yomichan/ext/js/display/element-overflow-controller.js

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JavaScript
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/*
* Copyright (C) 2021-2022 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/>.
*/
class ElementOverflowController {
constructor() {
this._elements = [];
this._checkTimer = null;
this._eventListeners = new EventListenerCollection();
this._windowEventListeners = new EventListenerCollection();
this._dictionaries = new Map();
this._updateBind = this._update.bind(this);
this._onWindowResizeBind = this._onWindowResize.bind(this);
this._onToggleButtonClickBind = this._onToggleButtonClick.bind(this);
}
setOptions(options) {
this._dictionaries.clear();
for (const {name, definitionsCollapsible} of options.dictionaries) {
let collapsible = false;
let collapsed = false;
switch (definitionsCollapsible) {
case 'expanded':
collapsible = true;
break;
case 'collapsed':
collapsible = true;
collapsed = true;
break;
}
if (!collapsible) { continue; }
this._dictionaries.set(name, {collapsed});
}
}
addElements(entry) {
if (this._dictionaries.size === 0) { return; }
const elements = entry.querySelectorAll('.definition-item-inner');
let any = false;
for (const element of elements) {
const {dictionary} = element.parentNode.dataset;
const dictionaryInfo = this._dictionaries.get(dictionary);
if (typeof dictionaryInfo === 'undefined') { continue; }
this._updateElement(element);
this._elements.push(element);
if (dictionaryInfo.collapsed) {
element.classList.add('collapsed');
}
const button = element.querySelector('.definition-item-expansion-button');
if (button !== null) {
this._eventListeners.addEventListener(button, 'click', this._onToggleButtonClickBind, false);
}
any = true;
}
if (any && this._windowEventListeners.size === 0) {
this._windowEventListeners.addEventListener(window, 'resize', this._onWindowResizeBind, false);
}
}
clearElements() {
if (this._elements.length === 0) { return; }
this._elements = [];
this._windowEventListeners.removeAllEventListeners();
}
// Private
_onWindowResize() {
if (this._checkTimer !== null) {
this._cancelIdleCallback(this._checkTimer);
}
this._checkTimer = this._requestIdleCallback(this._updateBind, 100);
}
_onToggleButtonClick(e) {
const container = e.currentTarget.closest('.definition-item-inner');
if (container === null) { return; }
container.classList.toggle('collapsed');
}
_update() {
for (const element of this._elements) {
this._updateElement(element);
}
}
_updateElement(element) {
const {classList} = element;
classList.add('collapse-test');
const collapsible = element.scrollHeight > element.clientHeight || element.scrollWidth > element.clientWidth;
classList.toggle('collapsible', collapsible);
classList.remove('collapse-test');
}
_requestIdleCallback(callback, timeout) {
if (typeof requestIdleCallback === 'function') {
return requestIdleCallback(callback, {timeout});
} else {
return setTimeout(callback, timeout);
}
}
_cancelIdleCallback(handle) {
if (typeof cancelIdleCallback === 'function') {
cancelIdleCallback(handle);
} else {
clearTimeout(handle);
}
}
}