/* * Copyright (C) 2019-2020 Alex Yatskov <alex@foosoft.net> * Author: Alex Yatskov <alex@foosoft.net> * * 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 * DOM * TextSourceRange * docRangeFromPoint */ class TextScanner { constructor(node, ignoreElements, ignorePoints) { this.node = node; this.ignoreElements = ignoreElements; this.ignorePoints = ignorePoints; this.ignoreNodes = null; this.scanTimerPromise = null; this.causeCurrent = null; this.textSourceCurrent = null; this.pendingLookup = false; this.options = null; this.enabled = false; this.eventListeners = new EventListenerCollection(); this.primaryTouchIdentifier = null; this.preventNextContextMenu = false; this.preventNextMouseDown = false; this.preventNextClick = false; this.preventScroll = false; } onMouseOver(e) { if (this.ignoreElements.includes(e.target)) { this.scanTimerClear(); } } onMouseMove(e) { this.scanTimerClear(); if (this.pendingLookup || DOM.isMouseButtonDown(e, 'primary')) { return; } const scanningOptions = this.options.scanning; const scanningModifier = scanningOptions.modifier; if (!( TextScanner.isScanningModifierPressed(scanningModifier, e) || (scanningOptions.middleMouse && DOM.isMouseButtonDown(e, 'auxiliary')) )) { return; } const search = async () => { if (scanningModifier === 'none') { if (!await this.scanTimerWait()) { // Aborted return; } } await this.searchAt(e.clientX, e.clientY, 'mouse'); }; search(); } onMouseDown(e) { if (this.preventNextMouseDown) { this.preventNextMouseDown = false; this.preventNextClick = true; e.preventDefault(); e.stopPropagation(); return false; } if (DOM.isMouseButtonDown(e, 'primary')) { this.scanTimerClear(); this.onSearchClear(true); } } onMouseOut() { this.scanTimerClear(); } onClick(e) { if (this.preventNextClick) { this.preventNextClick = false; e.preventDefault(); e.stopPropagation(); return false; } } onAuxClick() { this.preventNextContextMenu = false; } onContextMenu(e) { if (this.preventNextContextMenu) { this.preventNextContextMenu = false; e.preventDefault(); e.stopPropagation(); return false; } } onTouchStart(e) { if (this.primaryTouchIdentifier !== null || e.changedTouches.length === 0) { return; } this.preventScroll = false; this.preventNextContextMenu = false; this.preventNextMouseDown = false; this.preventNextClick = false; const primaryTouch = e.changedTouches[0]; if (DOM.isPointInSelection(primaryTouch.clientX, primaryTouch.clientY, this.node.getSelection())) { return; } this.primaryTouchIdentifier = primaryTouch.identifier; if (this.pendingLookup) { return; } const textSourceCurrentPrevious = this.textSourceCurrent !== null ? this.textSourceCurrent.clone() : null; this.searchAt(primaryTouch.clientX, primaryTouch.clientY, 'touchStart') .then(() => { if ( this.textSourceCurrent === null || this.textSourceCurrent.equals(textSourceCurrentPrevious) ) { return; } this.preventScroll = true; this.preventNextContextMenu = true; this.preventNextMouseDown = true; }); } onTouchEnd(e) { if ( this.primaryTouchIdentifier === null || TextScanner.getTouch(e.changedTouches, this.primaryTouchIdentifier) === null ) { return; } this.primaryTouchIdentifier = null; this.preventScroll = false; this.preventNextClick = false; // Don't revert context menu and mouse down prevention, // since these events can occur after the touch has ended. // this.preventNextContextMenu = false; // this.preventNextMouseDown = false; } onTouchCancel(e) { this.onTouchEnd(e); } onTouchMove(e) { if (!this.preventScroll || !e.cancelable || this.primaryTouchIdentifier === null) { return; } const primaryTouch = TextScanner.getTouch(e.changedTouches, this.primaryTouchIdentifier); if (primaryTouch === null) { return; } this.searchAt(primaryTouch.clientX, primaryTouch.clientY, 'touchMove'); e.preventDefault(); // Disable scroll } async onSearchSource(_textSource, _cause) { throw new Error('Override me'); } onError(error) { logError(error, false); } async scanTimerWait() { const delay = this.options.scanning.delay; const promise = promiseTimeout(delay, true); this.scanTimerPromise = promise; try { return await promise; } finally { if (this.scanTimerPromise === promise) { this.scanTimerPromise = null; } } } scanTimerClear() { if (this.scanTimerPromise !== null) { this.scanTimerPromise.resolve(false); this.scanTimerPromise = null; } } setEnabled(enabled) { if (enabled) { if (!this.enabled) { this.hookEvents(); this.enabled = true; } } else { if (this.enabled) { this.eventListeners.removeAllEventListeners(); this.enabled = false; } this.onSearchClear(false); } } hookEvents() { let eventListenerInfos = this.getMouseEventListeners(); if (this.options.scanning.touchInputEnabled) { eventListenerInfos = eventListenerInfos.concat(this.getTouchEventListeners()); } for (const [node, type, listener, options] of eventListenerInfos) { this.eventListeners.addEventListener(node, type, listener, options); } } getMouseEventListeners() { return [ [this.node, 'mousedown', this.onMouseDown.bind(this)], [this.node, 'mousemove', this.onMouseMove.bind(this)], [this.node, 'mouseover', this.onMouseOver.bind(this)], [this.node, 'mouseout', this.onMouseOut.bind(this)] ]; } getTouchEventListeners() { return [ [this.node, 'click', this.onClick.bind(this)], [this.node, 'auxclick', this.onAuxClick.bind(this)], [this.node, 'touchstart', this.onTouchStart.bind(this)], [this.node, 'touchend', this.onTouchEnd.bind(this)], [this.node, 'touchcancel', this.onTouchCancel.bind(this)], [this.node, 'touchmove', this.onTouchMove.bind(this), {passive: false}], [this.node, 'contextmenu', this.onContextMenu.bind(this)] ]; } setOptions(options) { this.options = options; this.setEnabled(this.options.general.enable); } async searchAt(x, y, cause) { try { this.scanTimerClear(); if (this.pendingLookup) { return; } for (const ignorePointFn of this.ignorePoints) { if (await ignorePointFn(x, y)) { return; } } const textSource = docRangeFromPoint(x, y, this.options.scanning.deepDomScan); try { if (this.textSourceCurrent !== null && this.textSourceCurrent.equals(textSource)) { return; } this.pendingLookup = true; const result = await this.onSearchSource(textSource, cause); if (result !== null) { this.causeCurrent = cause; this.textSourceCurrent = textSource; if (this.options.scanning.selectText) { textSource.select(); } } this.pendingLookup = false; } finally { if (textSource !== null) { textSource.cleanup(); } } } catch (e) { this.onError(e); } } setTextSourceScanLength(textSource, length) { textSource.setEndOffset(length); if (this.ignoreNodes === null || !textSource.range) { return; } length = textSource.text().length; while (textSource.range && length > 0) { const nodes = TextSourceRange.getNodesInRange(textSource.range); if (!TextSourceRange.anyNodeMatchesSelector(nodes, this.ignoreNodes)) { break; } --length; textSource.setEndOffset(length); } } onSearchClear(_) { if (this.textSourceCurrent !== null) { if (this.options.scanning.selectText) { this.textSourceCurrent.deselect(); } this.textSourceCurrent = null; } } getCurrentTextSource() { return this.textSourceCurrent; } setCurrentTextSource(textSource) { return this.textSourceCurrent = textSource; } static isScanningModifierPressed(scanningModifier, mouseEvent) { switch (scanningModifier) { case 'alt': return mouseEvent.altKey; case 'ctrl': return mouseEvent.ctrlKey; case 'shift': return mouseEvent.shiftKey; case 'none': return true; default: return false; } } static getTouch(touchList, identifier) { for (const touch of touchList) { if (touch.identifier === identifier) { return touch; } } return null; } }