I am use Flutter for web for make website. I want make webpage scroll when user scroll down like normal website.
I am try use Stack so I can place custom background behind widgets. This background must scroll when user scroll (must stick to widgets in front so background change).
(I cannot set background color using Scaffold because my background is use CustomPainter)
But I want center the widgets on webpage, so I wrap SingleChildScrollView in Center widget. But now on large horizontal screen the CustomPaintWidget() is not fill screen (there is blank space). I have try replace my CustomPaintWidget() with Container to test, but same issue.
Here my code:
Center(
child: SingleChildScrollView(
child:Stack(children: <Widget>[
CustomPaintWidget(),
Widgets(),
],),
Anyone know solution?
How to center widgets but also make background stretch?
Thanks!
SingleChildScrollView by definition shriknwraps it's child.
What you should try is
return SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: ConstrainedBox(
//Use MediaQuery.of(context).size.height for max Height
constraints: BoxConstraints(minHeight: MediaQuery.of(context).size.height),
child: Center(
child: //Widget,
),
),
);
I think you can try something like:
#override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
children: <Widget>[
CustomPaintWidget(),
Center(
child: SingleChildScrollView(
child: Widgets(),
),
)
],
));
}
read that post, I think is all you need https://medium.com/#swav.kulinski/spike-parallax-in-flutter-seven-lines-of-code-16a1890d8d32
I know it is too late to answer but s.o may need it in future
You have to use Stack
for instance:
your MainClass:
class _BodyState extends State<Body> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
children: [
ScrollViewClass(),
Column(
children: [
//YOUR ITEMS
]),
);
ScrollviewClass:
class ScrollViewClass extends StatefulWidget {
#override
_ScrollViewClassState createState() => _ScrollViewClassState();
}
class _ScrollViewClassState extends State<ScrollViewClass> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
margin: EdgeInsets.only(top: 260, bottom: 100),
child: ListView(
children: [
Container(
child: SingleChildScrollView(
scrollDirection: Axis.vertical,
child: ConstrainedBox(
//Use MediaQuery.of(context).size.height for max Height
constraints: BoxConstraints(
minHeight: MediaQuery.of(context).size.height),
child: Column(
children: [
//ADD YOUR ITEMS LIKE IMAGE, TEXT, CARD ETC...
Center(child: Image.asset('assets/app_name.png')),
Center(child: Image.asset('assets/app_name.png')),
Center(child: Image.asset('assets/app_name.png')),
Center(child: Image.asset('assets/app_name.png')),
Center(child: Text('fdgdfg')),
Center(child: Text('fdgdfg')),
],
)),
),
)
],
),
));
}
}
I know this is not the OP's scenario, but for others - If there is something above your scroll view, using the full height of the page will cause the scrollview to scroll prematurely, because the combined height of the widgets is now greater than the page height. Use LayoutBuilder instead of MediaQuery.of(context).size.height.
LayoutBuilder(builder: ((context, constraints) {
return SingleChildScrollView(
child: ConstrainedBox(
constraints: BoxConstraints(
minHeight: constraints.maxHeight),
child: Center(child: child)),
);
})
Related
I'm trying to use a GridView to handle displays for multiple Card, each Card contains of an Image. Unfortunately it turns out that the Image is taking a larger height than its parent (see attached picture for the details).
I'm pretty new to Flutter layout so any ideas why this is happening and how I can resolve this? I want the layout to be something like this:
Display 2 cards on each line.
The Card width or height should not be fixed.
The Image height should be scaled according to its width.
class SquadSelectionScreen extends StatelessWidget {
final List<Team> teams;
const SquadSelectionScreen({super.key, required this.teams});
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Squads'),
),
body: GridView.count(
crossAxisSpacing: 10,
crossAxisCount: 2,
padding: const EdgeInsets.all(16),
children: teams
.map(
(team) => SquadView(team: team),
)
.toList(),
),
);
}
}
class SquadView extends StatelessWidget {
final Team team;
const SquadView({super.key, required this.team});
#override
Widget build(BuildContext context) {
return InkWell(
onTap: () {
context.push('/squads/${team.code}');
},
child: Card(
elevation: 1,
child: Column(
children: [
Image(
image: NetworkImage(team.imageUrl),
),
const SizedBox(
height: 8,
),
Center(
child: Text(team.name),
),
],
),
),
);
}
}
Using GridView.count has a very visible drawback, namely the size of the aspect ratio of the grid will always be one (1:1 or Square) and can't be changed.
So if you look at the code above, you can't set an image with the same aspect ratio because the text will sink.
The first suggestion for me if you still want to use GridView.count is
Wrapping your Image with AspectRatio that has value higher than one (example set Ratio to 4/3, 5/3, 16/9, or landscape looks). Note: 4/3 = is higher than 1, 16/9 = is higher than 1, etc..
Then wrap the Text Widget with Expanded()
Example code:
class SquadView extends StatelessWidget {
final Team team;
const SquadView({super.key, required this.team});
#override
Widget build(BuildContext context) {
return InkWell(
onTap: () {},
child: Card(
elevation: 1,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
AspectRatio(
aspectRatio: 4/3, // you can set the value to 16/9 or anything that result is higher than one
child: Image(
image: NetworkImage(team.imageUrl),
fit: BoxFit.cover, // set How the image looks to Fit
),
),
const SizedBox(
height: 8,
),
Expanded(
child: Center(
child: Text(team.name, overflow: TextOverflow.ellipsis),
),
),
],
),
),
),
);
}
}
I suggest you try GridView.builder or another GridView. You can look at the documentation here
or this third package this will be good for to try flutter_staggered_grid_view. The flutter_staggered_grid_view is more flexible to create GridView with various size.
I have a SingleChildScrollView and inside it I have a list with some cards, that you can remove ou add more. I need to fix an add button at the bottom of the screen, when the card list is not scrollable yet, but when the card list increase size and the scrollview is able to scroll now (to see all the content), the button must follow the list and not keep fixed at the bottom anymore.
For now, what I did to solve this, was check the scroll view every time that a card is added ou removed, if I checked that the screen is now scrollable or not scrollable I change some properties of my build widget:
SingleChildScrollView(
controller: _scrollController,
physics: AlwaysScrollableScrollPhysics(),
child: Container(
height: isNotScrollable
? _pageSize - (_appBarSize + _notifySize)
: null,
padding: const EdgeInsets.symmetric(
horizontal: Constraints.paddingNormal),
child: Column(
.....
and after the list render I create the button like this
isNotScrollable
? Expanded(
child: Container(),
)
: Container(),
CVButton(
color: Palette.white,
Basically, my idea is: if the screen is not scrollable yet (the list content fits in the screen size) I will set a height to the container inside scrollview and add a Expanded() widget before the add button (so the button will stay in the bottom of the container), but if the screen is scrollable (the list content not fits inside the screen size) so I remove the container height and the Expanded widget, then the button will follow the list now as normally.
I don't know if this is the better way to deal with that, I want to know if there is some way to do this without this 'dinamic' way that I am doing, only with fixed widgets and not changing the widget according to the state of the scrollview.
An example when the list becomes scrollable and the button will keep at list bottom
Here the list is not scrollable yet but the button must be at the screen bottom and not list bottom
(I dont wanna use bottomNavBar)
Anyone has any idea how I can solve this?
I have a solution for this. check the code bellow. I added some buttons to add or remove cards. The main trick is to use constraints like minHeight.
import 'package:flutter/material.dart';
class BottomButton extends StatefulWidget {
#override
_BottomButtonState createState() => _BottomButtonState();
}
class _BottomButtonState extends State<BottomButton> {
List<Widget> cards = [];
#override
Widget build(BuildContext context) {
var appBar2 = AppBar(
actions: [
IconButton(
icon: Icon(Icons.add),
onPressed: () {
_addCard();
}),
IconButton(
icon: Icon(Icons.remove),
onPressed: () {
_removeCard();
}),
],
);
return Scaffold(
appBar: appBar2,
body: Container(
height: MediaQuery.of(context).size.height -
(MediaQuery.of(context).padding.top + appBar2.preferredSize.height),
alignment: Alignment.topCenter,
child: ListView(
primary: true,
children: [
Container(
constraints: BoxConstraints(
minHeight: MediaQuery.of(context).size.height -
(MediaQuery.of(context).padding.top +
appBar2.preferredSize.height),
),
alignment: Alignment.topCenter,
child: Column(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Container(
constraints: BoxConstraints(
minHeight: MediaQuery.of(context).size.height -
(MediaQuery.of(context).padding.top +
appBar2.preferredSize.height +
50),
),
alignment: Alignment.topCenter,
child: Column(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.start,
children: cards,
),
),
ElevatedButton(
child: Text('this is a button'),
onPressed: () {},
),
],
),
)
],
),
),
);
}
void _addCard() {
Widget card = Card(
child: Container(
height: 100,
color: Colors.red,
padding: EdgeInsets.all(2),
),
);
setState(() {
cards.add(card);
});
}
void _removeCard() {
setState(() {
cards.removeLast();
});
}
}
I am trying to display a ListView Horizontal n times in Stack or Row. But in the end all the ListViews are piled up instead shows one by one from top to bottom.
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Prueba para trabajar en el proyecto"),
),
body: Stack(
children: <Widget>[
_crearLista(),
_crearLista(),
_crearLista(),
_crearLista(),
_crearLista(),
//_crearLoading(),
],
),
);
}
Widget _crearLista() {
return Container(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Flexible(
child: Container(
width: MediaQuery.of(context).size.width,
height: MediaQuery.of(context).size.height * 0.25,
decoration: BoxDecoration(),
child: ListView.builder(
scrollDirection: Axis.horizontal,
itemCount: _listaNumeros.length,
itemBuilder: (BuildContext context, int index) {
//return image
},
controller: _scrollController,
),
),
)
],
),
);
}
Any suggestions? please. I want to show all the LsitViews.
A Stack widget puts its children above each other (overlapped or piled up) at the left top corner of the stack by default. Unless you position each child using a Positioned or Align widget. To have all the children one below the other (starting from top of the screen towards bottom), you need to use a Column instead of Stack.
Stack children behave like layers, one covers second, etc.
If you want one child exactly below another, there is ListView and Column
As in the image shown above, I want widget 2 to always be at least the height of the remaining space available.
But widget 2 might contain so many ListTiles so that they can not be displayed without scrolling. But scrolling should affect widget 1 and widget 2. What is the best way to implement something like this?
Wrap Widget 2 in an Expanded Widget.
To scroll both Widget 1 and Widget 2, wrap both of them in a SingleChildScrollView Widget.
If you can distinguish between the case with a few and many elements (for example during loading), you can use CustomScrollView with SliverFillRemaining for this:
var _isLoading = true;
#override
Widget build(BuildContext context) {
return CustomScrollView(
slivers: [
_buildWidget1(),
_buildWidget2(),
],
);
}
Widget _buildWidget1() {
return SliverToBoxAdapter(
child: Container(height: 400, color: Colors.blue),
);
}
Widget _buildWidget2() {
if(_isLoading) {
return SliverFillRemaining(
hasScrollBody: false,
child: Center(child: const CircularProgressIndicator()),
);
} else {
return SliverFixedExtentList(
delegate: SliverChildBuilderDelegate(
_buildItem,
childCount: childCount,
),
itemExtent: 56,
);
}
}
A simple way to do that would be to place your widgets in Column and wrap it with a single child scroll view. For the ListView use shrinkWrap as true and physics you can set to NeverScrollableScrollPhysics
Here is an example
SingleChildScrollView(
child: Column(
children: [
Container(
height: MediaQuery.of(context).size.height / 2,
color: Colors.red,
),
ListView.builder(
shrinkWrap:true,
physics:NeverScrollableScrollPhysics(),
itemCount: 100,
itemBuilder: (context, index) => Text("$index"),
),
],
),
);
Hope this helps!
var widgetHeight = MediaQuery.of(context).size.height - fixedSize;
return SingleChildScrollView(
child: Container(
height: widgetHeight,
child: Widget2
)
)
I display a custom-made bottom app bar in a Stack because of keyboard padding reasons. The custom widget is fully opaque as it should be until it's a child of a Stack in which case, the content behind it starts to be visible since the color's opacity somehow changes.
As you can see, it's only the "main" color that's transparent. Icons remain opaque.
This is the build method of my custom BottomBar widget which is then just regularly put into a Stack. I have tried using a Material and even a simple Container in place of the BottomAppBar widget but the results are the same.
#override
Widget build(BuildContext context) {
return BottomAppBar(
color: Colors.blue.withOpacity(1),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
IconButton(
icon: Icon(MdiIcons.plusBoxOutline),
onPressed: () {},
),
Text('Edited 11:57'),
IconButton(
icon: Icon(MdiIcons.dotsVertical),
onPressed: () {},
),
],
),
);
}
Can you interact with the BottomAppBar ? It looks like an order problem. Try to put the BottomAppBar as last in the Stack children.
Note that BottomAppBar doesn't have a constant size, if you did not add it to Scaffold bottomNavigationBar named parameter has a size if this is not null. Below is peace of code in Scaffold dart file:
double bottomNavigationBarTop;
if (hasChild(_ScaffoldSlot.bottomNavigationBar)) {
final double bottomNavigationBarHeight = layoutChild(_ScaffoldSlot.bottomNavigationBar, fullWidthConstraints).height;
bottomWidgetsHeight += bottomNavigationBarHeight;
bottomNavigationBarTop = math.max(0.0, bottom - bottomWidgetsHeight);
positionChild(_ScaffoldSlot.bottomNavigationBar, Offset(0.0, bottomNavigationBarTop));
}
You can even develop your own Widget without BottomAppBar but if you want things like centerDocked and things like circular notched, you will have to do more stuff (anyway you have flexibility to custom design the way you want).
Here is a simple example to do that(one way to do that):
import 'package:flutter/material.dart';
class CustomBottomBar extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
children: <Widget>[
Container(
margin: EdgeInsets.only(bottom: 50),
color: Colors.greenAccent, // if you want this color under bottom bar add the margin to list view
child: ListView.builder(
itemCount: 100,
itemBuilder: (_, int index) => Text("Text $index"),
),
),
Positioned(
bottom: 0,
child: Container(
color: Colors.amber.withOpacity(.5),
width: MediaQuery.of(context).size.width,
height: 50,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: List.generate(4, (int index) => Text("Text $index")), // you can make these clickable by wrapping with InkWell or any gesture widget
),
),
),
],
),
);
}
}