@woosh/meep-engine/src/core/model/ObservedEnum.js

Pure JavaScript game engine. Fully featured and production ready.

import { assert } from "../assert.js";
import Signal from "../events/signal/Signal.js";

class ObservedEnum {
    /**
     * @template T
     * @param {T} value
     * @param {Object.<string,T>} validSet
     * @constructor
     */
    constructor(value, validSet) {
        assert.equal(typeof validSet, "object", `ValidSet must be of type "object", instead was ${typeof validSet}`);
        assert.notEqual(Object.values(validSet).indexOf(value), -1, `Value must be one of [${Object.values(validSet).join(", ")}], instead was "${value}"`);

        /**
         *
         * @type {T}
         * @private
         */
        this.__value = value;
        this.__validSet = validSet;

        this.onChanged = new Signal();
    }

    /**
     *
     * @returns {Object<string, T>}
     */
    getValidValueSet() {
        return this.__validSet;
    }

    /**
     *
     * @param {T} value
     * @returns {ObservedEnum}
     */
    set(value) {
        assert.notEqual(Object.values(this.__validSet).indexOf(value), -1, `Value must be one of [${Object.values(this.__validSet).join(", ")}], instead was "${value}"`);

        const oldValue = this.__value;
        if (oldValue !== value) {
            this.__value = value;
            this.onChanged.dispatch(value, oldValue);
        }

        return this;
    }

    /**
     * @template X
     * @param {ObservedEnum<X>} other
     * @returns {boolean}
     */
    equals(other) {
        return this.__value === other.__value;
    }

    /**
     *
     * @param {ObservedEnum} other
     */
    copy(other) {
        this.set(other.getValue());
    }

    /**
     *
     * @returns {T}
     */
    getValue() {
        return this.__value;
    }

    invert() {
        this.set(!this.__value);
    }

    /**
     *
     * @param {function(T,T)} processor
     */
    process(processor) {
        this.onChanged.add(processor);

        processor(this.__value, this.__value);
    }

    toJSON() {
        return this.__value;
    }

    fromJSON(obj) {
        this.set(obj);
    }
}

export default ObservedEnum;