stateDesignPattern.ts

abstract class AnimationState {
    abstract name  : string;

    sprite: Sprite;

    constructor(context? : Sprite, state? : AnimationState){
        if(context)
            this.sprite = context;
        else if(state){
            this.sprite = state.sprite;
        }
    }

    isPlaying: boolean;

    stop() : void {
        this.isPlaying = false;
    }

    play() : void {
        this.isPlaying = true;
    }

    abstract setDying() : void;
    abstract setRunning() : void;
    abstract setIdle() : void;

}

class IdleAnimation extends AnimationState{

    name: string = "IDLE";

    setDying(): void {
        this.sprite.animation = new DyingAnimation(this.sprite);
    }

    setRunning(): void {
        this.sprite.animation = new RunningAnimation(this.sprite);
    }

    setIdle(): void {
        //can't set IDLE when already IDLE
        return;
    }
}

class DyingAnimation extends AnimationState{

    name: string = "DYING";

    animationTime: number = 5000;

    //can't change ANIMATION when dying
    constructor(context? : Sprite, state? : AnimationState){
        super();
        setTimeout(() => {this.kill()} , this.animationTime);
    }

    kill(){
        this.sprite.kill();
    }
    setDying(): void {

    }

    setRunning(): void {
    }

    setIdle(): void {
    }
}

class RunningAnimation extends AnimationState{

    name: string = "RUNNING";

    setDying(): void {
        this.sprite.animation = new DyingAnimation(this.sprite);
    }

    setRunning(): void {
    }

    setIdle(): void {
        this.sprite.animation = new IdleAnimation(this.sprite);
    }
}

class Sprite {

    private _animationState : AnimationState;


    constructor(){
        this._animationState = new IdleAnimation(this);
    }

    get animation(){
        return this._animationState;
    }
    set animation(s){
        this._animationState = s;
    }

    kill(){
        //remove game object
    }

}