avocado-old/packages/topdown/traits/layered.trait.js

import {Trait} from '@avocado/entity';

export class Layered extends Trait {

  static type() {
    return 'layered';
  }

  constructor(entity, params, state) {
    super(entity, params, state);
    this.entity.layer = null;
  }

  destroy() {
    this.entity.removeFromLayer();
  }

  methods() {
    return {

      removeFromLayer: () => {
        const layer = this.entity.layer;
        if (!layer) {
          return;
        }
        this.entity.layer = null;
        this.entity.emit('removedFromLayer', layer);
      },

      setIntoLayer: (layer) => {
        this.entity.layer = layer;
        this.entity.emit('addedToLayer');
      },

    };
  }

}