tentone.escher.js/source/objects/Text.js

import {Object2D} from "../Object2D.js";
import {ColorStyle} from "./style/ColorStyle";

/**
 * Text element, used to draw single line text into the canvas.
 *
 * For multi line text with support for line break check {MultiLineText} object.
 *
 * @class
 * @extends {Object2D}
 */
function Text()
{
	Object2D.call(this);

	/**
	 * Text value displayed by this element.
	 *
	 * @type {string}
	 */
	this.text = "";

	/**
	 * Font of the text.
	 *
	 * @type {string}
	 */
	this.font = "16px Arial";

	/**
	 * Style of the object border line. If set null it is ignored.
	 *
	 * @type {Style}
	 */
	this.strokeStyle = null;

	/**
	 * Line width, only used if a valid strokeStyle is defined.
	 *
	 * @type {number}
	 */
	this.lineWidth = 1;

	/**
	 * CSS background color of the box. If set null it is ignored.
	 *
	 * @type {Style}
	 */
	this.fillStyle = new ColorStyle("#000000");

	/**
	 * Text align property. Same values as used for canvas text applies
	 *
	 * Check documentation at https://developer.mozilla.org/en-US/docs/Web/CSS/text-align for mode details about this property.
	 *
	 * @type {string}
	 */
	this.textAlign = "center";

	/**
	 * Text baseline defines the vertical position of the text relative to the imaginary line Y position. Same values as used for canvas text applies
	 *
	 * Check documentation at https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/textBaseline for mode details about this property.
	 *
	 * @type {string}
	 */
	this.textBaseline = "middle";
}

Text.prototype = Object.create(Object2D.prototype);
Text.prototype.constructor = Text;
Text.prototype.type = "Text";
Object2D.register(Text, "Text");

Text.prototype.draw = function(context, viewport, canvas)
{
	context.font = this.font;
	context.textAlign = this.textAlign;
	context.textBaseline = this.textBaseline;
	
	if(this.fillStyle !== null)
	{
		context.fillStyle = this.fillStyle.get(context);
		context.fillText(this.text, 0, 0);
	}

	if(this.strokeStyle !== null)
	{
		context.strokeStyle = this.strokeStyle.get(context);
		context.strokeText(this.text, 0, 0);
	}
};

Text.prototype.serialize = function(recursive)
{
	var data = Object2D.prototype.serialize.call(this, recursive);

	data.text = this.text;
	data.font = this.font;
	data.strokeStyle = this.strokeStyle !== null ? this.strokeStyle.serialize() : null;
	data.lineWidth = this.lineWidth;
	data.fillStyle = this.fillStyle !== null ? this.fillStyle.serialize() : null;
	data.textAlign = this.textAlign;
	data.textBaseline = this.textBaseline;

	return data;
};

Text.prototype.parse = function(data, root)
{
	Object2D.prototype.parse.call(this, data, root);

	this.text = data.text;
	this.font = data.font;
	this.strokeStyle = data.strokeStyle !== null ? Style.parse(data.strokeStyle) : null;
	this.lineWidth = data.lineWidth;
	this.fillStyle = data.fillStyle !== null ? Style.parse(data.fillStyle) : null;
	this.textAlign = data.textAlign;
	this.textBaseline = data.textBaseline;
};

export {Text};