/* * Copyright (C) 2023 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 . */ import {DOMTextScanner} from './dom-text-scanner.js'; import {TextSourceElement} from './text-source-element.js'; import {TextSourceRange} from './text-source-range.js'; /** * This class contains utility functions related to the HTML document. */ export class DocumentUtil { /** * Scans the document for text or elements with text information at the given coordinate. * Coordinates are provided in [client space](https://developer.mozilla.org/en-US/docs/Web/CSS/CSSOM_View/Coordinate_systems). * @param {number} x The x coordinate to search at. * @param {number} y The y coordinate to search at. * @param {import('document-util').GetRangeFromPointOptions} options Options to configure how element detection is performed. * @returns {?TextSourceRange|TextSourceElement} A range for the hovered text or element, or `null` if no applicable content was found. */ static getRangeFromPoint(x, y, options) { for (const handler of this._getRangeFromPointHandlers) { const r = handler(x, y, options); if (r !== null) { return r; } } const {deepContentScan, normalizeCssZoom} = options; const elements = this._getElementsFromPoint(x, y, deepContentScan); /** @type {?HTMLDivElement} */ let imposter = null; /** @type {?HTMLDivElement} */ let imposterContainer = null; /** @type {?Element} */ let imposterSourceElement = null; if (elements.length > 0) { const element = elements[0]; switch (element.nodeName.toUpperCase()) { case 'IMG': case 'BUTTON': case 'SELECT': return TextSourceElement.create(element); case 'INPUT': if (/** @type {HTMLInputElement} */ (element).type === 'text') { imposterSourceElement = element; [imposter, imposterContainer] = this._createImposter(/** @type {HTMLInputElement} */ (element), false); } break; case 'TEXTAREA': imposterSourceElement = element; [imposter, imposterContainer] = this._createImposter(/** @type {HTMLTextAreaElement} */ (element), true); break; } } const range = this._caretRangeFromPointExt(x, y, deepContentScan ? elements : [], normalizeCssZoom); if (range !== null) { if (imposter !== null) { this._setImposterStyle(/** @type {HTMLDivElement} */ (imposterContainer).style, 'z-index', '-2147483646'); this._setImposterStyle(imposter.style, 'pointer-events', 'none'); return TextSourceRange.createFromImposter(range, /** @type {HTMLDivElement} */ (imposterContainer), /** @type {HTMLElement} */ (imposterSourceElement)); } return TextSourceRange.create(range); } else { if (imposterContainer !== null) { const {parentNode} = imposterContainer; if (parentNode !== null) { parentNode.removeChild(imposterContainer); } } return null; } } /** * Registers a custom handler for scanning for text or elements at the input position. * @param {import('document-util').GetRangeFromPointHandler} handler The handler callback which will be invoked when calling `getRangeFromPoint`. */ static registerGetRangeFromPointHandler(handler) { this._getRangeFromPointHandlers.push(handler); } /** * Extract a sentence from a document. * @param {TextSourceRange|TextSourceElement} source The text source object, either `TextSourceRange` or `TextSourceElement`. * @param {boolean} layoutAwareScan Whether or not layout-aware scan mode should be used. * @param {number} extent The length of the sentence to extract. * @param {boolean} terminateAtNewlines Whether or not a sentence should be terminated at newline characters. * @param {import('text-scanner').SentenceTerminatorMap} terminatorMap A mapping of characters that terminate a sentence. * @param {import('text-scanner').SentenceForwardQuoteMap} forwardQuoteMap A mapping of quote characters that delimit a sentence. * @param {import('text-scanner').SentenceBackwardQuoteMap} backwardQuoteMap A mapping of quote characters that delimit a sentence, which is the inverse of forwardQuoteMap. * @returns {{text: string, offset: number}} The sentence and the offset to the original source. */ static extractSentence(source, layoutAwareScan, extent, terminateAtNewlines, terminatorMap, forwardQuoteMap, backwardQuoteMap) { // Scan text source = source.clone(); const startLength = source.setStartOffset(extent, layoutAwareScan); const endLength = source.setEndOffset(extent * 2 - startLength, true, layoutAwareScan); const text = source.text(); const textLength = text.length; const textEndAnchor = textLength - endLength; let pos1 = startLength; let pos2 = textEndAnchor; // Move backward let quoteStack = []; for (; pos1 > 0; --pos1) { const c = text[pos1 - 1]; if (c === '\n' && terminateAtNewlines) { break; } if (quoteStack.length === 0) { const terminatorInfo = terminatorMap.get(c); if (typeof terminatorInfo !== 'undefined') { if (terminatorInfo[0]) { --pos1; } break; } } let quoteInfo = forwardQuoteMap.get(c); if (typeof quoteInfo !== 'undefined') { if (quoteStack.length === 0) { if (quoteInfo[1]) { --pos1; } break; } else if (quoteStack[0] === c) { quoteStack.pop(); continue; } } quoteInfo = backwardQuoteMap.get(c); if (typeof quoteInfo !== 'undefined') { quoteStack.unshift(quoteInfo[0]); } } // Move forward quoteStack = []; for (; pos2 < textLength; ++pos2) { const c = text[pos2]; if (c === '\n' && terminateAtNewlines) { break; } if (quoteStack.length === 0) { const terminatorInfo = terminatorMap.get(c); if (typeof terminatorInfo !== 'undefined') { if (terminatorInfo[1]) { ++pos2; } break; } } let quoteInfo = backwardQuoteMap.get(c); if (typeof quoteInfo !== 'undefined') { if (quoteStack.length === 0) { if (quoteInfo[1]) { ++pos2; } break; } else if (quoteStack[0] === c) { quoteStack.pop(); continue; } } quoteInfo = forwardQuoteMap.get(c); if (typeof quoteInfo !== 'undefined') { quoteStack.unshift(quoteInfo[0]); } } // Trim whitespace for (; pos1 < startLength && this._isWhitespace(text[pos1]); ++pos1) { /* NOP */ } for (; pos2 > textEndAnchor && this._isWhitespace(text[pos2 - 1]); --pos2) { /* NOP */ } // Result return { text: text.substring(pos1, pos2), offset: startLength - pos1 }; } /** * Computes the scaling adjustment that is necessary for client space coordinates based on the * CSS zoom level. * @param {?Node} node A node in the document. * @returns {number} The scaling factor. */ static computeZoomScale(node) { if (this._cssZoomSupported === null) { // @ts-expect-error - zoom is a non-standard property that exists in Chromium-based browsers this._cssZoomSupported = (typeof document.createElement('div').style.zoom === 'string'); } if (!this._cssZoomSupported) { return 1; } // documentElement must be excluded because the computer style of its zoom property is inconsistent. // * If CSS `:root{zoom:X;}` is specified, the computed zoom will always report `X`. // * If CSS `:root{zoom:X;}` is not specified, the computed zoom report the browser's zoom level. // Therefor, if CSS root zoom is specified as a value other than 1, the adjusted {x, y} values // would be incorrect, which is not new behaviour. let scale = 1; const {ELEMENT_NODE, DOCUMENT_FRAGMENT_NODE} = Node; const {documentElement} = document; for (; node !== null && node !== documentElement; node = node.parentNode) { const {nodeType} = node; if (nodeType === DOCUMENT_FRAGMENT_NODE) { const {host} = /** @type {ShadowRoot} */ (node); if (typeof host !== 'undefined') { node = host; } continue; } else if (nodeType !== ELEMENT_NODE) { continue; } const zoomString = getComputedStyle(/** @type {HTMLElement} */ (node)).getPropertyValue('zoom'); if (typeof zoomString !== 'string' || zoomString.length === 0) { continue; } const zoom = Number.parseFloat(zoomString); if (!Number.isFinite(zoom) || zoom === 0) { continue; } scale *= zoom; } return scale; } /** * Converts a rect based on the CSS zoom scaling for a given node. * @param {DOMRect} rect The rect to convert. * @param {Node} node The node to compute the zoom from. * @returns {DOMRect} The updated rect, or the same rect if no change is needed. */ static convertRectZoomCoordinates(rect, node) { const scale = this.computeZoomScale(node); return (scale === 1 ? rect : new DOMRect(rect.left * scale, rect.top * scale, rect.width * scale, rect.height * scale)); } /** * Converts multiple rects based on the CSS zoom scaling for a given node. * @param {DOMRect[]|DOMRectList} rects The rects to convert. * @param {Node} node The node to compute the zoom from. * @returns {DOMRect[]} The updated rects, or the same rects array if no change is needed. */ static convertMultipleRectZoomCoordinates(rects, node) { const scale = this.computeZoomScale(node); if (scale === 1) { return [...rects]; } const results = []; for (const rect of rects) { results.push(new DOMRect(rect.left * scale, rect.top * scale, rect.width * scale, rect.height * scale)); } return results; } /** * Checks whether a given point is contained within a rect. * @param {number} x The horizontal coordinate. * @param {number} y The vertical coordinate. * @param {DOMRect} rect The rect to check. * @returns {boolean} `true` if the point is inside the rect, `false` otherwise. */ static isPointInRect(x, y, rect) { return ( x >= rect.left && x < rect.right && y >= rect.top && y < rect.bottom ); } /** * Checks whether a given point is contained within any rect in a list. * @param {number} x The horizontal coordinate. * @param {number} y The vertical coordinate. * @param {DOMRect[]|DOMRectList} rects The rect to check. * @returns {boolean} `true` if the point is inside any of the rects, `false` otherwise. */ static isPointInAnyRect(x, y, rects) { for (const rect of rects) { if (this.isPointInRect(x, y, rect)) { return true; } } return false; } /** * Checks whether a given point is contained within a selection range. * @param {number} x The horizontal coordinate. * @param {number} y The vertical coordinate. * @param {Selection} selection The selection to check. * @returns {boolean} `true` if the point is inside the selection, `false` otherwise. */ static isPointInSelection(x, y, selection) { for (let i = 0; i < selection.rangeCount; ++i) { const range = selection.getRangeAt(i); if (this.isPointInAnyRect(x, y, range.getClientRects())) { return true; } } return false; } /** * Gets an array of the active modifier keys. * @param {KeyboardEvent|MouseEvent|TouchEvent} event The event to check. * @returns {import('input').ModifierKey[]} An array of modifiers. */ static getActiveModifiers(event) { /** @type {import('input').ModifierKey[]} */ const modifiers = []; if (event.altKey) { modifiers.push('alt'); } if (event.ctrlKey) { modifiers.push('ctrl'); } if (event.metaKey) { modifiers.push('meta'); } if (event.shiftKey) { modifiers.push('shift'); } return modifiers; } /** * Gets an array of the active modifier keys and buttons. * @param {KeyboardEvent|MouseEvent|TouchEvent} event The event to check. * @returns {import('input').Modifier[]} An array of modifiers and buttons. */ static getActiveModifiersAndButtons(event) { /** @type {import('input').Modifier[]} */ const modifiers = this.getActiveModifiers(event); if (event instanceof MouseEvent) { this._getActiveButtons(event, modifiers); } return modifiers; } /** * Gets an array of the active buttons. * @param {MouseEvent} event The event to check. * @returns {import('input').ModifierMouseButton[]} An array of modifiers and buttons. */ static getActiveButtons(event) { /** @type {import('input').ModifierMouseButton[]} */ const buttons = []; this._getActiveButtons(event, buttons); return buttons; } /** * Adds a fullscreen change event listener. This function handles all of the browser-specific variants. * @param {EventListener} onFullscreenChanged The event callback. * @param {?import('../core.js').EventListenerCollection} eventListenerCollection An optional `EventListenerCollection` to add the registration to. */ static addFullscreenChangeEventListener(onFullscreenChanged, eventListenerCollection=null) { const target = document; const options = false; const fullscreenEventNames = [ 'fullscreenchange', 'MSFullscreenChange', 'mozfullscreenchange', 'webkitfullscreenchange' ]; for (const eventName of fullscreenEventNames) { if (eventListenerCollection === null) { target.addEventListener(eventName, onFullscreenChanged, options); } else { eventListenerCollection.addEventListener(target, eventName, onFullscreenChanged, options); } } } /** * Returns the current fullscreen element. This function handles all of the browser-specific variants. * @returns {?Element} The current fullscreen element, or `null` if the window is not fullscreen. */ static getFullscreenElement() { return ( document.fullscreenElement || // @ts-expect-error - vendor prefix document.msFullscreenElement || // @ts-expect-error - vendor prefix document.mozFullScreenElement || // @ts-expect-error - vendor prefix document.webkitFullscreenElement || null ); } /** * Gets all of the nodes within a `Range`. * @param {Range} range The range to check. * @returns {Node[]} The list of nodes. */ static getNodesInRange(range) { const end = range.endContainer; const nodes = []; for (let node = /** @type {?Node} */ (range.startContainer); node !== null; node = this.getNextNode(node)) { nodes.push(node); if (node === end) { break; } } return nodes; } /** * Gets the next node after a specified node. This traverses the DOM in its logical order. * @param {Node} node The node to start at. * @returns {?Node} The next node, or `null` if there is no next node. */ static getNextNode(node) { let next = /** @type {?Node} */ (node.firstChild); if (next === null) { while (true) { next = node.nextSibling; if (next !== null) { break; } next = node.parentNode; if (next === null) { break; } node = next; } } return next; } /** * Checks whether any node in a list of nodes matches a selector. * @param {Node[]} nodes The list of ndoes to check. * @param {string} selector The selector to test. * @returns {boolean} `true` if any element node matches the selector, `false` otherwise. */ static anyNodeMatchesSelector(nodes, selector) { const ELEMENT_NODE = Node.ELEMENT_NODE; // This is a rather ugly way of getting the "node" variable to be a nullable for (let node of /** @type {(?Node)[]} */ (nodes)) { while (node !== null) { if (node.nodeType !== ELEMENT_NODE) { node = node.parentNode; continue; } if (/** @type {HTMLElement} */ (node).matches(selector)) { return true; } break; } } return false; } /** * Checks whether every node in a list of nodes matches a selector. * @param {Node[]} nodes The list of ndoes to check. * @param {string} selector The selector to test. * @returns {boolean} `true` if every element node matches the selector, `false` otherwise. */ static everyNodeMatchesSelector(nodes, selector) { const ELEMENT_NODE = Node.ELEMENT_NODE; // This is a rather ugly way of getting the "node" variable to be a nullable for (let node of /** @type {(?Node)[]} */ (nodes)) { while (true) { if (node === null) { return false; } if (node.nodeType === ELEMENT_NODE && /** @type {HTMLElement} */ (node).matches(selector)) { break; } node = node.parentNode; } } return true; } /** * Checks whether the meta key is supported in the browser on the specified operating system. * @param {string} os The operating system to check. * @param {string} browser The browser to check. * @returns {boolean} `true` if supported, `false` otherwise. */ static isMetaKeySupported(os, browser) { return !(browser === 'firefox' || browser === 'firefox-mobile') || os === 'mac'; } /** * Checks whether an element on the page that can accept input is focused. * @returns {boolean} `true` if an input element is focused, `false` otherwise. */ static isInputElementFocused() { const element = document.activeElement; if (element === null) { return false; } const type = element.nodeName.toUpperCase(); switch (type) { case 'INPUT': case 'TEXTAREA': case 'SELECT': return true; default: return element instanceof HTMLElement && element.isContentEditable; } } /** * Offsets an array of DOMRects by a given amount. * @param {DOMRect[]} rects The DOMRects to offset. * @param {number} x The horizontal offset amount. * @param {number} y The vertical offset amount. * @returns {DOMRect[]} The DOMRects with the offset applied. */ static offsetDOMRects(rects, x, y) { const results = []; for (const rect of rects) { results.push(new DOMRect(rect.left + x, rect.top + y, rect.width, rect.height)); } return results; } /** * Gets the parent writing mode of an element. * See: https://developer.mozilla.org/en-US/docs/Web/CSS/writing-mode. * @param {?Element} element The HTML element to check. * @returns {import('document-util').NormalizedWritingMode} The writing mode. */ static getElementWritingMode(element) { if (element !== null) { const {writingMode} = getComputedStyle(element); if (typeof writingMode === 'string') { return this.normalizeWritingMode(writingMode); } } return 'horizontal-tb'; } /** * Normalizes a CSS writing mode value by converting non-standard and deprecated values * into their corresponding standard vaules. * @param {string} writingMode The writing mode to normalize. * @returns {import('document-util').NormalizedWritingMode} The normalized writing mode. */ static normalizeWritingMode(writingMode) { switch (writingMode) { case 'tb': return 'vertical-lr'; case 'tb-rl': return 'vertical-rl'; case 'horizontal-tb': case 'vertical-rl': case 'vertical-lr': case 'sideways-rl': case 'sideways-lr': return writingMode; default: // 'lr', 'lr-tb', 'rl' return 'horizontal-tb'; } } /** * Converts a value from an element to a number. * @param {string} valueString A string representation of a number. * @param {import('document-util').ToNumberConstraints} constraints An object which might contain `min`, `max`, and `step` fields which are used to constrain the value. * @returns {number} The parsed and constrained number. */ static convertElementValueToNumber(valueString, constraints) { let value = Number.parseFloat(valueString); if (!Number.isFinite(value)) { value = 0; } const min = this._convertToNumberOrNull(constraints.min); const max = this._convertToNumberOrNull(constraints.max); const step = this._convertToNumberOrNull(constraints.step); if (typeof min === 'number') { value = Math.max(value, min); } if (typeof max === 'number') { value = Math.min(value, max); } if (typeof step === 'number' && step !== 0) { value = Math.round(value / step) * step; } return value; } /** * @param {string} value * @returns {?import('input').Modifier} */ static normalizeModifier(value) { switch (value) { case 'alt': case 'ctrl': case 'meta': case 'shift': case 'mouse0': case 'mouse1': case 'mouse2': case 'mouse3': case 'mouse4': case 'mouse5': return value; default: return null; } } /** * @param {string} value * @returns {?import('input').ModifierKey} */ static normalizeModifierKey(value) { switch (value) { case 'alt': case 'ctrl': case 'meta': case 'shift': return value; default: return null; } } // Private /** * @param {MouseEvent} event The event to check. * @param {import('input').ModifierMouseButton[]|import('input').Modifier[]} array */ static _getActiveButtons(event, array) { let {buttons} = event; if (typeof buttons === 'number' && buttons > 0) { for (let i = 0; i < 6; ++i) { const buttonFlag = (1 << i); if ((buttons & buttonFlag) !== 0) { array.push(/** @type {import('input').ModifierMouseButton} */ (`mouse${i}`)); buttons &= ~buttonFlag; if (buttons === 0) { break; } } } } } /** * @param {CSSStyleDeclaration} style * @param {string} propertyName * @param {string} value */ static _setImposterStyle(style, propertyName, value) { style.setProperty(propertyName, value, 'important'); } /** * @param {HTMLInputElement|HTMLTextAreaElement} element * @param {boolean} isTextarea * @returns {[imposter: ?HTMLDivElement, container: ?HTMLDivElement]} */ static _createImposter(element, isTextarea) { const body = document.body; if (body === null) { return [null, null]; } const elementStyle = window.getComputedStyle(element); const elementRect = element.getBoundingClientRect(); const documentRect = document.documentElement.getBoundingClientRect(); let left = elementRect.left - documentRect.left; let top = elementRect.top - documentRect.top; // Container const container = document.createElement('div'); const containerStyle = container.style; this._setImposterStyle(containerStyle, 'all', 'initial'); this._setImposterStyle(containerStyle, 'position', 'absolute'); this._setImposterStyle(containerStyle, 'left', '0'); this._setImposterStyle(containerStyle, 'top', '0'); this._setImposterStyle(containerStyle, 'width', `${documentRect.width}px`); this._setImposterStyle(containerStyle, 'height', `${documentRect.height}px`); this._setImposterStyle(containerStyle, 'overflow', 'hidden'); this._setImposterStyle(containerStyle, 'opacity', '0'); this._setImposterStyle(containerStyle, 'pointer-events', 'none'); this._setImposterStyle(containerStyle, 'z-index', '2147483646'); // Imposter const imposter = document.createElement('div'); const imposterStyle = imposter.style; let value = element.value; if (value.endsWith('\n')) { value += '\n'; } imposter.textContent = value; for (let i = 0, ii = elementStyle.length; i < ii; ++i) { const property = elementStyle[i]; this._setImposterStyle(imposterStyle, property, elementStyle.getPropertyValue(property)); } this._setImposterStyle(imposterStyle, 'position', 'absolute'); this._setImposterStyle(imposterStyle, 'top', `${top}px`); this._setImposterStyle(imposterStyle, 'left', `${left}px`); this._setImposterStyle(imposterStyle, 'margin', '0'); this._setImposterStyle(imposterStyle, 'pointer-events', 'auto'); if (isTextarea) { if (elementStyle.overflow === 'visible') { this._setImposterStyle(imposterStyle, 'overflow', 'auto'); } } else { this._setImposterStyle(imposterStyle, 'overflow', 'hidden'); this._setImposterStyle(imposterStyle, 'white-space', 'nowrap'); this._setImposterStyle(imposterStyle, 'line-height', elementStyle.height); } container.appendChild(imposter); body.appendChild(container); // Adjust size const imposterRect = imposter.getBoundingClientRect(); if (imposterRect.width !== elementRect.width || imposterRect.height !== elementRect.height) { const width = parseFloat(elementStyle.width) + (elementRect.width - imposterRect.width); const height = parseFloat(elementStyle.height) + (elementRect.height - imposterRect.height); this._setImposterStyle(imposterStyle, 'width', `${width}px`); this._setImposterStyle(imposterStyle, 'height', `${height}px`); } if (imposterRect.left !== elementRect.left || imposterRect.top !== elementRect.top) { left += (elementRect.left - imposterRect.left); top += (elementRect.top - imposterRect.top); this._setImposterStyle(imposterStyle, 'left', `${left}px`); this._setImposterStyle(imposterStyle, 'top', `${top}px`); } imposter.scrollTop = element.scrollTop; imposter.scrollLeft = element.scrollLeft; return [imposter, container]; } /** * @param {number} x * @param {number} y * @param {boolean} all * @returns {Element[]} */ static _getElementsFromPoint(x, y, all) { if (all) { // document.elementsFromPoint can return duplicates which must be removed. const elements = document.elementsFromPoint(x, y); return elements.filter((e, i) => elements.indexOf(e) === i); } const e = document.elementFromPoint(x, y); return e !== null ? [e] : []; } /** * @param {number} x * @param {number} y * @param {Range} range * @param {boolean} normalizeCssZoom * @returns {boolean} */ static _isPointInRange(x, y, range, normalizeCssZoom) { // Require a text node to start const {startContainer} = range; if (startContainer.nodeType !== Node.TEXT_NODE) { return false; } // Convert CSS zoom coordinates if (normalizeCssZoom) { const scale = this.computeZoomScale(startContainer); x /= scale; y /= scale; } // Scan forward const nodePre = range.endContainer; const offsetPre = range.endOffset; try { const {node, offset, content} = new DOMTextScanner(nodePre, offsetPre, true, false).seek(1); range.setEnd(node, offset); if (!this._isWhitespace(content) && this.isPointInAnyRect(x, y, range.getClientRects())) { return true; } } finally { range.setEnd(nodePre, offsetPre); } // Scan backward const {node, offset, content} = new DOMTextScanner(startContainer, range.startOffset, true, false).seek(-1); range.setStart(node, offset); if (!this._isWhitespace(content) && this.isPointInAnyRect(x, y, range.getClientRects())) { // This purposefully leaves the starting offset as modified and sets the range length to 0. range.setEnd(node, offset); return true; } // No match return false; } /** * @param {string} string * @returns {boolean} */ static _isWhitespace(string) { return string.trim().length === 0; } /** * @param {number} x * @param {number} y * @returns {?Range} */ static _caretRangeFromPoint(x, y) { if (typeof document.caretRangeFromPoint === 'function') { // Chrome, Edge return document.caretRangeFromPoint(x, y); } // @ts-expect-error - caretPositionFromPoint is non-standard if (typeof document.caretPositionFromPoint === 'function') { // Firefox return this._caretPositionFromPoint(x, y); } // No support return null; } /** * @param {number} x * @param {number} y * @returns {?Range} */ static _caretPositionFromPoint(x, y) { // @ts-expect-error - caretPositionFromPoint is non-standard const position = /** @type {(x: number, y: number) => ?{offsetNode: Node, offset: number}} */ (document.caretPositionFromPoint)(x, y); if (position === null) { return null; } const node = position.offsetNode; if (node === null) { return null; } let offset = 0; const {nodeType} = node; switch (nodeType) { case Node.TEXT_NODE: offset = position.offset; break; case Node.ELEMENT_NODE: // Elements with user-select: all will return the element // instead of a text point inside the element. if (this._isElementUserSelectAll(/** @type {Element} */ (node))) { return this._caretPositionFromPointNormalizeStyles(x, y, /** @type {Element} */ (node)); } break; } try { const range = document.createRange(); range.setStart(node, offset); range.setEnd(node, offset); return range; } catch (e) { // Firefox throws new DOMException("The operation is insecure.") // when trying to select a node from within a ShadowRoot. return null; } } /** * @param {number} x * @param {number} y * @param {Element} nextElement * @returns {?Range} */ static _caretPositionFromPointNormalizeStyles(x, y, nextElement) { const previousStyles = new Map(); try { while (true) { if (nextElement instanceof HTMLElement) { this._recordPreviousStyle(previousStyles, nextElement); nextElement.style.setProperty('user-select', 'text', 'important'); } // @ts-expect-error - caretPositionFromPoint is non-standard const position = /** @type {(x: number, y: number) => ?{offsetNode: Node, offset: number}} */ (document.caretPositionFromPoint)(x, y); if (position === null) { return null; } const node = position.offsetNode; if (node === null) { return null; } let offset = 0; const {nodeType} = node; switch (nodeType) { case Node.TEXT_NODE: offset = position.offset; break; case Node.ELEMENT_NODE: // Elements with user-select: all will return the element // instead of a text point inside the element. if (this._isElementUserSelectAll(/** @type {Element} */ (node))) { if (previousStyles.has(node)) { // Recursive return null; } nextElement = /** @type {Element} */ (node); continue; } break; } try { const range = document.createRange(); range.setStart(node, offset); range.setEnd(node, offset); return range; } catch (e) { // Firefox throws new DOMException("The operation is insecure.") // when trying to select a node from within a ShadowRoot. return null; } } } finally { this._revertStyles(previousStyles); } } /** * @param {number} x * @param {number} y * @param {Element[]} elements * @param {boolean} normalizeCssZoom * @returns {?Range} */ static _caretRangeFromPointExt(x, y, elements, normalizeCssZoom) { let previousStyles = null; try { let i = 0; let startContinerPre = null; while (true) { const range = this._caretRangeFromPoint(x, y); if (range === null) { return null; } const startContainer = range.startContainer; if (startContinerPre !== startContainer) { if (this._isPointInRange(x, y, range, normalizeCssZoom)) { return range; } startContinerPre = startContainer; } if (previousStyles === null) { previousStyles = new Map(); } i = this._disableTransparentElement(elements, i, previousStyles); if (i < 0) { return null; } } } finally { if (previousStyles !== null && previousStyles.size > 0) { this._revertStyles(previousStyles); } } } /** * @param {Element[]} elements * @param {number} i * @param {Map} previousStyles * @returns {number} */ static _disableTransparentElement(elements, i, previousStyles) { while (true) { if (i >= elements.length) { return -1; } const element = elements[i++]; if (this._isElementTransparent(element)) { if (element instanceof HTMLElement) { this._recordPreviousStyle(previousStyles, element); element.style.setProperty('pointer-events', 'none', 'important'); } return i; } } } /** * @param {Map} previousStyles * @param {Element} element */ static _recordPreviousStyle(previousStyles, element) { if (previousStyles.has(element)) { return; } const style = element.hasAttribute('style') ? element.getAttribute('style') : null; previousStyles.set(element, style); } /** * @param {Map} previousStyles */ static _revertStyles(previousStyles) { for (const [element, style] of previousStyles.entries()) { if (style === null) { element.removeAttribute('style'); } else { element.setAttribute('style', style); } } } /** * @param {Element} element * @returns {boolean} */ static _isElementTransparent(element) { if ( element === document.body || element === document.documentElement ) { return false; } const style = window.getComputedStyle(element); return ( parseFloat(style.opacity) <= 0 || style.visibility === 'hidden' || (style.backgroundImage === 'none' && this._isColorTransparent(style.backgroundColor)) ); } /** * @param {string} cssColor * @returns {boolean} */ static _isColorTransparent(cssColor) { return this._transparentColorPattern.test(cssColor); } /** * @param {Element} element * @returns {boolean} */ static _isElementUserSelectAll(element) { return getComputedStyle(element).userSelect === 'all'; } /** * @param {string|number|undefined} value * @returns {?number} */ static _convertToNumberOrNull(value) { if (typeof value !== 'number') { if (typeof value !== 'string' || value.length === 0) { return null; } value = parseFloat(value); } return !Number.isNaN(value) ? value : null; } } /** @type {RegExp} */ // eslint-disable-next-line no-underscore-dangle DocumentUtil._transparentColorPattern = /rgba\s*\([^)]*,\s*0(?:\.0+)?\s*\)/; /** @type {?boolean} */ // eslint-disable-next-line no-underscore-dangle DocumentUtil._cssZoomSupported = null; /** @type {import('document-util').GetRangeFromPointHandler[]} */ // eslint-disable-next-line no-underscore-dangle DocumentUtil._getRangeFromPointHandlers = [];