void changeData()
{
this.setState(() => {
this._tween = new BarChartTween(
this._tween.evaluate(this._animation),
BarChart.random(size)
);
this._animation.forward(from: 0.0f);
});
}
void initState()
{
base.initState();
this._animation = new AnimationController(
duration: new TimeSpan(0, 0, 0, 0, 300),
vsync: this
);
this._tween = new BarChartTween(
BarChart.empty(),
BarChart.random(size)
);
this._animation.forward();
}