jspdf.plugin.addimage.js

/** @preserve 
jsPDF addImage plugin (JPEG only at this time)
Copyright (c) 2012 https://github.com/siefkenj/
*/

/**
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * ====================================================================
 */

;(function(jsPDFAPI) {
'use strict'

var namespace = 'addImage_'

// takes a string imgData containing the raw bytes of
// a jpeg image and returns [width, height]
// Algorithm from: http://www.64lines.com/jpeg-width-height
var getJpegSize = function(imgData) {
	'use strict'
	var width, height;
	// Verify we have a valid jpeg header 0xff,0xd8,0xff,0xe0,?,?,'J','F','I','F',0x00
	if (!imgData.charCodeAt(0) === 0xff ||
		!imgData.charCodeAt(1) === 0xd8 ||
		!imgData.charCodeAt(2) === 0xff ||
		!imgData.charCodeAt(3) === 0xe0 ||
		!imgData.charCodeAt(6) === 'J'.charCodeAt(0) ||
		!imgData.charCodeAt(7) === 'F'.charCodeAt(0) ||
		!imgData.charCodeAt(8) === 'I'.charCodeAt(0) ||
		!imgData.charCodeAt(9) === 'F'.charCodeAt(0) ||
		!imgData.charCodeAt(10) === 0x00) {
			throw new Error('getJpegSize requires a binary jpeg file')
	}
	var blockLength = imgData.charCodeAt(4)*256 + imgData.charCodeAt(5);
	var i = 4, len = imgData.length;
	while ( i < len ) {
		i += blockLength;
		if (imgData.charCodeAt(i) !== 0xff) {
			throw new Error('getJpegSize could not find the size of the image');
		}
		if (imgData.charCodeAt(i+1) === 0xc0) {
			height = imgData.charCodeAt(i+5)*256 + imgData.charCodeAt(i+6);
			width = imgData.charCodeAt(i+7)*256 + imgData.charCodeAt(i+8);
			return [width, height];
		} else {
			i += 2;
			blockLength = imgData.charCodeAt(i)*256 + imgData.charCodeAt(i+1)
		}
	}
}
// Image functionality ported from pdf.js
, putImage = function(img) {
	var objectNumber = this.internal.newObject()
	, out = this.internal.write
	, putStream = this.internal.putStream

	img['n'] = objectNumber

	out('<</Type /XObject')
	out('/Subtype /Image')
	out('/Width ' + img['w'])
	out('/Height ' + img['h'])
	if (img['cs'] === 'Indexed') {
		out('/ColorSpace [/Indexed /DeviceRGB '
				+ (img['pal'].length / 3 - 1) + ' ' + (objectNumber + 1)
				+ ' 0 R]');
	} else {
		out('/ColorSpace /' + img['cs']);
		if (img['cs'] === 'DeviceCMYK') {
			out('/Decode [1 0 1 0 1 0 1 0]');
		}
	}
	out('/BitsPerComponent ' + img['bpc']);
	if ('f' in img) {
		out('/Filter /' + img['f']);
	}
	if ('dp' in img) {
		out('/DecodeParms <<' + img['dp'] + '>>');
	}
	if ('trns' in img && img['trns'].constructor == Array) {
		var trns = '';
		for ( var i = 0; i < img['trns'].length; i++) {
			trns += (img[trns][i] + ' ' + img['trns'][i] + ' ');
			out('/Mask [' + trns + ']');
		}
	}
	if ('smask' in img) {
		out('/SMask ' + (objectNumber + 1) + ' 0 R');
	}
	out('/Length ' + img['data'].length + '>>');

	putStream(img['data']);

	out('endobj');
}
, putResourcesCallback = function() {
	var images = this.internal.collections[namespace + 'images']
	for ( var i in images ) {
		putImage.call(this, images[i])
	}
}
, putXObjectsDictCallback = function(){
	var images = this.internal.collections[namespace + 'images']
	, out = this.internal.write
	, image
	for (var i in images) {
		image = images[i]
		out(
			'/I' + image['i']
			, image['n']
			, '0'
			, 'R'
		)
	}
}

jsPDFAPI.addImage = function(imageData, format, x, y, w, h) {
	'use strict'

	if (format.toUpperCase() !== 'JPEG') {
		throw new Error('addImage currently only supports format \'JPEG\', not \''+format+'\'');
	}

	var imageIndex
	, images = this.internal.collections[namespace + 'images']
	, coord = this.internal.getCoordinateString
	, vcoord = this.internal.getVerticalCoordinateString

	if (images){
		// this is NOT the first time this method is ran on this instance of jsPDF object.
		imageIndex = Object.keys ? 
		Object.keys(images).length :
		(function(o){
			var i = 0
			for (var e in o){if(o.hasOwnProperty(e)){ i++ }}
			return i
		})(images)
	} else {
		// this is the first time this method is ran on this instance of jsPDF object.
		imageIndex = 0
		this.internal.collections[namespace + 'images'] = images = {}
		this.internal.events.subscribe('putResources', putResourcesCallback)
		this.internal.events.subscribe('putXobjectDict', putXObjectsDictCallback)
	}

	var dims = getJpegSize(imageData);
	var info = {
		w : dims[0],
		h : dims[1],
		cs : 'DeviceRGB',
		bpc : 8,
		f : 'DCTDecode',
		i : imageIndex,
		data : imageData
		// n: objectNumber will be added by putImage code

	};
	images[imageIndex] = info
	if (!w && !h) {
		w = -96;
		h = -96;
	}
	if (w < 0) {
		w = (-1) * info['w'] * 72 / w / this.internal.scaleFactor;
	}
	if (h < 0) {
		h = (-1) * info['h'] * 72 / h / this.internal.scaleFactor;
	}
	if (w === 0) {
		w = h * info['w'] / info['h'];
	}
	if (h === 0) {
		h = w * info['h'] / info['w'];
	}

	this.internal.write(
		'q'
		, coord(w)
		, '0 0'
		, coord(h) // TODO: check if this should be shifted by vcoord
		, coord(x)
		, vcoord(y + h)
		, 'cm /I'+info['i']
		, 'Do Q'
	)

	return this 
}

})(jsPDF.API)