/* * Copyright (C) 2023-2024 Yomitan Authors * Copyright (C) 2016-2022 Yomichan Authors * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ import {readCodePointsBackward, readCodePointsForward} from '../data/sandbox/string-util.js'; import {DocumentUtil} from './document-util.js'; /** * This class represents a text source that is attached to a HTML element, such as an <img> * with alt text or a <button>. */ export class TextSourceElement { /** * Creates a new instance of the class. * @param {Element} element The source element. * @param {string} fullContent The string representing the element's full text value. * @param {number} startOffset The text start offset position within the full content. * @param {number} endOffset The text end offset position within the full content. */ constructor(element, fullContent, startOffset, endOffset) { /** @type {Element} */ this._element = element; /** @type {string} */ this._fullContent = fullContent; /** @type {number} */ this._startOffset = startOffset; /** @type {number} */ this._endOffset = endOffset; /** @type {string} */ this._content = this._fullContent.substring(this._startOffset, this._endOffset); } /** * Gets the type name of this instance. * @type {'element'} */ get type() { return 'element'; } /** * The source element. * @type {Element} */ get element() { return this._element; } /** * The string representing the element's full text value. * @type {string} */ get fullContent() { return this._fullContent; } /** * The text start offset position within the full content. * @type {number} */ get startOffset() { return this._startOffset; } /** * The text end offset position within the full content. * @type {number} */ get endOffset() { return this._endOffset; } /** * Creates a clone of the instance. * @returns {TextSourceElement} The new clone. */ clone() { return new TextSourceElement(this._element, this._fullContent, this._startOffset, this._endOffset); } /** * Performs any cleanup that is necessary after the element has been used. */ cleanup() { // NOP } /** * Gets the selected text of element, which is a substring of the full content * starting at `startOffset` and ending at `endOffset`. * @returns {string} The text content. */ text() { return this._content; } /** * Moves the end offset of the text by a set amount of unicode codepoints. * @param {number} length The maximum number of codepoints to move by. * @param {boolean} fromEnd Whether to move the offset from the current end position (if `true`) or the start position (if `false`). * @returns {number} The actual number of characters (not codepoints) that were read. */ setEndOffset(length, fromEnd) { const offset = fromEnd ? this._endOffset : this._startOffset; length = Math.min(this._fullContent.length - offset, length); if (length > 0) { length = readCodePointsForward(this._fullContent, offset, length).length; } this._endOffset = offset + length; this._content = this._fullContent.substring(this._startOffset, this._endOffset); return length; } /** * Moves the start offset of the text by a set amount of unicode codepoints. * @param {number} length The maximum number of codepoints to move by. * @returns {number} The actual number of characters (not codepoints) that were read. */ setStartOffset(length) { length = Math.min(this._startOffset, length); if (length > 0) { length = readCodePointsBackward(this._fullContent, this._startOffset - 1, length).length; } this._startOffset -= length; this._content = this._fullContent.substring(this._startOffset, this._endOffset); return length; } /** * Gets the rects that represent the position and bounds of the text source. * @returns {DOMRect[]} The rects. */ getRects() { return DocumentUtil.convertMultipleRectZoomCoordinates(this._element.getClientRects(), this._element); } /** * Gets writing mode that is used for this element. * See: https://developer.mozilla.org/en-US/docs/Web/CSS/writing-mode. * @returns {import('document-util').NormalizedWritingMode} The writing mode. */ getWritingMode() { return 'horizontal-tb'; } /** * Selects the text source in the document. */ select() { // NOP } /** * Deselects the text source in the document. */ deselect() { // NOP } /** * Checks whether another text source has the same starting point. * @param {import('text-source').TextSource} other The other source to test. * @returns {boolean} `true` if the starting points are equivalent, `false` otherwise. */ hasSameStart(other) { return ( typeof other === 'object' && other !== null && other instanceof TextSourceElement && this._element === other.element && this._fullContent === other.fullContent && this._startOffset === other.startOffset ); } /** * Gets a list of the nodes in this text source's range. * @returns {Node[]} The nodes in the range. */ getNodesInRange() { return [this._element]; } /** * Creates a new instance for a given element. * @param {Element} element The source element. * @returns {TextSourceElement} A new instance of the class corresponding to the element. */ static create(element) { return new TextSourceElement(element, this._getElementContent(element), 0, 0); } /** * Gets the full content string for a given element. * @param {Element} element The element to get the full content of. * @returns {string} The content string. */ static _getElementContent(element) { let content = ''; switch (element.nodeName.toUpperCase()) { case 'BUTTON': { const {textContent} = /** @type {HTMLButtonElement} */ (element); if (textContent !== null) { content = textContent; } } break; case 'IMG': { const alt = /** @type {HTMLImageElement} */ (element).getAttribute('alt'); if (typeof alt === 'string') { content = alt; } } break; case 'SELECT': { const {selectedIndex, options} = /** @type {HTMLSelectElement} */ (element); if (selectedIndex >= 0 && selectedIndex < options.length) { const {textContent} = options[selectedIndex]; if (textContent !== null) { content = textContent; } } } break; case 'INPUT': { content = /** @type {HTMLInputElement} */ (element).value; } break; } // Remove zero-width space and zero-width non-joiner content = content.replace(/[\u200b\u200c]/g, ''); return content; } }