestureFactory and use RawGestureDetector to work around this issue. However, this might be more than you need for your application and in my opinion is the more complicated route. The route I went still involves just GestureDetector obviously you would need to expand on this as it only draws one oval at this time but that should be easy.
Offset position = Offset(0, 0);
bool isTapped = false;
double width = 50;
double height = 50;
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.black,
body: Stack(
children: <Widget>[
Center(
child: Padding(
padding: const EdgeInsets.all(30.0),
child: GestureDetector(
child: GridView(
physics: NeverScrollableScrollPhysics(), //Very Important if
// you don't have this line you will have conflicting touch inputs and with
// gridview being the child will win
shrinkWrap: true,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 4,
childAspectRatio: 2,
),
children: <Widget>[
...letters
.map(
(letter) => Text(
letter,
textAlign: TextAlign.center,
style: TextStyle(
color: Colors.amber,
fontSize: 18,
),
),
)
.toList(),
],
),
onTapDown: (TapDownDetails details) {
//User Taps Screen
print('Global Position: ${details.globalPosition}');
setState(() {
position = Offset(
details.globalPosition.dx - 25,
details.globalPosition.dy - 25,
);
isTapped = true;
});
print(position);
},
onVerticalDragUpdate: (DragUpdateDetails details) {
print('${details.delta.dy}');
setState(() {
height += details.delta.dy;
});
},
onHorizontalDragUpdate: (DragUpdateDetails details) {
print('${details.delta.dx}');
setState(() {
width += details.delta.dx;
});
},
onTapCancel: () {
//User has released finger from screen
//Validate Word??
},
),
),
),
Positioned(
top: position.dy,
left: position.dx,
child: Container(
height: height,
width: width,
decoration: ShapeDecoration(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(30),
side: BorderSide(
color: isTapped ? Colors.blue : Colors.transparent,
width: 3.0),
),
),
),
),
],
),
);
}
Flutter Deep Dive: Gestures found this very helpful key to figuring this all out.
