flutter/lib/pages/video/components/ads.dart

/// 可拖拽广告红包组件
library;

import 'package:flutter/material.dart';

class Ads extends StatefulWidget {
  const Ads({super.key});

  @override
  State<Ads> createState() => _AdsState();
}

class _AdsState extends State<Ads> with WidgetsBindingObserver {
  double winWidth = 0.0;
  double winHeight = 0.0;
  double dx = 10.0;
  double dy = 120.0;
  double ballWidth = 50.0;
  double ballHeight = 50.0;
  bool isAnimate = false;
  // 是否显示
  bool isVisible = true;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    WidgetsBinding.instance.addPostFrameCallback((_) {
      updateResize();
    });
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  // 监听窗口尺寸变化
  @override
  void didChangeMetrics() {
    super.didChangeMetrics();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      updateResize();
    });
  }

  // 更新设备尺寸
  void updateResize() {
    setState(() {
      winWidth = MediaQuery.of(context).size.width;
      winHeight = MediaQuery.of(context).size.height;
    });
  }

  // 拖拽更新
  void onPanUpdate(Offset position) {
    isAnimate = false;
    dx = position.dx - ballWidth / 2;
    dy = position.dy - ballHeight / 2;
    setState(() {});
  }

  // 拖拽结束
  void onPanEnd(Offset position) {
    isAnimate = true;
    if (dx + ballWidth / 2 < winWidth / 2) {
      dx = 10.0;
    } else {
      dx = winWidth - ballWidth - 10.0;
    }
    if (dy + ballHeight > winHeight / 2) {
      dy = winHeight / 2 - ballHeight;
    } else if (dy < 120) {
      dy = 120.0;
    }
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Visibility(
      visible: isVisible,
      child: AnimatedPositioned(
        duration: Duration(milliseconds: isAnimate ? 200 : 0),
        left: dx,
        top: dy,
        child: GestureDetector(
          behavior: HitTestBehavior.opaque,
          onPanUpdate: (DragUpdateDetails details) {
            onPanUpdate(details.globalPosition);
          },
          onPanEnd: (details) {
            onPanEnd(details.globalPosition);
          },
          onTap: () {
            debugPrint('click ads');
          },
          child: Stack(
            children: [
              SizedBox(
                  height: ballHeight,
                  width: ballWidth,
                  child: UnconstrainedBox(
                    child: Container(
                      height: 40.0,
                      width: 40.0,
                      decoration: BoxDecoration(
                        color: Colors.black.withAlpha(50),
                        borderRadius: BorderRadius.circular(100.0),
                      ),
                      child: UnconstrainedBox(
                        child: Image.asset(
                          'assets/images/hbico.png',
                          width: 25.0,
                          fit: BoxFit.contain,
                        ),
                      ),
                    ),
                  )),
              Positioned(
                right: 0,
                top: 0,
                child: GestureDetector(
                  child: Icon(
                    Icons.close,
                    color: Colors.white,
                    size: 10.0,
                  ),
                  onTap: () {
                    setState(() {
                      isVisible = false;
                    });
                  },
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}