diff options
Diffstat (limited to 'ext/js/dom/text-source-generator.js')
| -rw-r--r-- | ext/js/dom/text-source-generator.js | 601 |
1 files changed, 600 insertions, 1 deletions
diff --git a/ext/js/dom/text-source-generator.js b/ext/js/dom/text-source-generator.js index 0435e69b..a5529779 100644 --- a/ext/js/dom/text-source-generator.js +++ b/ext/js/dom/text-source-generator.js @@ -16,9 +16,14 @@ */ import {DocumentUtil} from './document-util.js'; +import {DOMTextScanner} from './dom-text-scanner.js'; +import {TextSourceElement} from './text-source-element.js'; +import {TextSourceRange} from './text-source-range.js'; export class TextSourceGenerator { constructor() { + /** @type {RegExp} @readonly */ + this._transparentColorPattern = /rgba\s*\([^)]*,\s*0(?:\.0+)?\s*\)/; /** @type {import('text-source-generator').GetRangeFromPointHandler[]} @readonly */ this._getRangeFromPointHandlers = []; } @@ -34,7 +39,7 @@ export class TextSourceGenerator { const result = handler(x, y, options); if (result !== null) { return result; } } - return DocumentUtil.getRangeFromPoint(x, y, options); + return this._getRangeFromPointInternal(x, y, options); } /** @@ -44,4 +49,598 @@ export class TextSourceGenerator { registerGetRangeFromPointHandler(handler) { this._getRangeFromPointHandlers.push(handler); } + + /** + * Extract a sentence from a document. + * @param {import('text-source').TextSource} 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. + */ + 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; + + /** Relative start position of the sentence (inclusive). */ + let cursorStart = startLength; + /** Relative end position of the sentence (exclusive). */ + let cursorEnd = textEndAnchor; + + // Move backward + let quoteStack = []; + for (; cursorStart > 0; --cursorStart) { + // Check if the previous character should be included. + let c = text[cursorStart - 1]; + if (c === '\n' && terminateAtNewlines) { break; } + + if (quoteStack.length === 0) { + let terminatorInfo = terminatorMap.get(c); + if (typeof terminatorInfo !== 'undefined') { + // Include the previous character while it is a terminator character and is included at start. + while (terminatorInfo[0] && cursorStart > 0) { + --cursorStart; + if (cursorStart === 0) { break; } + c = text[cursorStart - 1]; + terminatorInfo = terminatorMap.get(c); + if (typeof terminatorInfo === 'undefined') { break; } + } + break; + } + } + + let quoteInfo = forwardQuoteMap.get(c); + if (typeof quoteInfo !== 'undefined') { + if (quoteStack.length === 0) { + // Include the previous character while it is a quote character and is included at start. + while (quoteInfo[1] && cursorStart > 0) { + --cursorStart; + if (cursorStart === 0) { break; } + c = text[cursorStart - 1]; + quoteInfo = forwardQuoteMap.get(c); + if (typeof quoteInfo === 'undefined') { break; } + } + 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 (; cursorEnd < textLength; ++cursorEnd) { + // Check if the following character should be included. + let c = text[cursorEnd]; + if (c === '\n' && terminateAtNewlines) { break; } + + if (quoteStack.length === 0) { + let terminatorInfo = terminatorMap.get(c); + if (typeof terminatorInfo !== 'undefined') { + // Include the following character while it is a terminator character and is included at end. + while (terminatorInfo[1] && cursorEnd < textLength) { + ++cursorEnd; + if (cursorEnd === textLength) { break; } + c = text[cursorEnd]; + terminatorInfo = terminatorMap.get(c); + if (typeof terminatorInfo === 'undefined') { break; } + } + break; + } + } + + let quoteInfo = backwardQuoteMap.get(c); + if (typeof quoteInfo !== 'undefined') { + if (quoteStack.length === 0) { + // Include the following character while it is a quote character and is included at end. + while (quoteInfo[1] && cursorEnd < textLength) { + ++cursorEnd; + if (cursorEnd === textLength) { break; } + c = text[cursorEnd]; + quoteInfo = forwardQuoteMap.get(c); + if (typeof quoteInfo === 'undefined') { break; } + } + break; + } else if (quoteStack[0] === c) { + quoteStack.pop(); + continue; + } + } + + quoteInfo = forwardQuoteMap.get(c); + if (typeof quoteInfo !== 'undefined') { + quoteStack.unshift(quoteInfo[0]); + } + } + + // Trim whitespace + for (; cursorStart < startLength && this._isWhitespace(text[cursorStart]); ++cursorStart) { /* NOP */ } + for (; cursorEnd > textEndAnchor && this._isWhitespace(text[cursorEnd - 1]); --cursorEnd) { /* NOP */ } + + // Result + return { + text: text.substring(cursorStart, cursorEnd), + offset: startLength - cursorStart + }; + } + + /** + * 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 {?import('text-source').TextSource} A range for the hovered text or element, or `null` if no applicable content was found. + */ + _getRangeFromPointInternal(x, y, options) { + 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; + } + } + + /** + * @param {CSSStyleDeclaration} style + * @param {string} propertyName + * @param {string} value + */ + _setImposterStyle(style, propertyName, value) { + style.setProperty(propertyName, value, 'important'); + } + + /** + * @param {HTMLInputElement|HTMLTextAreaElement} element + * @param {boolean} isTextarea + * @returns {[imposter: ?HTMLDivElement, container: ?HTMLDivElement]} + */ + _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[]} + */ + _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} + */ + _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 = DocumentUtil.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) && DocumentUtil.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) && DocumentUtil.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 {number} x + * @param {number} y + * @returns {?Range} + */ + _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} + */ + _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} + */ + _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} + */ + _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<Element, ?string>} previousStyles + * @returns {number} + */ + _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<Element, ?string>} previousStyles + * @param {Element} element + */ + _recordPreviousStyle(previousStyles, element) { + if (previousStyles.has(element)) { return; } + const style = element.hasAttribute('style') ? element.getAttribute('style') : null; + previousStyles.set(element, style); + } + + /** + * @param {Map<Element, ?string>} previousStyles + */ + _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} + */ + _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} + */ + _isColorTransparent(cssColor) { + return this._transparentColorPattern.test(cssColor); + } + + /** + * @param {Element} element + * @returns {boolean} + */ + _isElementUserSelectAll(element) { + return getComputedStyle(element).userSelect === 'all'; + } + + /** + * @param {string} string + * @returns {boolean} + */ + _isWhitespace(string) { + return string.trim().length === 0; + } } |