# Source: src/gameobjects/components/LifeSpan.js

    /**
    * @author       Richard Davey <rich@photonstorm.com>
    * @copyright    2016 Photon Storm Ltd.
    * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
    */

    /**
    * LifeSpan Component Features.
    *
    * @class
    */
    Phaser.Component.LifeSpan = function () {};

    /**
     * The LifeSpan component preUpdate handler.
     * Called automatically by the Game Object.
     *
     * @method
     */
    Phaser.Component.LifeSpan.preUpdate = function () {

        if (this.lifespan > 0)
        {
            this.lifespan -= this.game.time.physicsElapsedMS;

            if (this.lifespan <= 0)
            {
                this.kill();
                return false;
            }
        }

        return true;

    };

    Phaser.Component.LifeSpan.prototype = {

        /**
        * A useful flag to control if the Game Object is alive or dead.
        *
        * This is set automatically by the Health components `damage` method should the object run out of health.
        * Or you can toggle it via your game code.
        *
        * This property is mostly just provided to be used by your game - it doesn't effect rendering or logic updates.
        * However you can use `Group.getFirstAlive` in conjunction with this property for fast object pooling and recycling.
        * @property {boolean} alive
        * @default
        */
        alive: true,

        /**
        * The lifespan allows you to give a Game Object a lifespan in milliseconds.
        *
        * Once the Game Object is 'born' you can set this to a positive value.
        *
        * It is automatically decremented by the millisecond equivalent of `game.time.physicsElapsed` each frame.
        * When it reaches zero it will call the `kill` method.
        *
        * Very handy for particles, bullets, collectibles, or any other short-lived entity.
        *
        * @property {number} lifespan
        * @default
        */
        lifespan: 0,

        /**
        * Brings a 'dead' Game Object back to life, optionally resetting its health value in the process.
        *
        * A resurrected Game Object has its `alive`, `exists` and `visible` properties all set to true.
        *
        * It will dispatch the `onRevived` event. Listen to `events.onRevived` for the signal.
        *
        * @method
        * @param {number} [health=100] - The health to give the Game Object. Only set if the GameObject has the Health component.
        * @return {PIXI.DisplayObject} This instance.
        */
        revive: function (health) {

            if (health === undefined) { health = 100; }

            this.alive = true;
            this.exists = true;
            this.visible = true;

            if (typeof this.setHealth === 'function')
            {
                this.setHealth(health);
            }

            if (this.events)
            {
                this.events.onRevived$dispatch(this);
            }

            return this;

        },

        /**
        * Kills a Game Object. A killed Game Object has its `alive`, `exists` and `visible` properties all set to false.
        *
        * It will dispatch the `onKilled` event. You can listen to `events.onKilled` for the signal.
        *
        * Note that killing a Game Object is a way for you to quickly recycle it in an object pool,
        * it doesn't destroy the object or free it up from memory.
        *
        * If you don't need this Game Object any more you should call `destroy` instead.
        *
        * @method
        * @return {PIXI.DisplayObject} This instance.
        */
        kill: function () {

            this.alive = false;
            this.exists = false;
            this.visible = false;

            if (this.events)
            {
                this.events.onKilled$dispatch(this);
            }

            return this;

        }

    };