imagemagick-async/im_modules/Drawables/Effects/Mod/Color/hue.js

An API for Image Magick commands.

let Path = require('path');

let PathParts = __dirname.split(Path.sep);
let index = PathParts.indexOf('imagemagick-async');
let RootDir = PathParts.slice(0, index + 1).join(Path.sep);

let Err = require(Path.join(RootDir, 'error.js'));
let Validate = require(Path.join(RootDir, 'validate.js'));
let Filepath = require(Path.join(RootDir, 'filepath.js')).Filepath;
let ColorBaseClass = require(Path.join(Filepath.ModColorDir(), 'colorbaseclass.js')).ColorBaseClass;

//------------------------------

class Hue extends ColorBaseClass {
  constructor(builder) {
    super(builder);
  }

  /**
   * @override
   */
  static get Builder() {
    class Builder {
      constructor() {
        this.name = 'Hue';
        this.args = {};
      }

      /**
       * @param {string} str The path of the image file you are modifying.
       */
      source(str) {
        this.args.source = str;
        return this;
      }

      /**
       * @param {number} n Hue value between 0 and 200. A value of 100 will make no changes.
       */
      value(n) {
        this.args.value = n;
        return this;
      }

      build() {
        return new Hue(this);
      }
    }
    return new Builder();
  }

  /**
   * @returns {Array<string|number>} Returns an array of image magick arguments associated with this layer.
   */
  Args() {
    return ['-modulate', `100,100,${this.args.value}`];
  }

  /**
   * @override
   */
  Errors() {
    let params = Hue.Parameters();
    let errors = [];
    let prefix = 'HUE_COLOR_MOD_ERROR';

    let sourceErr = Err.ErrorMessage.Builder
      .prefix(prefix)
      .varName('Source')
      .condition(
        new Err.StringCondition.Builder(this.args.source)
          .isempty(false)
          .isWhitespace(false)
          .build()
      )
      .build()
      .String();

    if (sourceErr)
      errors.push(sourceErr);

    let valueErr = Err.ErrorMessage.Builder
      .prefix(prefix)
      .varName('Value')
      .condition(
        new Err.NumberCondition.Builder(this.args.value)
          .isInteger(true)
          .min(params.value.min)
          .max(params.value.max)
          .build()
      )
      .build()
      .String();

    if (sourceErr)
      errors.push(sourceErr);

    return errors;
  }

  /**
   * @override
   */
  IsConsolidatable() {
    return true;
  }

  /**
   * @override
   */
  static Parameters() {
    return {
      source: {
        type: 'string',
        required: true
      },
      value: {
        type: 'number',
        min: 0,
        max: 200,
        required: true
      }
    };
  }
}

//---------------------------
// EXPORTS

exports.Hue = Hue;