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-rw-r--r--ext/mixed/js/text-scanner.js378
1 files changed, 378 insertions, 0 deletions
diff --git a/ext/mixed/js/text-scanner.js b/ext/mixed/js/text-scanner.js
new file mode 100644
index 00000000..ac5d68d1
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+++ b/ext/mixed/js/text-scanner.js
@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) 2019 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 <http://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);
+ 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;
+ }
+}