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samples/isolate_example/lib/page_one.dart

103 lines
2.6 KiB

// Copyright 2019-present the Flutter authors. All Rights Reserved.
//
// 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.
import 'package:flutter/material.dart';
class PerformancePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
SmoothAnimationWidget(),
],
),
);
}
}
class SmoothAnimationWidget extends StatefulWidget {
@override
SmoothAnimationWidgetState createState() => SmoothAnimationWidgetState();
}
class SmoothAnimationWidgetState extends State<SmoothAnimationWidget>
with TickerProviderStateMixin {
AnimationController _controller;
var borderRadius;
@override
void initState() {
super.initState();
_controller = AnimationController(
duration: const Duration(seconds: 1),
vsync: this,
)..addStatusListener(
(status) {
if (status == AnimationStatus.completed) {
_controller.reverse();
} else if (status == AnimationStatus.dismissed) {
_controller.forward();
}
},
);
borderRadius = BorderRadiusTween(
begin: BorderRadius.circular(100.0),
end: BorderRadius.circular(0.0),
).animate(
CurvedAnimation(
parent: _controller,
curve: Curves.linear,
),
);
_controller.forward();
}
@override
Widget build(BuildContext context) {
return AnimatedBuilder(
animation: borderRadius,
builder: (context, child) {
return Center(
child: Container(
child: new FlutterLogo(
size: 200,
),
alignment: Alignment.bottomCenter,
width: 350,
height: 200,
decoration: BoxDecoration(
gradient: LinearGradient(
begin: Alignment.topLeft,
colors: [Colors.blueAccent, Colors.redAccent],
),
borderRadius: borderRadius.value,
),
),
);
},
);
}
@override
void dispose() {
_controller.dispose();
super.dispose();
}
}