Let an object move with AnimatedPositioned - flutter

Question

I asked this question in this link Transition with futter move object
how i can make movig an object with AnimatedPositioned ? if i want an object move with a value = 1, or a value = 10
or something like that:
i = 0;
i++;
or
i = 0;
i = i + 10;
how i can do that with AnimatedPositioned

Answer 1

You only need to update position value from your AnimatedPositioned:
AnimatedPositioned(
width: selected ? 200.0 : 50.0,
height: selected ? 50.0 : 200.0,
top: selected ? 50.0 : 150.0,
duration: const Duration(seconds: 2),
curve: Curves.fastOutSlowIn,
child: GestureDetector(
onTap: () {
setState(() {
selected = !selected;
});
},
child: Container(
color: Colors.blue,
child: const Center(child: Text('Tap me')),
),
),
)
Just change that values to yours.
Full example:
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
static const String _title = 'Flutter Code Sample';
#override
Widget build(BuildContext context) {
return MaterialApp(
title: _title,
home: Scaffold(
appBar: AppBar(title: const Text(_title)),
body: const Center(
child: MyStatefulWidget(),
),
),
);
}
}
class MyStatefulWidget extends StatefulWidget {
const MyStatefulWidget({Key? key}) : super(key: key);
#override
State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
bool selected = false;
#override
Widget build(BuildContext context) {
return SizedBox(
width: 200,
height: 350,
child: Stack(
children: <Widget>[
AnimatedPositioned(
width: selected ? 200.0 : 50.0,
height: selected ? 50.0 : 200.0,
top: selected ? 50.0 : 150.0,
duration: const Duration(seconds: 2),
curve: Curves.fastOutSlowIn,
child: GestureDetector(
onTap: () {
setState(() {
selected = !selected;
});
},
child: Container(
color: Colors.blue,
child: const Center(child: Text('Tap me')),
),
),
),
],
),
);
}
}
Info: https://api.flutter.dev/flutter/widgets/AnimatedPositioned-class.html