I'm creating a dashboard which contain Tween animation for two widgets, Text and two Container. But, I want to make the two Container's opacity changing slowly from invisible to visible...so I used AnimatedOpacity. But I don't know how to do it...
Any help would be appreciated..
class _IntroState extends State<Intro> with SingleTickerProviderStateMixin {
Animation animation;
AnimationController animationController;
#override
void initState() {
super.initState();
animationController = AnimationController(
duration: Duration(seconds: 2),
vsync: this,
);
animation = Tween(begin: -1.0, end: 0.0).animate(CurvedAnimation(
parent: animationController, curve: Curves.fastOutSlowIn));
animationController.forward();
}
#override
Widget build(BuildContext context) {
bool _visible = false;
final double width = MediaQuery.of(context).size.width;
return AnimatedBuilder(
animation: animationController,
builder: (BuildContext context, Widget child) {
return Scaffold(
//BODDY
body: ListView(
hildren:<Widget>[
new Stack(
children: <Widget>[
new Transform(
//ANIMATED OPACITY
new AnimatedOpacity(
opacity: _visible ? 0.0 : 1.0,
duration: Duration(milliseconds: 500),
child: new Padding(
padding: const EdgeInsets.symmetric(
horizontal: 12.0),
child: new Row(
children: <Widget>[
Expanded(
child: Row(
children: <Widget>[
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 8.0),
child: Container(
child: Column(
children: <Widget>[
//THIS THE CONTAINER
new Container(. . .),
new Container(. . .)
Instead of AnimatedOpacity, use a FadeTransition widget. This gives you manual control over the animation:
#override
Widget build(BuildContext context) {
return FadeTransition(
opacity: animationController.drive(CurveTween(curve: Curves.easeOut)),
child: ...,
);
}
To make a StatelessWidget or StatefulWidget fade in automatically on creation, TweenAnimationBuilder provides an even easier solution:
class MyWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return TweenAnimationBuilder<double>(
tween: Tween<double>(begin: 0.0, end: 1.0),
curve: Curves.ease,
duration: const Duration(seconds: 1),
builder: (BuildContext context, double opacity, Widget? child) {
return Opacity(
opacity: opacity,
child: Container(width: 20, height: 20, color: Colors.red)
);
});
}
}
See my Codepen for a complete example: https://codepen.io/atok/pen/BaZVRPr
Best regards
For anyone who'd like to fade a widget automatically as soon as the page is rendered and still wants to use AnimatedOpacity, you can put the call to change the state of the opacity in the WidgetsBinding's addPostFrameCallback callback.
Put this code below in your initState.
WidgetsBinding.instance.addPostFrameCallback((_) {
setState(() {
_opacity = 1;
});
});
I totally recommend using #boformer 's answer above.
But, I played around with your code and wanted to show you how you can call setState to trigger the AnimatedOpacity, so you can see that it is working without onTap or GestureDetector as you were thinking in the comments above.
I got your code and played around with it. What I did is, simply added a status listener to your animation controller and when the controller is done. I triggered the visibility boolean in setState. Then it will change the visibility of the containers.
// When animation finished change the visibility.
animationController.addStatusListener((status){
if (status == AnimationStatus.completed) {
setState(() {
// This is opposite, because it's implemented opposite in your code.
_visible = false;
});
}
});
Related
this is my animation code.
late AnimationController _controller;
late Animation<Color?> _color;
#override
void initState() {
super.initState();
_controller = AnimationController(
duration: Duration(milliseconds: 1350),
vsync: this,
)..forward();
_color = ColorTween(begin: Colors.grey.shade400, end: Colors.amber)
.animate(_controller);
}
and I make Grid and apply animationBuilder.
GridView.builder(
...
child: cardButtons(subject[index], _color),)
return GestureDetector(
onTap: () {
doMultiSelection(item.toString());
setState(() {});
},
child: AnimatedBuilder(
animation: _color,
builder: (context, child) {
return Card(
// check if the index is equal to the selected Card integer
color: selectedItem.contains(item.toString())
? _color.value
: Colors.grey.shade400,
child: Container(
height: 200,
width: 200,
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
I want to active animation(_color.value) whenever i click.
But it can olny work one time. How can I fix it?
I'm looking for a solution where i can hide a widget and only when some button is pressed the visual effect should be the container dropping from top to bottom.
Example: by pressing the action button a container is shown animated from top to bottom. This container is above everything.
Currently my Widget Build structure is the following:
Container
Stack
TheBlueContainerHere()
Flex
Flexible
ListView Builder
I'm not sure if this is the right structure to proceed, but i have not yet figure out a better one.
How can i build something like this?
Solved.
By following this example flutter notify from top of the screen i was able to create what i wanted.
When the action button is pressed:
Navigator.push(
context,
PageRouteBuilder(
opaque: false,
pageBuilder: (BuildContext context, _, __) {
return FunkyNotification();
},
),
);
And the respective code of FunkyNotification() is:
class FunkyNotification extends StatefulWidget {
#override
State<StatefulWidget> createState() => FunkyNotificationState();
}
class FunkyNotificationState extends State<FunkyNotification>
with SingleTickerProviderStateMixin {
AnimationController controller;
Animation<Offset> position;
#override
void initState() {
super.initState();
controller =
AnimationController(vsync: this, duration: Duration(milliseconds: 750));
position = Tween<Offset>(begin: Offset(0.0, -4.0), end: Offset.zero)
.animate(CurvedAnimation(parent: controller, curve: Curves.decelerate));
controller.forward();
}
#override
Widget build(BuildContext context) {
return SafeArea(
child: Material(
color: Colors.transparent,
child: Align(
alignment: Alignment.topCenter,
child: Padding(
padding: EdgeInsets.only(top: 56.0),
child: SlideTransition(
position: position,
child: Container(
height: 200,
width: double.infinity,
margin: EdgeInsets.only(left: 10, right: 10),
padding: EdgeInsets.all(15),
decoration: BoxDecoration(
color: Colors.blue,
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(5),
bottomRight: Radius.circular(5),
),
),
),
),
),
),
),
);
}
}
I'm building a Flutter app, mainly for iOS.
One of my views has a text field, and iOS keyboard appears when you tap on it. The problem is - layout does not change smoothly like it does in native iOS apps. Instead, it instantly jumps to the final available screen height even before keyboard opening animation finishes.
I tried wrapping my SafeArea element in AnimatedSize and AnimatedContainer - it didn't help.
My layout code:
SafeArea(child:
Column(children:[
TextField(...)
])
)
How can I make the layout resize smoothly when the keyboard appears?
Expected:
Actual
I use something like that:
AnimatedPadding(
padding: MediaQuery.of(context).viewInsets,
duration: const Duration(milliseconds: 100),
curve: Curves.decelerate,
child: ....
)
This animates the padding based on the viewInsets(software keyboard height).
The desired output can be achieved using AnimatedPadding Widget, though this is not perfect, but better than nothing :d
Open issue as of 15/03/21, for reference
import 'dart:math';
import 'package:flutter/material.dart';
final Color darkBlue = Color.fromARGB(255, 18, 32, 47);
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
debugShowCheckedModeBanner: false,
home: Scaffold(
body: Center(
child: MyWidget(),
),
),
);
}
}
class MyWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return SafeArea(
bottom: false,
child: Scaffold(
// !!! Important part > to disable default scaffold insets
resizeToAvoidBottomInset: false,
appBar: AppBar(
title: Text("Appbar Title"),
),
body: Stack(
children: [
Scrollbar(
child: ListView.builder(
padding: EdgeInsets.all(0.0),
itemCount: 30,
itemBuilder: (context, i) {
return Container(
height: 100,
width: double.infinity,
color: Colors
.primaries[Random().nextInt(Colors.primaries.length)],
);
},
),
),
Align(
alignment: Alignment.bottomLeft,
child: AnimatedPadding(
padding: MediaQuery.of(context).viewInsets,
// You can change the duration and curve as per your requirement:
duration: const Duration(milliseconds: 200),
curve: Curves.decelerate,
child: InputField()),
)
],
)),
);
}
}
class InputField extends StatefulWidget {
InputField({Key key}) : super(key: key);
#override
_InputFieldState createState() => _InputFieldState();
}
class _InputFieldState extends State<InputField> {
#override
Widget build(BuildContext context) {
return Container(
color: Colors.grey[100],
padding: const EdgeInsets.symmetric(vertical: 6),
child: Row(
children: [
SizedBox(
width: 60,
child: Icon(Icons.add_a_photo),
),
Flexible(
child: TextField(
style: Theme.of(context).textTheme.bodyText1,
decoration: InputDecoration(
border: InputBorder.none,
hintText: 'Enter text...',
),
),
),
SizedBox(
width: 60,
child: Icon(Icons.send),
),
],
),
);
}
}
Output ->
You can use this package keyboard_visibility and listen to keyboard visibility. Then you can give your logic to implement your feature like you can shorten the home container height. That's not perfect . But I think it's the only way right now.
You need to use keyboard_visibility package and use it to trigger your AnimatedContainer or AnimatedPadding
bool _isKeyboardActive = false;
#override
void initState() {
super.initState();
//add keyboard visibility Listener
KeyboardVisibility.onChange.listen((event) {
setState(() {
_isKeyboardActive = event;
});
});
}
Widget build(BuildContext context){
return AnimatedContainer(
width: _isKeyboardActive ? 200 : MediaQuery.of(context).size.width,
height: 60,
color: Colors.red,
duration: Duration(milliseconds: 600)
)
}
use this as a basis.
You should try setting resizeToAvoidBottomPadding: false like so:
return Scaffold(
key: _scaffoldKey,
resizeToAvoidBottomPadding: false,
I'm trying to create a widget that has a button and whenever that button is pressed, a list opens up underneath it filling in all of the space under the button. I implemented it with a simple Column, something like this:
class _MyCoolWidgetState extends State<MyCoolWidget> {
...
#override
Widget build(BuildContext context) {
return new Column(
children: <Widget>[
new MyButton(...),
isPressed ? new Expanded(
child: new SizedBox(
width: MediaQuery.of(context).size.width,
child: new MyList()
)
) : new Container()
]
)
}
}
This works totally fine in a lot of cases, but not all.
The problem I'm having with creating this widget is that if a MyCoolWidget is placed inside a Row for example with other widgets, lets say other MyCoolWidgets, the list is constrained by the width that the Row implies on it.
I tried fixing this with an OverflowBox, but with no luck unfortunately.
This widget is different from tabs in the sense that they can be placed anywhere in the widget tree and when the button is pressed, the list will fill up all the space under the button even if this means neglecting constraints.
The following image is a representation of what I'm trying to achieve in which "BUTTON1" and "BUTTON2" or both MyCoolWidgets in a Row:
Edit: Snippet of the actual code
class _MyCoolWidgetState extends State<MyCoolWidget> {
bool isTapped = false;
#override
Widget build(BuildContext context) {
return new Column(
children: <Widget>[
new SizedBox(
height: 20.0,
width: 55.0,
child: new Material(
color: Colors.red,
child: new InkWell(
onTap: () => setState(() => isTapped = !isTapped),
child: new Text("Surprise"),
),
),
),
bottomList()
],
);
}
Widget comboList() {
if (isTapped) {
return new Expanded(
child: new OverflowBox(
child: new Container(
color: Colors.orange,
width: MediaQuery.of(context).size.width,
child: new ListView( // Random list
children: <Widget>[
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
new Text("ok"),
],
)
)
),
);
} else {
return new Container();
}
}
}
I'm using it as follows:
class Home extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new Row(
children: <Widget>[
new Expanded(child: new MyCoolWidget()),
new Expanded(child: new MyCoolWidget()),
]
)
}
}
Here is a screenshot of what the code is actually doing:
From the comments, it was clarified that what the OP wants is this:
Making a popup that covers everything and goes from wherever the button is on the screen to the bottom of the screen, while also filling it horizontally, regardless of where the button is on the screen. It would also toggle open/closed when the button is pressed.
There are a few options for how this could be done; the most basic would be to use a Dialog & showDialog, except that it has some issues around SafeArea that make that difficult. Also, the OP is asking for the button to toggle rather than pressing anywhere not the dialog (which is what dialog does - either that or blocks touches behind the dialog).
This is a working example of how to do something like this. Full disclaimer - I'm not stating that this is a good thing to do, or even a good way to do it... but it is a way to do it.
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
// We're extending PopupRoute as it (and ModalRoute) do a lot of things
// that we don't want to have to re-create. Unfortunately ModalRoute also
// adds a modal barrier which we don't want, so we have to do a slightly messy
// workaround for that. And this has a few properties we don't really care about.
class NoBarrierPopupRoute<T> extends PopupRoute<T> {
NoBarrierPopupRoute({#required this.builder});
final WidgetBuilder builder;
#override
Color barrierColor;
#override
bool barrierDismissible = true;
#override
String barrierLabel;
#override
Widget buildPage(BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
return new Builder(builder: builder);
}
#override
Duration get transitionDuration => const Duration(milliseconds: 100);
#override
Iterable<OverlayEntry> createOverlayEntries() sync* {
// modalRoute creates two overlays - the modal barrier, then the
// actual one we want that displays our page. We simply don't
// return the modal barrier.
// Note that if you want a tap anywhere that isn't the dialog (list)
// to close it, then you could delete this override.
yield super.createOverlayEntries().last;
}
#override
Widget buildTransitions(
BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation, Widget child) {
// if you don't want a transition, remove this and set transitionDuration to 0.
return new FadeTransition(opacity: new CurvedAnimation(parent: animation, curve: Curves.easeOut), child: child);
}
}
class PopupButton extends StatefulWidget {
final String text;
final WidgetBuilder popupBuilder;
PopupButton({#required this.text, #required this.popupBuilder});
#override
State<StatefulWidget> createState() => PopupButtonState();
}
class PopupButtonState extends State<PopupButton> {
bool _active = false;
#override
Widget build(BuildContext context) {
return new FlatButton(
onPressed: () {
if (_active) {
Navigator.of(context).pop();
} else {
RenderBox renderbox = context.findRenderObject();
Offset globalCoord = renderbox.localToGlobal(new Offset(0.0, context.size.height));
setState(() => _active = true);
Navigator
.of(context, rootNavigator: true)
.push(
new NoBarrierPopupRoute(
builder: (context) => new Padding(
padding: new EdgeInsets.only(top: globalCoord.dy),
child: new Builder(builder: widget.popupBuilder),
),
),
)
.then((val) => setState(() => _active = false));
}
},
child: new Text(widget.text),
);
}
}
class MyApp extends StatefulWidget {
#override
State<StatefulWidget> createState() => MyAppState();
}
class MyAppState extends State<MyApp> {
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new SafeArea(
child: new Container(
color: Colors.white,
child: new Column(children: [
new PopupButton(
text: "one",
popupBuilder: (context) => new Container(
color: Colors.blue,
),
),
new PopupButton(
text: "two",
popupBuilder: (context) => new Container(color: Colors.red),
)
]),
),
),
);
}
}
For even more outlandish suggestions, you can take the finding the location part of this and look at this answer which describes how to create a child that isn't constrained by it's parent's position.
However you end up doing this, it's probably best that the list not to be a direct child of the button as a lot of things in flutter depend on a child's sizing and making it be able to expand to the full screen size could quite easily cause problems.
I'm looking to animate the scale of a container using the transform property of an AnimatedContainer; however, the scale is not being transitioned and jumps directly from start to end.
Code Snippet:
var container = new AnimatedContainer(
duration: const Duration(milliseconds: 200),
width: 50.0,
height: 50.0,
// selected is a bool that will be toggled
transform: selected ? new Matrix4.identity() : new Matrix4.identity().scaled(0.2,0.2),
decoration: new BoxDecoration(
shape: BoxShape.circle,
backgroundColor: Colors.blue[500],
),
child: new Center(
child: new Icon(
Icons.check,
color: Colors.white,
),
)
);
Any insight on what's going on?
AnimatedContainer supports animting it's transform value, as follow:
/// scale to 95%, centerred
final width = 200.0;
final height = 300.0;
bool shouldScaleDown = true;// change value when needed
AnimatedContainer(
color: Colors.blueAccent,
width: width,
height: height,
duration: Duration(milliseconds: 100),
transform: (shouldScaleDown
? (Matrix4.identity()
..translate(0.025 * width, 0.025 * height)// translate towards right and down
..scale(0.95, 0.95))// scale with to 95% anchorred at topleft of the AnimatedContainer
: Matrix4.identity()),
child: Container(),
);
I'm afraid transform is one of the properties we don't animate (child is another). If you want to animate the scale, you can use ScaleTransition.
ScaleTransition: https://docs.flutter.io/flutter/widgets/ScaleTransition-class.html
Bug for Matrix lerp: https://github.com/flutter/flutter/issues/443
you can Animate using the Animated Builder,the below code will scale a Text from font Size 20-35 in 4 secs let me break this into steps to make you better understand
1.you need to implement your class from TickerProviderStateMixin.
2.You need an AnimationController and a Animation variables;
3.wrap your widget inside an AnimatedBuilder (note AnimatedBuilder must return a Widget at least a container) and add a controller to the animation as
animation: _controller,
and builder Which returns the AnimatedWidget
4.In the init method intialize the controller with vsync and the Duration of Animation.
and the animation with the Tweenit takes begin and end values which define the initial and final values of your Widget to be animated
for me, in this case, it was text widget so the begin and end Values will be corresponding to the fontSize.which receives variable values as animation.value
5.Finally How do you want the animation effect To be will be specified by the animate which takes in controller and the Curve effect
Here is a Working example
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<SplashScreen>
with TickerProviderStateMixin {
AnimationController _controller;
Animation _animation;
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Color(0xFF005CA9),
body: Center(
child: AnimatedBuilder(
animation: _controller,
builder: (BuildContext context, Widget child) {
return Container(
child: Text(
'Hello World',
style: TextStyle(
color: Colors.white,
fontSize: _animation.value,
),
),
);
},
),
));
}
void initState() {
super.initState();
_controller =
AnimationController(vsync: this, duration: Duration(seconds: 4));
_animation = Tween<double>(
begin: 20,
end: 35,
).animate(
CurvedAnimation(
parent: _controller,
curve: Curves.ease,
),
);
_controller.forward();
}
}
the code above produces the following output