How to get a value from a setter method?-CodePudding

I have this setter method that I got from a YouTube video by Coding with Adam:

class SpriteAnimation{
  images = [];
  constructor(fileNameTemplate, numberOfImages, timerCount, state, stopAtEnd) {
    for (let i = 1; i <= numberOfImages; i  ) {
      const image = img(fileNameTemplate.replace("?", i));
      this.images.push(image);
    }
    this.timerCount = timerCount;
    this.timerCountDefault = this.timerCount;
    this.imageIndex = 0;
    this.state = state;
    this.stopAtEnd = stopAtEnd;
  }

  isFor(state) {
    return this.state === state;
  }

  reset() {
    this.imageIndex = 0;
  }

  getImage() {
    this.#setImageIndex();
    return this.images[this.imageIndex];
  }
  
  #setImageIndex() {
    this.timerCount--;
    if (this.timerCount <= 0 && !this.#shouldStop()) {
      this.timerCount = this.timerCountDefault;
      this.imageIndex  ;
      if (this.imageIndex >= this.images.length) { 
        this.imageIndex = 0;
      }
    }
  }

  #shouldStop(){
    return this.stopAtEnd && this.imageIndex === this.images.length -1;
  }
}

I need to get the value of the imageIndex as the animation is playing so I thought I should get it through the #setImageIndex() method, but I don't have any idea how.

I tried using a getter method for it:

  getImageIndex(){
    return this.imageIndex;
  }

But it only returned 0.

Any help is appreciated, thank you!

CodePudding user response：

If you are only getting 0, it means that the imageIndex property is not being updated during the animation. try this code

class SpriteAnimation {
  images = [];
  timerCount = 0;
  timerCountDefault = 0;
  imageIndex = 0;
  state = "";
  stopAtEnd = false;

  constructor(fileNameTemplate, numberOfImages, timerCount, state, stopAtEnd) {
  for (let i = 1; i <= numberOfImages; i  ) {
  const image = img(fileNameTemplate.replace("?", i));
  this.images.push(image);
  }
  this.timerCount = timerCount;
  this.timerCountDefault = timerCount;
  this.state = state;
  this.stopAtEnd = stopAtEnd;
  }

  isFor(state) {
  return this.state === state;
  }

  reset() {
  this.imageIndex = 0;
  this.timerCount = this.timerCountDefault;
   }

  getImage() {
  this.timerCount--;
  if (this.timerCount <= 0 && !this.shouldStop()) {
  this.timerCount = this.timerCountDefault;
  this.imageIndex  ;
  if (this.imageIndex >= this.images.length) {
    this.imageIndex = 0;
  }
  }
  return this.images[this.imageIndex];
  }

  getImageIndex() {
  return this.imageIndex;
   }

  shouldStop() {
  return this.stopAtEnd && this.imageIndex === this.images.length - 1;
   }
  }