@atlaskit/breadcrumbs/dist/esm/components/internal/use-overflow-collapse.js

Breadcrumbs are a navigation system used to show a user's location in a site or app.

import _slicedToArray from "@babel/runtime/helpers/slicedToArray";
function _createForOfIteratorHelper(r, e) { var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (!t) { if (Array.isArray(r) || (t = _unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) { t && (r = t); var _n = 0, F = function F() {}; return { s: F, n: function n() { return _n >= r.length ? { done: !0 } : { done: !1, value: r[_n++] }; }, e: function e(r) { throw r; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var o, a = !0, u = !1; return { s: function s() { t = t.call(r); }, n: function n() { var r = t.next(); return a = r.done, r; }, e: function e(r) { u = !0, o = r; }, f: function f() { try { a || null == t.return || t.return(); } finally { if (u) throw o; } } }; }
function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
import { useCallback, useEffect, useLayoutEffect as useRealLayoutEffect, useRef, useState } from 'react';

// The ellipsis trigger is a compact IconButton (24px) plus the trailing separator (24px).
var ELLIPSIS_WIDTH_ESTIMATE = 48;

// Measurements need layout timing in the browser, but should be a no-op for SSR.
var useLayoutEffect = typeof window === 'undefined' ? useEffect : useRealLayoutEffect;
function setsEqual(a, b) {
  if (a.size !== b.size) {
    return false;
  }
  var _iterator = _createForOfIteratorHelper(a),
    _step;
  try {
    for (_iterator.s(); !(_step = _iterator.n()).done;) {
      var v = _step.value;
      if (!b.has(v)) {
        return false;
      }
    }
  } catch (err) {
    _iterator.e(err);
  } finally {
    _iterator.f();
  }
  return true;
}
function getMiddleOutCollapseOrder(itemCount) {
  var lastIndex = itemCount - 1;
  var middleIndex = Math.floor((itemCount - 1) / 2);
  var collapseOrder = [];
  if (middleIndex > 0 && middleIndex < lastIndex) {
    collapseOrder.push(middleIndex);
  }
  for (var distance = 1; distance < itemCount; distance++) {
    var leftIndex = middleIndex - distance;
    var rightIndex = middleIndex + distance;
    if (leftIndex > 0) {
      collapseOrder.push(leftIndex);
    }
    if (rightIndex < lastIndex) {
      collapseOrder.push(rightIndex);
    }
  }
  return collapseOrder;
}

// eslint-disable-next-line @repo/internal/react/require-jsdoc
export default function useOverflowCollapse(itemCount) {
  var itemRefs = useRef([]);
  var containerRef = useRef(null);
  var naturalWidths = useRef([]);
  var naturalWidthsReady = useRef(false);
  var _useState = useState(false),
    _useState2 = _slicedToArray(_useState, 2),
    naturalWidthsReadyState = _useState2[0],
    setNaturalWidthsReadyState = _useState2[1];
  var _useState3 = useState(new Set()),
    _useState4 = _slicedToArray(_useState3, 2),
    collapsedIndices = _useState4[0],
    setCollapsedIndices = _useState4[1];

  // Intentionally runs after each render until refs have committed and natural widths are measured.
  // eslint-disable-next-line react-hooks/exhaustive-deps
  useLayoutEffect(function () {
    if (naturalWidthsReady.current) {
      return;
    }
    var widths = itemRefs.current.map(function (el) {
      var _el$offsetWidth;
      return (_el$offsetWidth = el === null || el === void 0 ? void 0 : el.offsetWidth) !== null && _el$offsetWidth !== void 0 ? _el$offsetWidth : 0;
    });
    if (widths.some(function (w) {
      return w > 0;
    })) {
      naturalWidths.current = widths;
      naturalWidthsReady.current = true;
      setNaturalWidthsReadyState(true);
    }
  });
  var recalculate = useCallback(function () {
    var container = containerRef.current;
    if (!container || !naturalWidthsReady.current) {
      return;
    }
    var availableWidth = container.offsetWidth;
    var widths = naturalWidths.current;
    if (itemCount <= 2) {
      setCollapsedIndices(function (prev) {
        return prev.size === 0 ? prev : new Set();
      });
      return;
    }
    var totalWidth = widths.reduce(function (sum, w) {
      return sum + w;
    }, 0);
    if (totalWidth <= availableWidth) {
      setCollapsedIndices(function (prev) {
        return prev.size === 0 ? prev : new Set();
      });
      return;
    }
    var usedWidth = totalWidth;
    var newCollapsed = new Set();
    var _iterator2 = _createForOfIteratorHelper(getMiddleOutCollapseOrder(itemCount)),
      _step2;
    try {
      for (_iterator2.s(); !(_step2 = _iterator2.n()).done;) {
        var _widths$index;
        var index = _step2.value;
        if (newCollapsed.size === 0) {
          usedWidth += ELLIPSIS_WIDTH_ESTIMATE;
        }
        newCollapsed.add(index);
        usedWidth -= (_widths$index = widths[index]) !== null && _widths$index !== void 0 ? _widths$index : 0;
        if (usedWidth <= availableWidth) {
          break;
        }
      }

      // At the smallest sizes, even first + ellipsis + last may not fit.
      // In that case, also collapse the first item so only ellipsis + last is shown.
      // Note: this branch is only reachable when itemCount > 2 (the early return above
      // handles itemCount <= 2), so collapsing index 0 here always leaves at least one
      // visible item (the last) plus the ellipsis trigger.
    } catch (err) {
      _iterator2.e(err);
    } finally {
      _iterator2.f();
    }
    if (usedWidth > availableWidth) {
      newCollapsed.add(0);
    }
    setCollapsedIndices(function (prev) {
      return setsEqual(prev, newCollapsed) ? prev : newCollapsed;
    });
  }, [itemCount]);
  var registerItem = useCallback(function (index) {
    return function (el) {
      itemRefs.current[index] = el;
    };
  }, []);
  var observerRef = useRef(null);
  var registerContainer = useCallback(function (el) {
    var _observerRef$current;
    // Disconnect any existing observer
    (_observerRef$current = observerRef.current) === null || _observerRef$current === void 0 || _observerRef$current.disconnect();
    containerRef.current = el;
    if (!el) {
      return;
    }
    if (typeof ResizeObserver === 'undefined') {
      return;
    }

    // Set up ResizeObserver immediately when container mounts
    var observer = new ResizeObserver(function () {
      recalculate();
    });
    observer.observe(el);
    observerRef.current = observer;
  }, [recalculate]);
  useEffect(function () {
    if (naturalWidthsReadyState) {
      recalculate();
    }
  }, [naturalWidthsReadyState, recalculate]);

  // Cleanup observer on unmount
  useEffect(function () {
    return function () {
      var _observerRef$current2;
      (_observerRef$current2 = observerRef.current) === null || _observerRef$current2 === void 0 || _observerRef$current2.disconnect();
    };
  }, []);
  useEffect(function () {
    naturalWidthsReady.current = false;
    naturalWidths.current = [];
    setNaturalWidthsReadyState(false);
    setCollapsedIndices(new Set());
  }, [itemCount]);
  return {
    collapsedIndices: collapsedIndices,
    naturalWidthsReady: naturalWidthsReadyState,
    registerItem: registerItem,
    registerContainer: registerContainer
  };
}