Change scrollView offset without callback listener - flutter

I want to change scrollView's offset with code so I use ScrollController:
ScrollController _controller;
_controller.addListener(() {
print('call listener');
});
My way to change offset:
_controller.jumpTo(200);
it will callback listener once.
or
_controller.animateTo(200, duration: Duration(milliseconds: 1), curve: Curves.linear);
it will callback listener, too.
I wonder is there any way to change scrollView offset without callback listener.
Here is all my code and you can coppy and test:
import 'package:flutter/material.dart';
class SingleChildScrollViewDemoPage extends StatefulWidget {
SingleChildScrollViewDemoPage({Key key}) : super(key: key);
#override
_SingleChildScrollViewDemoPageState createState() =>
_SingleChildScrollViewDemoPageState();
}
class _SingleChildScrollViewDemoPageState
extends State<SingleChildScrollViewDemoPage> {
ScrollController _controller;
#override
void initState() {
super.initState();
_controller = ScrollController();
_controller.addListener(() {
print('call listener');
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('SingleChildScrollView')),
body: SingleChildScrollView(
controller: _controller,
child: Column(
children: [
RaisedButton(
child: Text('change offset'),
onPressed: () {
//_controller.jumpTo(200);
_controller.animateTo(200,
duration: Duration(milliseconds: 1), curve: Curves.linear);
},
),
Container(
width: 375,
height: 200,
color: Colors.red,
),
SizedBox(height: 30),
Container(
width: 375,
height: 3000,
color: Colors.green,
),
],
),
),
);
}
}

Related

Persistent Navigation Bar only in some pages

Stackoverflowers!
I'm using an BottomAppBar inside the bottomNavigationBar section of the Scaffold. The problem is that it doesn't persists while I'm navigating. I used the persistent_bottom_nav_bar plugin, but it doesn't work with my custom navigation bar because it has a ripple animation in one button and a bottomSheet that is over the keyboard.
home_page.dart
This file has the CustomNavigationBar and the main pages for each item on it.
class HomePage extends StatefulWidget {
const HomePage({super.key});
#override
State<HomePage> createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
NavigationProvider? navigationProvider;
AnimationController? rippleController;
AnimationController? scaleController;
Animation<double>? rippleAnimation;
Animation<double>? scaleAnimation;
#override
void initState() {
super.initState();
rippleController = AnimationController(
vsync: this, duration: const Duration(milliseconds: 500));
scaleController = AnimationController(
vsync: this, duration: const Duration(milliseconds: 500))
..addStatusListener((status) {
if (status == AnimationStatus.completed) {
scaleController!.reverse();
Navigator.push(
context,
PageTransition(
type: PageTransitionType.bottomToTop,
child: pages.elementAt(2),
childCurrent: widget,
fullscreenDialog: true,
)).whenComplete(() => setState(() {
buttonColor = Colors.black;
}));
}
});
rippleAnimation =
Tween<double>(begin: 80.0, end: 90.0).animate(rippleController!)
..addStatusListener((status) {
if (status == AnimationStatus.completed) {
rippleController!.reverse();
} else if (status == AnimationStatus.dismissed) {
rippleController!.forward();
}
});
scaleAnimation =
Tween<double>(begin: 1.0, end: 30.0).animate(scaleController!);
rippleController!.forward();
}
#override
void dispose() {
rippleController!.dispose();
scaleController!.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
navigationProvider = Provider.of<NavigationProvider>(context);
return Scaffold(
body:
pages.elementAt(navigationProvider!.bottomNavigationBarSelectedIndex),
bottomNavigationBar: CustomNavigationBar(
rippleController: rippleController,
scaleController: scaleController,
rippleAnimation: rippleAnimation,
scaleAnimation: scaleAnimation),
);
}
}
custom_navigation_bar.dart
This file contains the properties of the CustomNavigationBar.
class CustomNavigationBar extends StatefulWidget {
const CustomNavigationBar({
super.key,
this.rippleController,
this.scaleController,
this.rippleAnimation,
this.scaleAnimation,
});
final AnimationController? rippleController;
final AnimationController? scaleController;
final Animation<double>? rippleAnimation;
final Animation<double>? scaleAnimation;
#override
State<CustomNavigationBar> createState() => _CustomNavigationBarState();
}
class _CustomNavigationBarState extends State<CustomNavigationBar> {
#override
Widget build(BuildContext context) {
final navigationProvider = Provider.of<NavigationProvider>(context);
return BottomAppBar(
child: IconTheme(
data: const IconThemeData(color: Colors.black, size: 36),
child: Padding(
padding: const EdgeInsets.fromLTRB(10, 5, 10, 5),
child: Row(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Wrap(
crossAxisAlignment: WrapCrossAlignment.center,
direction: Axis.vertical,
children: [
IconButton(
icon: ...,
padding: ...,
constraints: ...,
onPressed: () {
//Here I change the selected index with Provider.
...
},
),
Text(
title,
style: ...,
),
],
),
const Spacer(),
Wrap(...),
const Spacer(),
InkWell(
onTap: () {
setState(
() {
//Executes the ripple animation.
widget.scaleController!.forward();
},
);
},
child: AnimatedBuilder(
animation: widget.scaleAnimation!,
builder: (context, child) => Transform.scale(
scale: widget.scaleAnimation!.value,
child: Container(
width: 50,
height: 50,
margin: const EdgeInsets.all(10),
decoration: const BoxDecoration(
shape: BoxShape.circle, color: Colors.blue),
child: Icon(Icons.add,
color: widget.scaleAnimation!.value == 1.0
? Colors.white
: Colors.blue),
),
),
),
),
const Spacer(),
Wrap(...),
const Spacer(),
Wrap(...),
],
),
),
),
);
}
}
As you can see, I use Provider to manage the state of the CustomNavigationBar when it changes the index.
Example of what I want:
This app is Splitwise and it has some pages with the navigation bar and others without it. That ripple animation is similar to mine. Also the bottom sheet has the same effect in my app.
I'll wait for all your suggestions, thanks!

animation with bloc package on flutter

please check my code I want to use this animation with the bloc package,
and also I want to use that without StatefulWidget class :
class LoadingScreen extends StatefulWidget {
const LoadingScreen({Key? key}) : super(key: key);
#override
State<LoadingScreen> createState() => _LoadingScreenState();
}
class _LoadingScreenState extends State<LoadingScreen>
with TickerProviderStateMixin {
late AnimationController controller;
late AnimationController controller2;
late Animation<Offset> disk;
late Animation<Offset> offset;
int diskPicW = 0;
#override
void initState() {
super.initState();
controller =
AnimationController(vsync: this, duration: Duration(seconds: 1));
controller2 = AnimationController(
vsync: this, duration: Duration(seconds: 1, milliseconds: 500));
offset = Tween<Offset>(begin: Offset(1.0, 0.0), end: Offset.zero)
.animate(controller);
disk = Tween<Offset>(begin: Offset(-1.0, 0.0), end: Offset.zero)
.animate(controller2);
controller.forward();
controller2.forward();
Timer(Duration(seconds: 2, milliseconds: 500), (() {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FirstPage(),
));
}));
}
SizeController() {
setState(() {});
}
#override
void dispose() {
super.dispose();
controller.dispose();
controller2.dispose();
}
#override
Widget build(BuildContext context) {
print(MediaQuery.of(context).size.width);
print(MediaQuery.of(context).size.height);
return Scaffold(
backgroundColor: color3,
body: Stack(
children: [
SlideTransition(
position: offset,
child: Center(
child: Image.asset(
'assets/001.png',
width: 150,
height: 150,
),
),
),
SlideTransition(
position: disk,
child: AnimatedBuilder(
animation: controller2.view,
builder: (context, child) {
return Transform.rotate(
angle: controller2.value * 2 * pi,
child: child,
);
},
child: Center(
child: Image.asset(
'assets/disk2.png',
width: 130,
height: 130,
),
),
),
),
SlideTransition(
position: offset,
child: Center(
child: Image.asset(
'assets/002.png',
width: 150,
height: 150,
),
),
)
],
),
);
}
}
This is my simple animation code
How can I run this animation using the bloc package?
I want without using the StatefulWidget class make that
I want to use the bloc package and I don't know how
Please teach me, thank you

animate widgets based on condition in scaffold body

I have a widget, with a scaffold. His body is x widget, how do I animate in the y widget on the body instead of the x widget?
The widgets are like:
Scaffold(
body: condition ? X() : Y(),
)
When the condition goes from true to false or false to true, I want the Y or X widget to animate in. How can I do this?
You can change the Offset values to get your desired result
class Test extends StatefulWidget {
#override
_TestState createState() => _TestState();
}
class _TestState extends State<Test>
with SingleTickerProviderStateMixin {
bool condition;
AnimationController _controller;
Animation<Offset> _offsetAnimation;
#override
void initState() {
condition = false;
_controller = AnimationController(
duration: const Duration(seconds: 1),
vsync: this,
);
_offsetAnimation =
Tween<Offset>(begin: Offset(0.0, -5.0), end: Offset.zero)
.animate(CurvedAnimation(
curve: Curves.linear,
parent: _controller,
));
super.initState();
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: InkWell(
onTap: () {
setState(() {
condition = true;
});
_controller.forward();
},
child: Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Container(
color: Colors.red,
width: 200,
height: 200,
),
if (condition)
SlideTransition(
position: _offsetAnimation,
child: Container(
color: Colors.green,
width: 100,
height: 100,
),
),
],
),
),
),
);
}
}

Heigh Change Tween Animation Issue in Flutter

I want to animate the Height of My container
What I am try to do is :
class _AddVehicleState extends State<AddVehicle>
with SingleTickerProviderStateMixin {
AnimationController _otherFieldsAnimationController;
Animation<double> _heightAnimation;
override
void initState() {
_otherFieldsAnimationController = AnimationController(
vsync: this,
duration: const Duration(milliseconds: 3000),
);
_heightAnimation = new Tween<double>(begin: 400.0, end: 20.0)
.animate(_otherFieldsAnimationController);
_otherFieldsAnimationController.forward();
}
#override
Widget build(BuildContext context) {
return new WillPopScope(
onWillPop: _onWillPop,
child: new Scaffold(body: Builder(builder: (scaffoldContext1) {
scaffoldContext = scaffoldContext1;
return Stack(
children: <Widget>[
new Container(
decoration: getGradientBackground(),
child: ListView(
children: <Widget>[
Container(
color: Colors.white70,
height: _heightAnimation.value,
child: Center(
child: Text('HEY'),
));
.
.
.
.
.
As you can see the container contains the height of Animation.
All the other animation on this page works perfectly but this container is not being animated.
Any particular reason? Or am I missing something?
You can use the animated container like this
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> with SingleTickerProviderStateMixin {
AnimationController _controller;
Animation<double> _animation;
var _duration = const Duration(milliseconds: 3000);
#override
void initState() {
super.initState();
_controller = AnimationController(
vsync: this,
duration: _duration,
)..addListener(() {
setState(() {});
});
_animation =
new Tween<double>(begin: 20.0, end: 400.0).animate(_controller);
_controller.forward();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Stackoverflow'),
),
body: Center(
child: AnimatedContainer(
duration: _duration,
height: _animation.value,
width: 200,
color: Colors.amber,
),
));
}
}

How to rotate an image using Flutter AnimationController and Transform?

I have star png image and I need to rotate the star using Flutter AnimationController and Transformer. I couldn't find any documents or example for image rotation animation.
Any idea How to rotate an image using Flutter AnimationController and Transform?
UPDATE:
class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
AnimationController animationController;
#override
void initState() {
super.initState();
animationController = new AnimationController(
vsync: this,
duration: new Duration(milliseconds: 5000),
);
animationController.forward();
animationController.addListener(() {
setState(() {
if (animationController.status == AnimationStatus.completed) {
animationController.repeat();
}
});
});
}
#override
Widget build(BuildContext context) {
return new Container(
alignment: Alignment.center,
color: Colors.white,
child: new AnimatedBuilder(
animation: animationController,
child: new Container(
height: 80.0,
width: 80.0,
child: new Image.asset('images/StarLogo.png'),
),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: animationController.value,
child: _widget,
);
},
),
);
}
}
Full example (null safe):
Press "go" makes the star icon spin until you press "stop".
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>
with SingleTickerProviderStateMixin {
late AnimationController _controller;
#override
void initState() {
_controller = AnimationController(
duration: const Duration(milliseconds: 5000),
vsync: this,
);
super.initState();
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Demo"),
),
body: Center(
child: Column(
children: <Widget>[
RotationTransition(
turns: Tween(begin: 0.0, end: 1.0).animate(_controller),
child: Icon(Icons.stars),
),
ElevatedButton(
child: Text("go"),
onPressed: () => _controller.forward(),
),
ElevatedButton(
child: Text("reset"),
onPressed: () => _controller.reset(),
),
],
),
),
);
}
}
Step by step guide:
First, let your widget state class implement SingleTickerProviderStateMixin.
Secondly, define an AnimationController and don't forget to dispose it. If you are not yet using null-safe, remove the late keyword.
late AnimationController _controller;
#override
void initState() {
_controller = AnimationController(
duration: const Duration(milliseconds: 5000),
vsync: this,
);
super.initState();
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
Then wrap your Widget with RotationTransition.
RotationTransition(
turns: Tween(begin: 0.0, end: 1.0).animate(_controller),
child: Icon(Icons.stars),
),
Finally, call methods on the AnimationController to start/stop animation.
Run the animation once, use .forward
Loop the animation, use .repeat
Stop immediately, use .stop
Stop and set it back to original rotation, use .reset
Stop and animate to a rotation value, use .animateTo
Screenshot (Null Safe)
Full code:
import 'dart:math' as math;
class _FooPageState extends State<FooPage> with SingleTickerProviderStateMixin{
late final AnimationController _controller = AnimationController(vsync: this, duration: Duration(seconds: 2))..repeat();
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: AnimatedBuilder(
animation: _controller,
builder: (_, child) {
return Transform.rotate(
angle: _controller.value * 2 * math.pi,
child: child,
);
},
child: FlutterLogo(size: 200),
),
),
);
}
}
Here my example of rotating image. I don't know - but maybe it suits for you
AnimationController rotationController;
#override
void initState() {
rotationController = AnimationController(duration: const Duration(milliseconds: 500), vsync: this);
super.initState();
}
//...
RotationTransition(
turns: Tween(begin: 0.0, end: 1.0).animate(rotationController),
child: ImgButton(...)
//...
rotationController.forward(from: 0.0); // it starts the animation
UPD - how to solve problem with Transform.rotate
In your case all works exactly as you've written - it rotates image from 0.0 to 1.0 (it's default parameters for AnimationController). For full circle you have to set upper parameter to 2 * pi (from math package)
import 'dart:math';
//...
animationController = AnimationController(vsync: this, duration: Duration(seconds: 5), upperBound: pi * 2);
Here i rotate 3 images at once... images saved in assets folder... if you want you can use network images also... i am here rotate 3 images on 3 speeds...
import 'package:flutter/material.dart';
import 'package:fynd/services/auth.dart';
import 'dart:async';
import 'package:fynd/services/cons.dart';
class SplashScreen extends StatefulWidget {
_SplashScreen createState() => new _SplashScreen();
}
class _SplashScreen extends State<StatefulWidget>
with SingleTickerProviderStateMixin {
AnimationController animationController;
#override
void initState() {
super.initState();
animationController = new AnimationController(
vsync: this,
duration: new Duration(seconds: 5),
);
animationController.repeat();
}
#override
Widget build(BuildContext context) {
return new Container(
alignment: Alignment.center,
color: Colors.white,
child: new AnimatedBuilder(
animation: animationController,
child: new Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/images/splash_circle3.png'))),
child: new AnimatedBuilder(
animation: animationController,
child: new Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/images/splash_circle2.png'))),
child: new AnimatedBuilder(
animation: animationController,
child: Container(
child: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage(
'assets/images/splash_circle1.png'))),
)),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: animationController.value * 4,
child: _widget,
);
}),
),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: animationController.value * 5,
child: _widget,
);
},
),
),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: animationController.value * 6,
child: _widget,
);
},
),
);
}
}
here i put the animated builder in Stack. then you can animate image rotate right(clockwise) and rotate left(anti clockwise).
import 'package:flutter/material.dart';
import 'package:fynd/services/auth.dart';
import 'dart:async';
import 'package:fynd/services/cons.dart';
class SplashScreen extends StatefulWidget {
_SplashScreen createState() => new _SplashScreen();
}
class _SplashScreen extends State<StatefulWidget>
with SingleTickerProviderStateMixin {
AnimationController animationController;
#override
void initState() {
super.initState();
animationController = new AnimationController(
vsync: this,
duration: new Duration(seconds: 5),
);
animationController.repeat();
}
#override
Widget build(BuildContext context)
return new Container(
alignment: Alignment.center,
color: Colors.white,
child: new Stack(children: <Widget>[
new AnimatedBuilder(
animation: animationController,
child :Container(
decoration: BoxDecoration(
image: DecorationImage(image: AssetImage('assets/images/splash_circle3.png'),fit: BoxFit.cover)),
),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: animationController.value * 10,
child: _widget,
);
},
),
new AnimatedBuilder(
animation: animationController,
child: Container(
decoration: BoxDecoration(
image: DecorationImage(image: AssetImage('assets/images/splash_circle2.png'),fit: BoxFit.cover)),
),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: -animationController.value * 10,
child: _widget,
);
},
),
new AnimatedBuilder(
animation: animationController,
child: Container(
decoration: BoxDecoration(
image: DecorationImage(image: AssetImage('assets/images/splash_circle1.png'), fit: BoxFit.cover)),
),
builder: (BuildContext context, Widget _widget) {
return new Transform.rotate(
angle: animationController.value * 10,
child: _widget,
);
}),
],),
);
}
}
Flutter also has the widget AnimatedRotation (docs) which makes rotating something much easier.
You only need a double to set the state of the rotation. It works in a percentage of rotation, if you turn it into degrees, it will be 0.0 = 0deg, 1.0 = 360deg
double turns = 0.0;
AnimatedRotation(
duration: const Duration(milliseconds: 500),
turns: turns,
child: const Icon(Icons.refresh),
)
To make the rotation happen you only need to update the state, and Flutter will execute the animation automatically
void _changeRotation() {
setState(() => turns += 1.0 / 8.0);
}
Full example taken from the Flutter docs to rotate the flutter Logo
class LogoRotate extends StatefulWidget {
const LogoRotate({Key? key}) : super(key: key);
#override
State<LogoRotate> createState() => LogoRotateState();
}
class LogoRotateState extends State<LogoRotate> {
double turns = 0.0;
void _changeRotation() {
setState(() => turns += 1.0 / 8.0);
}
#override
Widget build(BuildContext context) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
ElevatedButton(
onPressed: _changeRotation,
child: const Text('Rotate Logo'),
),
Padding(
padding: const EdgeInsets.all(50),
child: AnimatedRotation(
turns: turns,
duration: const Duration(seconds: 1),
child: const FlutterLogo(),
),
),
],
);
}
}
class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
AnimationController animationController;
#override
void initState() {
super.initState();
animationController = new AnimationController(
vsync: this,
duration: new Duration(milliseconds: 5000),
);
animationController.repeat();
}
#override
Widget build(BuildContext context) {
return new Container(
alignment: Alignment.center,
color: Colors.white,
child: RotationTransition(
child: Icon(Icons.refresh),
turns: controller,
)
);
}
}
_controller = AnimationController(duration: const Duration(seconds: 3), vsync: this);
_animation = Tween(begin: 0.0, end: 250.0).animate(_controller)
..addListener(() {
setState(() {});
})
..addStatusListener((state) {
if (state == AnimationStatus.completed) {
print("complete");
}
});
_controller.forward();
new Future.delayed(
const Duration(seconds: 5),
() => Navigator.push(
context,
MaterialPageRoute(builder: (context) => SignScreen()),
));
full example just call
ImageAnimateRotate( your widget )
class ImageAnimateRotate extends StatefulWidget {
final Widget child;
const ImageAnimateRotate({Key? key, required this.child}) : super(key: key);
#override
_ImageAnimateRotateState createState() => _ImageAnimateRotateState();
}
class _ImageAnimateRotateState extends State<ImageAnimateRotate> with SingleTickerProviderStateMixin {
late final AnimationController _controller;
#override
void initState() {
super.initState();
_controller = AnimationController(vsync: this, duration: Duration(seconds: 20))..repeat();
}
#override
Widget build(BuildContext context) {
return Center(
child: AnimatedBuilder(
animation: _controller,
builder: (_, child) {
return Transform.rotate(
angle: _controller.value * 2 * math.pi,
child: child,
);
},
child: widget.child,
),
);
}
}