yomichan/ext/js/core.js

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JavaScript
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/*
* Copyright (C) 2019-2021 Yomichan Authors
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*
* 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
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
/**
* Converts an `Error` object to a serializable JSON object.
* @param error An error object to convert.
* @returns A simple object which can be serialized by `JSON.stringify()`.
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*/
function serializeError(error) {
try {
if (typeof error === 'object' && error !== null) {
return {
name: error.name,
message: error.message,
stack: error.stack,
data: error.data
};
}
} catch (e) {
// NOP
}
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return {
value: error,
hasValue: true
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};
}
/**
* Converts a serialized erorr into a standard `Error` object.
* @param serializedError A simple object which was initially generated by serializeError.
* @returns A new `Error` instance.
*/
function deserializeError(serializedError) {
if (serializedError.hasValue) {
return serializedError.value;
}
const error = new Error(serializedError.message);
error.name = serializedError.name;
error.stack = serializedError.stack;
error.data = serializedError.data;
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return error;
}
/**
* Checks whether a given value is a non-array object.
* @param value The value to check.
* @returns `true` if the value is an object and not an array, `false` otherwise.
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*/
function isObject(value) {
return typeof value === 'object' && value !== null && !Array.isArray(value);
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}
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/**
* Converts any string into a form that can be passed into the RegExp constructor.
* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
* @param string The string to convert to a valid regular expression.
* @returns The escaped string.
*/
function escapeRegExp(string) {
return string.replace(/[.*+\-?^${}()|[\]\\]/g, '\\$&');
}
/**
* Reverses a string.
* @param string The string to reverse.
* @returns The returned string, which retains proper UTF-16 surrogate pair order.
*/
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function stringReverse(string) {
return [...string].reverse().join('');
}
/**
* Creates a deep clone of an object or value. This is similar to `JSON.parse(JSON.stringify(value))`.
* @param value The value to clone.
* @returns A new clone of the value.
* @throws An error if the value is circular and cannot be cloned.
*/
const clone = (() => {
// eslint-disable-next-line no-shadow
function clone(value) {
if (value === null) { return null; }
switch (typeof value) {
case 'boolean':
case 'number':
case 'string':
case 'bigint':
case 'symbol':
case 'undefined':
return value;
default:
return cloneInternal(value, new Set());
}
}
function cloneInternal(value, visited) {
if (value === null) { return null; }
switch (typeof value) {
case 'boolean':
case 'number':
case 'string':
case 'bigint':
case 'symbol':
case 'undefined':
return value;
case 'function':
return cloneObject(value, visited);
case 'object':
return Array.isArray(value) ? cloneArray(value, visited) : cloneObject(value, visited);
}
}
function cloneArray(value, visited) {
if (visited.has(value)) { throw new Error('Circular'); }
try {
visited.add(value);
const result = [];
for (const item of value) {
result.push(cloneInternal(item, visited));
}
return result;
} finally {
visited.delete(value);
}
}
function cloneObject(value, visited) {
if (visited.has(value)) { throw new Error('Circular'); }
try {
visited.add(value);
const result = {};
for (const key in value) {
if (Object.prototype.hasOwnProperty.call(value, key)) {
result[key] = cloneInternal(value[key], visited);
}
}
return result;
} finally {
visited.delete(value);
}
}
return clone;
})();
/**
* Checks if an object or value is deeply equal to another object or value.
* @param value1 The first value to check.
* @param value2 The second value to check.
* @returns `true` if the values are the same object, or deeply equal without cycles. `false` otherwise.
*/
const deepEqual = (() => {
// eslint-disable-next-line no-shadow
function deepEqual(value1, value2) {
if (value1 === value2) { return true; }
const type = typeof value1;
if (typeof value2 !== type) { return false; }
switch (type) {
case 'object':
case 'function':
return deepEqualInternal(value1, value2, new Set());
default:
return false;
}
}
function deepEqualInternal(value1, value2, visited1) {
if (value1 === value2) { return true; }
const type = typeof value1;
if (typeof value2 !== type) { return false; }
switch (type) {
case 'object':
case 'function':
{
if (value1 === null || value2 === null) { return false; }
const array = Array.isArray(value1);
if (array !== Array.isArray(value2)) { return false; }
if (visited1.has(value1)) { return false; }
visited1.add(value1);
return array ? areArraysEqual(value1, value2, visited1) : areObjectsEqual(value1, value2, visited1);
}
default:
return false;
}
}
function areObjectsEqual(value1, value2, visited1) {
const keys1 = Object.keys(value1);
const keys2 = Object.keys(value2);
if (keys1.length !== keys2.length) { return false; }
const keys1Set = new Set(keys1);
for (const key of keys2) {
if (!keys1Set.has(key) || !deepEqualInternal(value1[key], value2[key], visited1)) { return false; }
}
return true;
}
function areArraysEqual(value1, value2, visited1) {
const length = value1.length;
if (length !== value2.length) { return false; }
for (let i = 0; i < length; ++i) {
if (!deepEqualInternal(value1[i], value2[i], visited1)) { return false; }
}
return true;
}
return deepEqual;
})();
/**
* Creates a new base-16 (lower case) string of a sequence of random bytes of the given length.
* @param length The number of bytes the string represents. The returned string's length will be twice as long.
* @returns A string of random characters.
*/
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function generateId(length) {
const array = new Uint8Array(length);
crypto.getRandomValues(array);
let id = '';
for (const value of array) {
id += value.toString(16).padStart(2, '0');
}
return id;
}
/**
* Creates an unresolved promise that can be resolved later, outside the promise's executor function.
* @returns An object `{promise, resolve, reject}`, containing the promise and the resolve/reject functions.
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*/
function deferPromise() {
let resolve;
let reject;
const promise = new Promise((resolve2, reject2) => {
resolve = resolve2;
reject = reject2;
});
return {promise, resolve, reject};
}
/**
* Creates a promise that is resolved after a set delay.
* @param delay How many milliseconds until the promise should be resolved. If 0, the promise is immediately resolved.
* @param resolveValue Optional; the value returned when the promise is resolved.
* @returns A promise with two additional properties: `resolve` and `reject`, which can be used to complete the promise early.
*/
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function promiseTimeout(delay, resolveValue) {
if (delay <= 0) {
const promise = Promise.resolve(resolveValue);
promise.resolve = () => {}; // NOP
promise.reject = () => {}; // NOP
return promise;
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}
let timer = null;
let {promise, resolve, reject} = deferPromise();
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const complete = (callback, value) => {
if (callback === null) { return; }
if (timer !== null) {
clearTimeout(timer);
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timer = null;
}
resolve = null;
reject = null;
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callback(value);
};
const resolveWrapper = (value) => complete(resolve, value);
const rejectWrapper = (value) => complete(reject, value);
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timer = setTimeout(() => {
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timer = null;
resolveWrapper(resolveValue);
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}, delay);
promise.resolve = resolveWrapper;
promise.reject = rejectWrapper;
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return promise;
}
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/**
* Creates a promise that will resolve after the next animation frame, using `requestAnimationFrame`.
* @param timeout Optional; a maximum duration (in milliseconds) to wait until the promise resolves. If null or omitted, no timeout is used.
* @returns A promise that is resolved with `{time, timeout}`, where `time` is the timestamp from `requestAnimationFrame`,
* and `timeout` is a boolean indicating whether the cause was a timeout or not.
* @throws The promise throws an error if animation is not supported in this context, such as in a service worker.
*/
function promiseAnimationFrame(timeout=null) {
return new Promise((resolve, reject) => {
if (typeof cancelAnimationFrame !== 'function' || typeof requestAnimationFrame !== 'function') {
reject(new Error('Animation not supported in this context'));
return;
}
let timer = null;
let frameRequest = null;
const onFrame = (time) => {
frameRequest = null;
if (timer !== null) {
clearTimeout(timer);
timer = null;
}
resolve({time, timeout: false});
};
const onTimeout = () => {
timer = null;
if (frameRequest !== null) {
// eslint-disable-next-line no-undef
cancelAnimationFrame(frameRequest);
frameRequest = null;
}
resolve({time: performance.now(), timeout: true});
};
// eslint-disable-next-line no-undef
frameRequest = requestAnimationFrame(onFrame);
if (typeof timeout === 'number') {
timer = setTimeout(onTimeout, timeout);
}
});
}
/**
* Base class controls basic event dispatching.
*/
class EventDispatcher {
/**
* Creates a new instance.
*/
constructor() {
this._eventMap = new Map();
}
/**
* Triggers an event with the given name and specified argument.
* @param eventName The string representing the event's name.
* @param details Optional; the argument passed to the callback functions.
* @returns `true` if any callbacks were registered, `false` otherwise.
*/
trigger(eventName, details) {
const callbacks = this._eventMap.get(eventName);
if (typeof callbacks === 'undefined') { return false; }
for (const callback of callbacks) {
callback(details);
}
return true;
}
/**
* Adds a single event listener to a specific event.
* @param eventName The string representing the event's name.
* @param callback The event listener callback to add.
*/
on(eventName, callback) {
let callbacks = this._eventMap.get(eventName);
if (typeof callbacks === 'undefined') {
callbacks = [];
this._eventMap.set(eventName, callbacks);
}
callbacks.push(callback);
}
/**
* Removes a single event listener from a specific event.
* @param eventName The string representing the event's name.
* @param callback The event listener callback to add.
* @returns `true` if the callback was removed, `false` otherwise.
*/
off(eventName, callback) {
const callbacks = this._eventMap.get(eventName);
if (typeof callbacks === 'undefined') { return true; }
const ii = callbacks.length;
for (let i = 0; i < ii; ++i) {
if (callbacks[i] === callback) {
callbacks.splice(i, 1);
if (callbacks.length === 0) {
this._eventMap.delete(eventName);
}
return true;
}
}
return false;
}
/**
* Checks if an event has any listeners.
* @param eventName The string representing the event's name.
* @returns `true` if the event has listeners, `false` otherwise.
*/
hasListeners(eventName) {
const callbacks = this._eventMap.get(eventName);
return (typeof callbacks !== 'undefined' && callbacks.length > 0);
}
}
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/**
* Class which stores event listeners added to various objects, making it easy to remove them in bulk.
*/
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class EventListenerCollection {
/**
* Creates a new instance.
*/
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constructor() {
this._eventListeners = [];
}
/**
* Returns the number of event listeners that are currently in the object.
* @returns The number of event listeners that are currently in the object.
*/
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get size() {
return this._eventListeners.length;
}
/**
* Adds an event listener of a generic type.
* @param type The type of event listener, which can be 'addEventListener', 'addListener', or 'on'.
* @param object The object to add the event listener to.
* @param args The argument array passed to the object's event listener adding function.
* @throws An error if type is not an expected value.
*/
addGeneric(type, object, ...args) {
switch (type) {
case 'addEventListener': return this.addEventListener(object, ...args);
case 'addListener': return this.addListener(object, ...args);
case 'on': return this.on(object, ...args);
default: throw new Error(`Invalid type: ${type}`);
}
}
/**
* Adds an event listener using `object.addEventListener`. The listener will later be removed using `object.removeEventListener`.
* @param object The object to add the event listener to.
* @param args The argument array passed to the `addEventListener`/`removeEventListener` functions.
*/
addEventListener(object, ...args) {
object.addEventListener(...args);
this._eventListeners.push(['removeEventListener', object, ...args]);
}
/**
* Adds an event listener using `object.addListener`. The listener will later be removed using `object.removeListener`.
* @param object The object to add the event listener to.
* @param args The argument array passed to the `addListener`/`removeListener` function.
*/
addListener(object, ...args) {
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object.addListener(...args);
this._eventListeners.push(['removeListener', object, ...args]);
}
/**
* Adds an event listener using `object.on`. The listener will later be removed using `object.off`.
* @param object The object to add the event listener to.
* @param args The argument array passed to the `on`/`off` function.
*/
on(object, ...args) {
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object.on(...args);
this._eventListeners.push(['off', object, ...args]);
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}
/**
* Removes all event listeners added to objects for this instance and clears the internal list of event listeners.
*/
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removeAllEventListeners() {
if (this._eventListeners.length === 0) { return; }
for (const [removeFunctionName, object, ...args] of this._eventListeners) {
switch (removeFunctionName) {
case 'removeEventListener':
object.removeEventListener(...args);
break;
case 'removeListener':
object.removeListener(...args);
break;
case 'off':
object.off(...args);
break;
default:
throw new Error(`Unknown remove function: ${removeFunctionName}`);
}
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}
this._eventListeners = [];
}
}
/**
* Class representing a generic value with an override stack.
* Changes can be observed by listening to the 'change' event.
*/
class DynamicProperty extends EventDispatcher {
/**
* Creates a new instance with the specified value.
* @param value The value to assign.
*/
constructor(value) {
super();
this._value = value;
this._defaultValue = value;
this._overrides = [];
}
/**
* Gets the default value for the property, which is assigned to the
* public value property when no overrides are present.
*/
get defaultValue() {
return this._defaultValue;
}
/**
* Assigns the default value for the property. If no overrides are present
* and if the value is different than the current default value,
* the 'change' event will be triggered.
* @param value The value to assign.
*/
set defaultValue(value) {
this._defaultValue = value;
if (this._overrides.length === 0) { this._updateValue(); }
}
/**
* Gets the current value for the property, taking any overrides into account.
*/
get value() {
return this._value;
}
/**
* Gets the number of overrides added to the property.
*/
get overrideCount() {
return this._overrides.length;
}
/**
* Adds an override value with the specified priority to the override stack.
* Values with higher priority will take precedence over those with lower.
* For tie breaks, the override value added first will take precedence.
* If the newly added override has the highest priority of all overrides
* and if the override value is different from the current value,
* the 'change' event will be fired.
* @param value The override value to assign.
* @param priority The priority value to use, as a number.
* @returns A string token which can be passed to the clearOverride function
* to remove the override.
*/
setOverride(value, priority=0) {
const overridesCount = this._overrides.length;
let i = 0;
for (; i < overridesCount; ++i) {
if (priority > this._overrides[i].priority) { break; }
}
const token = generateId(16);
this._overrides.splice(i, 0, {value, priority, token});
if (i === 0) { this._updateValue(); }
return token;
}
/**
* Removes a specific override value. If the removed override
* had the highest priority, and the new value is different from
* the previous value, the 'change' event will be fired.
* @param token The token for the corresponding override which is to be removed.
* @returns true if an override was returned, false otherwise.
*/
clearOverride(token) {
for (let i = 0, ii = this._overrides.length; i < ii; ++i) {
if (this._overrides[i].token === token) {
this._overrides.splice(i, 1);
if (i === 0) { this._updateValue(); }
return true;
}
}
return false;
}
/**
* Updates the current value using the current overrides and default value.
* If the new value differs from the previous value, the 'change' event will be fired.
*/
_updateValue() {
const value = this._overrides.length > 0 ? this._overrides[0].value : this._defaultValue;
if (this._value === value) { return; }
this._value = value;
this.trigger('change', {value});
}
}