react-horizontal-scrolling-menu

保存并恢复滚动位置

横向轨道每次卸载都会忘记自己的偏移：路由离开再返回、折叠某个区块，它就跳回起点。此示例在用户滚动时保存偏移，并在挂载时写回，让菜单精确地回到他们离开时的位置。
#01
#02
#03
#04
#05
#06
#07
#08
#09
#10
#11
#12
#13
#14

把这一行滚到某处，卸载菜单，再重新挂载——轨道会以同样的偏移回来。

在 Storybook 中实时编辑此示例

工作原理

整个功能由两个回调承担。onUpdate 在用户滚动、菜单可见性状态变化时触发；savePos 读取 api.scrollContainer.current.scrollLeft 并写入 sessionStorage。在下一次挂载时，onInit 把保存的值直接赋回 scrollLeft——一次普通的属性写入，因此恢复是即时的，而不是在用户面前重播动画。

在重新挂载、重载与返回导航下存续

sessionStorage 比组件更长寿：客户端路由切换、条件渲染与整页重载都会回到保存的偏移，且该值按标签页隔离，两个标签页不会互相覆盖。对于历史导航，该 story 还设置了 window.history.scrollRestoration = ’manual’，避免在后退与前进时浏览器自己的滚动恢复与手动恢复互相冲突。

注意

完整源码

完整且可直接复制粘贴——这正是背后这份文件的 可在 Storybook 中实时编辑的版本.

Position.source.tsx
import 'react-horizontal-scrolling-menu/dist/styles.css';

import styled from '@emotion/styled';
import React from 'react';
import {
  type publicApiType,
  ScrollMenu,
  VisibilityContext,
} from 'react-horizontal-scrolling-menu';

export function Position() {
  const [items] = React.useState(() => getItems());
  const [selected, setSelected] = React.useState<string[]>([]);

  const isItemSelected = (id: string): boolean =>
    !!selected.find((el) => el === id);

  const handleItemClick = (itemId: string) => {
    const itemSelected = isItemSelected(itemId);

    setSelected((currentSelected: string[]) =>
      itemSelected
        ? currentSelected.filter((el) => el !== itemId)
        : currentSelected.concat(itemId),
    );
  };

  const { getPosition, setPosition, reset } = usePosition();
  const savePos = React.useCallback(
    (api: publicApiType) => {
      setPosition(api.scrollContainer.current?.scrollLeft ?? 0);
    },
    [setPosition],
  );
  const restorePosition = React.useCallback(
    (api: publicApiType) => {
      const node = api.scrollContainer.current;

      if (node) {
        node.scrollLeft = getPosition();
      }
    },
    [getPosition],
  );

  const [key, setKey] = React.useState(() => String(Math.random()));
  const reload = React.useCallback(() => setKey(String(Math.random())), []);

  return (
    <>
      <ScrollMenu
        LeftArrow={LeftArrow}
        RightArrow={RightArrow}
        onWheel={onWheel}
        onUpdate={savePos}
        onInit={restorePosition}
        key={key}
      >
        {items.map(({ id }) => (
          <Card
            title={id}
            itemId={id} // NOTE: itemId is required for track items
            key={id}
            onClick={() => handleItemClick(id)}
            selected={isItemSelected(id)}
          />
        ))}
      </ScrollMenu>
      <div>
        <button onClick={reset} data-testid="reset">
          Reset position
        </button>
        <button onClick={reload} data-testid="reload">
          Reload
        </button>
      </div>
    </>
  );
}

const usePosition = () => {
  React.useEffect(() => {
    window.history.scrollRestoration = 'manual';
  }, []);

  const setPosition = React.useCallback((pos: number | string) => {
    sessionStorage.setItem('position', String(pos));
  }, []);
  const getPosition = () => +(sessionStorage.getItem('position') || 0);
  const reset = React.useCallback(
    () => sessionStorage.removeItem('position'),
    [],
  );

  return { getPosition, setPosition, reset };
};

export default Position;

function LeftArrow() {
  const visibility = React.useContext<publicApiType>(VisibilityContext);

  const disabled = visibility.useLeftArrowVisible();

  return (
    <Arrow
      disabled={disabled}
      onClick={() => visibility.scrollPrev()}
      testId="left-arrow"
    >
      Left
    </Arrow>
  );
}

function RightArrow() {
  const visibility = React.useContext<publicApiType>(VisibilityContext);

  const disabled = visibility.useRightArrowVisible();

  return (
    <Arrow
      disabled={disabled}
      onClick={() => visibility.scrollNext()}
      testId="right-arrow"
    >
      Right
    </Arrow>
  );
}

function Arrow({
  children,
  disabled,
  onClick,
  className,
  testId,
}: {
  children: React.ReactNode;
  disabled: boolean;
  onClick: VoidFunction;
  className?: string;
  testId: string;
}) {
  return (
    <ArrowButton
      disabled={disabled}
      onClick={onClick}
      className={'arrow' + `-${className}`}
      data-testid={testId}
    >
      {children}
    </ArrowButton>
  );
}
const ArrowButton = styled('button')((props) => ({
  cursor: 'pointer',
  display: 'flex',
  flexDirection: 'column',
  justifyContent: 'center',
  marginBottom: '2px',
  opacity: props.disabled ? '0' : '1',
  userSelect: 'none',
  borderRadius: '6px',
  borderWidth: '1px',
}));

function Card({
  onClick,
  selected,
  title,
  itemId,
}: {
  onClick: (context: publicApiType) => void;
  selected: boolean;
  title: string;
  itemId: string;
}) {
  const visibility = React.useContext<publicApiType>(VisibilityContext);
  const isVisible = visibility.useIsVisible(itemId, true);

  return (
    <CardBody
      data-cy={itemId}
      onClick={() => onClick(visibility)}
      onKeyDown={(ev: React.KeyboardEvent) => {
        ev.code === 'Enter' && onClick(visibility);
      }}
      data-testid="card"
      role="button"
      tabIndex={0}
      className="card"
      visible={isVisible}
      selected={selected}
    >
      <div className="header">
        <div>{title}</div>
        <div className="visible">visible: {JSON.stringify(isVisible)}</div>
        <div className="selected">selected: {JSON.stringify(!!selected)}</div>
      </div>
      <div className="background" />
    </CardBody>
  );
}
const CardBody = styled('div')<{ selected?: boolean; visible?: boolean }>(
  (props) => ({
    border: '1px solid',
    display: 'inline-block',
    margin: '0 10px',
    width: '160px',
    userSelect: 'none',
    borderRadius: '8px',
    overflow: 'hidden',

    '& .header': {
      backgroundColor: 'white',
    },

    '& .visible': {
      backgroundColor: props.visible ? 'transparent' : 'gray',
    },

    '& .background': {
      backgroundColor: props.selected ? 'green' : 'bisque',
      height: '200px',
    },
  }),
);

const getId = (index: number) => `${'test'}${index}`;

const getItems = () =>
  Array(10)
    .fill(0)
    .map((_, ind) => ({ id: getId(ind) }));

function onWheel(apiObj: publicApiType, ev: React.WheelEvent): void {
  // NOTE: no good standart way to distinguish touchpad scrolling gestures
  // but can assume that gesture will affect X axis, mouse scroll only Y axis
  // of if deltaY too small probably is it touchpad
  const isThouchpad = Math.abs(ev.deltaX) !== 0 || Math.abs(ev.deltaY) < 15;

  if (isThouchpad) {
    ev.stopPropagation();
    return;
  }

  if (ev.deltaY < 0) {
    apiObj.scrollNext();
  } else {
    apiObj.scrollPrev();
  }
}

相关示例

全部 21 个示例