//返回鍵旋轉(zhuǎn)角度，初始旋轉(zhuǎn)45度，使其初始樣式為 +
var angle = (pi / 4).obs;

///關(guān)閉按鈕旋轉(zhuǎn)動(dòng)畫控制器
late final AnimationController closeController;
late final Animation<double> closeAnimation;

///返回鍵旋轉(zhuǎn)動(dòng)畫
closeController = AnimationController(
  duration: const Duration(milliseconds: 300),
  vsync: provider,
);

///返回鍵旋轉(zhuǎn)動(dòng)畫
closeController = AnimationController(
  duration: const Duration(milliseconds: 300),
  vsync: provider,
);

///頁面渲染完才開始執(zhí)行，不然第一次打開不會(huì)啟動(dòng)動(dòng)畫
WidgetsBinding.instance.addPostFrameCallback((duration) {
  closeAnimation =
      Tween(begin: pi / 4, end: pi / 2).animate(closeController)
        ..addListener(() {
          angle.value = closeAnimation.value;
        });
  closeController.forward();
});


///關(guān)閉按鈕點(diǎn)擊事件
void close() {
  ///反轉(zhuǎn)動(dòng)畫，并關(guān)閉頁面
  Future.delayed(
     const Duration(milliseconds: 120), () {
    Get.back();
  });

  closeController.reverse();
}


IconButton(
    onPressed: null,
    alignment: Alignment.center,
    icon: Transform.rotate(
      angle: controller.angle.value,
      child: SvgPicture.asset(
        "assets/user/ic-train-car-close.svg",
        width: 18,
        height: 18,
        color: Colors.black,
      ),
    ))

//透明度變化
List<AnimationController> opacityControllerList = [];
//上移動(dòng)畫，由于每個(gè)欄目的移動(dòng)速度不一樣，需要用List保存四個(gè)AnimationController，
//如果想像閑魚那種整體上移，則只用一個(gè)AnimationController即可。
List<AnimationController> offsetControllerList = [];
List<Animation<Offset>> offsetAnimationList = [];

//之所以用addIf，是因?yàn)轫?xiàng)目中這幾個(gè)欄目的顯示是動(dòng)態(tài)顯示的，這里就直接寫成true
Column(
    children: []
      ..addIf(
          true,
          buildItem('assets/user/ic-train-nomal-car.webp',"學(xué)車加練","自主預(yù)約，快速拿證"))
      ..addIf(
          true,
          buildItem('assets/user/ic-train-fuuxn-car.webp',"有證復(fù)訓(xùn)","優(yōu)質(zhì)陪練，輕松駕車"))
      ..addIf(
          true,
          buildItem('assets/user/ic-train-jiaxun-car.webp',"模擬加訓(xùn)","考前加訓(xùn)，臨考不懼"))
      ..addIf(
          true,
          buildItem('assets/user/ic-train-jiakao-car.webp',"駕考報(bào)名","快捷報(bào)名無門檻"))
      ..add(playWidget())
      ..addAll([
        17.space,
      ]),
   )
      
//僅僅是為了在offsetController全部初始化完后執(zhí)行play()
Widget playWidget() {
  //執(zhí)行動(dòng)畫
  play();
  return Container();
}

int i = 0;

Widget buildItem(String img,String tab,String slogan) {
  //由于底部欄目是動(dòng)態(tài)顯示的，需要在創(chuàng)建Widget時(shí)一同創(chuàng)建offsetController和offsetAnimation
  i++;
  AnimationController offsetController = AnimationController(
    duration: Duration(milliseconds: 100 + i * 20),
    vsync: this,
  );
  Animation<Offset> offsetAnimation = Tween<Offset>(
    begin: const Offset(0, 2.5),
    end: const Offset(0, 0),
  ).animate(CurvedAnimation(
    parent: offsetController,
    // curve: Curves.easeInOutSine,
    curve: const Cubic(0.12, 0.28, 0.48, 1),
  ));

  AnimationController opacityController = AnimationController(
      duration: const Duration(milliseconds: 500),
      lowerBound: 0.2,
      upperBound: 1.0,
      vsync: this);

  opacityControllerList.add(opacityController);
  offsetControllerList.add(offsetController);
  offsetAnimationList.add(offsetAnimation);

  return SlideTransition(
    position: offsetAnimation,
    child: FadeTransition(
        opacity: opacityController,
        child: Container(
            margin: EdgeInsets.only(bottom: 16),
            height: 62,
            decoration: BoxDecoration(
                borderRadius: BorderRadius.all(Radius.circular(12)),
                color: const Color(0xfffafafa)),
            child:
            Row(mainAxisAlignment: MainAxisAlignment.center, children: [
              24.space,
              Image.asset(img, width: 44, height: 44),
              12.space,
              Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(tab,
                        style: const TextStyle(
                            color: Color(0XFF000000),
                            fontSize: 16,
                            fontWeight: FontWeight.bold)),
                    Text(slogan,
                        style: const TextStyle(
                            color: Color(0XFF6e6e6e), fontSize: 12)),
                  ]).expanded,
              Image.asset("assets/user/ic-train-arrow.webp",
                  width: 44, height: 44),
              17.space
            ])).inkWell(
            onTap: () {},
            delayMilliseconds: 50)),
  );
}

//執(zhí)行動(dòng)畫
void play() async {
  for (int i = 0; i < offsetControllerList.length; i++) {
    opacityControllerList[i].forward();

    ///欄目正序依次延遲(40 + 2 * i) * i的時(shí)間,曲線速率
    Future.delayed(Duration(milliseconds: (40 + 2 * i) * i), () {
      offsetControllerList[i]
          .forward()
          .whenComplete(() => offsetControllerList[i].stop());
    });
  }
}



///關(guān)閉按鈕點(diǎn)擊事件
void close() {
  ///反轉(zhuǎn)動(dòng)畫，并關(guān)閉頁面
  Future.delayed(
     const Duration(milliseconds: 120), () {
    Get.back();
  });

  for (int i = offsetControllerList.length - 1; i >= 0; i--) {
    ///欄目倒敘依次延遲(40 + 2 * (offsetControllerList.length-1-i)) * (offsetControllerList.length-1-i))的時(shí)間
    Future.delayed(
        Duration(
            milliseconds:
            (40 + 2 * (offsetControllerList.length-1-i)) * (offsetControllerList.length-1-i)), () {
      offsetControllerList[i].reverse();
    });
  }
  opacityTopController.reverse();
}

///圖片透明度漸變動(dòng)畫控制器
late final AnimationController imgController;

///圖片透明度漸變動(dòng)畫
imgController = AnimationController(
    duration: const Duration(milliseconds: 500),
    lowerBound: 0.0,
    upperBound: 1.0,
    vsync: provider);
imgController.forward().whenComplete(() => imgController.stop());

///漸變過渡
FadeTransition(
  opacity: imgController,
  child:
  Image.asset("assets/user/ic-traincar-guide.webp"),
),

///關(guān)閉按鈕點(diǎn)擊事件
void close() {
  imgController.reverse();
}

///頂部標(biāo)題下移動(dòng)畫控制器
late final AnimationController offsetTopController;
late final Animation<Offset> offsetTopAnimation;

///頂部標(biāo)題漸變動(dòng)畫控制器
late final AnimationController opacityTopController;


///頂部標(biāo)題上移動(dòng)畫
offsetTopController = AnimationController(
  duration: const Duration(milliseconds: 300),
  vsync: provider,
);
offsetTopController
    .forward()
    .whenComplete(() => offsetTopController.stop());
offsetTopAnimation = Tween<Offset>(
  begin: const Offset(0, -0.8),
  end: const Offset(0, 0),
).animate(CurvedAnimation(
  parent: offsetTopController,
  curve: Curves.easeInOutCubic,
));
offsetTopController
    .forward()
    .whenComplete(() => offsetTopController.stop());
    
//UI
SlideTransition(
    position: offsetTopAnimation,
    child: FadeTransition(
        opacity: opacityTopController,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          mainAxisAlignment: MainAxisAlignment.start,
          mainAxisSize: MainAxisSize.min,
          children: [
            80.space,
            const Text(
              '練車指南',
              style: TextStyle(
                color: Color(0XFF141414),
                fontSize: 32,
                fontWeight: FontWeight.w800,
              ),
            ),
            2.space,
            const Text('易練只為您提供優(yōu)質(zhì)教練，為您的安全保駕護(hù)航',
                style: TextStyle(
                    color: Color(0XFF141414),
                    fontSize: 15)),
          ],
        ))),
        

///關(guān)閉按鈕點(diǎn)擊事件
void close() {
  offsetTopController.reverse();
  opacityTopController.reverse();

}

///關(guān)閉時(shí)注銷動(dòng)畫
void dispose() {
  for (int i = offsetControllerList.length - 1; i > 0; i--) {
    offsetControllerList[i].dispose();
  }
  offsetTopController.dispose();
  opacityTopController.dispose();
  imgController.dispose();
  closeController.dispose();
}