I'm currently working on a Flutter project. I have been given Icons by the designer.
One of the Icons looks like this
Now I'd like to fill the inside of the Icon with color so that it looks like this
How can I achieve this in flutter? I really tried a lot. Like using ClipRect and other Classes. But none gave the desired results.
Try this one.
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,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
bool _isBluetoothOn = false;
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
IconButton(
onPressed: () async {
print(_isBluetoothOn);
setState(() {
_isBluetoothOn = !_isBluetoothOn;
});
print(_isBluetoothOn);
},
icon: Icon(
_isBluetoothOn ? Icons.favorite : Icons.favorite_border,
color: Colors.greenAccent,
size: 40,
),
),
],
),
),
);
}
}
You can simply ask designer for filled icons too and show them when they are clicked.
So it goes like this:
if button clicked:
show filledIcon
else:
show unfilledIcon
You can code that in Flutter like:
icon:clicked? Icon(filledIcon):Icon(unfilledIcon)
This is the easiest way to do this.
Related
I am learning flutter, and I would like to know how to pass a variable or a method between 2 different files (to add additional widgets).
In my example, I took the code provided by flutter when we create a new project, to this code, I added a second file called "second.dart" in which I get the variable "_counter" in the file main "main.dart" which I multiply by 10.
main.dart
import 'package:flutter/material.dart';
import 'second.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
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 _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
Container(
child: Second(),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
second.dart
import 'package:flutter/material.dart';
import 'main.dart';
class Second extends StatefulWidget {
#override
_SecondState createState() => _SecondState();
}
class _SecondState extends State<Second> {
int counter10 = _MyHomePageState._counter * 10;
#override
Widget build(BuildContext context) {
return Container(
color: Colors.red,
width: 200,
height: 300,
child: Text('My increment * 10 : $counter10 '),
);
}
}
however, I have this error."_MyHomePageState" is highlighted in red.
lib/second.dart:11:18: Error: Getter not found: '_MyHomePageState'.
var counter10 =_MyHomePageState._counter * 10;
Thank you for your help
See this isn't the way how we pass variables to the other files or other widgets. To create a widget you need to choose between stateful or stateless if you want to manipulate state from inside of the Second class declare it as a stateful but in your case you need to have a stateless widget.
For Example this:
class Second extends StatelessWidget {
final int counter;
const Second({Key key, this.counter}) : super(key: key);
#override
Widget build(BuildContext context) {
return Container(
color: Colors.red,
width: 200,
height: 300,
child: Text('My increment * 10 : ${counter * 10} '));
}
}
And Pass this variable from your first that is like this :
import 'package:flutter/material.dart';
import 'second.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
Container(
child: Second(counter:_counter),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
Note : You can share normal variables by referring them across classes but they shouldn't be private eg have an _ in front of them. Another thing even if you share your variable it wont have any effect on the Second Page directly as flutter doesn't know that it is changing and rather just treat it as an instance.
You can share static data using classes:
example
class AppStrings {
static Color appColor = Colors.blue;
}
And later refer to it as AppStrings.appColor
There are some points that you should do in your codes:
when we use underscore as the first character of the variable name, it means that this variable is private! so you can not use int counter10 = _MyHomePageState._counter * 10; in the second widget!
if you want to pass variables to the child widget, you need to create a constructor as follow:
class Second extends StatefulWidget {
int counter;
Second(this.counter);
#override
_SecondState createState() => _SecondState();
}
now you can pass _countre variable to the Second widget:
Container(
child: Second(_counter),
),
please let me know if there is any problem or error.
I am currently working on an app; I want to change the value of a String which is declared in another dart file and then pass that changed state to the stateful widget.
I.E;
I create a file called as "Body.dart" file where I have declared a String called as 'scale' who's value initially is "Empty".
Later when a button in another dart file "scale_button" is pressed, I want to assign the string scale = "Hello" in my Body.dart file. So that the stateful widget also displays the same on the screen.
You can use provider(or any other state management) package in that case. In yaml file add, provider: ^4.3.2+4
class HomeApp extends StatefulWidget {
#override
_HomeAppState createState() => _HomeAppState();
}
class _HomeAppState extends State<HomeApp> {
StringProvider _stringProvider;
#override
void initState() {
super.initState();
_stringProvider = Provider.of<StringProvider>(context, listen: false);
}
void updateString() {
_stringProvider.setString('hai');
}
#override
Widget build(BuildContext context) {
StringProvider _stringProvider = Provider.of<StringProvider>(context);
return Scaffold(
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Container(
child: Text(
_stringProvider.str,
style: TextStyle(
fontSize: 22,
),
),
),
RaisedButton(
onPressed: updateString,
child: Text('Click'),
),
],
),
),
);
}
}
// class for storing data(StringProvider.dart)
import 'package:flutter/material.dart';
class StringProvider extends ChangeNotifier { // create a common file for data
String _str = 'hello';
String get str => _str;
void setString(String st) {
_str = st;
notifyListeners();
}
}
When you create a new Flutter project the sample code of the counter shows you how to do this. Check out the comments in the next code:
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
// here is passing a String to MyHomePage.
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
// And here you can see how to make the widget wait for a variable
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
Full code of Sample Counter App
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
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 _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
I want to make a User's settings screen with a couple of FlatButtons. I want to use onPressed function to create String when the button is pressed and than pass it further to Settings object and save it on disk.
The problem is - I'm new to Dart/Flutter and completely out of ideas here. I have read the docs about Shared Preferences, Streams, Async etc., but I was unable to find an answer to:
How can I create a String by using onPressed?
Can someone tell me how the code would look like or is it even the right approach to solve it this way.
Thanks in advance!
Alright , you can do it in multiple ways.
Here i created an example for you copy/paste run it so you can understand .
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
List<String> settings = new List();
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
(settings.isEmpty) ?Center(child:Text("no settings found")) :
ListView.builder(shrinkWrap: true,itemCount: settings.length,itemBuilder: (context,i)
{
return Center(child: Text("${settings[i]}"));
})
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: ()
{
setState(() {
settings.add('random setting');
});
},
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
explanation :
i created List settings wich has no data at the beginning.
and i check if setting are empty i show empty settings , else it will render the data.
the button with + sign is adding new strings to the list and will rebuild the widget to show it . with setState({});
hope that helps.
Is there a way to make Scaffold.bottomSheet partly transparent (like for a notch that shows the body content behind it)? I noticed that even adding just Text implicitly puts a white background (Material?) below it, and I think this is not configurable.
class MyHomePage extends StatefulWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
color: Colors.blue,
child: // ...
),
bottomSheet: Text('This is a bottom sheet'),
);
}
}
FWIW, Scaffold.bottomNavigationBar supports being semi-transparent (e.g. you can have a notch around FAB).
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
home: MyHomePage(title: 'Flutter Demo Home Page'),
theme: ThemeData(
bottomSheetTheme: BottomSheetThemeData(
backgroundColor: Colors.black.withOpacity(0.5)),
),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.blue,
appBar: AppBar(
title: Text(widget.title),
),
body: Center(),
bottomSheet: Container(
height: 40,
width: MediaQuery.of(context).size.width,
child: Center(child: Text('semi transparent bottom sheet :)', style: TextStyle(color: Colors.white),))
),
);
}
}
this was previously posted
The default FAB in the demo app has shadows and a ripple effect when touched.
However, when the FAB is moved to another class, it suddenly loses this effect, which makes it look rather plain.
Is it possible to bring the shadows and ripple animations to the plain looking FAB while keeping it in a separate class?
Main.dart
import 'package:test_app/TestItem1.dart';
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new TestItem1(),
);
}
}
TestItem1.dart
import 'package:flutter/material.dart';
class TestItem1 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Scaffold(
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Text(
'test 1',
),
new Text(
'test1',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: new FloatingActionButton(
tooltip: 'Increment',
onPressed: null,
child: new Icon(Icons.add),
),
);
}
}
The floating action button is disabled by default if you gave nothing to
onPresss()
if you don't want to give in onPress just pass (){} an anonymous method