40 lines
1.3 KiB
Plaintext
40 lines
1.3 KiB
Plaintext
/*
|
|
* Copyright 2020 Adobe. All rights reserved.
|
|
* This file is licensed to you under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License. You may obtain a copy
|
|
* of the License at http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software distributed under
|
|
* the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
|
|
* OF ANY KIND, either express or implied. See the License for the specific language
|
|
* governing permissions and limitations under the License.
|
|
*/
|
|
|
|
import {Collection, Node} from '@react-types/shared';
|
|
import {getChildNodes} from './getChildNodes';
|
|
|
|
const cache = new WeakMap<Iterable<unknown>, number>();
|
|
|
|
export function getItemCount<T>(collection: Collection<Node<T>>): number {
|
|
let count = cache.get(collection);
|
|
if (count != null) {
|
|
return count;
|
|
}
|
|
|
|
// TS isn't smart enough to know we've ensured count is a number, so use a new variable
|
|
let counter = 0;
|
|
let countItems = (items: Iterable<Node<T>>) => {
|
|
for (let item of items) {
|
|
if (item.type === 'section') {
|
|
countItems(getChildNodes(item, collection));
|
|
} else {
|
|
counter++;
|
|
}
|
|
}
|
|
};
|
|
|
|
countItems(collection);
|
|
cache.set(collection, counter);
|
|
return counter;
|
|
}
|