App_Flutter/lib/view/component/loading.dart

import 'dart:math';

import 'package:fast/utils/size_fit.dart';
import 'package:flutter/material.dart';

class Loading extends StatefulWidget {
  bool showBg = true;
  Loading({Key? key, bool? showBackground}) : super(key: key) {
    if (showBackground != null) {
      showBg = showBackground;
    }
  }

  @override
  State<Loading> createState() => _LoadingState();
}

class _LoadingState extends State<Loading> with SingleTickerProviderStateMixin {
  late AnimationController controller;
  late Animation animation;

  @override
  void initState() {
    controller = AnimationController(
        vsync: this, duration: const Duration(milliseconds: 1200));
    animation = Tween(begin: 0.0, end: 2 * pi).animate(controller);
    controller.addListener(() {
      setState(() {});
    });
    controller.repeat();
    super.initState();
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    SizeFit.initialize(context);
    return SizedBox(
      width: 144.px,
      height: 150.px,
      child: Container(
        alignment: Alignment.center,
        child: Container(
          width: 144.px,
          height: 150.px,
          alignment: Alignment.center,
          child: Transform.rotate(
            angle: animation.value,
            child: Image.asset(
              'assets/images/loading.png',
              width: 80.px,
              height: 80.px,
            ),
          ),
          decoration: widget.showBg
              ? BoxDecoration(
                  color: const Color(0xFF313F52),
                  borderRadius: BorderRadius.all(Radius.circular(32.px)),
                  boxShadow: [
                      BoxShadow(
                          color: const Color(0xFF000D1F),
                          blurRadius: 24.px,
                          offset: Offset(0, 12.px))
                    ])
              : const BoxDecoration(color: Colors.transparent),
        ),
      ),
    );
  }
}