@mui/base/useList/useListItem.js

A library of headless ('unstyled') React UI components and low-level hooks.

import _extends from "@babel/runtime/helpers/esm/extends";
import * as React from 'react';
import { unstable_useForkRef as useForkRef, unstable_useEnhancedEffect as useEnhancedEffect } from '@mui/utils';
import useForcedRerendering from '../utils/useForcedRerendering';
import { ListActionTypes } from './listActions.types';
import { ListContext } from './ListContext';

/**
 * Contains the logic for an item of a list-like component (e.g. Select, Menu, etc.).
 * It provides information about the item's state (selected, highlighted) and
 * handles the item's mouse events.
 *
 * @template ItemValue The type of the item's value. This should be consistent with the type of useList's `items` parameter.
 * @ignore - internal hook.
 */
export default function useListItem(parameters) {
  const {
    handlePointerOverEvents = false,
    item,
    rootRef: externalRef
  } = parameters;
  const itemRef = React.useRef(null);
  const handleRef = useForkRef(itemRef, externalRef);
  const listContext = React.useContext(ListContext);
  if (!listContext) {
    throw new Error('useListItem must be used within a ListProvider');
  }
  const {
    dispatch,
    getItemState,
    registerHighlightChangeHandler,
    registerSelectionChangeHandler
  } = listContext;
  const {
    highlighted,
    selected,
    focusable
  } = getItemState(item);
  const rerender = useForcedRerendering();
  useEnhancedEffect(() => {
    function updateHighlightedState(highlightedItem) {
      if (highlightedItem === item && !highlighted) {
        rerender();
      } else if (highlightedItem !== item && highlighted) {
        rerender();
      }
    }
    return registerHighlightChangeHandler(updateHighlightedState);
  });
  useEnhancedEffect(() => {
    function updateSelectedState(selectedItems) {
      if (!selected) {
        if (selectedItems.includes(item)) {
          rerender();
        }
      } else if (!selectedItems.includes(item)) {
        rerender();
      }
    }
    return registerSelectionChangeHandler(updateSelectedState);
  }, [registerSelectionChangeHandler, rerender, selected, item]);
  const createHandleClick = React.useCallback(other => event => {
    var _other$onClick;
    (_other$onClick = other.onClick) == null ? void 0 : _other$onClick.call(other, event);
    if (event.defaultPrevented) {
      return;
    }
    dispatch({
      type: ListActionTypes.itemClick,
      item,
      event
    });
  }, [dispatch, item]);
  const createHandlePointerOver = React.useCallback(other => event => {
    var _other$onMouseOver;
    (_other$onMouseOver = other.onMouseOver) == null ? void 0 : _other$onMouseOver.call(other, event);
    if (event.defaultPrevented) {
      return;
    }
    dispatch({
      type: ListActionTypes.itemHover,
      item,
      event
    });
  }, [dispatch, item]);
  let tabIndex;
  if (focusable) {
    tabIndex = highlighted ? 0 : -1;
  }
  const getRootProps = (otherHandlers = {}) => _extends({}, otherHandlers, {
    onClick: createHandleClick(otherHandlers),
    onPointerOver: handlePointerOverEvents ? createHandlePointerOver(otherHandlers) : undefined,
    ref: handleRef,
    tabIndex
  });
  return {
    getRootProps,
    highlighted,
    rootRef: handleRef,
    selected
  };
}