Flutter 1 positional argument expected, but 0 found - flutter

I have created a page with a side drawer which when pressed on the magnifying glass icon opens search requirements for different recipes e.g vegetarian, gluten free etc. I want the recipes to be shown on the page once the side drawer is closed.
I have created a widget called RecipeList() which has all of the code to retrieve the recipes from API and works perfectly on its own page without a side drawer. I wish to call this RecipeList() widget so that when the side drawer is closed they are displayed.
I'm having an error on the 7th line from the bottom, calling the RecipeList() widget it says "1 positional argument(s) expected, but 0 found.Try adding the missing arguments." I feel like I'm missing something that may be pretty obvious to fresh eyes?
Please see this images as references in case I didn't explain it well enough :)
HOW I WISH FOR THE RECIPES TO BE DISPLAYED WHEN THE SIDE BAR IS CLOSED (THIS WORKS ON A PAGE WITHOUT THE SIDE BAR):
CURRENTLY HOW THE SIDE BAR OPENS:
THE PAGE I WISH FOR THE RECIPES TO BE DISPLAYED ON:
//SIDE DRAWER BUILD
Widget build (BuildContext context) {
return Scaffold(
extendBodyBehindAppBar: true,
body: SwipeDrawer(
radius: 20,
key: drawerKey,
hasClone: false,
bodyBackgroundPeekSize: 30,
backgroundColor: Colors.white,
drawer: buildDrawer(),
child: buildBody(),
),
);
}
//WIDGET RESPONSIBLE FOR SHOWING RECIPES FROM API
Widget RecipeList(BuildContext context) {
return Scaffold(
body:
mapResponse==null?Container(): SingleChildScrollView(
child:Column(
children: <Widget> [
ListView.builder(
//SHRINKWRAP ADJUSTS THE BOXES TO FIT THE SCREEN
shrinkWrap: true,
itemBuilder: (context,index){
return Container(
//RECIPE PAGE LAYOUT DESIGN
//EACH RECIPE IS SHOWN WITH ITS TITLE & CALORIES IN A LITTLE RECTANGLE WITH IMAGE
//SETTING UP EACH RECIPE RECTANGLE PLACE HOLDER
margin: EdgeInsets.symmetric(horizontal: 22, vertical: 10),
width: MediaQuery.of(context).size.width,
height: 180,
decoration: BoxDecoration(
color: Colors.black,
borderRadius: BorderRadius.circular(15),
boxShadow: [
BoxShadow(
color: Colors.black.withOpacity(0.6),
offset: Offset(0.0,10.0,),
blurRadius: 10.0,
spreadRadius: -6.0,
),
],
//EACH RECIPES IMAGE GOES HERE
image: DecorationImage(
colorFilter: ColorFilter.mode(
Colors.black.withOpacity(0.35),
BlendMode.multiply,
),
//IMAGE IS FETCHED FROM API
image: NetworkImage(listOfResults[index]['image']),
fit: BoxFit.cover,
),),
//EACH RECIPES TITLE IS HERE
child: Stack(
children: [
Align(
child: Padding(
padding: EdgeInsets.symmetric(horizontal: 5.0),
child: Text(
//TITLE IS FETCHED FROM API
listOfResults[index]['title'],
style: TextStyle(
fontSize: 19,
color: Colors.white.withOpacity(1.0)
),
overflow: TextOverflow.ellipsis,
maxLines: 2,
textAlign: TextAlign.center,
),
),
alignment: Alignment.center,
),
//EACH RECIPES CALORIES IS HERE
Align(
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Container(
padding: EdgeInsets.all(5),
margin: EdgeInsets.all(10),
decoration: BoxDecoration(
color: Colors.black.withOpacity(0.4),
borderRadius: BorderRadius.circular(15),
),
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.end,
children: [
Icon(Icons.star,color: Colors.yellow,size: 18),
SizedBox(width: 7),
Text(
//CALORIES IS FETCHED FROM API
listOfResults[index]['spoonacularScore'].toString(),
style: TextStyle(
color: Colors.white.withOpacity(1.0)),
),
],
),
),
Container(
padding: EdgeInsets.all(5),
margin: EdgeInsets.all(10),
decoration: BoxDecoration(
color: Colors.black.withOpacity(0.4),
borderRadius: BorderRadius.circular(15),
),
child: Row(
children: [
Icon(
Icons.schedule,
color: Colors.yellow,
size: 18,
),
SizedBox(width: 7),
Text(listOfResults[index]['readyInMinutes'].toString(),
style: TextStyle(
color: Colors.white.withOpacity(1.0)),),
],
),
)
],
),
alignment: Alignment.bottomLeft,
)]
) );
},
//IF THE LIST OF RESULTS RETRIEVED FROM API IS NONE, ITEMCOUNT IS EQUAL TO 0. OTHERWISE ITEMCOUNT IS EQUAL TO LENGTH OF THE LIST OF RESULTS
itemCount: listOfResults==null ? 0 : listOfResults.length)
],
),
));
}
//DISPLAY RECIPES ON PAGE SCREEN FROM API SEARCH
Widget buildBody() {
return Column(
children: [
// build your appBar
AppBar(
title: Text('Recipes'),
leading: InkWell(
onTap: () {
if (drawerKey.currentState.isOpened()) {
drawerKey.currentState.closeDrawer();
} else {
drawerKey.currentState.openDrawer();
}
},
child: Icon(Icons.search)),
),
//MAIN SCREEN
Expanded(
child: Container(
color: Colors.white,
child: RecipeList(),
),
),
],
);
}
}

The error explanation is that you defined RecipeList like this:
Widget RecipeList(BuildContext context)
And you call constructor like this:
child: RecipeList(),
As you pass no parameter you got this error, you need to suppress positionnali parameter in Widget définition or pass parameter when you instanciate Widget.

Related

How do I get a black banner with text to dynamically show depending upon what a user does on another screen in Flutter?

I am tasked with the challenge of getting a black banner to show when a user returns from a screen on that same tab upon ordering an item on another screen. The current code below only shows the black banner appropriately if the user leaves by selecting another tab then returns to the screen. The part that I need to be dynamically presented starts with "if (OrderProvider.listOrderSummary.isNotEmpty)". I believe that this involves making a stateless widget stateful, but that results in errors that suggest that may not be the right approach.
class GridItems extends StatelessWidget {
GridItems({#required this.infinityPageController});
final InfinityPageController infinityPageController;
#override
Widget build(BuildContext context) {
final List<Item> itemList = Provider.of<List<Item>>(context);
if (itemList == null) {
return Center(
child: CupertinoActivityIndicator(
radius: 20,
),
);
}
final List<Item> mapItemList = itemList.toList();
return Column(
children: <Widget>[
TopMenuNavigation(
infinityPageController: infinityPageController,
title: 'ALL ITEMS',
),
Divider(
color: Colors.grey,
),
Expanded(
child: GridView.builder(
gridDelegate:
SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
itemCount: itemList.length,
itemBuilder: (BuildContext contex, int index) {
return Center(
child: InkWell(
onTap: () {
Navigator.of(context)
.pushNamed('/order', arguments: mapItemList[index]);
},
child: Container(
width: 310,
margin: EdgeInsets.all(7),
decoration: BoxDecoration(
color: Colors.white,
border: Border.all(width: 1, color: Colors.grey),
borderRadius: BorderRadius.all(
Radius.circular(7.0),
),
),
child: Column(
children: <Widget>[
Container(
padding: EdgeInsets.only(left: 10, top: 10),
width: double.infinity,
child: Text('${mapItemList[index].itemName}'),
),
Expanded(
child: Image.network(
'${mapItemList[index].imageUrl}',
),
),
],
),
),
),
);
},
),
),
if (OrderProvider.listOrderSummary.isNotEmpty)
GestureDetector(
onTap: () {
Navigator.of(context).pushNamed('/review_order');
},
child: Container(
height: 55,
color: Colors.black,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Spacer(),
Text(
'REVIEW ORDER (${OrderProvider.listOrderSummary.length} items)',
style: TextStyle(
fontSize: 17,
color: Colors.white,
fontFamily: 'OpenSans',
fontWeight: FontWeight.bold),
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SizedBox(width: 8),
Icon(
Icons.navigate_next,
color: Colors.white,
size: 35,
),
SizedBox(
width: MediaQuery.of(context).size.height * 0.065,
),
],
),
),
)
else
SizedBox(),
],
);
}
}
You have to somehow rebuild your screen (or part of it) where you want to return to. This is where a state-management solution should come into place :).
Create a BLoC or a ValueNotifier and rebuild the widget with a StreamBuilder or a ValueListenableBuilder. If you want to make it simple just create a shared state inside a stateful widget between your tab screens and call setState if the black banner should appear

Widget which adjusts to the children size?

Is there a widget in Flutter which adjusts itself on the content of it's children which are in Rows and Columns?
I can't seem to find anything related, and I am constantly hit with infinite overflows errors.....
As an example, lets say I would have 3 Widgets in a Row, 1 of which is a text, which I cannot guess how long it will be, but I need to expand the parent as much as the widget needs and at the sametime wrap the text
I would have something like:
Row(
children: [
Expanded(child: Widget1(....)),
Expended(child: Text(.....)),
Expanded(child: Widget2(....))
]
)
Right?
I would want the parent of the row to expand as much as it needs for the children to be shown, I want to align Widget1 and Widget2 in different ways (1-center, 2-bottom).
If I put them in Column I can center Widget1, but I cannot put Widget2 at the bottom because if I put Column to max size it overflows, if I don't it doesn't align...
How would you do it?
I really don't understand the logic behind the inifnite layout thing....
For example, here is where I am stuck at the moment.
return Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Container(
padding: EdgeInsets.all(10),
decoration: BoxDecoration(
boxShadow: [
BoxShadow(
color: Global.findCategory(event.categId).color.withAlpha(150),
blurRadius: 20,
spreadRadius: -20,
offset: Offset(0, 5)
)
],
color: Colors.white,
borderRadius: BorderRadius.circular(30)
),
child: Row(
children: <Widget>[
Align(
alignment: Alignment.center,
child: Padding(
padding: const EdgeInsets.all(5.0),
child: Container(
width: Global.scaleSmallDevice(context) * 64,
height: Global.scaleSmallDevice(context) * 64,
decoration: BoxDecoration(
shape: BoxShape.rectangle,
borderRadius: BorderRadius.circular(10),
image: DecorationImage(
fit: BoxFit.cover,
image: event.image
)
)
),
)
,
),
Flexible(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisSize: MainAxisSize.min,
children: <Widget>[
CustomText(
text: title,
color: Global.findCategory(event.categId).color,
fontSize: 16,
),
Flexible(
child: CustomText(
text: shortInfo,
color: Global.findCategory(event.categId).color,
fontSize: 12,
),
)
],
),
),
Stack(
alignment: Alignment.bottomCenter,
children: <Widget>[
Align(
alignment: Alignment.bottomCenter,
child: StatefulBuilder(
builder: (context, setState) {
IconData buttonIcon = (event.favorite) ? Icons.favorite : Icons.favorite_border;
return SplashButton(
splashColor: Global.findCategory(event.categId).color,
child: Icon(buttonIcon, color: Global.findCategory(event.categId).color, size: 30),
onTap: () async {
await event.setFavorite(context);
setState(() {
buttonIcon = (event.favorite) ? Icons.favorite : Icons.favorite_border;
});
}
);
},
),
),
],
),
),
],
);
}
In this case I want the StatefulBuilder widget to be on the bottom and the entire container be as small as the column with the CustomText widgets.
The widget with image inside I want it to be centered, while the text to be fully available to the user.
If I don't add a Column as Container, it goes as the height allows it and the StatefulBuilder widget center itself at the bottom, in the curent code it's at the center.....
Sorry if I'm not coherent, it's a bit late and I am tired after coding all day and stuck at this widget for a few hours.

Multiple buttons/Texts in a circle in flutter

I'm trying to create a circle in the flutter. I want to add multiple buttons and bound them in a circle like this.
The marked fields are supposed to be buttons and Course 1 is just the text.
I am able to create something like this but it is only string splitted in the button.
Here is my code for this. I'm not getting any idea about how to do this task. I'm new to flutter.
import 'package:flutter/material.dart';
void main(){runApp(MyApp());}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: new AppBar(
title: Text("Student home"),
),
body:Center(
child: Container(
margin: EdgeInsets.all(10),
padding: EdgeInsets.all(10),
width: 200,
height: 200,
child: Center(
child: Text("Course 1 \n Course 2",
style: TextStyle(fontSize: 12.0,
fontStyle: FontStyle.italic,
),
textAlign: TextAlign.center,
),
),
decoration: BoxDecoration(
border:Border.all(width:3),
borderRadius: BorderRadius.all(
Radius.circular(50),
),
color: Colors.yellow,
),
),
)
),
);
}
}
try shape: BoxShape.circle,,
Container(
width: 100,
height: 100,
decoration: BoxDecoration(
border: Border.all(width: 2),
shape: BoxShape.circle,
// You can use like this way or like the below line
//borderRadius: new BorderRadius.circular(30.0),
color: Colors.amber,
),
child:Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('ABC'),
Text('XYZ'),
Text('LOL'),
],
),
),
Output
is this design that you want?
it contain two button and one text widget
body: Center(
child: Container(
margin: EdgeInsets.all(10),
padding: EdgeInsets.all(10),
width: 200,
height: 200,
child: Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
"Course 1",
style: TextStyle(
fontSize: 12.0,
fontStyle: FontStyle.italic,
),
textAlign: TextAlign.center,
),
MaterialButton(
onPressed: () {
//do whatever you want
},
child: Text("Mark Attendance"),
),
MaterialButton(
onPressed: () {
//do whatever you want
},
child: Text("Mark Attendance"),
),
],
),
),
decoration: BoxDecoration(
border: Border.all(width: 3),
borderRadius: BorderRadius.all(
Radius.circular(200),
),
color: Colors.yellow,
),
),
),
There are multiple ways to make the border round. As of now you are using fixed height and width always use greater number for border-radius.
For eg.
when your heigh is 200X200 use 150-200 number for border-radius.
here is the code which works fine when you have fixed height and width of the container.
Note: This works only fine when your heigh and width is fixed for the container because the padding in the code is static.If you want dynamic then please use the screen calculation techniques to make if responsive
Making any widget clickable in the Flutter.
There are a couple of Widgets available to make any widget clickable
Gesture Detector
This widget has many methods including onTap() which means you can attach a callback when the user clicks on the widget. For eg (this is used in your code)
GestureDetector(
onTap: (){}, //this is call back on tap
child: Text("Mark Attendance")
)
InkWell Widget (Note: This widget will only work when it is a child of the Material widget)
Material(
child: InkWell(
onTap: (){},
child: Text("Mark Attendance"),
),
)
Here is the working code.
import 'package:flutter/material.dart';
void main(){runApp(MyApp());}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: new AppBar(
title: Text("Student home"),
),
body:Center(
child: Container(
margin: EdgeInsets.all(10),
padding: EdgeInsets.all(10),
width: 200,
height: 200,
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(bottom:40.0,top: 20.0),
child: Text("Course 1"),
),
Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: GestureDetector(
onTap: (){},
child: Text("Mark Attendance")),
),
Padding(
padding: const EdgeInsets.all(8.0),
child:Material(
child: InkWell(
onTap: (){},
child: Text("Mark Attendance"),
),
)
),
],)
],
),
decoration: BoxDecoration(
border:Border.all(width:3),
borderRadius: BorderRadius.all(
Radius.circular(150),
),
color: Colors.yellow,
),
),
)
),
);
} }
Note: Material widget always set the background as white for the text
widget
Thanks, I hope is information was helpfull

How to put scroll view inside stack widget in flutter

I am making a flutter application in which i uses body as a stack and in this stack i have two child.One is main body and other is back button which is at top of screen.The first child of stack is scrollview.Here is my build method.
Widget build(BuildContext context) {
return Scaffold(
//debugShowCheckedModeBanner: false,
key: scaffoldKey,
backgroundColor: Color(0xFF5E68A6),
body: Stack(
children: <Widget>[
Container(
margin: const EdgeInsets.fromLTRB(0.0, 10.0 , 0.0 , 0.0 ),
height: double.infinity,
child:CustomScrollView(
slivers: <Widget>[
new Container(
margin: EdgeInsets.all(15.0),
child:Text(getTitle(),
style: TextStyle(fontSize: 20.0,fontWeight: FontWeight.bold,color: Colors.white),
),
),
//middle section
_isLoading == false ?
new Expanded(child: GridView.builder(
itemCount: sub_categories_list.length,
physics: const NeverScrollableScrollPhysics(),
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
itemBuilder: (context, position){
return InkWell(
child: new Container(
//color: Colors.white,
padding: EdgeInsets.all(20),
margin: EdgeInsets.all(10),
height: 130,
width: 130,
child: new Center(
child :
Text(sub_categories_list[position].name,
style: TextStyle(fontSize: 18.0,fontWeight: FontWeight.bold),
)
),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.all(Radius.circular(16)),
// border: Border.all(color: Colors.black, width: 3),
),
),
onTap: () {
//write here
// Fluttertoast.showToast(msg: "You clicked id :"+sub_categories_list[position].cat_id.toString());
Navigator.pushNamed(context, '/advicemyself');
},
);
}
))
:
CircularProgressIndicator(),
Container(
margin: EdgeInsets.all(18.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
mainAxisSize: MainAxisSize.max,
children: <Widget>[
new Column(
children: <Widget>[
Image.asset('assets/bt1.png'),
Container(
margin: EdgeInsets.all(10.0),
child: Text("FIND HELP",
style: TextStyle(fontSize: 18.0,color: Colors.white),
),
)
],
),
new Column(
children: <Widget>[
Image.asset('assets/bt2.png'),
Container(
margin: EdgeInsets.all(10.0),
child: Text("HOME",
style: TextStyle(fontSize: 18.0,color: Colors.white),
),
)
],
),
new Column(
mainAxisAlignment:MainAxisAlignment.spaceEvenly,
children: <Widget>[
Image.asset('assets/bt3.png'),
Container(
margin: EdgeInsets.all(10.0),
child: Text("CALL 999",
style: TextStyle(fontSize: 18.0,color: Colors.white),
),
)
],
),
],
),
),
],
),
),
Positioned(
left: 10,
top: 30,
child: IconButton(
icon: Icon(Icons.arrow_back),
onPressed: () => {
//go back
},
color: Colors.white,
iconSize: 30,
),
),
// makeview()
],
),
// This trailing comma makes auto-formatting nicer for build methods.
);
}
I have also tried using SingleChildScrollView but that also does not works.What i am doing wrong here ?
Here is link to the design which i want to make.
https://imgur.com/a/w7nLmKC
The back should be above scroll view so i used stack widget.
Running your sample code, there doesn't seem to be a need for overlapping widgets. Using Stack seems to be unnecessary. One way you could do is by using Column widget, and using Expanded as you see fit.
Widget build(BuildContext context) {
return Scaffold(
body: Column(
children: [
Widget(), // back button goes here
CustomScrollView(...),
],
),
);
}
Otherwise, if you really need to use Stack, the scroll function should work fine. I've tried this locally and the Stack widget doesn't interfere with scrolling of Slivers, ListView, and GridView.
Stack(
children: [
/// Can be GridView, Slivers
ListView.builder(),
/// Back button
Container(),
],
),

Button with column for child not using align

I'm attempting to layout some buttons in a flutter app towards the bottom of the screen as seen here:
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
centerTitle: true,
),
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('images/foo.jpeg'),
fit: BoxFit.cover),
),
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 10),
child: _buttonsOne(),
),
Expanded(
child: Text(''),
),
Padding(
padding: EdgeInsets.only(bottom: 10),
child: _buttonsTwo(),
),
],
),
),
);
Counter buttons is setup thusly:
Widget _buttonsTwo() {
return Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
_oneButton(),
_twoButton(),
_threeButton(),
_fourButton()
],
);
}
My problem is two of the buttons are using glyphs that cause them to be just right of center. Prior to attempting this layout I structured raised buttons with columns so that I could use an Align to pull these icons to the left a bit, as seen here for one of the buttons:
Widget _threeButton() {
return RaisedButton(
onPressed: () {},
elevation: 10,
color: Colors.red,
textColor: Colors.white,
padding: EdgeInsets.all(10.0),
child: Column(
children: <Widget>[
Align(
alignment: Alignment(-0.4, 0),
child: Icon(
Class.icon_name,
size: 30,
),
),
Text(
_fooCount.toString(),
style: TextStyle(fontSize: 25),
)
],
),
);
}
And here's the result I'm getting:
As you can see, the icons for the two rightmost buttons are still a little to the right. I've tried using RaisedButton.icon to no avail as it causes the icons to overlap the text, even restructuring them in a row to try and make wider buttons. What am I missing?
Try using Transform widget instead of Align and translate the X axis:
Transform(
transform: Matrix4.identity()..translate(-7.0),
child: Icon(
FiveRingsDB.conflict_political,
size: 30,
),
),
Text(
_militaryCount.toString(),
style: TextStyle(fontSize: 25),
)