qualifiers/autoFocus.ts

import {QualifierValue} from "../internal/qualifier/QualifierValue.js";
import {FocusOnValue} from "./focusOn.js";

/**
 * @summary qualifier
 * @namespace AutoFocus
 * @memberOf Qualifiers
 * @see Visit {@link Qualifiers.Gravity|Gravity} for an example
 */


/**
 * @memberOf Qualifiers.AutoFocus
 * @extends {SDK.QualifierValue}
 * @see Visit {@link Qualifiers.Gravity|Gravity} for an example
 */
class AutoFocus extends QualifierValue {
  readonly focusOn: FocusOnValue;
  private _weight: number | string;
  private shouldAvoid: boolean;

  /**
   * @summary qualifier
   * @description Specifies the object to focus on automatically
   * Accepts an AutoFocusObject (which is just a wrapper for a FocusOn object, but with extra method: avoid, weight)
   * @param {Qualifiers.FocusOn} obj The object to focus on.
   * @param {number} weight
   */
  static focusOn(obj: FocusOnValue, weight?: number): AutoFocus {
    return new AutoFocus(obj, weight);
  }

  constructor(focusOn: FocusOnValue, weight?: number | string) {
    super();
    this._weight = weight;
    this.focusOn = focusOn;
    this.shouldAvoid = false;
  }

  private shouldAddWeight() {
    return typeof this._weight === 'number' || typeof this._weight === 'string' || this.shouldAvoid;
  }

  /**
   * @summary qualifier
   * @desc Get the name of the of the object
   */
  private getName(): string {
    return this.focusOn.name;
  }

  /**
   * @summary qualifier
   * @desc Get the weight for the object
   */
  private getWeight(): number | string {
    if (this.shouldAvoid) {
      return 'avoid';
    } else {
      return this._weight;
    }
  }

  /**
   * @summary qualifier
   * @desc Return the string representation of this QualifierValue
   */
  toString(): string {
    // Future proofing, in case we'd like to support some custom string in the future, or if data is coming from a DB
    if (this.shouldAddWeight()) {
      return `${this.getName()}_${this.getWeight()}`;
    } else {
      return `${this.getName()}`;
    }
  }

  /**
   * @summary qualifier
   * @description Sets the importance level of the object within the automatic gravity algorithm
   * @param {numebr} w The focus weight for the object
   * @return {this}
   */
  weight(w: number | string): this {
    this._weight = w;
    return this;
  }

  /**
   * @summary qualifier
   * @description Attempts to avoid the detected object in the image
   * @return {this}
   */
  avoid(): this {
    this.shouldAvoid = true;
    return this;
  }
}

const focusOn = AutoFocus.focusOn;

export {AutoFocus, focusOn};