/zf/library/Zend/Pdf/Resource/Font/FontDescriptor.php

  1<?php
  2/**
  3 * Zend Framework
  4 *
  5 * LICENSE
  6 *
  7 * This source file is subject to the new BSD license that is bundled
  8 * with this package in the file LICENSE.txt.
  9 * It is also available through the world-wide-web at this URL:
 10 * http://framework.zend.com/license/new-bsd
 11 * If you did not receive a copy of the license and are unable to
 12 * obtain it through the world-wide-web, please send an email
 13 * to license@zend.com so we can send you a copy immediately.
 14 *
 15 * @category   Zend
 16 * @package    Zend_Pdf
 17 * @subpackage Fonts
 18 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 19 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 20 * @version    $Id: FontDescriptor.php 23775 2011-03-01 17:25:24Z ralph $
 21 */
 22
 23
 24/** Internally used classes */
 25require_once 'Zend/Pdf/Element/Array.php';
 26require_once 'Zend/Pdf/Element/Dictionary.php';
 27require_once 'Zend/Pdf/Element/Name.php';
 28require_once 'Zend/Pdf/Element/Numeric.php';
 29
 30/** Zend_Pdf_Font */
 31require_once 'Zend/Pdf/Font.php';
 32
 33
 34/**
 35 * FontDescriptor implementation
 36 *
 37 * A font descriptor specifies metrics and other attributes of a simple font or a
 38 * CIDFont as a whole, as distinct from the metrics of individual glyphs. These font
 39 * metrics provide information that enables a viewer application to synthesize a
 40 * substitute font or select a similar font when the font program is unavailable. The
 41 * font descriptor may also be used to embed the font program in the PDF file.
 42 *
 43 * @package    Zend_Pdf
 44 * @subpackage Fonts
 45 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 46 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 47 */
 48class Zend_Pdf_Resource_Font_FontDescriptor
 49{
 50    /**
 51     * Object constructor
 52     * @throws Zend_Pdf_Exception
 53     */
 54    public function __construct()
 55    {
 56        require_once 'Zend/Pdf/Exception.php';
 57        throw new Zend_Pdf_Exception('Zend_Pdf_Resource_Font_FontDescriptor is not intended to be instantiated');
 58    }
 59
 60    /**
 61     * Object constructor
 62     *
 63     * The $embeddingOptions parameter allows you to set certain flags related
 64     * to font embedding. You may combine options by OR-ing them together. See
 65     * the EMBED_ constants defined in {@link Zend_Pdf_Font} for the list of
 66     * available options and their descriptions.
 67     *
 68     * Note that it is not requried that fonts be embedded within the PDF file
 69     * to use them. If the recipient of the PDF has the font installed on their
 70     * computer, they will see the correct fonts in the document. If they don't,
 71     * the PDF viewer will substitute or synthesize a replacement.
 72     *
 73     *
 74     * @param Zend_Pdf_Resource_Font $font Font
 75     * @param Zend_Pdf_FileParser_Font_OpenType $fontParser Font parser object containing parsed TrueType file.
 76     * @param integer $embeddingOptions Options for font embedding.
 77     * @return Zend_Pdf_Element_Dictionary
 78     * @throws Zend_Pdf_Exception
 79     */
 80    static public function factory(Zend_Pdf_Resource_Font $font, Zend_Pdf_FileParser_Font_OpenType $fontParser, $embeddingOptions)
 81    {
 82        /* The font descriptor object contains the rest of the font metrics and
 83         * the information about the embedded font program (if applicible).
 84         */
 85        $fontDescriptor = new Zend_Pdf_Element_Dictionary();
 86
 87        $fontDescriptor->Type     = new Zend_Pdf_Element_Name('FontDescriptor');
 88        $fontDescriptor->FontName = new Zend_Pdf_Element_Name($font->getResource()->BaseFont->value);
 89
 90        /* The font flags value is a bitfield that describes the stylistic
 91         * attributes of the font. We will set as many of the bits as can be
 92         * determined from the font parser.
 93         */
 94        $flags = 0;
 95        if ($fontParser->isMonospaced) {    // bit 1: FixedPitch
 96            $flags |= 1 << 0;
 97        }
 98        if ($fontParser->isSerifFont) {    // bit 2: Serif
 99            $flags |= 1 << 1;
100        }
101        if (! $fontParser->isAdobeLatinSubset) {    // bit 3: Symbolic
102            $flags |= 1 << 2;
103        }
104        if ($fontParser->isScriptFont) {    // bit 4: Script
105            $flags |= 1 << 3;
106        }
107        if ($fontParser->isAdobeLatinSubset) {    // bit 6: Nonsymbolic
108            $flags |= 1 << 5;
109        }
110        if ($fontParser->isItalic) {    // bit 7: Italic
111            $flags |= 1 << 6;
112        }
113        // bits 17-19: AllCap, SmallCap, ForceBold; not available
114        $fontDescriptor->Flags = new Zend_Pdf_Element_Numeric($flags);
115
116        $fontBBox = array(new Zend_Pdf_Element_Numeric($font->toEmSpace($fontParser->xMin)),
117                          new Zend_Pdf_Element_Numeric($font->toEmSpace($fontParser->yMin)),
118                          new Zend_Pdf_Element_Numeric($font->toEmSpace($fontParser->xMax)),
119                          new Zend_Pdf_Element_Numeric($font->toEmSpace($fontParser->yMax)));
120        $fontDescriptor->FontBBox     = new Zend_Pdf_Element_Array($fontBBox);
121
122        $fontDescriptor->ItalicAngle  = new Zend_Pdf_Element_Numeric($fontParser->italicAngle);
123
124        $fontDescriptor->Ascent       = new Zend_Pdf_Element_Numeric($font->toEmSpace($fontParser->ascent));
125        $fontDescriptor->Descent      = new Zend_Pdf_Element_Numeric($font->toEmSpace($fontParser->descent));
126
127        $fontDescriptor->CapHeight    = new Zend_Pdf_Element_Numeric($fontParser->capitalHeight);
128        /**
129         * The vertical stem width is not yet extracted from the OpenType font
130         * file. For now, record zero which is interpreted as 'unknown'.
131         * @todo Calculate value for StemV.
132         */
133        $fontDescriptor->StemV        = new Zend_Pdf_Element_Numeric(0);
134
135        $fontDescriptor->MissingWidth = new Zend_Pdf_Element_Numeric($fontParser->glyphWidths[0]);
136
137        /* Set up font embedding. This is where the actual font program itself
138         * is embedded within the PDF document.
139         *
140         * Note that it is not requried that fonts be embedded within the PDF
141         * document to use them. If the recipient of the PDF has the font
142         * installed on their computer, they will see the correct fonts in the
143         * document. If they don't, the PDF viewer will substitute or synthesize
144         * a replacement.
145         *
146         * There are several guidelines for font embedding:
147         *
148         * First, the developer might specifically request not to embed the font.
149         */
150        if (!($embeddingOptions & Zend_Pdf_Font::EMBED_DONT_EMBED)) {
151
152            /* Second, the font author may have set copyright bits that prohibit
153             * the font program from being embedded. Yes this is controversial,
154             * but it's the rules:
155             *   http://partners.adobe.com/public/developer/en/acrobat/sdk/FontPolicies.pdf
156             *
157             * To keep the developer in the loop, and to prevent surprising bug
158             * reports of "your PDF doesn't have the right fonts," throw an
159             * exception if the font cannot be embedded.
160             */
161            if (! $fontParser->isEmbeddable) {
162                /* This exception may be suppressed if the developer decides that
163                 * it's not a big deal that the font program can't be embedded.
164                 */
165                if (!($embeddingOptions & Zend_Pdf_Font::EMBED_SUPPRESS_EMBED_EXCEPTION)) {
166                    $message = 'This font cannot be embedded in the PDF document. If you would like to use '
167                             . 'it anyway, you must pass Zend_Pdf_Font::EMBED_SUPPRESS_EMBED_EXCEPTION '
168                             . 'in the $options parameter of the font constructor.';
169                    require_once 'Zend/Pdf/Exception.php';
170                    throw new Zend_Pdf_Exception($message, Zend_Pdf_Exception::FONT_CANT_BE_EMBEDDED);
171                }
172
173            } else {
174                /* Otherwise, the default behavior is to embed all custom fonts.
175                 */
176                /* This section will change soon to a stream object data
177                 * provider model so that we don't have to keep a copy of the
178                 * entire font in memory.
179                 *
180                 * We also cannot build font subsetting until the data provider
181                 * model is in place.
182                 */
183                $fontFile = $fontParser->getDataSource()->readAllBytes();
184                $fontFileObject = $font->getFactory()->newStreamObject($fontFile);
185                $fontFileObject->dictionary->Length1 = new Zend_Pdf_Element_Numeric(strlen($fontFile));
186                if (!($embeddingOptions & Zend_Pdf_Font::EMBED_DONT_COMPRESS)) {
187                    /* Compress the font file using Flate. This generally cuts file
188                     * sizes by about half!
189                     */
190                    $fontFileObject->dictionary->Filter = new Zend_Pdf_Element_Name('FlateDecode');
191                }
192                if ($fontParser instanceof Zend_Pdf_FileParser_Font_OpenType_Type1 /* not implemented now */) {
193                    $fontDescriptor->FontFile  = $fontFileObject;
194                } else if ($fontParser instanceof Zend_Pdf_FileParser_Font_OpenType_TrueType) {
195                    $fontDescriptor->FontFile2 = $fontFileObject;
196                } else {
197                    $fontDescriptor->FontFile3 = $fontFileObject;
198                }
199            }
200        }
201
202        return $fontDescriptor;
203    }
204}