【 开源计划 - Flutter组件 】 星星也可以如此闪耀 flutter_star

dependencies:
  flutter_star: $lastVersion

---->[StarScore 星星显示组件]----
[1] 比如显示4.2: 会有5颗星, 前四颗填满，后一刻填充20%
StarScore 为 Stateless组件，仅负责显示的需求

---->[CustomRating 星星评分组件]----
[2] 可指定最大值，也就是显示多少个星星
[3] 点击时会改变状态，进行评分,支持半星评分
[4] 支持评分回调

---->[StarWidget组件]----
[5]. 可定义星星的显示进度情况 0% ~ 100 % 无死角
[6]. 可定义星星的角数
[7]. 可定义星星的颜色、大小 

StarScore(
  score: 4.8,
  star: Star(
      fillColor: Colors.tealAccent,
      emptyColor: Colors.grey.withAlpha(88)),
  tail: Column(
    children: <Widget>[
      Text("综合评分"),
      Text("4.8"),
    ],
  ),
),

CustomRating(onRating: (s) {
   print(s);
 }),

CustomRating(
     max: 6,
     score: 3.0,
     star: Star(
         num: 12,
         fillColor: Colors.orangeAccent,
         fat: 0.6,
         emptyColor: Colors.grey.withAlpha(88)),
    onRating: (s) {
       print(s);
     }),

class Star {
  final int num;
  final double progress;
  final Color emptyColor;
  final Color fillColor;
  final double size;
  final double fat;

  const Star({this.progress = 0,
    this.fat = 0.5,
      this.fillColor = Colors.yellow,
    this.emptyColor = Colors.grey,
    this.num = 5,
    this.size = 25});
}

class _StarPainter extends CustomPainter {
  Star star;
  Paint _paint;
  Paint _filePaint;
  Path _path;
  double _radius;

  _StarPainter(this.star) {
    _paint = Paint()
      ..color = (star.emptyColor)
      ..isAntiAlias = true;

    _filePaint = Paint()
      ..color = (star.fillColor);
    _path = Path();
    _radius = star.size / 2.0;

  }
  @override
  void paint(Canvas canvas, Size size) {
    //TODO 绘制
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    return true;
  }
}

  Path nStarPath(int num, double R, double r, {dx = 0, dy = 0, rotate = 0}) {
    _path.reset(); //重置路径
    double perRad = 2 * pi / num; //每份的角度
    double radA = perRad / 2 / 2 + rotate; //a角
    double radB = 2 * pi / (num - 1) / 2 - radA / 2 + radA + rotate; //起始b角
    _path.moveTo(cos(radA) * R + dx, -sin(radA) * R + dy); //移动到起点
    for (int i = 0; i < num; i++) {
      //循环生成点，路径连至
      _path.lineTo(
          cos(radA + perRad * i) * R + dx, -sin(radA + perRad * i) * R + dy);
      _path.lineTo(
          cos(radB + perRad * i) * r + dx, -sin(radB + perRad * i) * r + dy);
    }
    _path.close();
    return _path;
  }

class _StarPainter extends CustomPainter {
 ...
  _StarPainter(this.star) {
    ...
    _path = Path();
    _radius = star.size / 2.0;
    nStarPath(star.num, _radius, _radius * star.fat);
  }

  @override
  void paint(Canvas canvas, Size size) {
    canvas.translate(_radius, _radius);
    canvas.drawPath(_path, _paint);
    canvas.clipRect(Rect.fromLTRB(
        -_radius, -_radius, _radius * 2 * star.progress - _radius, _radius));
    canvas.drawPath(_path, _filePaint);
  }

 class StarWidget extends StatelessWidget {
  final Star star;

  StarWidget({this.star = const Star()});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: star.size,
      height: star.size,
      child: CustomPaint(
        painter: _StarPainter(star),
      ),
    );
  }
}

class StarScore extends StatelessWidget {
  final Star star;
  final double score;
  final Widget tail;

  StarScore({this.star = const Star(), this.score, this.tail});

  @override
  Widget build(BuildContext context) {
    var li = <StarWidget>[];
    int count = score.floor();
    for (int i = 0; i < count; i++) {
      li.add(StarWidget(star: star.copyWith(progress: 1.0)));
    }
    if (score - count > 0) {
      li.add(StarWidget(star: star.copyWith(progress: score - count)));
    }
    return Wrap(
      crossAxisAlignment: WrapCrossAlignment.center,
      children: [
        ...li,
        SizedBox(
          width: 10,
        ),
        if (tail!=null) tail
      ],
    );
  }
}

class CustomRating extends StatefulWidget {
  final int max;
  final Star star;
  final double score;
  final Function(double) onRating;

  CustomRating(
      {this.max = 5,
      this.score = 0,
      this.star = const Star(),
      @required this.onRating})
      : assert(score <= max);

  @override
  _CustomRatingState createState() => _CustomRatingState();
}

class _CustomRatingState extends State<CustomRating> {
  double _score;

  @override
  void initState() {
    _score = widget.score;
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    var li = <StarWidget>[];

    int count = _score.floor(); //满星
    for (int i = 0; i < count; i++) {
      li.add(StarWidget(star: widget.star.copyWith(progress: 1.0)));
    }

    if (_score != widget.max.toDouble())
      li.add(StarWidget(
          star: widget.star.copyWith(progress: _score - count))); //不满星

    var empty = widget.max - count - 1; // 空星
    for (int i = 0; i < empty; i++) {
      li.add(StarWidget(star: widget.star.copyWith(progress: 0)));
    }
    return GestureDetector(
      onTapDown: (d) {
        setState(() {
          _score = d.localPosition.dx / widget.star.size;
          if (_score - _score.floor() > 0.5) {
            _score = _score.floor() + 1.0;
          } else {
            _score = _score.floor() + 0.5;
          }

          if (_score >= widget.max.toDouble()) {
            _score = widget.max.toDouble();
          }
          widget.onRating(_score);
        });
      },
      child: Wrap(
        children: li,
      ),
    );
  }
}
复制代码

name 是名称
description 是描述 60 ~ 180 之间，太短或太长会扣分
version 版本
author 作者信息，会报warning 但我就想写
homepage 主页

---->[pubspec.yaml]----
name: flutter_star
description: You can create a star easily and decide how many angle or color of the star, even the fat and progress of the star.
version: 0.1.2
author: 张风捷特烈<1981462002@qq.com>
homepage: https://juejin.im/user/5b42c0656fb9a04fe727eb37/collections

flutter packages pub publish --server=https://pub.dartlang.org