Easily add animations on your screen with AnimatedWidgets.
Optimized for MVVM using Bloc, updating the enabled value of the widget will forward or reverse the animation.
Available widgets : TranslationAnimatedWidget, OpacityAnimatedWidget, RotationAnimatedWidget, ScaleAnimatedWidget, SizeAnimatedWidget
For example : add a TranslationAnimatedWidget on a button, then activate it to display it !
TranslationAnimatedWidget(
enabled: this.displayMyWidget, //update this boolean to forward/reverse the animation
values: [
Offset(0, 200), // disabled value value
Offset(0, 250), //intermediate value
Offset(0, 0) //enabled value
],
child: /* your widget */
),
or using a tween constructor
RotationAnimatedWidget.tween(
enabled: this.displayMyWidget, //update this boolean to forward/reverse the animation
rotationDisabled: Rotation.degrees(z: 0),
rotationEnabled: Rotation.degrees(z: 90),
child: /* your widget */
),
Don't hesitate to compose them
TranslationAnimatedWidget.tween(
enabled: this.displayMyWidget,
translationDisabled: Offset(0, 200),
translationEnabled: Offset(0, 0),
child:
OpacityAnimatedWidget.tween(
enabled: this.displayMyWidget,
opacityDisabled: 0,
opacityEnabled: 1,
child: /* your widget */
),
),
Example using a Stateful Widget
class _StatefulScreenState extends State<StatefulScreen> {
// will determine if the opacity animation is launched
bool _display = false;
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
body: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
children: [
//wrap your widget with OpacityAnimatedWidget
OpacityAnimatedWidget.tween(
opacityEnabled: 1, //define start value
opacityDisabled: 0, //and end value
enabled: _display, //bind with the boolean
child: Container(
height: 200,
width: 200,
child: FlutterLogo(
style: FlutterLogoStyle.stacked,
),
),
),
RaisedButton(
color: Colors.blue,
child: Text(
_display ? "hide logo" : "display logo",
style: TextStyle(color: Colors.white),
),
onPressed: () {
setState(() {
//will fire the animation
_display = !_display;
});
},
)
],
),
);
}
}
Example using bloc pattern
class FirstScreenBloc extends Bloc {
final _viewState = BehaviorSubject<FirstScreenViewState>.seeded(FirstScreenViewState());
Observable<FirstScreenViewState> get viewState => _viewState;
void onClicked() {
_viewState.add(FirstScreenViewState(buttonVisible: true));
}
void onDismissClicked() {
_viewState.add(FirstScreenViewState(buttonVisible: false));
}
@override
void dispose() {
_viewState.close();
}
}
class FirstScreenViewState {
final bool buttonVisible;
const FirstScreenViewState({
this.buttonVisible = false,
});
}class FirstScreenView extends StatelessWidget {
@override
Widget build(BuildContext context) {
final bloc = BlocProvider.of<FirstScreenBloc>(context);
return StreamBuilder<FirstScreenViewState>(
stream: bloc.viewState,
builder: (context, snapshot) {
final viewState = snapshot.data;
return Stack(
fit: StackFit.expand,
children: [
_buildInputButton(onClicked: () {
bloc.onClicked();
}),
Positioned(
bottom: 20,
left: 20,
right: 20,
child: TranslationAnimatedWidget(
enabled: viewState.buttonVisible, //will forward/reverse the animation
curve: Curves.easeIn,
duration: Duration(seconds: 1),
values: [
Offset(0, 200),
Offset(0, -50),
Offset(0, 0),
],
child: RaisedButton(
onPressed: () {
bloc.onDismissClicked();
},
child: Text("Dismiss"),
),
),
),
],
);
}
);
}
}
RotationAnimatedWidget.tween(
enabled: enabled,
rotationDisabled: Rotation.deg(),
rotationEnabled: Rotation.deg(z: 90, x: 80),
child: /* your widget */
),
RotationAnimatedWidget.tween(
enabled: enabled,
rotation: Rotation.deg(),
rotationEnabled: Rotation.deg(z: 90, x: 80),
child: /* your widget */
),ScaleAnimatedWidget.tween(
enabled: this._enabled,
duration: Duration(milliseconds: 600),
scaleDisabled: 0.5,
scaleEnabled: 1,
//your widget
child: Container(
height: 200,
width: 200,
child: FlutterLogo(
style: FlutterLogoStyle.stacked,
),
),
),
SizeAnimatedWidget(
enabled: this._enabled,
duration: Duration(milliseconds: 1500),
values: [Size(100, 100), Size(100, 150), Size(200, 150), Size(200, 200)],
curve: Curves.linear,
//your widget
child: Container(
decoration: BoxDecoration(
border: Border.all(color: Colors.blue)
),
child: FlutterLogo(
style: FlutterLogoStyle.stacked,
),
),
),
ShakeAnimatedWidget(
enabled: this._enabled,
duration: Duration(milliseconds: 1500),
shakeAngle: Rotation.deg(z: 40),
curve: Curves.linear,
child: FlutterLogo(
style: FlutterLogoStyle.stacked,
),
),
CustomAnimatedWidget(
enabled: this._enabled,
duration: Duration(seconds: 3),
curve: Curves.easeOut,
builder: (context, percent) { //for custom animation, use builders
final int displayedDate = (2018 * percent).floor();
return Text(
"current year : $displayedDate",
style: TextStyle(color: Colors.blue),
);
},
),
Animated widget is available at https://pub.dev/packages/animated_widgets
dependencies:
animated_widgets:
For help getting started with Flutter, view our online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.
Copyright 2019 florent37, Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
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distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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