| /** |
| * @license |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * 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 CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| import type { TextPositionSelector } from '@apache-annotator/selector'; |
| import { describeTextPosition as abstractDescribeTextPosition } from '@apache-annotator/selector'; |
| import { ownerDocument } from '../owner-document'; |
| import { TextNodeChunker } from '../text-node-chunker'; |
| |
| /** |
| * Returns a {@link TextPositionSelector} that points at the target text within |
| * the given scope. |
| * |
| * When no scope is given, the position is described relative to the document |
| * as a whole. Note this means all the characters in all Text nodes are counted |
| * to determine the target’s position, including those in the `<head>` and |
| * whitespace, hence even a minor modification could make the selector point to |
| * a different text than its original target. |
| * |
| * @example |
| * ``` |
| * const target = window.getSelection().getRangeAt(0); |
| * const selector = await describeTextPosition(target); |
| * console.log(selector); |
| * // { |
| * // type: 'TextPositionSelector', |
| * // start: 702, |
| * // end: 736 |
| * // } |
| * ``` |
| * |
| * @param range - The range of characters that the selector should describe |
| * @param maybeScope - A {@link https://developer.mozilla.org/en-US/docs/Web/API/Range |
| * | Range} that serves as the ‘document’ for purposes of finding occurrences |
| * and determining prefix and suffix. Defaults to span the full Document |
| * containing the range. |
| * @returns The selector describing `range` within `scope`. |
| * |
| * @public |
| */ |
| export async function describeTextPosition( |
| range: Range, |
| maybeScope?: Range, |
| ): Promise<TextPositionSelector> { |
| // Default to search in the whole document. |
| let scope: Range; |
| if (maybeScope !== undefined) { |
| scope = maybeScope; |
| } else { |
| const document = ownerDocument(range); |
| scope = document.createRange(); |
| scope.selectNodeContents(document); |
| } |
| |
| const textChunks = new TextNodeChunker(scope); |
| if (textChunks.currentChunk === null) |
| throw new RangeError('Range does not contain any Text nodes.'); |
| |
| return await abstractDescribeTextPosition( |
| textChunks.rangeToChunkRange(range), |
| textChunks, |
| ); |
| } |
