yomichan/ext/mixed/js/text-scanner.js
2020-01-01 12:00:31 -05:00

379 lines
11 KiB
JavaScript

/*
* 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/>.
*/
class TextScanner {
constructor(node, ignoreNodes, ignoreElements, ignorePoints) {
this.node = node;
this.ignoreNodes = (Array.isArray(ignoreNodes) && ignoreNodes.length > 0 ? ignoreNodes.join(',') : null);
this.ignoreElements = ignoreElements;
this.ignorePoints = ignorePoints;
this.scanTimerPromise = null;
this.textSourceCurrent = null;
this.pendingLookup = false;
this.options = null;
this.enabled = false;
this.eventListeners = [];
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.getIndexOfTouch(e.changedTouches, this.primaryTouchIdentifier) < 0
) {
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 touches = e.changedTouches;
const index = TextScanner.getIndexOfTouch(touches, this.primaryTouchIdentifier);
if (index < 0) {
return;
}
const primaryTouch = touches[index];
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.clearEventListeners();
this.enabled = false;
}
this.onSearchClear(false);
}
}
hookEvents() {
let eventListeners = this.getMouseEventListeners();
if (this.options.scanning.touchInputEnabled) {
eventListeners = eventListeners.concat(this.getTouchEventListeners());
}
for (const [node, type, listener, options] of eventListeners) {
this.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)]
];
}
addEventListener(node, type, listener, options) {
node.addEventListener(type, listener, options);
this.eventListeners.push([node, type, listener, options]);
}
clearEventListeners() {
for (const [node, type, listener, options] of this.eventListeners) {
node.removeEventListener(type, listener, options);
}
this.eventListeners = [];
}
setOptions(options) {
this.options = options;
}
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);
if (this.textSourceCurrent !== null && this.textSourceCurrent.equals(textSource)) {
return;
}
try {
this.pendingLookup = true;
const result = await this.onSearchSource(textSource, cause);
if (result !== null) {
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 getIndexOfTouch(touchList, identifier) {
for (const i in touchList) {
const t = touchList[i];
if (t.identifier === identifier) {
return i;
}
}
return -1;
}
}