Reputation: 502
I'm using the transform
property of the Container
widget to rotate it around the Z-axis ,
just like that :
transform: Matrix4.rotationZ(10 * pi/180)
in the following snippet:
Scaffold(
resizeToAvoidBottomInset: false,
body: Stack(
children: <Widget>[
Container(
// margin: EdgeInsets.symmetric(vertical: 20.0,horizontal: 10.0),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage(
"assets/img/women.png",
),
fit: BoxFit.scaleDown,
),
),
),
SingleChildScrollView(
child: Container(
width: deviceSize.width,
height: deviceSize.height,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Flexible(
child: Container(
margin: EdgeInsets.only(bottom: 90.0),
padding:
EdgeInsets.symmetric(vertical: 10.0, horizontal: 15),
transform: Matrix4.rotationZ(10 * pi / 180)
..translate(10.0),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(25),
color: Colors.orange,
boxShadow: [
BoxShadow(
blurRadius: 20.0,
color: Colors.orange,
offset: Offset(5, 7),
)
],
),
child: Text(
'Shopping Universe',
style: TextStyle(
color: Colors.white,
fontSize: 60.0,
fontFamily: 'Piedra',
fontWeight: FontWeight.w200,
),
),
),
),
Flexible(
child: AuthCard(),
),
],
),
),
),
],
),
);
How to change the rotation point and set it to the center of gravity
of the container
?
I could reposition it after that using translate ,something like that Matrix4.rotationZ(15 * pi/180)..translate(10.0)
But i'm not happy with that method ,
Could someone help me please ?
Any suggestions or advice would be appreciated. Thanks.
Upvotes: 1
Views: 4978
Reputation: 1296
You can wrap the Container
with a Transform
widget and set origin
property to whatever you wish.
If you want the origin
to be in the center of the Container
, you have to do something like origin: Offset(containerWidth/2, containerHeight/2)
.
And as your Container
doesn't have a specific height(only the width is known_same as its parent), you have to find its size. You can use RenderBox
for that. Here you can find a tutorial on how to achive this.
import 'package:flutter/material.dart';
import 'auth_card.dart';
import 'dart:math' as Math;
class Test extends StatefulWidget {
@override
_TestState createState() => _TestState();
}
class _TestState extends State<Test> {
GlobalKey _containerKey = GlobalKey();
Size _containerSize = Size(0, 0);
@override
void initState() {
WidgetsBinding.instance.addPostFrameCallback(_afterLayout);
super.initState();
}
Size _getSize() {
final RenderBox renderBoxRed =
_containerKey.currentContext.findRenderObject();
return renderBoxRed.size;
}
_afterLayout(_) {
_containerSize = _getSize();
setState(() {});
}
@override
Widget build(BuildContext context) {
Size deviceSize = MediaQuery.of(context).size;
return Scaffold(
resizeToAvoidBottomInset: false,
body: Stack(
children: <Widget>[
Container(
// margin: EdgeInsets.symmetric(vertical: 20.0,horizontal: 10.0),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage(
"assets/img/women.png",
),
fit: BoxFit.scaleDown,
),
),
),
SingleChildScrollView(
child: Container(
width: deviceSize.width,
height: deviceSize.height,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Flexible(
child: Transform(
transform: Matrix4.rotationZ(10 * Math.pi / 180),
origin: Offset(
_containerSize.width / 2, _containerSize.height / 2),
child: Container(
key: _containerKey,
margin: EdgeInsets.only(bottom: 20.0),
padding: EdgeInsets.symmetric(
vertical: 20.0, horizontal: 15),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(25),
color: Colors.orange,
boxShadow: [
BoxShadow(
blurRadius: 20.0,
color: Colors.orange,
offset: Offset(5, 7),
)
],
),
child: Text(
'Shopping Universe',
style: TextStyle(
color: Colors.white,
fontSize: 60.0,
fontFamily: 'Piedra',
fontWeight: FontWeight.w200,
),
),
),
),
),
Flexible(
child: AuthCard()
),
],
),
),
),
],
),
);
}
}
But note that:
Setting an origin is equivalent to conjugating the transform matrix by a translation. This property is provided just for convenience.
Upvotes: 2