I need a Column to expand to a constrained width. So it expands until the maxWidth but doesn't mind being smaller if there isn't enough space. But the Expanded ignores the ConstrainedBox.
Row(
children: [
const Spacer(),
Expanded(
child: ConstrainedBox(
constraints: const BoxConstraints(maxWidth: 50),
child: Column(
children: [
Expanded(child: Container(color: Colors.red)),
Expanded(child: Container(color: Colors.green)),
],
),
),
),
],
)
Here's my full code for context:
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: GetBuilder<TimerController>(
builder: (_) => CustomBackground(
color: _timerController.currentChild?.color ?? Colors.blue,
child: SafeArea(
child: Center(
child: Padding(
padding:
EdgeInsets.symmetric(horizontal: AppSizes.pagePadding),
child: OrientationBuilder(
builder: (context, orientation) =>
(orientation == Orientation.portrait)
? ConstrainedBox(
constraints: BoxConstraints(
maxWidth: AppSizes.maxWidth,
minWidth: AppSizes.minWidth,
),
child: Column(
children: [
SizedBox(height: AppSizes.pagePadding),
Expanded(child: TimerClock()),
Expanded(
child: Column(
children: [
NameText(),
ControlButtons(),
SizedBox(height: 25),
Expanded(child: QueueList()),
],
),
),
],
),
)
: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Expanded(
child: ConstrainedBox(
constraints: BoxConstraints(
maxWidth: AppSizes.maxWidth,
minWidth: AppSizes.minWidth,
),
child: Padding(
padding: const EdgeInsets.symmetric(
vertical: AppSizes.pagePadding),
child: TimerClock(),
),
),
),
SizedBox(width: AppSizes.pagePadding),
Expanded(
child: ConstrainedBox(
constraints: BoxConstraints(
maxWidth: AppSizes.maxWidth, // this get's ignored
minWidth: AppSizes.minWidth,
),
child: Column(
children: [
Expanded(child: NameText()),
ControlButtons(),
SizedBox(height: 25),
Expanded(child: QueueList()),
],
),
),
),
],
),
),
),
),
),
),
),
),
);
}
And if I remove the Expanded, the Column has a fixed width (maxWidth) and throws an error if there isn't enough space.
Change the outer most Expanded to a Flexible. Then the child ConstrainedBox will be respected.
In my case I also added a width:double.infinity to the child of the Flexible to force the widget to always be as big as the maxWidth, and only reduce its size when there is no space.
My example:
Flexible(
child: Container(
constraints: BoxConstraints(maxWidth: screenWidth * 0.25),
width: double.infinity,
),
);
You are using Expanded in a Column widget which means that it will try to expand to fill the space vertically (based on the height of the parent not its width). As mentioned in the documentation of Expanded:
Using an Expanded widget makes a child of a Row, Column, or Flex
expand to fill the available space along the main axis (e.g.,
horizontally for a Row or vertically for a Column).
source
And as you did not precise a maxHeight in your constraints it will be considered as double.infinity.
Related
I am using a CustomScrollView and tried to limit its children's size by using BoxConstraints but they are simply ignored. My text expands to the width of the screen and I don't understand why.
This is my code:
SliverToBoxAdapter(
child: ConstrainedBox(
constraints: maxWidthConstraint,
child: Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
widget.project.description,
),
],
),
),
),
),
What am I missing here? Let me know if you need any more info!
The parent forces it to be the full width so you can wrap it with UnconstrainedBox or Align or Center widget to get rid of that behavior.
SliverToBoxAdapter(
child: UnconstrainedBox( // this should allow it to have its own constraints
child: ConstrainedBox(
constraints: maxWidthConstraint,
child: Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
widget.project.description,
),
],
),
),
),
),
)
So I'm working on my first Project. Basically I want to alignment 4 containers equally. they should have same size H/W so i could scroll on them whenever extra data has been put into them later.....
Here's my Code
Widget build(BuildContext context) {
return Center(
child: Scaffold(
body: Center(
child: Padding(
padding: const EdgeInsets.all(20.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Row(
children: [
Row(
children: [
VerticalText1(),
DoBuilder(),
],
),
Column(
children: const [
SizedBox(
width: 10,
)
],
),
Column(
children: [
DecideBuilder(),
],
),
],
),
Row(
children: const [
SizedBox(
height: 10,
)
],
),
Row(
children: [
Row(
children: [
VerticalText2(),
DelegateBuilder(),
],
),
Column(
children: const [
SizedBox(
width: 10,
)
],
),
Align(
alignment: Alignment.bottomLeft,
child: DeleteBuilder(),
),
So I'm working on my first Project. Basically I want to alignment 4 containers equally. they should have same size H/W so i could scroll on them whenever extra data has been put into them later.....So I'm working on my first Project. Basically I want to alignment 4 containers equally. they should have same size H/W so i could scroll on them whenever extra data has been put into them later.....
for me I'm also a beginner in flutter but I know something that if you want actual size for container and you want it to be some kind of responsive you have 2 ways to do that:
first you can use:
(Mediaquery).of(context).size.width or
(media.query).of(context).size.height
that will give you the size of your screen and you can use as much as you need from it for each container for example:
Container(
child:,
width: (MediaQuery.of(context).size.width / 2))
that will give you half of your screen width what ever the device run the app the size will be the same for the screen size
and other way you can use expanded widget:
put every container in expanded widget and give the flex parameter value of one
here is an example:
Row(children:[
Expanded(flex:1,child:Container()),
Expanded(flex:1,child:Container()),]),
expanded will sum the flexes and will divide the space of the screen on element all equal repeat the above code in single Column has 2 Rows and I hope your code will work as you want
Instead of row and column, you should try with the GridView otherwise you can try with media query height and width.
GridView.builder(
itemCount: 4,
gridDelegate:
SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
itemBuilder: (BuildContext context, int index) {
return new Card(
child: Container(
color: Colors.green,
child: Center(child: Text("$index"),),
),
);
},
)
And Using Column and row
idget build(BuildContext context) {
double height = MediaQuery.of(context).size.height;
double width = MediaQuery.of(context).size.width-20;
return Scaffold(
appBar: AppBar(
title: Text("widget.title"),
),
body: Stack(
children: [
Column(
children: [
Expanded(
child: Row(
children: [
Container(
height: height / 2,
width: width/2,
color: Colors.green,
),
SizedBox(width: 10,),
Container(
height: height / 2,
width: width / 2,
color: Colors.green,
)
],
),
),
SizedBox(height: 10,),
Expanded(
child: Row(
children: [
Container(
height: height / 2,
width: width / 2,
color: Colors.green,
),
SizedBox(width: 10,),
Container(
height: height / 2,
width: width / 2,
color: Colors.green,
)
],
),
),
],
),
Center(
child: Padding(
padding: const EdgeInsets.only(right:10.0),
child: CircleAvatar(child: Icon(Icons.home),),
),
)
],
),
);
}
Output:
I want to have a container with a flexible body (red) height and a fixed button height (gray).
The complete container should be as small as possible and have a max height.
If the content is overflowing the max height it should be scrollable.
I'm new to flutter, so I have no idea how to achieve this.
I tried it with a ConstraintBox with maxHeight, but then the whole container is bigger then it have to be, when the content is small.
return Container(
child: Column(
children: [
ConstrainedBox(
maxHeight: 400
child: //SomeWidget that could overflow
),
Container(
height: 150,
child: Center(
child: TextButton(child: Text('OK'))
),
)
],
),
);
Can someone help?
You can set constraints of your Container. Also you can use Flexible and SingleChildScrollView
Container(
constraints: BoxConstraints(
maxHeight: 300,
),
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
Flexible(
child: SingleChildScrollView(
child: Column(
children: [
//SomeWidget that could overflow
],
),
)),
Container(
color: Colors.amber,
height: 150,
child:
Center(child: TextButton(onPressed: () {}, child: Text('OK'))),
)
],
),
)
I've achieved it now, with that code:
Container(
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
Flexible(
child: SingleChildScrollView(
child: //SomeWidget that could overflow
),
),
Container(
alignment: Alignment.bottomCenter,
child: TextButton(
child: Text('OK')
)
)
]
)
)
According to your UI i think this one will be perfect, and let me know if you need any changes. use constraints to change size.
final widgets = List.generate(
12,
(index) => Container(
height: 100,
color: index % 2 == 0 ? Colors.cyanAccent : Colors.greenAccent,
child: Text("item $index"),
),
);
#override
Widget build(BuildContext context) {
return Scaffold(
body: LayoutBuilder(
builder: (context, constraints) => Stack(
children: [
Align(
alignment: Alignment.topCenter,
child: SizedBox(
///* used 90% of screen for items
height: constraints.maxHeight * .9,
child: ListView(
children: [
Center(child: Text("inside listView")),
///your widgets
...widgets,
Center(child: Text("End of listView")),
],
),
),
),
Positioned(
bottom: 0,
left: 0,
right: 0,
child: Container(
color: Colors.grey.withOpacity(.3),
///* used 10% of screen for Button
height: constraints.maxHeight * .1,
child: Center(
child: TextButton(
child: Text('OK'),
onPressed: () {},
),
),
),
),
],
),
),
);
}
I started to develop in Flutter recently and I am having difficulties in centralizing a Widget completely in the available space of View.
This is how it looks:
And here's what I want to achieve:
And here's my code:
LayoutBuilder(builder:
(BuildContext context, BoxConstraints viewportConstraints) {
return SingleChildScrollView(
child: ConstrainedBox(
constraints: BoxConstraints(
minHeight: viewportConstraints.maxHeight,
),
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
Column(children: [
NavHeader("Deposit"),
BalanceHeader(widget.usd),
]),
Column(
mainAxisSize: MainAxisSize.min,
children: [
Text(
"How much do you want deposit?",
style:(
...
),
),
Container(
alignment: Alignment.center,
width: width * 0.4,
margin: EdgeInsets.only(top: 10),
child: Row(
...
),
),
],
),
],
),
),
);
}),
bottomNavigationBar: BottomAppBar(
...
),
),
);
}
By using MainAxisSize.min The height of the Column will be according to the combined height of its children and incoming height from the parent will be ignored. That means your column height has shrinked to its children.
There is you can use MainAxisSize.max instead of MainAxisSize.min to max height of column. And also you have to use mainAxisAlignment: MainAxisAlignment.center for aligning childrens to center of column.
Your Second Column
Column(
mainAxisSize: MainAxisSize.min,
children: [
Text(
"How much do you want deposit?",
style:(
...
),
),
Container(
alignment: Alignment.center,
width: width * 0.4,
margin: EdgeInsets.only(top: 10),
child: Row(
...
),
),
],
),
Edited Column
Column(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.center
children: [
Text(
"How much do you want deposit?",
style:(
...
),
),
Container(
alignment: Alignment.center,
width: width * 0.4,
margin: EdgeInsets.only(top: 10),
child: Row(
...
),
),
],
),
Well, there is a widget for that!
As for most things in flutter just Wrap the Widgets you want centered inside a Center widget and you should achieve what you want.
Column(
mainAxisAlignment: MainAxisAlignment.center,
children ... Your code
)
You could also wrap your widget with the Column widget and it will work only for the X coordinates.
(It has already been stated but poorly)
I'm re-writing a simple app which calculates averages. However, I have a hard time with a TextField. I would like it to be exactly as on a first screenshot.
The TextField's width is stretched, I don't want that. I want it to be exactly as it is on the screenshot.
Desired look:
What I have:
Code:
import 'package:flutter/material.dart';
import 'package:easy_localization/easy_localization.dart';
class ArithmeticAverageScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('arithmetic_average_title').tr(),
),
body: Container(
padding: EdgeInsets.all(16.0),
child: Column(
children: <Widget>[
Card(
child: Container(
padding: EdgeInsets.symmetric(vertical: 20.0),
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
ListTile(
leading: Icon(Icons.help),
title: Text('arithmetic_average_help').tr(),
subtitle: Text('arithmetic_average_help_content').tr(),
)
],
),
)
),
SizedBox(height: 16.0),
Card(
child: Container(
padding: EdgeInsets.symmetric(vertical: 20.0, horizontal: 20.0),
child: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text('arithmetic_average_your_grades', style: Theme.of(context).textTheme.headline5).tr(),
SizedBox(height: 16.0),
Text('arithmetic_average_grades_one_at_a_time', style: Theme.of(context).textTheme.headline6,).tr(),
SizedBox(height: 16.0),
Text('arithmetic_average_grade', style: Theme.of(context).textTheme.subtitle2).tr(),
TextField()
],
),
),
)
],
),
)
);
}
}
This will help you make generic width on all devices, so here width * 0.3 means it will take 30% of the screen width
Container(
width: MediaQuery.of(context).size.width * 0.3,
child: TextField(),
)
Use Row Widget, and put Expanded Widget as child Widget and inside that put your widgets, as Expanded will take up equal space.
return Row(
children: [
Expanded(
child: TextField();
),
Expanded(
child: Button();
)
],
);
When ever you want to play with height and width you can use the widget Container.If you want to play with a property which cannot found in the widget you are using wrap it with a widget with that property will help you.
Container(
margin: const EdgeInsets.only(right: 150),
child: new TextField(
decoration: new InputDecoration(
hintText: 'Grade',
)
)
)
You can try to wrap your TextField and Button with two Flexible widgets and apply desired proportions, e.g. 1:2 which would give you following result:
Row(
children: [
Flexible(
flex: 1,
child: TextField(),
),
Flexible(
flex: 2,
child: RaisedButton(
child: Text('Hello'), onPressed: () {}),
)
],
)
],
You can also replace the first Flexible with SizedBox and set an exact value, e.g:
Row(
children: [
SizedBox(
width: 100.0,
child: TextField(),
),
Flexible(
flex: 2,
child: RaisedButton(
child: Text('Hello'), onPressed: () {}),
)
],
)
],
TextField doesn't have an intrinsic size (width) constraint so it will always try to occupy all horizontal space. Flexible allows to constraint it to desired width in a Row.
Full example on DartPad.