Access variable built in different file/class - flutter

I have file.a which contains an array:
final _likes = <String>[];
Based on answers selected by the user, items are added to this array.
I want to then be able to, at the press of a button, display the items in the array to the user.
The issue is that the button I want the users to press is defined in file.b (as the Icon is on the AppBar).
How can I give file.b the ability to see the variable _likes and access the data in it, when it lives in file.a?
file.a:
import 'package:flutter/material.dart';
import './main.dart';
class Images extends StatefulWidget {
#override
_ImagesState createState() => _ImagesState();
}
class _ImagesState extends State<Images> with SingleTickerProviderStateMixin {
AnimationController _controller;
Animation _animation;
#override
// ignore: must_call_super
void initState() {
_controller = AnimationController(
vsync: this,
duration: Duration(seconds: 1),
);
_animation = Tween(
begin: 0.0,
end: 1.0,
).animate(_controller);
}
#override
dispose() {
_controller.dispose();
super.dispose();
}
int index = 0;
final likes = <String>[];
#override
Widget build(BuildContext context) {
_controller.forward();
return GestureDetector(
onHorizontalDragEnd: (DragEndDetails dragEndDetails) {
if (dragEndDetails.primaryVelocity == 0) return;
if (dragEndDetails.primaryVelocity.compareTo(0) == -1)
setState(() {
_controller.reset();
dateIdeas.removeAt(index);
});
else
setState(() {
_controller.reset();
likes.add(dateIdeas[index]['Description']);
dateIdeas.removeAt(index);
});
},
child: new Column(
children: <Widget>[
Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(left: 8.0, right: 8.0),
child: FadeTransition(
opacity: _animation,
child: Container(
decoration: BoxDecoration(
border: Border.all(
color: Colors.pink[200],
width: 7,
),
borderRadius: BorderRadius.circular(9),
),
child: new Container(
child: new Image.asset(dateIdeas[index]['Image']),
),
),
),
),
Container(
alignment: Alignment.topCenter,
child: Text(dateIdeas[index]['Description'],
style: TextStyle(
fontSize: 30,
color: Colors.black,
fontFamily: 'IndieFlower',
)),
),
],
),
],
)
],
),
);
}
}
file.b:
import 'package:flutter/material.dart';
import './surprises.dart';
import './images.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'SO Surprises',
theme: ThemeData(
primaryColor: Colors.pink[200],
),
home: MyHomePage(title: ''),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage>
{
int ideaCount = 1;
int _swipeCount = 0;
void _swipe() {
setState(() {
_swipeCount++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
actions: <Widget>[
Container(
height: 150,
width: 150,
child: IconButton(
icon: Image.asset('assets/images/SO.png'),
padding:
const EdgeInsets.only(right: 40.0, top: 10, bottom: 10.0),
),
),
GestureDetector(
onTap: () => print(Images.likes),
child: Padding(
padding: const EdgeInsets.only(right: 10.0),
child: Icon(
Icons.star,
color: Colors.white,// add custom icons also
),
),
),
],
),
body: _swipeCount == 0
? Stack(
children: <Widget>[
GestureDetector(
onHorizontalDragEnd: (DragEndDetails dragEndDetails) {
if(dragEndDetails.primaryVelocity == 0) return;
_swipe();
},
child: Container(
color: Colors.transparent,
alignment: Alignment.center,
child: Text("Swipe to get started! $_swipeCount"),
),
),
],
)
: Template(),
);
}
}

By prefixing your likes list with an underscore (_), it means you are making that method only accessible inside the class it belongs too.
To be able to use the method in other parts of your program, remove the underscore(_).
After removing the _, you are making the likes list accessible from other parts of your code.

Related

Flutter: Increase hitbox of GestureDetector

I am fairly new to flutter and currently trying to create a NavBar.
It looks like this:
If I click on the icon, the bar moves to the selected one and the content changes.
However, I have to hit the icon perfectly. I would like to have a "box" around it, so I can tap just near it. Basically divide the space into 3.
I tried the following:
Widget build(BuildContext context) {
return Container(
height: 60,
color: Color(0xff282424),
child: Stack(
children: [
Container(
child: Row(
children: items.map((x) => createNavBarItem(x)).toList(),
),
),
AnimatedContainer(
duration: Duration(milliseconds: 200),
alignment: Alignment(active.offset, 0.7),
child: AnimatedContainer(
duration: Duration(milliseconds: 400),
height: 5,
width: 50,
decoration: BoxDecoration(
color: active.color,
borderRadius: BorderRadius.circular(2.5)),
),
),
],
),
);
}
Widget createNavBarItem(MenuItem item) {
double width = MediaQuery.of(context).size.width;
return SizedBox(
width: width / items.length,
height: 55,
child: GestureDetector(
child: Icon(
Icons.access_time,
color: item.color,
size: 30,
),
onTap: () {
setState(() {
active = item;
navBarUpdate(item);
});
},
),
);
}
The items should take 1/3 of the width. It isn't working that way tho. Any idea on how to increase the "tappable" space?
EDIT
Full code:
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.\
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.red,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
var screens = [Text("Button1"), Text("Button2"), Text("Button3")];
int currentScreen = 0;
void changeIndex(int index) => setState(() {
currentScreen = index;
});
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
color: Colors.orange,
child: Stack(
children: [
SafeArea(child: screens[currentScreen]),
Container(
alignment: Alignment.bottomCenter, child: NavBar(changeIndex))
],
),
),
);
}
}
class MenuItem {
final String name;
final Color color;
final double offset;
MenuItem(this.name, this.color, this.offset);
}
class NavBar extends StatefulWidget {
#override
State<StatefulWidget> createState() => NavBarState(navBarUpdate);
late Function(int) navBarUpdate;
NavBar(this.navBarUpdate);
}
class NavBarState extends State<NavBar> {
var items = [
MenuItem("Test", Colors.red, -0.76),
MenuItem("Test2", Colors.green, 0),
MenuItem("Test3", Colors.yellow, 0.76)
];
late MenuItem active;
late Function(MenuItem) navBarUpdate;
#override
void initState() {
super.initState();
active = items[0];
}
NavBarState(Function(int) navBarUpdate) {
this.navBarUpdate = (item) {
navBarUpdate(items.indexOf(item));
};
}
#override
Widget build(BuildContext context) {
return Container(
height: 60,
color: Color(0xff282424),
child: Stack(
children: [
Container(
child: Row(
children: items.map((x) => createNavBarItem(x)).toList(),
),
),
AnimatedContainer(
duration: Duration(milliseconds: 200),
alignment: Alignment(active.offset, 0.7),
child: AnimatedContainer(
duration: Duration(milliseconds: 400),
height: 5,
width: 50,
decoration: BoxDecoration(
color: active.color,
borderRadius: BorderRadius.circular(2.5)),
),
),
],
),
);
}
Widget createNavBarItem(MenuItem item) {
double width = MediaQuery.of(context).size.width;
return SizedBox(
width: width / items.length,
height: 55,
child: GestureDetector(
child: Icon(
Icons.access_time,
color: item.color,
size: 30,
),
onTap: () {
setState(() {
active = item;
navBarUpdate(item);
});
},
),
);
}
}
You can use behavior: HitTestBehavior.translucent, or opaque on createNavBarItem
child: GestureDetector(
behavior: HitTestBehavior.translucent,
You can swap your GestureDetector on top level widget from Icon.
Widget createNavBarItem(MenuItem item) {
double width = MediaQuery.of(context).size.width;
return GestureDetector(
child: Container(
color: Colors.transparent,
width: width / items.length,
height: 55,
child: Icon(
Icons.access_time,
color: item.color,
size: 30,
),
),
onTap: () {
setState(() {
active = item;
navBarUpdate(item);
});
},
);
}

Not getting values when querying list in search bar implementation Flutter

I need some help when implementing the search bar funcionality in Flutter.
I am implementing flappy_search_bar: https://pub.dev/packages/flappy_search_bar
However, it does return any value when I try to search something.
Is there anything I am missing? Seems trivial this kind of implementations, just query some list and include the results in other list but I cannot figure out the way to do it.
class MainPage extends StatefulWidget {
const MainPage({Key? key}) : super(key: key);
#override
_MainPageState createState() => _MainPageState();
}
class _MainPageState extends State<MainPage> {
TextEditingController textController = TextEditingController();
Future<List<dynamic>> search(String search) async {
await Future.delayed(Duration(seconds: 2));
List<dynamic> dogs = BreedList.where((dog) => dog['breed'].contains(search)).toList();
return dogs;
// return List(search.length, (int index) {
// return DogClass(breed: "$search $index");
// });
}
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
body: Column(children: [
Container(
margin: const EdgeInsets.only(top: 60, bottom: 15),
padding: const EdgeInsets.only(left: 20, right: 20),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Center(
child: Container(
width: MediaQuery.of(context).size.width -
(MediaQuery.of(context).size.width / 3.5),
height: 80,
child: SearchBar<dynamic>(
searchBarStyle: SearchBarStyle(borderRadius: BorderRadius.circular(20)),
onSearch: search,
cancellationWidget: Text('Cancel'),
emptyWidget: SizedBox.shrink(),
shrinkWrap:true,
onItemFound: (dynamic dogs, int index) {
return Container(
child: ListTile(
title: Text(dogs.breed.toString())
),
);
}),
//child: const Icon(Icons.search, color: Colors.white),
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(Dimensions.radius20),
color: Colors.white),
),
)
],
),
),
//wrapping with this widgets the scroll problem is solved in list
const Expanded(
child: SingleChildScrollView(
child: BookPageBody(),
)),
]));
}
}

Flutter - Row added -> change the text of a container

I'm quite inexperienced with flutter and have created this script.
When you tap on the red container you create a Row of buttons,
I would like when I click on a button in the Row -> the text of the blue container becomes the same as the text contained in the tapped button
Anyone know how I can do?
Thank you :)
import 'package:flutter/material.dart';
import 'package:flutter/gestures.dart';
void main() => runApp(mainApp());
class mainApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return const MaterialApp(
home: Chat(),
);
}
}
class Chat extends StatefulWidget {
const Chat({Key? key}) : super(key: key);
#override
_ChatState createState() => _ChatState();
}
class _ChatState extends State<Chat> {
String text = 'Henlo i am Gabriele!';
List<Container> OutputList = [];
void tool(String text) async {
List ListText = text.split(' ');
for (var i in ListText) {
OutputList.add(
Container(
child: GestureDetector(
onTap: () {},
child: Padding(
padding: const EdgeInsets.all(4.0),
child: Container(
color: Colors.orange,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(i),
),
),
),
),
),
);
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Column(
children: [
GestureDetector(
onTap: () {
setState(() {
tool(text);
print(OutputList);
});
},
child: Container(
width: 150.0,
height: 50.0,
color: Colors.red,
child: Center(child: Text('START ->')),
),
),
SizedBox(height: 50.0),
Row(
children: OutputList,
),
SizedBox(height: 50.0),
Container(
color: Colors.blue,
width: 200.0,
height: 50.0,
child: Text(''),
),
],
),
),
);
}
}
Yes you can add a few line of code check here i try to solve.
import 'package:flutter/material.dart';
import 'package:flutter/gestures.dart';
void main() => runApp(mainApp());
class mainApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return const MaterialApp(
home: Chat(),
);
}
}
class Chat extends StatefulWidget {
const Chat({Key? key}) : super(key: key);
#override
_ChatState createState() => _ChatState();
}
class _ChatState extends State<Chat> {
String text = 'Henlo i am Gabriele!';
//step 1 create variable
String newGeneratedText = "";
List<Container> OutputList = [];
void tool(String text) async {
List ListText = text.split(' ');
for (var i in ListText) {
OutputList.add(
Container(
child: GestureDetector(
onTap: () {
//add logic here to concatinate values
setState(() {
newGeneratedText = newGeneratedText + " " + i;//added " " for one space
});
},
child: Padding(
padding: const EdgeInsets.all(4.0),
child: Container(
color: Colors.orange,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(i),
),
),
),
),
),
);
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Column(
children: [
GestureDetector(
onTap: () {
setState(() {
tool(text);
print(OutputList);
});
},
child: Container(
width: 150.0,
height: 50.0,
color: Colors.red,
child: Center(child: Text('START ->')),
),
),
SizedBox(height: 50.0),
Wrap( // added for fixing more values and solve overflow exceptions error
children: OutputList,
),
SizedBox(height: 50.0),
Container(
color: Colors.blue,
width: 200.0,
height: 50.0,
child: Text(newGeneratedText), //final print values
),
],
),
),
);
}
}

How do I schedule widget deletion as a future event?

I am looking for a way to do widget deletion in the future.
It's easiest to describe the problem through an example (and a MWE).
The user is presented with several AnimatedPositioneds containers, representing a card game.
The PositionedContainer part means that each card can be used for Gin Rummy, Bridge, or, in fact, any abstract numbers card game.
When the user clicks one card, the card slides up (using the Animated part of AnimatedContainer)
and then we'd like the card to be removed from the stack of widgets, i.e. to "disappear" (and not just hide through opacity)
import 'package:flutter/material.dart';
import 'dart:math';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('Cards'),
),
body: Center(
child: Container(
alignment: Alignment.center,
child: CardGameWidget(),
decoration: BoxDecoration(
border: Border.all(
color: Colors.blueAccent,
),
),
),
),
),
);
}
}
class CardGameWidget extends StatefulWidget {
#override
CardGameWidgetState createState() => CardGameWidgetState();
}
class CardGameWidgetState extends State<CardGameWidget> {
List<Card> cards = [];
CardGameWidgetState() {
for (var i = 0; i < 5; ++i) {
this.cards.add(Card(
offset: Offset(i * 100.0, 200),
number: Random().nextInt(1 << 16))
);
}
}
Function onTap(int index) => (newOffset) {
setState(() {
cards[index].offset += Offset(0,-100);
});
};
#override
Widget build(BuildContext context) {
List<CardWidget> cardWidgets = [];
for (int i = 0; i < this.cards.length; ++i) {
cardWidgets.add(CardWidget(
onTap: onTap(i),
offset: this.cards[i].offset,
number: this.cards[i].number,
));
}
return Stack(children: cardWidgets);
}
}
class Card {
Card({this.offset, this.number});
Offset offset;
int number;
}
class CardWidget extends StatelessWidget {
CardWidget({
Key key,
this.onTap,
this.offset,
this.number,
});
final Function onTap;
final Offset offset;
final int number;
_handleTap(details) {
onTap(details.globalPosition);
}
#override
Widget build(BuildContext context) {
return AnimatedPositioned(
left: this.offset.dx,
top: this.offset.dy,
width: 100,
height: 100,
duration: Duration(seconds: 1),
child: GestureDetector(
onTapUp: _handleTap,
child: Container(
color: Colors.cyan,
padding: EdgeInsets.all(10),
margin: EdgeInsets.all(10),
child: FittedBox(
clipBehavior: Clip.antiAlias,
alignment: Alignment.centerLeft,
fit: BoxFit.contain,
child: Text(this.number.toString()),
))),
);
}
}
How do I schedule widget deletion as a future event, after the completion of an animation?
You can look into AnimiatedList:
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(primarySwatch: Colors.blue, brightness: Brightness.dark),
home: SimpleAnimatedList(),
);
}
}
class SimpleAnimatedList extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: SliceAnimatedList(),
);
}
}
class SliceAnimatedList extends StatefulWidget {
#override
_SliceAnimatedListState createState() => _SliceAnimatedListState();
}
class _SliceAnimatedListState extends State<SliceAnimatedList> {
final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
List<int> _items = [];
int counter = 0;
Widget slideIt(BuildContext context, int index, animation) {
int item = _items[index];
TextStyle textStyle = Theme.of(context).textTheme.headline4;
return SlideTransition(
position: Tween<Offset>(
begin: const Offset(-1, 0),
end: Offset(0, 0),
).animate(animation),
child: SizedBox(
height: 128.0,
child: Card(
color: Colors.primaries[item % Colors.primaries.length],
child: Center(
child: Text('Item $item', style: textStyle),
),
),
),
);
}
#override
Widget build(BuildContext context) {
return Column(
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Expanded(
child: Container(
height: double.infinity,
child: AnimatedList(
key: listKey,
initialItemCount: _items.length,
itemBuilder: (context, index, animation) {
return slideIt(context, index, animation);
},
),
),
),
Container(
decoration: BoxDecoration(color: Colors.greenAccent),
child: Row(
mainAxisSize: MainAxisSize.max,
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
FlatButton(
onPressed: () {
setState(() {
listKey.currentState.insertItem(0,
duration: const Duration(milliseconds: 500));
_items = []
..add(counter++)
..addAll(_items);
});
},
child: Text(
"Add item to first",
style: TextStyle(color: Colors.black, fontSize: 20),
),
),
FlatButton(
onPressed: () {
if (_items.length <= 1) return;
listKey.currentState.removeItem(
0, (_, animation) => slideIt(context, 0, animation),
duration: const Duration(milliseconds: 500));
setState(() {
_items.removeAt(0);
});
},
child: Text(
"Remove first item",
style: TextStyle(color: Colors.black, fontSize: 20),
),
)
],
),
),
],
);
}
}

How to snap scroll effect in flutter?

With the normal scroll effect, you are free to scroll how much ever you want,
but I want to have a scrollable list but only scroll full widget or 1/4 of the widget.
something like this:-
How to get a scrolling effect?
You can use PageView.
Here is the sample code. It has the paging animation. It also has attached listener to the PageController, which is useful to get current state.
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
var _controller = PageController(viewportFraction: 0.6);
var _color = "";
#override
void initState() {
super.initState();
_controller.addListener(() {
if (_controller.page < 0.5) {
setState(() {
_color = "yellow";
});
}
if (_controller.page >= 0.5 && _controller.page < 1.5) {
setState(() {
_color = "red";
});
}
if (_controller.page >= 1.5 && _controller.page < 2) {
setState(() {
_color = "blue";
});
}
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Column(
children: [
SizedBox(
height: 200,
),
Text(
_color,
style: TextStyle(fontSize: 40),
),
SizedBox(
height: 100,
child: PageView(
controller: _controller,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: SizedBox(
child: Container(
color: Colors.amber,
),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: SizedBox(
width: 200,
child: Container(
color: Colors.red,
),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: SizedBox(
width: 200,
child: Container(
color: Colors.lightBlue,
),
),
),
],
),
),
],
));
}
}