Header image to show - flutter

I'm trying to get a header image to show on a page of an app but it's not showing up and the _header seems to be greyed out in my code. I'm missing something I guess that I'm unsure of. Edit: I need the header to show above the rows of content in the build.
Widget _header() {
return new Container(
child: new Row(
children:<Widget>[
new Column(
children: <Widget>[
Image.asset(
'assets/classes-Image.png',
),
],
),
],
),
);
}
Extra code below:
Widget build(BuildContext context) {
return new Scaffold(
appBar: AppBar(
title: const Text('Learn How to Paint'),
backgroundColor: Color(0xFF202945),
),
body: new Container(
child: ListView(
shrinkWrap: true,
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
new Column(
children: <Widget>[
Row(
children: <Widget>[
new Padding(
padding: const EdgeInsets.only(
left: 20.0,
),
),
Image.asset(
'assets/Profile-Photo.png',
),
new Padding(
padding: const EdgeInsets.only(
right: 20.0,
),
),
Text(
'Katherine G.',
),
],
),
],
),
```

You can achieve this by placing your header widget right before the Row widget.
The header is not showing because you didn't add it in the ListView.
I hope this solves your issue.

You need to be calling _header() from somewhere in your build function and give the result as a child to another widget. It being grayed out probably means you're not calling it.

Related

Having trouble centering a row widget

I have a Row widget on the bottom of the page that I can't center. I've tried all the mainAxisAlignment's and crossAxisAlignment's there are, as well as wrapping it in an Align widget and setting alignment to alignment.center and it's still on the left edge of the page. I've tried everything and am really stuck. Any help would be appreciated.
The Page (Updated)
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.lightBlue,
centerTitle: true,
elevation: 5,
title: Text("Pathomatic")),
body: Container(
decoration: new BoxDecoration(color: Colors.black),
child: SafeArea(
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Expanded(
flex: 2,
child: new Stack(
children: <Widget>[
new Container(
alignment: Alignment.center,
child: _cameraPreviewWidget(context),
),
new Align(
alignment: Alignment.center,
child: GestureDetector(
child: Stack(children: <Widget>[
Positioned(
top: yPosition,
left: xPosition,
child: Container(
// padding: EdgeInsets.only(top: 200.0, left: 20.0),
height: MediaQuery.of(context).size.height / 3,
width: MediaQuery.of(context).size.width / 3,
child:
Image.asset('assets/images/crosshair.png'),
),
),
]),
onPanUpdate: (tapInfo) {
setState(() {
xPosition += tapInfo.delta.dx;
yPosition += tapInfo.delta.dy;
});
}),
),
],
),
),
SizedBox(height: 5),
Row(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: [
Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
_cameraTogglesRowWidget(),
_mlTextWidget(),
],
),
_captureControlRowWidget(context),
//SizedBox(width: 50),
],
),
SizedBox(height: 5),
],
),
),
),
);
}
This is usually because the widget you are trying to center is actually stretching its container. Since it's the size of the screen, it's contents stick to the left. You should use the Flutter Inspector with select widget mode to actually see how large your row is. Then everything will make much more sense.
In your code, your Row is stretching. Try
Row(mainAxisSize: MainAxisSize.min
This should make it not grow. Alternatively, you can keep the row large but make it center its children:
Row(mainAxisAlignment: MainAxisAlignment.Center
Of course, with this approach its children will get close to each other in the center. You can use a SizedBox between them, or use some other way of spacing them apart.

Make a column in a ListView/SingleChildScrollView take up the REMAINING space of a screen

I am trying to build a registration screen, the concept that I have designed on adobe XD is that the registration Screen will have the app logo in the top center, a card with approximately 3-4 textfields/areas, a button in the bottom center. Since there will be multiple cards to fill I want a circular page indicator in the center to make it easier for the user to track the remaining data to fill as well as the user wont have to fill a really long list in a single screen.
What I have tried is
A SingleChildScrollView with a column inside it and the column has the first registration form to fill and another column inside it that has the button with the page indicator
A Stack and a pageviewbuilder this gave me the best results in terms of layout but the only issue is that when using the keyboard the widgets will throw a renderFlew overflow
and right now a listview with the form in it and a column that has the button and the page indicator
Things that I need:
the keyboard to not cause an issue with form
the code to be practical and consistent for multiple screen sizes
my latest code
#override
Widget build(BuildContext context) {
List<Widget> registrationForms = [EmailRegistrationForm()];
return Scaffold(
backgroundColor: Theme.of(context).backgroundColor,
body: ListView(
children: <Widget>[
Align(alignment: Alignment.center, child: registrationForms[0]),
Container(
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 5),
child: InkWell(
child: Text("Already have an account? Login!"),
),
),
PrimaryStyledButton(text: "Next", onPress: () {}),
CirclePageIndicator(
currentPageNotifier: _currentPageNotifier,
itemCount: registrationForms.length,
selectedDotColor: Theme.of(context).accentColor,
)
],
),
),
],
));
}
what is expected
so this is what ended up working for me, I realized that the list view is kinda useless so the structure became as follows:
SingleChildScrollView that has a sized box (size of the screen) and a column inside the sized box, the SingleChildScrollView is to stop the issue of the keyboard pushing things up as well giving the ability to scroll while filling the data
return Scaffold(
backgroundColor: Theme.of(context).backgroundColor,
body: SingleChildScrollView(
child: SizedBox(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(bottom: 10),
child: landingScreen.getLogoWidget(),
),
Expanded(
child: Align(
alignment: Alignment.center, child: registrationForms[0]),
),
Padding(
padding: EdgeInsets.only(bottom: 10),
child: Column(
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 5),
child: InkWell(
child: Text(ALREADY_REGISTERED_MSG),
),
),
PrimaryStyledButton(text: NEXT, onPress: () {
}, ),
Padding(
padding: EdgeInsets.symmetric(vertical: 8.0),
child: CirclePageIndicator(
currentPageNotifier: _currentPageNotifier,
itemCount: registrationForms.length,
selectedDotColor: Theme.of(context).accentColor,
),
)
],
),
),
],
),
),
));
Try using SingleChildScrollView with expanded widget
#override
Widget build(BuildContext context) {
List<Widget> registrationForms = [EmailRegistrationForm()];
return Scaffold(
backgroundColor: Theme.of(context).backgroundColor,
body: SingleChildScrollView(
child: Expanded(
child: Column(
children: <Widget>[
Align(alignment: Alignment.center, child: registrationForms[0]),
Container(
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 5),
child: InkWell(
child: Text("Already have an account? Login!"),
),
),
PrimaryStyledButton(text: "Next", onPress: () {}),
CirclePageIndicator(
currentPageNotifier: _currentPageNotifier,
itemCount: registrationForms.length,
selectedDotColor: Theme.of(context).accentColor,
)
],
),
),
],
),
),
),
);
}

How To Make A Widget Just Stick To Bottom Of Page

I am trying to build a view as in the image below.
The tweet your reply is just stack at the bottom while the other stuff are scrollable.
I've been banging my head on how to achieve this for a couple of hours.
Exactly;y like in the image below. There are four sections:
The post (tweet)
The row of icons
The comments (which scrolls)
The tweet your reply which is static
The solution would be to use the Align Widget. So in your Stack you would put as the last element in the stack:
Align(
alignment: Alignment.bottomCenter,
child: // your widget would go here
),
I'm judging by your question that you have figured out how to do all of the other parts, and was just wondering about the bottom part. You can use Align to align things in other ways as well (such as topCenter, bottomLeft, etc). Hope this helps, and if so please up vote and accept as answer and if not leave a comment below.
Edit:
I wouldn't use a Stack. I would wrap the entire widget tree in a Column, and put the post in a Expanded Widget with a flex factor of 1, and a Row of Icons below it. Then put a ListView in an Expanded Widget with a flex of 4 (you can experiment with values). And lastly in the Column I would add you "Tweet you reply" Widget.
Simple layout code to give you an idea of how to implement it:
Column(
children: <Widget>[
Expanded(
child: ListView(
shrinkWrap: true,
children: <Widget>[
//your post
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
// your icons
],
),
//your comments
],
),
),
Align(
alignment: Alignment.bottomCenter,
child: // you textField,
),
],
)
Try this
class Home extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Expanded(
child: Column(
children: <Widget>[
Container(
padding: EdgeInsets.all(50),
child: Center(
child: Text(
"A POST"
),
),
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Icon(Icons.details),
Icon(Icons.print),
Icon(Icons.translate),
Icon(Icons.map)
],
),
Expanded(
child: ListView(
children: List.generate(10, (index) => ListTile(title: Text("Comment $index"),)),
),
)
],
),
),
TextField(
decoration: InputDecoration(
labelText: "Tweet your reply"
),
)
],
),
),
);
}
}
The output:
If you want the post to scroll with it, this should help
import 'package:flutter/material.dart';
class Home extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Expanded(
child: SingleChildScrollView(
child: Column(
children: <Widget>[
Container(
padding: EdgeInsets.all(50),
child: Center(
child: Text(
"A POST"
),
),
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Icon(Icons.details),
Icon(Icons.print),
Icon(Icons.translate),
Icon(Icons.map)
],
),
Column(
children: List.generate(10, (index) => ListTile(title: Text("Comment $index"),)),
)
],
),
),
),
TextField(
decoration: InputDecoration(
labelText: "Tweet your reply"
),
)
],
),
),
);
}
}

When keyboard is shown, everything is pushed up and I get a error

I have the following code:
class _MyHomePageState extends State {
#override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return new Scaffold(
body: new Column(
children: [
new Container(
color: JBTheme.colorGreenBrand,
height: 130.0,
alignment: Alignment.bottomLeft,
child: new Center(
child: new Align(
alignment: Alignment.bottomCenter,
child: new Container(
color: JBTheme.colorOrange,
constraints: new BoxConstraints(maxWidth: 270.0),
child: new Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
new Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: [
new Image.asset("flags/flag_dk.png"),
new Container(
margin: const EdgeInsets.only(top: 4.0, bottom: 4.0),
child: new Text("Danmark"),
),
new Text("DKK")
],
),
new Expanded(child: new Image.asset("images/arrow.png")),
new Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: [
new Image.asset("flags/flag_us.png"),
new Container(
margin: const EdgeInsets.only(top: 4.0, bottom: 4.0),
child: new Text("USA"),
),
new Text("USD")
],
)
],
),
),
),
),
),
new Expanded(
child: new Container(
color: JBTheme.colorGreyMedium,
child: new Column(
children: [
new Expanded(child: new Container()),
new Padding(
padding: const EdgeInsets.only(bottom: 8.0),
child: new Card(
elevation: -8.0,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15.0),
),
child: new Container(
width: 200.0,
height: 30.0,
color: JBTheme.colorWhite,
child: new Stack(
children: [
new TextField(
textAlign: TextAlign.center
)
],
)
),
)
)
],
),
)),
new Container(
height: 260.0,
color: JBTheme.colorGreenMint,
)
],
));
}
}
And it looks like this:
But when I click the TextField and the keyboard opens I get this:
I did not expect all of my layout to be moved up by the full keyboard height, I would like it to only move up enough so that the focused TextField is visible (and not to give a error). How can I fix this, and why is it happening?
Thank you
Søren
There are two solutions to this problem.
Add resizeToAvoidBottomPadding: false to your Scaffold
Scaffold(
resizeToAvoidBottomPadding: false,
body: ...)
Put your Scaffold body inside a scrollableView (like SingleChildScrollView or ListView)
new Scaffold(
body: SingleChildScrollView(child: //your existing body
...)
You can find similar problem and answer here
This is Flutters way of showing us how many pixels of content will be hidden from users eyesight when using the keypad. Try setting resizeToAvoidBottomPadding to false... From docs:
Whether the body (and other floating widgets) should size themselves
to avoid the window's bottom padding.
Scaffold(
resizeToAvoidBottomPadding: false,
This will avoid the resizing so you will at least avoid the dev warning being shown. But remember user will not see some content, and also this is a developer warning.
Update on 17/10/2019
resizeToAvoidBottomPadding is now Deprecated.
Use resizeToAvoidBottomInset to specify if the body should resize when the keyboard appears.
Scaffold(
resizeToAvoidBottomInset: false,
If you just use SingleChildScrollView content looses vertical alignment. You can also wrap the SingleChildScrollView in a Center Widget.
child: Center(
child: SingleChildScrollView(
child: Column(
children: <Widget>...
A full description of this error and two possible solutions can be found on Medium article available on https://medium.com/zipper-studios/the-keyboard-causes-the-bottom-overflowed-error-5da150a1c660. The last one works great for me.

Flutter: Trying to bottom-center an item in a Column, but it keeps left-aligning

I'm trying to bottom-center a widget at the bottom of a Column, but it keeps aligning to the left.
return new Column(
new Stack(
new Positioned(
bottom: 0.0,
new Center(
new Container(),
),
),
),
);
The existence of the Positioned forces the Container to the left, instead of centering. Removing the Positioned, however, puts the Container in the middle-center.
Align is the way to go if you have only one child.
If you have more, consider doing something like this:
return new Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
// Your elements here
],
);
The easiest and the correct way to do it - use Spacer()
Example:
Column(
children: [
SomeWidgetOnTheTop(),
Spacer(),
SomeCenterredBottomWidget(),
],
);
Expanded(
child: Align(
alignment: FractionalOffset.bottomCenter,
child: Padding(
padding: EdgeInsets.only(bottom: 10.0),
child: //Your widget here,
),
),
),
I have used this approach,
What i want is, A layout always in bottom but whenever Keyboard pops-up that layout also comes over it
body: Container(
color: Colors.amber,
height: double.maxFinite,
child: new Stack(
//alignment:new Alignment(x, y)
children: <Widget>[
new Positioned(
child: myWidget(context, data.iconName, Colors.red),
),
new Positioned(
child: new Align(
alignment: FractionalOffset.bottomCenter,
child: myWidget(context, data.iconName, Colors.green)
),
)
],
),
),
1) You can use an Align widget, with FractionalOffset.bottomCenter.
2) You can also set left: 0.0 and right: 0.0 in the Positioned.
Just expanding the answers:
Spacer is an option no one mentioned yet; it is used in case you prefer not to use Positioned / Align.
Align works if you want to specify the alignment of a child inside a parent. Use it anywhere but directly inside Stack
Positioned is similar to Align, but works only under Stack directly.
Design everything using Expanded() is one of the easiest way to do this
Column(
children: [
Expanded(
child: Placeholder(),
flex: 1,
),
Expanded(
child: Placeholder(),
flex: 10,
),
Expanded(
flex: 2,
child: Placeholder(),
)
],
),
If you wish to leave content as it, can wrap it with scrollable.
Useful if you have inputs in the children:
return Stack(
children: <Widget>[
Positioned(
child: SingleChildScrollView(
child: Column(
children: children
..add(Container(
height: 56, // button heigh, so could scroll underlapping area
)))),
),
Positioned(
child: Align(
alignment: Alignment.bottomCenter,
child: button,
),
)
],
);
Widget _bottom() {
return Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Expanded(
child: Container(
color: Colors.amberAccent,
width: double.infinity,
child: SingleChildScrollView(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: new List<int>.generate(50, (index) => index + 1)
.map((item) {
return Text(
item.toString(),
style: TextStyle(fontSize: 20),
);
}).toList(),
),
),
),
),
Container(
color: Colors.blue,
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
'BoTToM',
textAlign: TextAlign.center,
style: TextStyle(fontSize: 33),
),
],
),
),
],
);
}
Wrap your Container in SingleChildScrollView() widget. Then it will not come above when keyboard pops up.
In addition of Stack:
to avoid floating container on keyboard, use this
return Scaffold(
appBar: getAppBar(title),
resizeToAvoidBottomInset: false,
body: