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+/*
+ * Copyright (C) 2020-2021 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
+ * SelectorObserver
+ * TaskAccumulator
+ */
+
+class DOMDataBinder {
+ constructor({selector, ignoreSelectors=[], createElementMetadata, compareElementMetadata, getValues, setValues, onError=null}) {
+ this._selector = selector;
+ this._ignoreSelectors = ignoreSelectors;
+ this._createElementMetadata = createElementMetadata;
+ this._compareElementMetadata = compareElementMetadata;
+ this._getValues = getValues;
+ this._setValues = setValues;
+ this._onError = onError;
+ this._updateTasks = new TaskAccumulator(this._onBulkUpdate.bind(this));
+ this._assignTasks = new TaskAccumulator(this._onBulkAssign.bind(this));
+ this._selectorObserver = new SelectorObserver({
+ selector,
+ ignoreSelector: (ignoreSelectors.length > 0 ? ignoreSelectors.join(',') : null),
+ onAdded: this._createObserver.bind(this),
+ onRemoved: this._removeObserver.bind(this),
+ onChildrenUpdated: this._onObserverChildrenUpdated.bind(this),
+ isStale: this._isObserverStale.bind(this)
+ });
+ }
+
+ observe(element) {
+ this._selectorObserver.observe(element, true);
+ }
+
+ disconnect() {
+ this._selectorObserver.disconnect();
+ }
+
+ async refresh() {
+ await this._updateTasks.enqueue(null, {all: true});
+ }
+
+ // Private
+
+ async _onBulkUpdate(tasks) {
+ let all = false;
+ const targets = [];
+ for (const [observer, task] of tasks) {
+ if (observer === null) {
+ if (task.data.all) {
+ all = true;
+ break;
+ }
+ } else {
+ targets.push([observer, task]);
+ }
+ }
+ if (all) {
+ targets.length = 0;
+ for (const observer of this._selectorObserver.datas()) {
+ targets.push([observer, null]);
+ }
+ }
+
+ const args = targets.map(([observer]) => ({
+ element: observer.element,
+ metadata: observer.metadata
+ }));
+ const responses = await this._getValues(args);
+ this._applyValues(targets, responses, true);
+ }
+
+ async _onBulkAssign(tasks) {
+ const targets = tasks;
+ const args = targets.map(([observer, task]) => ({
+ element: observer.element,
+ metadata: observer.metadata,
+ value: task.data.value
+ }));
+ const responses = await this._setValues(args);
+ this._applyValues(targets, responses, false);
+ }
+
+ _onElementChange(observer) {
+ const value = this._getElementValue(observer.element);
+ observer.value = value;
+ observer.hasValue = true;
+ this._assignTasks.enqueue(observer, {value});
+ }
+
+ _applyValues(targets, response, ignoreStale) {
+ if (!Array.isArray(response)) { return; }
+
+ for (let i = 0, ii = targets.length; i < ii; ++i) {
+ const [observer, task] = targets[i];
+ const {error, result} = response[i];
+ const stale = (task !== null && task.stale);
+
+ if (error) {
+ if (typeof this._onError === 'function') {
+ this._onError(error, stale, observer.element, observer.metadata);
+ }
+ continue;
+ }
+
+ if (stale && !ignoreStale) { continue; }
+
+ observer.value = result;
+ observer.hasValue = true;
+ this._setElementValue(observer.element, result);
+ }
+ }
+
+ _createObserver(element) {
+ const metadata = this._createElementMetadata(element);
+ const nodeName = element.nodeName.toUpperCase();
+ const observer = {
+ element,
+ type: (nodeName === 'INPUT' ? element.type : null),
+ value: null,
+ hasValue: false,
+ onChange: null,
+ metadata
+ };
+ observer.onChange = this._onElementChange.bind(this, observer);
+
+ element.addEventListener('change', observer.onChange, false);
+
+ this._updateTasks.enqueue(observer);
+
+ return observer;
+ }
+
+ _removeObserver(element, observer) {
+ element.removeEventListener('change', observer.onChange, false);
+ observer.onChange = null;
+ }
+
+ _onObserverChildrenUpdated(element, observer) {
+ if (observer.hasValue) {
+ this._setElementValue(element, observer.value);
+ }
+ }
+
+ _isObserverStale(element, observer) {
+ const {type, metadata} = observer;
+ const nodeName = element.nodeName.toUpperCase();
+ return !(
+ type === (nodeName === 'INPUT' ? element.type : null) &&
+ this._compareElementMetadata(metadata, this._createElementMetadata(element))
+ );
+ }
+
+ _setElementValue(element, value) {
+ switch (element.nodeName.toUpperCase()) {
+ case 'INPUT':
+ switch (element.type) {
+ case 'checkbox':
+ element.checked = value;
+ break;
+ case 'text':
+ case 'number':
+ element.value = value;
+ break;
+ }
+ break;
+ case 'TEXTAREA':
+ case 'SELECT':
+ element.value = value;
+ break;
+ }
+
+ const event = new CustomEvent('settingChanged', {detail: {value}});
+ element.dispatchEvent(event);
+ }
+
+ _getElementValue(element) {
+ switch (element.nodeName.toUpperCase()) {
+ case 'INPUT':
+ switch (element.type) {
+ case 'checkbox':
+ return !!element.checked;
+ case 'text':
+ return `${element.value}`;
+ case 'number':
+ return DOMDataBinder.convertToNumber(element.value, element);
+ }
+ break;
+ case 'TEXTAREA':
+ case 'SELECT':
+ return element.value;
+ }
+ return null;
+ }
+
+ // Utilities
+
+ static convertToNumber(value, constraints) {
+ value = parseFloat(value);
+ if (!Number.isFinite(value)) { return 0; }
+
+ let {min, max, step} = constraints;
+ min = DOMDataBinder.convertToNumberOrNull(min);
+ max = DOMDataBinder.convertToNumberOrNull(max);
+ step = DOMDataBinder.convertToNumberOrNull(step);
+ if (typeof min === 'number') { value = Math.max(value, min); }
+ if (typeof max === 'number') { value = Math.min(value, max); }
+ if (typeof step === 'number' && step !== 0) { value = Math.round(value / step) * step; }
+ return value;
+ }
+
+ static convertToNumberOrNull(value) {
+ if (typeof value !== 'number') {
+ if (typeof value !== 'string' || value.length === 0) {
+ return null;
+ }
+ value = parseFloat(value);
+ }
+ return !Number.isNaN(value) ? value : null;
+ }
+}