# All files / src/tree useTreeMovement.ts

100% Statements 205/205
100% Branches 19/19
100% Functions 5/5
100% Lines 205/205

Press n or j to go to the next uncovered block, b, p or k for the previous block.

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    2061x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    321x
    321x
    321x
    1x
    1x
    1x
    1x
    1x
    1x
    37x
    37x
    37x
    37x
    37x
    37x
    37x
    37x
    321x
    321x
    321x
    321x
    37x
    37x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    73x
    26x
    26x
    26x
    26x
    26x
    26x
    26x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
    1x
     "use client";
    import type {
      FocusEventHandler,
      KeyboardEventHandler,
      MouseEventHandler,
    } from "react";
    import { useRef } from "react";
    import type { KeyboardMovementProviderImplementation } from "../movement/types.js";
    import { useKeyboardMovementProvider } from "../movement/useKeyboardMovementProvider.js";
    import { getNextFocusableIndex } from "../movement/utils.js";
    import type { NonNullMutableRef } from "../types.js";
    import type { TreeItemMetadataLookup } from "./TreeProvider.js";
    import type { TreeData, TreeItemNode } from "./types.js";
    import type { TreeExpansion } from "./useTreeExpansion.js";
    import type { TreeItemChildIds } from "./useTreeItems.js";

    /**
     * This helps catch the edge case where the collapse transition has occurred for
     * a tree item group, but the user uses the `ArrowDown` key before it has
     * finished. So to do this:
     *
     * - find the parent group of the tree item
     * - find the tree item that controls the group (the element before the group)
     * - check if the `aria-expanded` state is `"false"` meaning it is considered
     *   closed
     *
     * @internal
     * @remarks \@since 6.0.0
     */
    const isParentItemCollapsing = (item: HTMLElement): boolean =>
      item
        .closest("[role='group']")
        ?.previousElementSibling?.getAttribute("aria-expanded") === "false";

    /**
     * @remarks \@since 6.0.0
     * @internal
     */
    const getVisibleTreeItems = (
      container: HTMLElement
    ): readonly HTMLElement[] => {
      const items = [
        ...container.querySelectorAll<HTMLElement>('[role="treeitem"]'),
      ];

      return items.filter(
        (item) =>
          // do not include items that have a `hidden` parent group
          item.offsetParent &&
          // do not include items that are about to become hidden
          !isParentItemCollapsing(item)
      );
    };

    /**
     * @remarks \@since 6.0.0
     * @internal
     */
    interface TreeMovementOptions<T extends TreeItemNode> extends TreeExpansion {
      data: TreeData<T>;
      onClick: MouseEventHandler<HTMLUListElement> | undefined;
      onFocus: FocusEventHandler<HTMLUListElement> | undefined;
      onKeyDown: KeyboardEventHandler<HTMLUListElement> | undefined;
      selectedIds: ReadonlySet<string>;
      treeItemChildIds: TreeItemChildIds;
    }

    /**
     * @remarks \@since 6.0.0
     * @internal
     */
    interface TreeMovement
      extends KeyboardMovementProviderImplementation<HTMLUListElement> {
      /**
       * This will be mutated by the `TreeItem` component and used to handle
       * keyboard movement.
       */
      metadataLookup: NonNullMutableRef<TreeItemMetadataLookup>;
    }

    /**
     * @remarks \@since 6.0.0
     * @internal
     */
    export function useTreeMovement<T extends TreeItemNode>(
      options: TreeMovementOptions<T>
    ): TreeMovement {
      const {
        onClick,
        onFocus,
        onKeyDown,
        data,
        expandedIds,
        selectedIds,
        treeItemChildIds,
        toggleTreeItemExpansion,
        expandMultipleTreeItems,
      } = options;

      const metadataLookup = useRef<TreeItemMetadataLookup>({
        expandable: {},
        disabledItems: {},
        elementToItem: {},
        itemToElement: {},
      });
      const movement = useKeyboardMovementProvider({
        onClick,
        onFocus,
        onKeyDown,
        extendKeyDown(movementData) {
          const { event, activeDescendantId, currentFocusIndex, setFocusIndex } =
            movementData;
          const { expandable, disabledItems, elementToItem, itemToElement } =
            metadataLookup.current;
          const itemId = elementToItem[activeDescendantId];
          const item = data[itemId];

          /* c8 ignore start */
          if (!item) {
            return;
          }
          /* c8 ignore end */

          const disabled = disabledItems[itemId];
          const expanded = expandedIds.has(itemId);

          let flagged = false;
          switch (event.key) {
            case "ArrowLeft":
              if (expanded && !disabled) {
                flagged = true;
                toggleTreeItemExpansion(itemId);
              } else if (item.parentId) {
                // do not flag for this case since setFocusIndex already does this
                const parentId = itemToElement[item.parentId];
                const focusables = getVisibleTreeItems(event.currentTarget);
                const index = focusables.findIndex(
                  (element) => element.id === parentId
                );
                setFocusIndex(index, focusables);
              }

              break;
            case "ArrowRight":
              if (expandable[itemId] && !disabled) {
                if (!expanded) {
                  flagged = true;
                  toggleTreeItemExpansion(itemId);
                } else {
                  // do not flag for this case since setFocusIndex already does this
                  const focusables = getVisibleTreeItems(event.currentTarget);
                  const index = getNextFocusableIndex({
                    loopable: false,
                    increment: true,
                    focusables,
                    includeDisabled: true,
                    currentFocusIndex: currentFocusIndex.current,
                  });

                  setFocusIndex(index, focusables);
                }
              }

              break;
            case "*": {
              flagged = true;
              const itemIds = treeItemChildIds.get(item.parentId);
              if (itemIds) {
                const expandableIds = [...itemIds].filter(
                  (itemId) => expandable[itemId]
                );
                if (expandableIds.length) {
                  expandMultipleTreeItems(
                    (prev) => new Set([...prev, ...expandableIds])
                  );
                  currentFocusIndex.current = -1;
                }
              }
              break;
            }
          }

          if (flagged) {
            event.stopPropagation();
            event.preventDefault();
          }
        },
        searchable: true,
        tabIndexBehavior: "virtual",
        getFocusableElements: getVisibleTreeItems,
        getDefaultFocusedIndex(options) {
          const { focusables } = options;
          const { elementToItem } = metadataLookup.current;

          return focusables.findIndex((element) =>
            selectedIds.has(elementToItem[element.id])
          );
        },
      });

      return {
        metadataLookup,
        ...movement,
      };
    }