import { useLayoutEffect, useState } from "react";
// 接收保存被監(jiān)聽dom的ref
const useResizeObserver = (ref: React.RefObject<HTMLElement>) => {
  const [width, setWidth] = useState<number>(0);
  useLayoutEffect(() => {
     // 使用ResizeObserver來(lái)監(jiān)聽DOM的變化
    const resizeObserver = new ResizeObserver(() => {
      setWidth((ref.current as HTMLElement).clientWidth);
    });
    resizeObserver.observe(ref.current as HTMLElement);
    return () => {
      resizeObserver.disconnect();
    };
  }, [ref]);
  return width;
};
export default useResizeObserver;

import React, {
  useMemo,
  useState,
  useRef,
  useLayoutEffect,
  useEffect,
} from "react";
import type { ReactElement } from "react";
import "./index.css";
import ArrowLeft from "@/assets/arrow-left.svg";
import ArrowRight from "@/assets/arrow-right.svg";
import useResizeObserver from "@/hooks/useResizeObserver";
export interface SliderContainerProps {
  width: number;
  children: ReactElement; // 需要包括的內(nèi)容
}
const LEFT = "left";
const RIGHT = "right";
export const SliderContainer: React.FC<SliderContainerProps> = ({
  width = "inherit",
  children,
}) => {
  const listRef = useRef<HTMLDivElement>(null);
  const containerRef = useRef<HTMLDivElement>(null);
  const containerWidth = useResizeObserver(containerRef);
  const [listWidth, setListWidth] = useState(0);
  const [translateX, setTranslateX] = useState(0);
  // 緩存
  const cache = useRef(containerWidth);
  // 處理容器寬度變化時(shí)，內(nèi)部元素的吸附效果
  useEffect(() => {
    if (
      containerWidth > cache.current && // 當(dāng)容器可拖拽時(shí)，表示用戶正在向右拖拽
      translateX < 0 && // 表示左側(cè)有內(nèi)容被隱藏
      listWidth - Math.abs(translateX) - containerWidth <= 0 //表示右側(cè)已經(jīng)沒(méi)有被隱藏的內(nèi)容了
    ) {
      const distance = containerWidth - cache.current;
      setTranslateX((cur) => cur + distance);
    }
    // 更新緩存
    cache.current = containerWidth;
  }, [containerWidth, translateX, listWidth]);
  useLayoutEffect(() => {
    setListWidth((listRef.current as HTMLDivElement).clientWidth);
  }, [children]);
  // 判斷按鈕是否可見
  const [leftArrowVisible, rightArrowVisible] = useMemo(() => {
    let leftArrowVisible,
      rightArrowVisible = false;
    // listWidth - Math.abs(translateX) - containerWidth 為右側(cè)隱藏內(nèi)容
    if (listWidth - Math.abs(translateX) - containerWidth > 0) {
      rightArrowVisible = true;
    }
    if (translateX < 0) {
      leftArrowVisible = true;
    }
    return [leftArrowVisible, rightArrowVisible];
  }, [listWidth, translateX, containerWidth]);
  const handleArrowClick = (direction: string) => {
    if (direction === LEFT) {
      // 左側(cè)隱藏內(nèi)容
      const leftSpaceWidth = Math.abs(translateX);
      if (leftSpaceWidth > containerWidth) {
        setTranslateX((cur) => cur + containerWidth);
      } else {
        setTranslateX((cur) => cur + leftSpaceWidth);
      }
    }
    if (direction === RIGHT) {
      // 右側(cè)隱藏內(nèi)容
      const rightSpaceWidth = listWidth - Math.abs(translateX) - containerWidth;
      if (rightSpaceWidth > containerWidth) {
        setTranslateX((cur) => cur - containerWidth);
      } else {
        setTranslateX((cur) => cur - rightSpaceWidth);
      }
    }
  };
  return (
    <div ref={containerRef} style={{ width: width }} className="container">
      {leftArrowVisible && (
        <>
          <button
            color="white"
            className="leftArrow btn"
            onClick={() => handleArrowClick(LEFT)}
          >
            <img src={ArrowLeft} alt="" />
          </button>
          <div className="linerGrid leftGradient"></div>
        </>
      )}
      <div
        ref={listRef}
        className="list"
        style={{
          transform: `translateX(${translateX}px)`,
          transition: "all 0.3s linear",
        }}
      >
        {children}
      </div>
      {rightArrowVisible && (
        <>
          <div className="linerGrid rightGradient"></div>
          <button
            color="white"
            className="rightArrow btn"
            onClick={() => handleArrowClick(RIGHT)}
          >
            <img src={ArrowRight} alt="" />
          </button>
        </>
      )}
    </div>
  );
};

.container {
  display: flex;
  overflow: hidden;
  position: relative;
  height: 100%;
}
.list {
  display: flex;
  align-items: center;
}
.btn {
  width: 40px;
  height: 100%;
  position: absolute;
  z-index: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}
.leftArrow {
  left: 0;
}
.rightArrow {
  right: 0;
  z-index: 0;
}
.linerGrid {
  position: absolute;
  width: 20px;
  height: 100%;
}
.leftGradient {
  left: 40px;
  z-index: 1;
  background: linear-gradient(to right, #fff, rgba(255, 255, 255, 0.2));
}
.rightGradient {
  right: 40px;
  background: linear-gradient(269.21deg, #ffffff, rgba(255, 255, 255, 0.2));
}

const list = [
  { key: "1", name: "列表項(xiàng)1" },
  { key: "2", name: "列表項(xiàng)2" },
  { key: "3", name: "列表項(xiàng)3" },
  { key: "4", name: "列表項(xiàng)4" },
  { key: "5", name: "列表項(xiàng)5" },
  { key: "6", name: "列表項(xiàng)6" },
  { key: "7", name: "列表項(xiàng)7" },
  { key: "8", name: "列表項(xiàng)8" },
  { key: "9", name: "列表項(xiàng)9" },
  { key: "10", name: "列表項(xiàng)10" },
];
function App() {
  return (
    <div className="App">
      <SliderContainer width={300}>
        <>
          {list.map((item) => (
            <div style={{ width: 100 }} key={item.key}>
              {item.name}
            </div>
          ))}
        </>
      </SliderContainer>
    </div>
  );
}