animated_widgets

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 */
),

screen

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 */
),

screen

Compose

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 */
    ),
),

screen

Opacity

screen

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;

              });
            },
          )
        ],
      ),
    );
  }
}

Translation

screen

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"),
                        ),

                      ),
                    ),
                  ],
               );
            }
        );
  }
}

Rotation

screen

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 */
),

Scale

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,
        ),
      ),
    ),

screen

Size

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,
        ),
      ),
    ),

screen

Shake

ShakeAnimatedWidget(
      enabled: this._enabled,
      duration: Duration(milliseconds: 1500),
      shakeAngle: Rotation.deg(z: 40),
      curve: Curves.linear,
      child: FlutterLogo(
        style: FlutterLogoStyle.stacked,
      ),
    ),

screen

Custom Animated

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),
        );
      },
),

screen

Flutter Package

Animated widget is available at https://pub.dev/packages/animated_widgets

dependencies:
  animated_widgets:

Getting Started with Flutter

For help getting started with Flutter, view our online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

License

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

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Libraries

animated_widgets
chain_tweens
custom_animated
i18n
opacity_animated
rotation_animated
scale_animated
shake_animated_widget
size_animated
tap_scale_animated
translation_animated

Dart

VM

dart:ffi
Foreign Function Interface for interoperability with the C programming language. [...]

Web

dart:html
HTML elements and other resources for web-based applications that need to interact with the browser and the DOM (Document Object Model). [...]
dart:js
Low-level support for interoperating with JavaScript. [...]
dart:js_util
Utility methods to efficiently manipulate typed JSInterop objects in cases where the name to call is not known at runtime. You should only use these methods when the same effect cannot be achieved with @JS annotations. These methods would be extension methods on JSObject if Dart supported extension methods.