@woosh/meep-engine/src/core/process/undo/Action.js

Pure JavaScript game engine. Fully featured and production ready.

/**
 * Base class for implementing reversible actions.
 * Actions are intended to be used in conjunction with {@link ActionProcessor}
 * @template CTX
 *
 * @author Alex Goldring
 * @copyright Company Named Limited (c) 2025
 */
export class Action {
    /**
     * How much memory does this action require, used by the ActionProcessor in order to decide how much history to keep
     * @return {number}
     */
    computeByteSize() {
        return 1;
    }

    /**
     * Apply action
     * @param {CTX} context
     */
    async apply(context) {
        throw new Error('Not Implemented. Needs to be overridden in subclass');
    }

    /**
     * Revert action, restoring state to just before this action was applied
     * @param {CTX} context
     */
    async revert(context) {
        throw new Error('Not Implemented. Needs to be overridden in subclass');
    }
}

/**
 * Used for quick instanceof checks
 * @type {boolean}
 */
Action.prototype.isAction = true;