lindell / JsBarcode

import { SIDE_BIN, MIDDLE_BIN } from './constants';

import encode from './encoder';

import Barcode from '../Barcode';

// Base class for EAN8 & EAN13

class EAN extends Barcode {

	constructor(data, options) {

		super(data, options);

		// Make sure the font is not bigger than the space between the guard bars

		this.fontSize = !options.flat && options.fontSize > options.width * 10

			? options.width * 10

			: options.fontSize;

		// Make the guard bars go down half the way of the text

		this.guardHeight = options.height + this.fontSize / 2 + options.textMargin;

	}

	encode() {

		return this.options.flat

			? this.encodeFlat()

			: this.encodeGuarded();

	}

	leftText(from, to) {

		return this.text.substr(from, to);

	}

	leftEncode(data, structure) {

		return encode(data, structure);

	}

	rightText(from, to) {

		return this.text.substr(from, to);

	}

	rightEncode(data, structure) {

		return encode(data, structure);

	}

	encodeGuarded() {

		const textOptions = { fontSize: this.fontSize };

		const guardOptions = { height: this.guardHeight };

		return [

			{ data: SIDE_BIN, options: guardOptions },

			{ data: this.leftEncode(), text: this.leftText(), options: textOptions },

			{ data: MIDDLE_BIN, options: guardOptions },

			{ data: this.rightEncode(), text: this.rightText(), options: textOptions },

			{ data: SIDE_BIN, options: guardOptions },

		];

	}

	encodeFlat() {

		const data = [

			SIDE_BIN,

			this.leftEncode(),

			MIDDLE_BIN,

			this.rightEncode(),

			SIDE_BIN

		];

		return {

			data: data.join(''),

			text: this.text

		};

	}

}

export default EAN;