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Diffstat (limited to 'ext/js/dom/document-util.js')
| -rw-r--r-- | ext/js/dom/document-util.js | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/ext/js/dom/document-util.js b/ext/js/dom/document-util.js new file mode 100644 index 00000000..513a0c05 --- /dev/null +++ b/ext/js/dom/document-util.js @@ -0,0 +1,570 @@ +/* + * Copyright (C) 2016-2021 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/>. + */ + +/* global + * DOMTextScanner + * TextSourceElement + * TextSourceRange + */ + +class DocumentUtil { + constructor() { + this._transparentColorPattern = /rgba\s*\([^)]*,\s*0(?:\.0+)?\s*\)/; + } + + getRangeFromPoint(x, y, deepContentScan) { + const elements = this._getElementsFromPoint(x, y, deepContentScan); + let imposter = null; + let imposterContainer = null; + let imposterSourceElement = null; + if (elements.length > 0) { + const element = elements[0]; + switch (element.nodeName.toUpperCase()) { + case 'IMG': + case 'BUTTON': + return new TextSourceElement(element); + case 'INPUT': + imposterSourceElement = element; + [imposter, imposterContainer] = this._createImposter(element, false); + break; + case 'TEXTAREA': + imposterSourceElement = element; + [imposter, imposterContainer] = this._createImposter(element, true); + break; + } + } + + const range = this._caretRangeFromPointExt(x, y, deepContentScan ? elements : []); + if (range !== null) { + if (imposter !== null) { + this._setImposterStyle(imposterContainer.style, 'z-index', '-2147483646'); + this._setImposterStyle(imposter.style, 'pointer-events', 'none'); + } + return new TextSourceRange(range, '', imposterContainer, imposterSourceElement); + } else { + if (imposterContainer !== null) { + imposterContainer.parentNode.removeChild(imposterContainer); + } + return null; + } + } + + /** + * Extract a sentence from a document. + * @param source The text source object, either `TextSourceRange` or `TextSourceElement`. + * @param layoutAwareScan Whether or not layout-aware scan mode should be used. + * @param extent The length of the sentence to extract. + * @param terminatorMap A mapping of characters that terminate a sentence. + * Format: + * ```js + * new Map([ [character: string, [includeCharacterAtStart: boolean, includeCharacterAtEnd: boolean]], ... ]) + * ``` + * @param forwardQuoteMap A mapping of quote characters that delimit a sentence. + * Format: + * ```js + * new Map([ [character: string, [otherCharacter: string, includeCharacterAtStart: boolean]], ... ]) + * ``` + * @param backwardQuoteMap A mapping of quote characters that delimit a sentence, + * which is the inverse of forwardQuoteMap. + * Format: + * ```js + * new Map([ [character: string, [otherCharacter: string, includeCharacterAtEnd: boolean]], ... ]) + * ``` + * @returns The sentence and the offset to the original source: `{sentence: string, offset: integer}`. + */ + extractSentence(source, layoutAwareScan, extent, terminatorMap, forwardQuoteMap, backwardQuoteMap) { + // Scan text + source = source.clone(); + const startLength = source.setStartOffset(extent, layoutAwareScan); + const endLength = source.setEndOffset(extent * 2 - startLength, layoutAwareScan, true); + 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') { 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') { 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 + }; + } + + static isPointInRect(x, y, rect) { + return ( + x >= rect.left && x < rect.right && + y >= rect.top && y < rect.bottom + ); + } + + static isPointInAnyRect(x, y, rects) { + for (const rect of rects) { + if (this.isPointInRect(x, y, rect)) { + return true; + } + } + return false; + } + + 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; + } + + static isMouseButtonPressed(mouseEvent, button) { + const mouseEventButton = mouseEvent.button; + switch (button) { + case 'primary': return mouseEventButton === 0; + case 'secondary': return mouseEventButton === 2; + case 'auxiliary': return mouseEventButton === 1; + default: return false; + } + } + + static getActiveModifiers(event) { + 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; + } + + static getActiveModifiersAndButtons(event) { + const modifiers = this.getActiveModifiers(event); + this._getActiveButtons(event, modifiers); + return modifiers; + } + + static getActiveButtons(event) { + const buttons = []; + this._getActiveButtons(event, buttons); + return buttons; + } + + 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); + } + } + } + + static getFullscreenElement() { + return ( + document.fullscreenElement || + document.msFullscreenElement || + document.mozFullScreenElement || + document.webkitFullscreenElement || + null + ); + } + + static getNodesInRange(range) { + const end = range.endContainer; + const nodes = []; + for (let node = range.startContainer; node !== null; node = this.getNextNode(node)) { + nodes.push(node); + if (node === end) { break; } + } + return nodes; + } + + static getNextNode(node) { + let next = 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; + } + + static anyNodeMatchesSelector(nodes, selector) { + const ELEMENT_NODE = Node.ELEMENT_NODE; + for (let node of nodes) { + for (; node !== null; node = node.parentNode) { + if (node.nodeType !== ELEMENT_NODE) { continue; } + if (node.matches(selector)) { return true; } + break; + } + } + return false; + } + + static everyNodeMatchesSelector(nodes, selector) { + const ELEMENT_NODE = Node.ELEMENT_NODE; + for (let node of nodes) { + while (true) { + if (node === null) { return false; } + if (node.nodeType === ELEMENT_NODE && node.matches(selector)) { break; } + node = node.parentNode; + } + } + return true; + } + + static isMetaKeySupported(os, browser) { + return !(browser === 'firefox' || browser === 'firefox-mobile') || os === 'mac'; + } + + 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(`mouse${i}`); + buttons &= ~buttonFlag; + if (buttons === 0) { break; } + } + } + } + } + + // Private + + _setImposterStyle(style, propertyName, value) { + style.setProperty(propertyName, value, 'important'); + } + + _createImposter(element, isTextarea) { + const body = document.body; + if (body === null) { return [null, null]; } + + const elementStyle = window.getComputedStyle(element); + const elementRect = element.getBoundingClientRect(); + const documentRect = document.documentElement.getBoundingClientRect(); + let left = elementRect.left - documentRect.left; + let top = elementRect.top - documentRect.top; + + // Container + const container = document.createElement('div'); + const containerStyle = container.style; + this._setImposterStyle(containerStyle, 'all', 'initial'); + this._setImposterStyle(containerStyle, 'position', 'absolute'); + this._setImposterStyle(containerStyle, 'left', '0'); + this._setImposterStyle(containerStyle, 'top', '0'); + this._setImposterStyle(containerStyle, 'width', `${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', `${height}px`); + } + if (imposterRect.x !== elementRect.x || imposterRect.y !== elementRect.y) { + left += (elementRect.left - imposterRect.left); + top += (elementRect.top - imposterRect.top); + this._setImposterStyle(imposterStyle, 'left', `${left}px`); + this._setImposterStyle(imposterStyle, 'top', `${top}px`); + } + + imposter.scrollTop = element.scrollTop; + imposter.scrollLeft = element.scrollLeft; + + return [imposter, container]; + } + + _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] : []; + } + + _isPointInRange(x, y, range) { + // Require a text node to start + if (range.startContainer.nodeType !== Node.TEXT_NODE) { + return false; + } + + // Scan forward + const nodePre = range.endContainer; + const offsetPre = range.endOffset; + try { + const {node, offset, content} = new DOMTextScanner(range.endContainer, range.endOffset, 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(range.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; + } + + _isWhitespace(string) { + return string.trim().length === 0; + } + + _caretRangeFromPoint(x, y) { + if (typeof document.caretRangeFromPoint === 'function') { + // Chrome, Edge + return document.caretRangeFromPoint(x, y); + } + + if (typeof document.caretPositionFromPoint === 'function') { + // Firefox + return this._caretPositionFromPoint(x, y); + } + + // No support + return null; + } + + _caretPositionFromPoint(x, y) { + const position = document.caretPositionFromPoint(x, y); + if (position === null) { + return null; + } + const node = position.offsetNode; + if (node === null) { + return null; + } + + const range = document.createRange(); + const offset = (node.nodeType === Node.TEXT_NODE ? position.offset : 0); + try { + range.setStart(node, offset); + range.setEnd(node, offset); + } catch (e) { + // Firefox throws new DOMException("The operation is insecure.") + // when trying to select a node from within a ShadowRoot. + return null; + } + return range; + } + + _caretRangeFromPointExt(x, y, elements) { + const modifications = []; + 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)) { + return range; + } + startContinerPre = startContainer; + } + + i = this._disableTransparentElement(elements, i, modifications); + if (i < 0) { + return null; + } + } + } finally { + if (modifications.length > 0) { + this._restoreElementStyleModifications(modifications); + } + } + } + + _disableTransparentElement(elements, i, modifications) { + while (true) { + if (i >= elements.length) { + return -1; + } + + const element = elements[i++]; + if (this._isElementTransparent(element)) { + const style = element.hasAttribute('style') ? element.getAttribute('style') : null; + modifications.push({element, style}); + element.style.setProperty('pointer-events', 'none', 'important'); + return i; + } + } + } + + _restoreElementStyleModifications(modifications) { + for (const {element, style} of modifications) { + if (style === null) { + element.removeAttribute('style'); + } else { + element.setAttribute('style', style); + } + } + } + + _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)) + ); + } + + _isColorTransparent(cssColor) { + return this._transparentColorPattern.test(cssColor); + } +} |