--- /dev/null
+<?php
+/**
+ * SVGMetadataExtractor.php
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Media
+ * @author Derk-Jan Hartman <hartman _at_ videolan d0t org>
+ * @author Brion Vibber
+ * @copyright Copyright © 2010-2010 Brion Vibber, Derk-Jan Hartman
+ * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License
+ */
+
+class SVGMetadataExtractor {
+ static function getMetadata( $filename ) {
+ $svg = new SVGReader( $filename );
+ return $svg->getMetadata();
+ }
+}
+
+class SVGReader {
+ const DEFAULT_WIDTH = 512;
+ const DEFAULT_HEIGHT = 512;
+ const NS_SVG = 'http://www.w3.org/2000/svg';
+
+ private $reader = null;
+ private $mDebug = false;
+ private $metadata = Array();
+
+ /**
+ * Constructor
+ *
+ * Creates an SVGReader drawing from the source provided
+ * @param $source String: URI from which to read
+ */
+ function __construct( $source ) {
+ global $wgSVGMetadataCutoff;
+ $this->reader = new XMLReader();
+
+ // Don't use $file->getSize() since file object passed to SVGHandler::getMetadata is bogus.
+ $size = filesize( $source );
+ if ( $size === false ) {
+ throw new MWException( "Error getting filesize of SVG." );
+ }
+
+ if ( $size > $wgSVGMetadataCutoff ) {
+ $this->debug( "SVG is $size bytes, which is bigger than $wgSVGMetadataCutoff. Truncating." );
+ $contents = file_get_contents( $source, false, null, -1, $wgSVGMetadataCutoff );
+ if ($contents === false) {
+ throw new MWException( 'Error reading SVG file.' );
+ }
+ $this->reader->XML( $contents, null, LIBXML_NOERROR | LIBXML_NOWARNING );
+ } else {
+ $this->reader->open( $source, null, LIBXML_NOERROR | LIBXML_NOWARNING );
+ }
+
+ $this->metadata['width'] = self::DEFAULT_WIDTH;
+ $this->metadata['height'] = self::DEFAULT_HEIGHT;
+
+ // Because we cut off the end of the svg making an invalid one. Complicated
+ // try catch thing to make sure warnings get restored. Seems like there should
+ // be a better way.
+ wfSuppressWarnings();
+ try {
+ $this->read();
+ } catch( Exception $e ) {
+ wfRestoreWarnings();
+ throw $e;
+ }
+ wfRestoreWarnings();
+ }
+
+ /*
+ * @return Array with the known metadata
+ */
+ public function getMetadata() {
+ return $this->metadata;
+ }
+
+ /*
+ * Read the SVG
+ */
+ public function read() {
+ $keepReading = $this->reader->read();
+
+ /* Skip until first element */
+ while( $keepReading && $this->reader->nodeType != XmlReader::ELEMENT ) {
+ $keepReading = $this->reader->read();
+ }
+
+ if ( $this->reader->localName != 'svg' || $this->reader->namespaceURI != self::NS_SVG ) {
+ throw new MWException( "Expected <svg> tag, got ".
+ $this->reader->localName . " in NS " . $this->reader->namespaceURI );
+ }
+ $this->debug( "<svg> tag is correct." );
+ $this->handleSVGAttribs();
+
+ $exitDepth = $this->reader->depth;
+ $keepReading = $this->reader->read();
+ while ( $keepReading ) {
+ $tag = $this->reader->localName;
+ $type = $this->reader->nodeType;
+ $isSVG = ($this->reader->namespaceURI == self::NS_SVG);
+
+ $this->debug( "$tag" );
+
+ if ( $isSVG && $tag == 'svg' && $type == XmlReader::END_ELEMENT && $this->reader->depth <= $exitDepth ) {
+ break;
+ } elseif ( $isSVG && $tag == 'title' ) {
+ $this->readField( $tag, 'title' );
+ } elseif ( $isSVG && $tag == 'desc' ) {
+ $this->readField( $tag, 'description' );
+ } elseif ( $isSVG && $tag == 'metadata' && $type == XmlReader::ELEMENT ) {
+ $this->readXml( $tag, 'metadata' );
+ } elseif ( $tag !== '#text' ) {
+ $this->debug( "Unhandled top-level XML tag $tag" );
+
+ if ( !isset( $this->metadata['animated'] ) ) {
+ // Recurse into children of current tag, looking for animation.
+ $this->animateFilter( $tag );
+ }
+ }
+
+ // Goto next element, which is sibling of current (Skip children).
+ $keepReading = $this->reader->next();
+ }
+
+ return true;
+ }
+
+ /*
+ * Read a textelement from an element
+ *
+ * @param String $name of the element that we are reading from
+ * @param String $metafield that we will fill with the result
+ */
+ private function readField( $name, $metafield=null ) {
+ $this->debug ( "Read field $metafield" );
+ if( !$metafield || $this->reader->nodeType != XmlReader::ELEMENT ) {
+ return;
+ }
+ $keepReading = $this->reader->read();
+ while( $keepReading ) {
+ if( $this->reader->localName == $name && $this->namespaceURI == self::NS_SVG && $this->reader->nodeType == XmlReader::END_ELEMENT ) {
+ break;
+ } elseif( $this->reader->nodeType == XmlReader::TEXT ){
+ $this->metadata[$metafield] = trim( $this->reader->value );
+ }
+ $keepReading = $this->reader->read();
+ }
+ }
+
+ /*
+ * Read an XML snippet from an element
+ *
+ * @param String $metafield that we will fill with the result
+ */
+ private function readXml( $metafield=null ) {
+ $this->debug ( "Read top level metadata" );
+ if( !$metafield || $this->reader->nodeType != XmlReader::ELEMENT ) {
+ return;
+ }
+ // TODO: find and store type of xml snippet. metadata['metadataType'] = "rdf"
+ $this->metadata[$metafield] = trim( $this->reader->readInnerXML() );
+ $this->reader->next();
+ }
+
+ /*
+ * Filter all children, looking for animate elements
+ *
+ * @param String $name of the element that we are reading from
+ */
+ private function animateFilter( $name ) {
+ $this->debug ( "animate filter" );
+ if( $this->reader->nodeType != XmlReader::ELEMENT ) {
+ return;
+ }
+ $exitDepth = $this->reader->depth;
+ $keepReading = $this->reader->read();
+ while( $keepReading ) {
+ if( $this->reader->localName == $name && $this->reader->depth <= $exitDepth
+ && $this->reader->nodeType == XmlReader::END_ELEMENT ) {
+ break;
+ } elseif ( $this->reader->namespaceURI == self::NS_SVG && $this->reader->nodeType == XmlReader::ELEMENT ) {
+ switch( $this->reader->localName ) {
+ case 'animate':
+ case 'set':
+ case 'animateMotion':
+ case 'animateColor':
+ case 'animateTransform':
+ $this->debug( "HOUSTON WE HAVE ANIMATION" );
+ $this->metadata['animated'] = true;
+ break;
+ }
+ }
+ $keepReading = $this->reader->read();
+ }
+ }
+
+ private function throwXmlError( $err ) {
+ $this->debug( "FAILURE: $err" );
+ wfDebug( "SVGReader XML error: $err\n" );
+ }
+
+ private function debug( $data ) {
+ if( $this->mDebug ) {
+ wfDebug( "SVGReader: $data\n" );
+ }
+ }
+
+ private function warn( $data ) {
+ wfDebug( "SVGReader: $data\n" );
+ }
+
+ private function notice( $data ) {
+ wfDebug( "SVGReader WARN: $data\n" );
+ }
+
+ /*
+ * Parse the attributes of an SVG element
+ *
+ * The parser has to be in the start element of <svg>
+ */
+ private function handleSVGAttribs( ) {
+ $defaultWidth = self::DEFAULT_WIDTH;
+ $defaultHeight = self::DEFAULT_HEIGHT;
+ $aspect = 1.0;
+ $width = null;
+ $height = null;
+
+ if( $this->reader->getAttribute('viewBox') ) {
+ // min-x min-y width height
+ $viewBox = preg_split( '/\s+/', trim( $this->reader->getAttribute('viewBox') ) );
+ if( count( $viewBox ) == 4 ) {
+ $viewWidth = $this->scaleSVGUnit( $viewBox[2] );
+ $viewHeight = $this->scaleSVGUnit( $viewBox[3] );
+ if( $viewWidth > 0 && $viewHeight > 0 ) {
+ $aspect = $viewWidth / $viewHeight;
+ $defaultHeight = $defaultWidth / $aspect;
+ }
+ }
+ }
+ if( $this->reader->getAttribute('width') ) {
+ $width = $this->scaleSVGUnit( $this->reader->getAttribute('width'), $defaultWidth );
+ }
+ if( $this->reader->getAttribute('height') ) {
+ $height = $this->scaleSVGUnit( $this->reader->getAttribute('height'), $defaultHeight );
+ }
+
+ if( !isset( $width ) && !isset( $height ) ) {
+ $width = $defaultWidth;
+ $height = $width / $aspect;
+ } elseif( isset( $width ) && !isset( $height ) ) {
+ $height = $width / $aspect;
+ } elseif( isset( $height ) && !isset( $width ) ) {
+ $width = $height * $aspect;
+ }
+
+ if( $width > 0 && $height > 0 ) {
+ $this->metadata['width'] = intval( round( $width ) );
+ $this->metadata['height'] = intval( round( $height ) );
+ }
+ }
+
+ /**
+ * Return a rounded pixel equivalent for a labeled CSS/SVG length.
+ * http://www.w3.org/TR/SVG11/coords.html#UnitIdentifiers
+ *
+ * @param $length String: CSS/SVG length.
+ * @param $viewportSize: Float optional scale for percentage units...
+ * @return float: length in pixels
+ */
+ static function scaleSVGUnit( $length, $viewportSize=512 ) {
+ static $unitLength = array(
+ 'px' => 1.0,
+ 'pt' => 1.25,
+ 'pc' => 15.0,
+ 'mm' => 3.543307,
+ 'cm' => 35.43307,
+ 'in' => 90.0,
+ 'em' => 16.0, // fake it?
+ 'ex' => 12.0, // fake it?
+ '' => 1.0, // "User units" pixels by default
+ );
+ $matches = array();
+ if( preg_match( '/^\s*(\d+(?:\.\d+)?)(em|ex|px|pt|pc|cm|mm|in|%|)\s*$/', $length, $matches ) ) {
+ $length = floatval( $matches[1] );
+ $unit = $matches[2];
+ if( $unit == '%' ) {
+ return $length * 0.01 * $viewportSize;
+ } else {
+ return $length * $unitLength[$unit];
+ }
+ } else {
+ // Assume pixels
+ return floatval( $length );
+ }
+ }
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff