react-resizable-panels/dist/react-resizable-panels.development.cjs.js

React components for resizable panel groups/layouts

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var React = require('react');

function _interopNamespace(e) {
  if (e && e.__esModule) return e;
  var n = Object.create(null);
  if (e) {
    Object.keys(e).forEach(function (k) {
      if (k !== 'default') {
        var d = Object.getOwnPropertyDescriptor(e, k);
        Object.defineProperty(n, k, d.get ? d : {
          enumerable: true,
          get: function () { return e[k]; }
        });
      }
    });
  }
  n["default"] = e;
  return Object.freeze(n);
}

var React__namespace = /*#__PURE__*/_interopNamespace(React);

const isBrowser = typeof window !== "undefined";

// This module exists to work around Webpack issue https://github.com/webpack/webpack/issues/14814

// eslint-disable-next-line no-restricted-imports

const {
  createElement,
  createContext,
  createRef,
  forwardRef,
  useCallback,
  useContext,
  useEffect,
  useImperativeHandle,
  useLayoutEffect,
  useMemo,
  useRef,
  useState
} = React__namespace;

// `toString()` prevents bundlers from trying to `import { useId } from 'react'`
const useId = React__namespace["useId".toString()];

const PanelGroupContext = createContext(null);
PanelGroupContext.displayName = "PanelGroupContext";

const useIsomorphicLayoutEffect = isBrowser ? useLayoutEffect : () => {};

const wrappedUseId = typeof useId === "function" ? useId : () => null;
let counter = 0;
function useUniqueId(idFromParams = null) {
  const idFromUseId = wrappedUseId();
  const idRef = useRef(idFromParams || idFromUseId || null);
  if (idRef.current === null) {
    idRef.current = "" + counter++;
  }
  return idFromParams !== null && idFromParams !== void 0 ? idFromParams : idRef.current;
}

function PanelWithForwardedRef({
  children,
  className: classNameFromProps = "",
  collapsedSize,
  collapsible,
  defaultSize,
  forwardedRef,
  id: idFromProps,
  maxSize,
  minSize,
  onCollapse,
  onExpand,
  onResize,
  order,
  style: styleFromProps,
  tagName: Type = "div",
  ...rest
}) {
  const context = useContext(PanelGroupContext);
  if (context === null) {
    throw Error(`Panel components must be rendered within a PanelGroup container`);
  }
  const {
    collapsePanel,
    expandPanel,
    getPanelSize,
    getPanelStyle,
    groupId,
    isPanelCollapsed,
    reevaluatePanelConstraints,
    registerPanel,
    resizePanel,
    unregisterPanel
  } = context;
  const panelId = useUniqueId(idFromProps);
  const panelDataRef = useRef({
    callbacks: {
      onCollapse,
      onExpand,
      onResize
    },
    constraints: {
      collapsedSize,
      collapsible,
      defaultSize,
      maxSize,
      minSize
    },
    id: panelId,
    idIsFromProps: idFromProps !== undefined,
    order
  });
  const devWarningsRef = useRef({
    didLogMissingDefaultSizeWarning: false
  });

  // Normally we wouldn't log a warning during render,
  // but effects don't run on the server, so we can't do it there
  {
    if (!devWarningsRef.current.didLogMissingDefaultSizeWarning) {
      if (!isBrowser && defaultSize == null) {
        devWarningsRef.current.didLogMissingDefaultSizeWarning = true;
        console.warn(`WARNING: Panel defaultSize prop recommended to avoid layout shift after server rendering`);
      }
    }
  }
  useIsomorphicLayoutEffect(() => {
    const {
      callbacks,
      constraints
    } = panelDataRef.current;
    const prevConstraints = {
      ...constraints
    };
    panelDataRef.current.id = panelId;
    panelDataRef.current.idIsFromProps = idFromProps !== undefined;
    panelDataRef.current.order = order;
    callbacks.onCollapse = onCollapse;
    callbacks.onExpand = onExpand;
    callbacks.onResize = onResize;
    constraints.collapsedSize = collapsedSize;
    constraints.collapsible = collapsible;
    constraints.defaultSize = defaultSize;
    constraints.maxSize = maxSize;
    constraints.minSize = minSize;

    // If constraints have changed, we should revisit panel sizes.
    // This is uncommon but may happen if people are trying to implement pixel based constraints.
    if (prevConstraints.collapsedSize !== constraints.collapsedSize || prevConstraints.collapsible !== constraints.collapsible || prevConstraints.maxSize !== constraints.maxSize || prevConstraints.minSize !== constraints.minSize) {
      reevaluatePanelConstraints(panelDataRef.current, prevConstraints);
    }
  });
  useIsomorphicLayoutEffect(() => {
    const panelData = panelDataRef.current;
    registerPanel(panelData);
    return () => {
      unregisterPanel(panelData);
    };
  }, [order, panelId, registerPanel, unregisterPanel]);
  useImperativeHandle(forwardedRef, () => ({
    collapse: () => {
      collapsePanel(panelDataRef.current);
    },
    expand: () => {
      expandPanel(panelDataRef.current);
    },
    getId() {
      return panelId;
    },
    getSize() {
      return getPanelSize(panelDataRef.current);
    },
    isCollapsed() {
      return isPanelCollapsed(panelDataRef.current);
    },
    isExpanded() {
      return !isPanelCollapsed(panelDataRef.current);
    },
    resize: size => {
      resizePanel(panelDataRef.current, size);
    }
  }), [collapsePanel, expandPanel, getPanelSize, isPanelCollapsed, panelId, resizePanel]);
  const style = getPanelStyle(panelDataRef.current, defaultSize);
  return createElement(Type, {
    ...rest,
    children,
    className: classNameFromProps,
    style: {
      ...style,
      ...styleFromProps
    },
    // CSS selectors
    "data-panel": "",
    "data-panel-id": panelId,
    "data-panel-group-id": groupId,
    // e2e test attributes
    "data-panel-collapsible": collapsible || undefined ,
    "data-panel-size": parseFloat("" + style.flexGrow).toFixed(1) 
  });
}
const Panel = forwardRef((props, ref) => createElement(PanelWithForwardedRef, {
  ...props,
  forwardedRef: ref
}));
PanelWithForwardedRef.displayName = "Panel";
Panel.displayName = "forwardRef(Panel)";

let currentCursorStyle = null;
let styleElement = null;
function getCursorStyle(state, constraintFlags) {
  if (constraintFlags) {
    const horizontalMin = (constraintFlags & EXCEEDED_HORIZONTAL_MIN) !== 0;
    const horizontalMax = (constraintFlags & EXCEEDED_HORIZONTAL_MAX) !== 0;
    const verticalMin = (constraintFlags & EXCEEDED_VERTICAL_MIN) !== 0;
    const verticalMax = (constraintFlags & EXCEEDED_VERTICAL_MAX) !== 0;
    if (horizontalMin) {
      if (verticalMin) {
        return "se-resize";
      } else if (verticalMax) {
        return "ne-resize";
      } else {
        return "e-resize";
      }
    } else if (horizontalMax) {
      if (verticalMin) {
        return "sw-resize";
      } else if (verticalMax) {
        return "nw-resize";
      } else {
        return "w-resize";
      }
    } else if (verticalMin) {
      return "s-resize";
    } else if (verticalMax) {
      return "n-resize";
    }
  }
  switch (state) {
    case "horizontal":
      return "ew-resize";
    case "intersection":
      return "move";
    case "vertical":
      return "ns-resize";
  }
}
function resetGlobalCursorStyle() {
  if (styleElement !== null) {
    document.head.removeChild(styleElement);
    currentCursorStyle = null;
    styleElement = null;
  }
}
function setGlobalCursorStyle(state, constraintFlags) {
  const style = getCursorStyle(state, constraintFlags);
  if (currentCursorStyle === style) {
    return;
  }
  currentCursorStyle = style;
  if (styleElement === null) {
    styleElement = document.createElement("style");
    document.head.appendChild(styleElement);
  }
  styleElement.innerHTML = `*{cursor: ${style}!important;}`;
}

function isKeyDown(event) {
  return event.type === "keydown";
}
function isMouseEvent(event) {
  return event.type.startsWith("mouse");
}
function isTouchEvent(event) {
  return event.type.startsWith("touch");
}

function getResizeEventCoordinates(event) {
  if (isMouseEvent(event)) {
    return {
      x: event.pageX,
      y: event.pageY
    };
  } else if (isTouchEvent(event)) {
    const touch = event.touches[0];
    if (touch && touch.pageX && touch.pageY) {
      return {
        x: touch.pageX,
        y: touch.pageY
      };
    }
  }
  return {
    x: Infinity,
    y: Infinity
  };
}

function getInputType() {
  if (typeof matchMedia === "function") {
    return matchMedia("(pointer:coarse)").matches ? "coarse" : "fine";
  }
}

const EXCEEDED_HORIZONTAL_MIN = 0b0001;
const EXCEEDED_HORIZONTAL_MAX = 0b0010;
const EXCEEDED_VERTICAL_MIN = 0b0100;
const EXCEEDED_VERTICAL_MAX = 0b1000;
const isCoarsePointer = getInputType() === "coarse";
let intersectingHandles = [];
let isPointerDown = false;
let ownerDocumentCounts = new Map();
let panelConstraintFlags = new Map();
const registeredResizeHandlers = new Set();
function registerResizeHandle(resizeHandleId, element, direction, hitAreaMargins, setResizeHandlerState) {
  var _ownerDocumentCounts$;
  const {
    ownerDocument
  } = element;
  const data = {
    direction,
    element,
    hitAreaMargins,
    setResizeHandlerState
  };
  const count = (_ownerDocumentCounts$ = ownerDocumentCounts.get(ownerDocument)) !== null && _ownerDocumentCounts$ !== void 0 ? _ownerDocumentCounts$ : 0;
  ownerDocumentCounts.set(ownerDocument, count + 1);
  registeredResizeHandlers.add(data);
  updateListeners();
  return function unregisterResizeHandle() {
    var _ownerDocumentCounts$2;
    panelConstraintFlags.delete(resizeHandleId);
    registeredResizeHandlers.delete(data);
    const count = (_ownerDocumentCounts$2 = ownerDocumentCounts.get(ownerDocument)) !== null && _ownerDocumentCounts$2 !== void 0 ? _ownerDocumentCounts$2 : 1;
    ownerDocumentCounts.set(ownerDocument, count - 1);
    updateListeners();
    if (count === 1) {
      ownerDocumentCounts.delete(ownerDocument);
    }
  };
}
function handlePointerDown(event) {
  const {
    x,
    y
  } = getResizeEventCoordinates(event);
  isPointerDown = true;
  recalculateIntersectingHandles({
    x,
    y
  });
  updateListeners();
  if (intersectingHandles.length > 0) {
    updateResizeHandlerStates("down", event);
    event.preventDefault();
  }
}
function handlePointerMove(event) {
  const {
    x,
    y
  } = getResizeEventCoordinates(event);
  if (isPointerDown) {
    intersectingHandles.forEach(data => {
      const {
        setResizeHandlerState
      } = data;
      setResizeHandlerState("move", "drag", event);
    });

    // Update cursor based on return value(s) from active handles
    updateCursor();
  } else {
    recalculateIntersectingHandles({
      x,
      y
    });
    updateResizeHandlerStates("move", event);
    updateCursor();
  }
  if (intersectingHandles.length > 0) {
    event.preventDefault();
  }
}
function handlePointerUp(event) {
  const {
    x,
    y
  } = getResizeEventCoordinates(event);
  panelConstraintFlags.clear();
  isPointerDown = false;
  if (intersectingHandles.length > 0) {
    event.preventDefault();
  }
  recalculateIntersectingHandles({
    x,
    y
  });
  updateResizeHandlerStates("up", event);
  updateCursor();
  updateListeners();
}
function recalculateIntersectingHandles({
  x,
  y
}) {
  intersectingHandles.splice(0);
  registeredResizeHandlers.forEach(data => {
    const {
      element,
      hitAreaMargins
    } = data;
    const {
      bottom,
      left,
      right,
      top
    } = element.getBoundingClientRect();
    const margin = isCoarsePointer ? hitAreaMargins.coarse : hitAreaMargins.fine;
    const intersects = x >= left - margin && x <= right + margin && y >= top - margin && y <= bottom + margin;
    if (intersects) {
      intersectingHandles.push(data);
    }
  });
}
function reportConstraintsViolation(resizeHandleId, flag) {
  panelConstraintFlags.set(resizeHandleId, flag);
}
function updateCursor() {
  let intersectsHorizontal = false;
  let intersectsVertical = false;
  intersectingHandles.forEach(data => {
    const {
      direction
    } = data;
    if (direction === "horizontal") {
      intersectsHorizontal = true;
    } else {
      intersectsVertical = true;
    }
  });
  let constraintFlags = 0;
  panelConstraintFlags.forEach(flag => {
    constraintFlags |= flag;
  });
  if (intersectsHorizontal && intersectsVertical) {
    setGlobalCursorStyle("intersection", constraintFlags);
  } else if (intersectsHorizontal) {
    setGlobalCursorStyle("horizontal", constraintFlags);
  } else if (intersectsVertical) {
    setGlobalCursorStyle("vertical", constraintFlags);
  } else {
    resetGlobalCursorStyle();
  }
}
function updateListeners() {
  ownerDocumentCounts.forEach((_, ownerDocument) => {
    const {
      body
    } = ownerDocument;
    body.removeEventListener("contextmenu", handlePointerUp);
    body.removeEventListener("mousedown", handlePointerDown);
    body.removeEventListener("mouseleave", handlePointerMove);
    body.removeEventListener("mousemove", handlePointerMove);
    body.removeEventListener("touchmove", handlePointerMove);
    body.removeEventListener("touchstart", handlePointerDown);
  });
  window.removeEventListener("mouseup", handlePointerUp);
  window.removeEventListener("touchcancel", handlePointerUp);
  window.removeEventListener("touchend", handlePointerUp);
  if (registerResizeHandle.length > 0) {
    if (isPointerDown) {
      if (intersectingHandles.length > 0) {
        ownerDocumentCounts.forEach((count, ownerDocument) => {
          const {
            body
          } = ownerDocument;
          if (count > 0) {
            body.addEventListener("contextmenu", handlePointerUp);
            body.addEventListener("mouseleave", handlePointerMove);
            body.addEventListener("mousemove", handlePointerMove);
            body.addEventListener("touchmove", handlePointerMove, {
              passive: false
            });
          }
        });
      }
      window.addEventListener("mouseup", handlePointerUp);
      window.addEventListener("touchcancel", handlePointerUp);
      window.addEventListener("touchend", handlePointerUp);
    } else {
      ownerDocumentCounts.forEach((count, ownerDocument) => {
        const {
          body
        } = ownerDocument;
        if (count > 0) {
          body.addEventListener("mousedown", handlePointerDown);
          body.addEventListener("mousemove", handlePointerMove);
          body.addEventListener("touchmove", handlePointerMove, {
            passive: false
          });
          body.addEventListener("touchstart", handlePointerDown);
        }
      });
    }
  }
}
function updateResizeHandlerStates(action, event) {
  registeredResizeHandlers.forEach(data => {
    const {
      setResizeHandlerState
    } = data;
    if (intersectingHandles.includes(data)) {
      if (isPointerDown) {
        setResizeHandlerState(action, "drag", event);
      } else {
        setResizeHandlerState(action, "hover", event);
      }
    } else {
      setResizeHandlerState(action, "inactive", event);
    }
  });
}

function assert(expectedCondition, message = "Assertion failed!") {
  if (!expectedCondition) {
    console.error(message);
    throw Error(message);
  }
}

const PRECISION = 10;

function fuzzyCompareNumbers(actual, expected, fractionDigits = PRECISION) {
  actual = parseFloat(actual.toFixed(fractionDigits));
  expected = parseFloat(expected.toFixed(fractionDigits));
  const delta = actual - expected;
  if (delta === 0) {
    return 0;
  } else {
    return delta > 0 ? 1 : -1;
  }
}

function fuzzyNumbersEqual(actual, expected, fractionDigits) {
  return fuzzyCompareNumbers(actual, expected, fractionDigits) === 0;
}

// Panel size must be in percentages; pixel values should be pre-converted
function resizePanel({
  panelConstraints: panelConstraintsArray,
  panelIndex,
  size
}) {
  const panelConstraints = panelConstraintsArray[panelIndex];
  assert(panelConstraints != null);
  let {
    collapsedSize = 0,
    collapsible,
    maxSize = 100,
    minSize = 0
  } = panelConstraints;
  if (fuzzyCompareNumbers(size, minSize) < 0) {
    if (collapsible) {
      // Collapsible panels should snap closed or open only once they cross the halfway point between collapsed and min size.
      const halfwayPoint = (collapsedSize + minSize) / 2;
      if (fuzzyCompareNumbers(size, halfwayPoint) < 0) {
        size = collapsedSize;
      } else {
        size = minSize;
      }
    } else {
      size = minSize;
    }
  }
  size = Math.min(maxSize, size);
  size = parseFloat(size.toFixed(PRECISION));
  return size;
}

// All units must be in percentages; pixel values should be pre-converted
function adjustLayoutByDelta({
  delta,
  layout: prevLayout,
  panelConstraints: panelConstraintsArray,
  pivotIndices,
  trigger
}) {
  if (fuzzyNumbersEqual(delta, 0)) {
    return prevLayout;
  }
  const nextLayout = [...prevLayout];
  const [firstPivotIndex, secondPivotIndex] = pivotIndices;
  assert(firstPivotIndex != null);
  assert(secondPivotIndex != null);
  let deltaApplied = 0;

  //const DEBUG = [];
  //DEBUG.push(`adjustLayoutByDelta() ${prevLayout.join(", ")}`);
  //DEBUG.push(`  delta: ${delta}`);
  //DEBUG.push(`  pivotIndices: ${pivotIndices.join(", ")}`);
  //DEBUG.push(`  trigger: ${trigger}`);
  //DEBUG.push("");

  // A resizing panel affects the panels before or after it.
  //
  // A negative delta means the panel(s) immediately after the resize handle should grow/expand by decreasing its offset.
  // Other panels may also need to shrink/contract (and shift) to make room, depending on the min weights.
  //
  // A positive delta means the panel(s) immediately before the resize handle should "expand".
  // This is accomplished by shrinking/contracting (and shifting) one or more of the panels after the resize handle.

  {
    // If this is a resize triggered by a keyboard event, our logic for expanding/collapsing is different.
    // We no longer check the halfway threshold because this may prevent the panel from expanding at all.
    if (trigger === "keyboard") {
      {
        // Check if we should expand a collapsed panel
        const index = delta < 0 ? secondPivotIndex : firstPivotIndex;
        const panelConstraints = panelConstraintsArray[index];
        assert(panelConstraints);

        //DEBUG.push(`edge case check 1: ${index}`);
        //DEBUG.push(`  -> collapsible? ${constraints.collapsible}`);
        if (panelConstraints.collapsible) {
          const prevSize = prevLayout[index];
          assert(prevSize != null);
          const panelConstraints = panelConstraintsArray[index];
          assert(panelConstraints);
          const {
            collapsedSize = 0,
            minSize = 0
          } = panelConstraints;
          if (fuzzyNumbersEqual(prevSize, collapsedSize)) {
            const localDelta = minSize - prevSize;
            //DEBUG.push(`  -> expand delta: ${localDelta}`);

            if (fuzzyCompareNumbers(localDelta, Math.abs(delta)) > 0) {
              delta = delta < 0 ? 0 - localDelta : localDelta;
              //DEBUG.push(`  -> delta: ${delta}`);
            }
          }
        }
      }

      {
        // Check if we should collapse a panel at its minimum size
        const index = delta < 0 ? firstPivotIndex : secondPivotIndex;
        const panelConstraints = panelConstraintsArray[index];
        assert(panelConstraints);
        const {
          collapsible
        } = panelConstraints;

        //DEBUG.push(`edge case check 2: ${index}`);
        //DEBUG.push(`  -> collapsible? ${collapsible}`);
        if (collapsible) {
          const prevSize = prevLayout[index];
          assert(prevSize != null);
          const panelConstraints = panelConstraintsArray[index];
          assert(panelConstraints);
          const {
            collapsedSize = 0,
            minSize = 0
          } = panelConstraints;
          if (fuzzyNumbersEqual(prevSize, minSize)) {
            const localDelta = prevSize - collapsedSize;
            //DEBUG.push(`  -> expand delta: ${localDelta}`);

            if (fuzzyCompareNumbers(localDelta, Math.abs(delta)) > 0) {
              delta = delta < 0 ? 0 - localDelta : localDelta;
              //DEBUG.push(`  -> delta: ${delta}`);
            }
          }
        }
      }
    }
    //DEBUG.push("");
  }

  {
    // Pre-calculate max available delta in the opposite direction of our pivot.
    // This will be the maximum amount we're allowed to expand/contract the panels in the primary direction.
    // If this amount is less than the requested delta, adjust the requested delta.
    // If this amount is greater than the requested delta, that's useful information too–
    // as an expanding panel might change from collapsed to min size.

    const increment = delta < 0 ? 1 : -1;
    let index = delta < 0 ? secondPivotIndex : firstPivotIndex;
    let maxAvailableDelta = 0;

    //DEBUG.push("pre calc...");
    while (true) {
      const prevSize = prevLayout[index];
      assert(prevSize != null);
      const maxSafeSize = resizePanel({
        panelConstraints: panelConstraintsArray,
        panelIndex: index,
        size: 100
      });
      const delta = maxSafeSize - prevSize;
      //DEBUG.push(`  ${index}: ${prevSize} -> ${maxSafeSize}`);

      maxAvailableDelta += delta;
      index += increment;
      if (index < 0 || index >= panelConstraintsArray.length) {
        break;
      }
    }

    //DEBUG.push(`  -> max available delta: ${maxAvailableDelta}`);
    const minAbsDelta = Math.min(Math.abs(delta), Math.abs(maxAvailableDelta));
    delta = delta < 0 ? 0 - minAbsDelta : minAbsDelta;
    //DEBUG.push(`  -> adjusted delta: ${delta}`);
    //DEBUG.push("");
  }

  {
    // Delta added to a panel needs to be subtracted from other panels (within the constraints that those panels allow).

    const pivotIndex = delta < 0 ? firstPivotIndex : secondPivotIndex;
    let index = pivotIndex;
    while (index >= 0 && index < panelConstraintsArray.length) {
      const deltaRemaining = Math.abs(delta) - Math.abs(deltaApplied);
      const prevSize = prevLayout[index];
      assert(prevSize != null);
      const unsafeSize = prevSize - deltaRemaining;
      const safeSize = resizePanel({
        panelConstraints: panelConstraintsArray,
        panelIndex: index,
        size: unsafeSize
      });
      if (!fuzzyNumbersEqual(prevSize, safeSize)) {
        deltaApplied += prevSize - safeSize;
        nextLayout[index] = safeSize;
        if (deltaApplied.toPrecision(3).localeCompare(Math.abs(delta).toPrecision(3), undefined, {
          numeric: true
        }) >= 0) {
          break;
        }
      }
      if (delta < 0) {
        index--;
      } else {
        index++;
      }
    }
  }
  //DEBUG.push(`after 1: ${nextLayout.join(", ")}`);
  //DEBUG.push(`  deltaApplied: ${deltaApplied}`);
  //DEBUG.push("");

  // If we were unable to resize any of the panels panels, return the previous state.
  // This will essentially bailout and ignore e.g. drags past a panel's boundaries
  if (fuzzyNumbersEqual(deltaApplied, 0)) {
    //console.log(DEBUG.join("\n"));
    return prevLayout;
  }
  {
    // Now distribute the applied delta to the panels in the other direction
    const pivotIndex = delta < 0 ? secondPivotIndex : firstPivotIndex;
    const prevSize = prevLayout[pivotIndex];
    assert(prevSize != null);
    const unsafeSize = prevSize + deltaApplied;
    const safeSize = resizePanel({
      panelConstraints: panelConstraintsArray,
      panelIndex: pivotIndex,
      size: unsafeSize
    });

    // Adjust the pivot panel before, but only by the amount that surrounding panels were able to shrink/contract.
    nextLayout[pivotIndex] = safeSize;

    // Edge case where expanding or contracting one panel caused another one to change collapsed state
    if (!fuzzyNumbersEqual(safeSize, unsafeSize)) {
      let deltaRemaining = unsafeSize - safeSize;
      const pivotIndex = delta < 0 ? secondPivotIndex : firstPivotIndex;
      let index = pivotIndex;
      while (index >= 0 && index < panelConstraintsArray.length) {
        const prevSize = nextLayout[index];
        assert(prevSize != null);
        const unsafeSize = prevSize + deltaRemaining;
        const safeSize = resizePanel({
          panelConstraints: panelConstraintsArray,
          panelIndex: index,
          size: unsafeSize
        });
        if (!fuzzyNumbersEqual(prevSize, safeSize)) {
          deltaRemaining -= safeSize - prevSize;
          nextLayout[index] = safeSize;
        }
        if (fuzzyNumbersEqual(deltaRemaining, 0)) {
          break;
        }
        if (delta > 0) {
          index--;
        } else {
          index++;
        }
      }
    }
  }
  //DEBUG.push(`after 2: ${nextLayout.join(", ")}`);
  //DEBUG.push(`  deltaApplied: ${deltaApplied}`);
  //DEBUG.push("");

  const totalSize = nextLayout.reduce((total, size) => size + total, 0);
  //DEBUG.push(`total size: ${totalSize}`);
  //console.log(DEBUG.join("\n"));

  if (!fuzzyNumbersEqual(totalSize, 100)) {
    return prevLayout;
  }
  return nextLayout;
}

function calculateAriaValues({
  layout,
  panelsArray,
  pivotIndices
}) {
  let currentMinSize = 0;
  let currentMaxSize = 100;
  let totalMinSize = 0;
  let totalMaxSize = 0;
  const firstIndex = pivotIndices[0];
  assert(firstIndex != null);

  // A panel's effective min/max sizes also need to account for other panel's sizes.
  panelsArray.forEach((panelData, index) => {
    const {
      constraints
    } = panelData;
    const {
      maxSize = 100,
      minSize = 0
    } = constraints;
    if (index === firstIndex) {
      currentMinSize = minSize;
      currentMaxSize = maxSize;
    } else {
      totalMinSize += minSize;
      totalMaxSize += maxSize;
    }
  });
  const valueMax = Math.min(currentMaxSize, 100 - totalMinSize);
  const valueMin = Math.max(currentMinSize, 100 - totalMaxSize);
  const valueNow = layout[firstIndex];
  return {
    valueMax,
    valueMin,
    valueNow
  };
}

function getResizeHandleElementsForGroup(groupId, scope = document) {
  return Array.from(scope.querySelectorAll(`[data-panel-resize-handle-id][data-panel-group-id="${groupId}"]`));
}

function getResizeHandleElementIndex(groupId, id, scope = document) {
  const handles = getResizeHandleElementsForGroup(groupId, scope);
  const index = handles.findIndex(handle => handle.getAttribute("data-panel-resize-handle-id") === id);
  return index !== null && index !== void 0 ? index : null;
}

function determinePivotIndices(groupId, dragHandleId, panelGroupElement) {
  const index = getResizeHandleElementIndex(groupId, dragHandleId, panelGroupElement);
  return index != null ? [index, index + 1] : [-1, -1];
}

function getPanelGroupElement(id, rootElement = document) {
  var _dataset;
  //If the root element is the PanelGroup
  if (rootElement instanceof HTMLElement && (rootElement === null || rootElement === void 0 ? void 0 : (_dataset = rootElement.dataset) === null || _dataset === void 0 ? void 0 : _dataset.panelGroupId) == id) {
    return rootElement;
  }

  //Else query children
  const element = rootElement.querySelector(`[data-panel-group][data-panel-group-id="${id}"]`);
  if (element) {
    return element;
  }
  return null;
}

function getResizeHandleElement(id, scope = document) {
  const element = scope.querySelector(`[data-panel-resize-handle-id="${id}"]`);
  if (element) {
    return element;
  }
  return null;
}

function getResizeHandlePanelIds(groupId, handleId, panelsArray, scope = document) {
  var _panelsArray$index$id, _panelsArray$index, _panelsArray$id, _panelsArray;
  const handle = getResizeHandleElement(handleId, scope);
  const handles = getResizeHandleElementsForGroup(groupId, scope);
  const index = handle ? handles.indexOf(handle) : -1;
  const idBefore = (_panelsArray$index$id = (_panelsArray$index = panelsArray[index]) === null || _panelsArray$index === void 0 ? void 0 : _panelsArray$index.id) !== null && _panelsArray$index$id !== void 0 ? _panelsArray$index$id : null;
  const idAfter = (_panelsArray$id = (_panelsArray = panelsArray[index + 1]) === null || _panelsArray === void 0 ? void 0 : _panelsArray.id) !== null && _panelsArray$id !== void 0 ? _panelsArray$id : null;
  return [idBefore, idAfter];
}

// https://www.w3.org/WAI/ARIA/apg/patterns/windowsplitter/

function useWindowSplitterPanelGroupBehavior({
  committedValuesRef,
  eagerValuesRef,
  groupId,
  layout,
  panelDataArray,
  panelGroupElement,
  setLayout
}) {
  const devWarningsRef = useRef({
    didWarnAboutMissingResizeHandle: false
  });
  useIsomorphicLayoutEffect(() => {
    if (!panelGroupElement) {
      return;
    }
    const resizeHandleElements = getResizeHandleElementsForGroup(groupId, panelGroupElement);
    for (let index = 0; index < panelDataArray.length - 1; index++) {
      const {
        valueMax,
        valueMin,
        valueNow
      } = calculateAriaValues({
        layout,
        panelsArray: panelDataArray,
        pivotIndices: [index, index + 1]
      });
      const resizeHandleElement = resizeHandleElements[index];
      if (resizeHandleElement == null) {
        {
          const {
            didWarnAboutMissingResizeHandle
          } = devWarningsRef.current;
          if (!didWarnAboutMissingResizeHandle) {
            devWarningsRef.current.didWarnAboutMissingResizeHandle = true;
            console.warn(`WARNING: Missing resize handle for PanelGroup "${groupId}"`);
          }
        }
      } else {
        const panelData = panelDataArray[index];
        assert(panelData);
        resizeHandleElement.setAttribute("aria-controls", panelData.id);
        resizeHandleElement.setAttribute("aria-valuemax", "" + Math.round(valueMax));
        resizeHandleElement.setAttribute("aria-valuemin", "" + Math.round(valueMin));
        resizeHandleElement.setAttribute("aria-valuenow", valueNow != null ? "" + Math.round(valueNow) : "");
      }
    }
    return () => {
      resizeHandleElements.forEach((resizeHandleElement, index) => {
        resizeHandleElement.removeAttribute("aria-controls");
        resizeHandleElement.removeAttribute("aria-valuemax");
        resizeHandleElement.removeAttribute("aria-valuemin");
        resizeHandleElement.removeAttribute("aria-valuenow");
      });
    };
  }, [groupId, layout, panelDataArray, panelGroupElement]);
  useEffect(() => {
    if (!panelGroupElement) {
      return;
    }
    const eagerValues = eagerValuesRef.current;
    assert(eagerValues);
    const {
      panelDataArray
    } = eagerValues;
    const groupElement = getPanelGroupElement(groupId, panelGroupElement);
    assert(groupElement != null, `No group found for id "${groupId}"`);
    const handles = getResizeHandleElementsForGroup(groupId, panelGroupElement);
    assert(handles);
    const cleanupFunctions = handles.map(handle => {
      const handleId = handle.getAttribute("data-panel-resize-handle-id");
      assert(handleId);
      const [idBefore, idAfter] = getResizeHandlePanelIds(groupId, handleId, panelDataArray, panelGroupElement);
      if (idBefore == null || idAfter == null) {
        return () => {};
      }
      const onKeyDown = event => {
        if (event.defaultPrevented) {
          return;
        }
        switch (event.key) {
          case "Enter":
            {
              event.preventDefault();
              const index = panelDataArray.findIndex(panelData => panelData.id === idBefore);
              if (index >= 0) {
                const panelData = panelDataArray[index];
                assert(panelData);
                const size = layout[index];
                const {
                  collapsedSize = 0,
                  collapsible,
                  minSize = 0
                } = panelData.constraints;
                if (size != null && collapsible) {
                  const nextLayout = adjustLayoutByDelta({
                    delta: fuzzyNumbersEqual(size, collapsedSize) ? minSize - collapsedSize : collapsedSize - size,
                    layout,
                    panelConstraints: panelDataArray.map(panelData => panelData.constraints),
                    pivotIndices: determinePivotIndices(groupId, handleId, panelGroupElement),
                    trigger: "keyboard"
                  });
                  if (layout !== nextLayout) {
                    setLayout(nextLayout);
                  }
                }
              }
              break;
            }
        }
      };
      handle.addEventListener("keydown", onKeyDown);
      return () => {
        handle.removeEventListener("keydown", onKeyDown);
      };
    });
    return () => {
      cleanupFunctions.forEach(cleanupFunction => cleanupFunction());
    };
  }, [panelGroupElement, committedValuesRef, eagerValuesRef, groupId, layout, panelDataArray, setLayout]);
}

function areEqual(arrayA, arrayB) {
  if (arrayA.length !== arrayB.length) {
    return false;
  }
  for (let index = 0; index < arrayA.length; index++) {
    if (arrayA[index] !== arrayB[index]) {
      return false;
    }
  }
  return true;
}

function getResizeEventCursorPosition(direction, event) {
  const isHorizontal = direction === "horizontal";
  const {
    x,
    y
  } = getResizeEventCoordinates(event);
  return isHorizontal ? x : y;
}

function calculateDragOffsetPercentage(event, dragHandleId, direction, initialDragState, panelGroupElement) {
  const isHorizontal = direction === "horizontal";
  const handleElement = getResizeHandleElement(dragHandleId, panelGroupElement);
  assert(handleElement);
  const groupId = handleElement.getAttribute("data-panel-group-id");
  assert(groupId);
  let {
    initialCursorPosition
  } = initialDragState;
  const cursorPosition = getResizeEventCursorPosition(direction, event);
  const groupElement = getPanelGroupElement(groupId, panelGroupElement);
  assert(groupElement);
  const groupRect = groupElement.getBoundingClientRect();
  const groupSizeInPixels = isHorizontal ? groupRect.width : groupRect.height;
  const offsetPixels = cursorPosition - initialCursorPosition;
  const offsetPercentage = offsetPixels / groupSizeInPixels * 100;
  return offsetPercentage;
}

// https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/movementX
function calculateDeltaPercentage(event, dragHandleId, direction, initialDragState, keyboardResizeBy, panelGroupElement) {
  if (isKeyDown(event)) {
    const isHorizontal = direction === "horizontal";
    let delta = 0;
    if (event.shiftKey) {
      delta = 100;
    } else if (keyboardResizeBy != null) {
      delta = keyboardResizeBy;
    } else {
      delta = 10;
    }
    let movement = 0;
    switch (event.key) {
      case "ArrowDown":
        movement = isHorizontal ? 0 : delta;
        break;
      case "ArrowLeft":
        movement = isHorizontal ? -delta : 0;
        break;
      case "ArrowRight":
        movement = isHorizontal ? delta : 0;
        break;
      case "ArrowUp":
        movement = isHorizontal ? 0 : -delta;
        break;
      case "End":
        movement = 100;
        break;
      case "Home":
        movement = -100;
        break;
    }
    return movement;
  } else {
    if (initialDragState == null) {
      return 0;
    }
    return calculateDragOffsetPercentage(event, dragHandleId, direction, initialDragState, panelGroupElement);
  }
}

function calculateUnsafeDefaultLayout({
  panelDataArray
}) {
  const layout = Array(panelDataArray.length);
  const panelConstraintsArray = panelDataArray.map(panelData => panelData.constraints);
  let numPanelsWithSizes = 0;
  let remainingSize = 100;

  // Distribute default sizes first
  for (let index = 0; index < panelDataArray.length; index++) {
    const panelConstraints = panelConstraintsArray[index];
    assert(panelConstraints);
    const {
      defaultSize
    } = panelConstraints;
    if (defaultSize != null) {
      numPanelsWithSizes++;
      layout[index] = defaultSize;
      remainingSize -= defaultSize;
    }
  }

  // Remaining size should be distributed evenly between panels without default sizes
  for (let index = 0; index < panelDataArray.length; index++) {
    const panelConstraints = panelConstraintsArray[index];
    assert(panelConstraints);
    const {
      defaultSize
    } = panelConstraints;
    if (defaultSize != null) {
      continue;
    }
    const numRemainingPanels = panelDataArray.length - numPanelsWithSizes;
    const size = remainingSize / numRemainingPanels;
    numPanelsWithSizes++;
    layout[index] = size;
    remainingSize -= size;
  }
  return layout;
}

// Layout should be pre-converted into percentages
function callPanelCallbacks(panelsArray, layout, panelIdToLastNotifiedSizeMap) {
  layout.forEach((size, index) => {
    const panelData = panelsArray[index];
    assert(panelData);
    const {
      callbacks,
      constraints,
      id: panelId
    } = panelData;
    const {
      collapsedSize = 0,
      collapsible
    } = constraints;
    const lastNotifiedSize = panelIdToLastNotifiedSizeMap[panelId];
    if (lastNotifiedSize == null || size !== lastNotifiedSize) {
      panelIdToLastNotifiedSizeMap[panelId] = size;
      const {
        onCollapse,
        onExpand,
        onResize
      } = callbacks;
      if (onResize) {
        onResize(size, lastNotifiedSize);
      }
      if (collapsible && (onCollapse || onExpand)) {
        if (onExpand && (lastNotifiedSize == null || lastNotifiedSize === collapsedSize) && size !== collapsedSize) {
          onExpand();
        }
        if (onCollapse && (lastNotifiedSize == null || lastNotifiedSize !== collapsedSize) && size === collapsedSize) {
          onCollapse();
        }
      }
    }
  });
}

function compareLayouts(a, b) {
  if (a.length !== b.length) {
    return false;
  } else {
    for (let index = 0; index < a.length; index++) {
      if (a[index] != b[index]) {
        return false;
      }
    }
  }
  return true;
}

// This method returns a number between 1 and 100 representing

// the % of the group's overall space this panel should occupy.
function computePanelFlexBoxStyle({
  defaultSize,
  dragState,
  layout,
  panelData,
  panelIndex,
  precision = 3
}) {
  const size = layout[panelIndex];
  let flexGrow;
  if (size == null) {
    // Initial render (before panels have registered themselves)
    // In order to support server rendering, fall back to default size if provided
    flexGrow = defaultSize !== null && defaultSize !== void 0 ? defaultSize : "1";
  } else if (panelData.length === 1) {
    // Special case: Single panel group should always fill full width/height
    flexGrow = "1";
  } else {
    flexGrow = size.toPrecision(precision);
  }
  return {
    flexBasis: 0,
    flexGrow,
    flexShrink: 1,
    // Without this, Panel sizes may be unintentionally overridden by their content
    overflow: "hidden",
    // Disable pointer events inside of a panel during resize
    // This avoid edge cases like nested iframes
    pointerEvents: dragState !== null ? "none" : undefined
  };
}

function debounce(callback, durationMs = 10) {
  let timeoutId = null;
  let callable = (...args) => {
    if (timeoutId !== null) {
      clearTimeout(timeoutId);
    }
    timeoutId = setTimeout(() => {
      callback(...args);
    }, durationMs);
  };
  return callable;
}

// PanelGroup might be rendering in a server-side environment where localStorage is not available
// or on a browser with cookies/storage disabled.
// In either case, this function avoids accessing localStorage until needed,
// and avoids throwing user-visible errors.
function initializeDefaultStorage(storageObject) {
  try {
    if (typeof localStorage !== "undefined") {
      // Bypass this check for future calls
      storageObject.getItem = name => {
        return localStorage.getItem(name);
      };
      storageObject.setItem = (name, value) => {
        localStorage.setItem(name, value);
      };
    } else {
      throw new Error("localStorage not supported in this environment");
    }
  } catch (error) {
    console.error(error);
    storageObject.getItem = () => null;
    storageObject.setItem = () => {};
  }
}

function getPanelGroupKey(autoSaveId) {
  return `react-resizable-panels:${autoSaveId}`;
}

// Note that Panel ids might be user-provided (stable) or useId generated (non-deterministic)
// so they should not be used as part of the serialization key.
// Using the min/max size attributes should work well enough as a backup.
// Pre-sorting by minSize allows remembering layouts even if panels are re-ordered/dragged.
function getPanelKey(panels) {
  return panels.map(panel => {
    const {
      constraints,
      id,
      idIsFromProps,
      order
    } = panel;
    if (idIsFromProps) {
      return id;
    } else {
      return order ? `${order}:${JSON.stringify(constraints)}` : JSON.stringify(constraints);
    }
  }).sort((a, b) => a.localeCompare(b)).join(",");
}
function loadSerializedPanelGroupState(autoSaveId, storage) {
  try {
    const panelGroupKey = getPanelGroupKey(autoSaveId);
    const serialized = storage.getItem(panelGroupKey);
    if (serialized) {
      const parsed = JSON.parse(serialized);
      if (typeof parsed === "object" && parsed != null) {
        return parsed;
      }
    }
  } catch (error) {}
  return null;
}
function loadPanelGroupState(autoSaveId, panels, storage) {
  var _loadSerializedPanelG, _state$panelKey;
  const state = (_loadSerializedPanelG = loadSerializedPanelGroupState(autoSaveId, storage)) !== null && _loadSerializedPanelG !== void 0 ? _loadSerializedPanelG : {};
  const panelKey = getPanelKey(panels);
  return (_state$panelKey = state[panelKey]) !== null && _state$panelKey !== void 0 ? _state$panelKey : null;
}
function savePanelGroupState(autoSaveId, panels, panelSizesBeforeCollapse, sizes, storage) {
  var _loadSerializedPanelG2;
  const panelGroupKey = getPanelGroupKey(autoSaveId);
  const panelKey = getPanelKey(panels);
  const state = (_loadSerializedPanelG2 = loadSerializedPanelGroupState(autoSaveId, storage)) !== null && _loadSerializedPanelG2 !== void 0 ? _loadSerializedPanelG2 : {};
  state[panelKey] = {
    expandToSizes: Object.fromEntries(panelSizesBeforeCollapse.entries()),
    layout: sizes
  };
  try {
    storage.setItem(panelGroupKey, JSON.stringify(state));
  } catch (error) {
    console.error(error);
  }
}

function validatePanelConstraints({
  panelConstraints: panelConstraintsArray,
  panelId,
  panelIndex
}) {
  {
    const warnings = [];
    const panelConstraints = panelConstraintsArray[panelIndex];
    assert(panelConstraints);
    const {
      collapsedSize = 0,
      collapsible = false,
      defaultSize,
      maxSize = 100,
      minSize = 0
    } = panelConstraints;
    if (minSize > maxSize) {
      warnings.push(`min size (${minSize}%) should not be greater than max size (${maxSize}%)`);
    }
    if (defaultSize != null) {
      if (defaultSize < 0) {
        warnings.push("default size should not be less than 0");
      } else if (defaultSize < minSize && (!collapsible || defaultSize !== collapsedSize)) {
        warnings.push("default size should not be less than min size");
      }
      if (defaultSize > 100) {
        warnings.push("default size should not be greater than 100");
      } else if (defaultSize > maxSize) {
        warnings.push("default size should not be greater than max size");
      }
    }
    if (collapsedSize > minSize) {
      warnings.push("collapsed size should not be greater than min size");
    }
    if (warnings.length > 0) {
      const name = panelId != null ? `Panel "${panelId}"` : "Panel";
      console.warn(`${name} has an invalid configuration:\n\n${warnings.join("\n")}`);
      return false;
    }
  }
  return true;
}

// All units must be in percentages; pixel values should be pre-converted
function validatePanelGroupLayout({
  layout: prevLayout,
  panelConstraints
}) {
  const nextLayout = [...prevLayout];
  const nextLayoutTotalSize = nextLayout.reduce((accumulated, current) => accumulated + current, 0);

  // Validate layout expectations
  if (nextLayout.length !== panelConstraints.length) {
    throw Error(`Invalid ${panelConstraints.length} panel layout: ${nextLayout.map(size => `${size}%`).join(", ")}`);
  } else if (!fuzzyNumbersEqual(nextLayoutTotalSize, 100)) {
    // This is not ideal so we should warn about it, but it may be recoverable in some cases
    // (especially if the amount is small)
    {
      console.warn(`WARNING: Invalid layout total size: ${nextLayout.map(size => `${size}%`).join(", ")}. Layout normalization will be applied.`);
    }
    for (let index = 0; index < panelConstraints.length; index++) {
      const unsafeSize = nextLayout[index];
      assert(unsafeSize != null);
      const safeSize = 100 / nextLayoutTotalSize * unsafeSize;
      nextLayout[index] = safeSize;
    }
  }
  let remainingSize = 0;

  // First pass: Validate the proposed layout given each panel's constraints
  for (let index = 0; index < panelConstraints.length; index++) {
    const unsafeSize = nextLayout[index];
    assert(unsafeSize != null);
    const safeSize = resizePanel({
      panelConstraints,
      panelIndex: index,
      size: unsafeSize
    });
    if (unsafeSize != safeSize) {
      remainingSize += unsafeSize - safeSize;
      nextLayout[index] = safeSize;
    }
  }

  // If there is additional, left over space, assign it to any panel(s) that permits it
  // (It's not worth taking multiple additional passes to evenly distribute)
  if (!fuzzyNumbersEqual(remainingSize, 0)) {
    for (let index = 0; index < panelConstraints.length; index++) {
      const prevSize = nextLayout[index];
      assert(prevSize != null);
      const unsafeSize = prevSize + remainingSize;
      const safeSize = resizePanel({
        panelConstraints,
        panelIndex: index,
        size: unsafeSize
      });
      if (prevSize !== safeSize) {
        remainingSize -= safeSize - prevSize;
        nextLayout[index] = safeSize;

        // Once we've used up the remainder, bail
        if (fuzzyNumbersEqual(remainingSize, 0)) {
          break;
        }
      }
    }
  }
  return nextLayout;
}

const LOCAL_STORAGE_DEBOUNCE_INTERVAL = 100;
const defaultStorage = {
  getItem: name => {
    initializeDefaultStorage(defaultStorage);
    return defaultStorage.getItem(name);
  },
  setItem: (name, value) => {
    initializeDefaultStorage(defaultStorage);
    defaultStorage.setItem(name, value);
  }
};
const debounceMap = {};
function PanelGroupWithForwardedRef({
  autoSaveId = null,
  children,
  className: classNameFromProps = "",
  direction,
  forwardedRef,
  id: idFromProps = null,
  onLayout = null,
  keyboardResizeBy = null,
  storage = defaultStorage,
  style: styleFromProps,
  tagName: Type = "div",
  ...rest
}) {
  const groupId = useUniqueId(idFromProps);
  const panelGroupElementRef = useRef(null);
  const [dragState, setDragState] = useState(null);
  const [layout, setLayout] = useState([]);
  const panelIdToLastNotifiedSizeMapRef = useRef({});
  const panelSizeBeforeCollapseRef = useRef(new Map());
  const prevDeltaRef = useRef(0);
  const committedValuesRef = useRef({
    autoSaveId,
    direction,
    dragState,
    id: groupId,
    keyboardResizeBy,
    onLayout,
    storage
  });
  const eagerValuesRef = useRef({
    layout,
    panelDataArray: [],
    panelDataArrayChanged: false
  });
  const devWarningsRef = useRef({
    didLogIdAndOrderWarning: false,
    didLogPanelConstraintsWarning: false,
    prevPanelIds: []
  });
  useImperativeHandle(forwardedRef, () => ({
    getId: () => committedValuesRef.current.id,
    getLayout: () => {
      const {
        layout
      } = eagerValuesRef.current;
      return layout;
    },
    setLayout: unsafeLayout => {
      const {
        onLayout
      } = committedValuesRef.current;
      const {
        layout: prevLayout,
        panelDataArray
      } = eagerValuesRef.current;
      const safeLayout = validatePanelGroupLayout({
        layout: unsafeLayout,
        panelConstraints: panelDataArray.map(panelData => panelData.constraints)
      });
      if (!areEqual(prevLayout, safeLayout)) {
        setLayout(safeLayout);
        eagerValuesRef.current.layout = safeLayout;
        if (onLayout) {
          onLayout(safeLayout);
        }
        callPanelCallbacks(panelDataArray, safeLayout, panelIdToLastNotifiedSizeMapRef.current);
      }
    }
  }), []);
  useIsomorphicLayoutEffect(() => {
    committedValuesRef.current.autoSaveId = autoSaveId;
    committedValuesRef.current.direction = direction;
    committedValuesRef.current.dragState = dragState;
    committedValuesRef.current.id = groupId;
    committedValuesRef.current.onLayout = onLayout;
    committedValuesRef.current.storage = storage;
  });
  useWindowSplitterPanelGroupBehavior({
    committedValuesRef,
    eagerValuesRef,
    groupId,
    layout,
    panelDataArray: eagerValuesRef.current.panelDataArray,
    setLayout,
    panelGroupElement: panelGroupElementRef.current
  });
  useEffect(() => {
    const {
      panelDataArray
    } = eagerValuesRef.current;

    // If this panel has been configured to persist sizing information, save sizes to local storage.
    if (autoSaveId) {
      if (layout.length === 0 || layout.length !== panelDataArray.length) {
        return;
      }
      let debouncedSave = debounceMap[autoSaveId];

      // Limit the frequency of localStorage updates.
      if (debouncedSave == null) {
        debouncedSave = debounce(savePanelGroupState, LOCAL_STORAGE_DEBOUNCE_INTERVAL);
        debounceMap[autoSaveId] = debouncedSave;
      }

      // Clone mutable data before passing to the debounced function,
      // else we run the risk of saving an incorrect combination of mutable and immutable values to state.
      const clonedPanelDataArray = [...panelDataArray];
      const clonedPanelSizesBeforeCollapse = new Map(panelSizeBeforeCollapseRef.current);
      debouncedSave(autoSaveId, clonedPanelDataArray, clonedPanelSizesBeforeCollapse, layout, storage);
    }
  }, [autoSaveId, layout, storage]);

  // DEV warnings
  useEffect(() => {
    {
      const {
        panelDataArray