includes/ImageFunctions.php

   1 <?php
   2 /**
   3  * Return a rounded pixel equivalent for a labeled CSS/SVG length.
   4  * http://www.w3.org/TR/SVG11/coords.html#UnitIdentifiers
   5  *
   6  * @param $length String: CSS/SVG length.
   7  * @return Integer: length in pixels
   8  */
   9 function wfScaleSVGUnit( $length ) {
  10         static $unitLength = array(
  11                 'px' => 1.0,
  12                 'pt' => 1.25,
  13                 'pc' => 15.0,
  14                 'mm' => 3.543307,
  15                 'cm' => 35.43307,
  16                 'in' => 90.0,
  17                 ''   => 1.0, // "User units" pixels by default
  18                 '%'  => 2.0, // Fake it!
  19                 );
  20         $matches = array();
  21         if( preg_match( '/^\s*(\d+(?:\.\d+)?)(em|ex|px|pt|pc|cm|mm|in|%|)\s*$/', $length, $matches ) ) {
  22                 $length = floatval( $matches[1] );
  23                 $unit = $matches[2];
  24                 return round( $length * $unitLength[$unit] );
  25         } else {
  26                 // Assume pixels
  27                 return round( floatval( $length ) );
  28         }
  29 }
  30
  31 class XmlSizeFilter {
  32         var $first = true;
  33         var $width = 256;
  34         var $height = 256;
  35         function filter( $name, $attribs ) {
  36                 if( $this->first ) {
  37                         if( isset( $attribs['width'] ) ) {
  38                                 $this->width = wfScaleSVGUnit( $attribs['width'] );
  39                         }
  40                         if( isset( $attribs['height'] ) ) {
  41                                 $this->height = wfScaleSVGUnit( $attribs['height'] );
  42                         }
  43                         $this->first = false;
  44                 }
  45         }
  46 }
  47
  48 /**
  49  * Compatible with PHP getimagesize()
  50  * @todo support gzipped SVGZ
  51  * @todo check XML more carefully
  52  * @todo sensible defaults
  53  *
  54  * @param $filename String: full name of the file (passed to php fopen()).
  55  * @return array
  56  */
  57 function wfGetSVGsize( $filename ) {
  58         $filter = new XmlSizeFilter();
  59         $xml = new XmlTypeCheck( $filename, array( $filter, 'filter' ) );
  60         if( $xml->wellFormed ) {
  61                 return array( $filter->width, $filter->height, 'SVG',
  62                         "width=\"$filter->width\" height=\"$filter->height\"" );
  63         }
  64
  65         return false;
  66 }
  67
  68 /**
  69  * Determine if an image exists on the 'bad image list'.
  70  *
  71  * The format of MediaWiki:Bad_image_list is as follows:
  72  *    * Only list items (lines starting with "*") are considered
  73  *    * The first link on a line must be a link to a bad image
  74  *    * Any subsequent links on the same line are considered to be exceptions,
  75  *      i.e. articles where the image may occur inline.
  76  *
  77  * @param $name string the image name to check
  78  * @param $contextTitle Title: the page on which the image occurs, if known
  79  * @return bool
  80  */
  81 function wfIsBadImage( $name, $contextTitle = false ) {
  82         static $badImages = false;
  83         wfProfileIn( __METHOD__ );
  84
  85         # Run the extension hook
  86         $bad = false;
  87         if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
  88                 wfProfileOut( __METHOD__ );
  89                 return $bad;
  90         }
  91
  92         if( !$badImages ) {
  93                 # Build the list now
  94                 $badImages = array();
  95                 $lines = explode( "\n", wfMsgForContentNoTrans( 'bad_image_list' ) );
  96                 foreach( $lines as $line ) {
  97                         # List items only
  98                         if ( substr( $line, 0, 1 ) !== '*' ) {
  99                                 continue;
 100                         }
 101
 102                         # Find all links
 103                         $m = array();
 104                         if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
 105                                 continue;
 106                         }
 107
 108                         $exceptions = array();
 109                         $imageDBkey = false;
 110                         foreach ( $m[1] as $i => $titleText ) {
 111                                 $title = Title::newFromText( $titleText );
 112                                 if ( !is_null( $title ) ) {
 113                                         if ( $i == 0 ) {
 114                                                 $imageDBkey = $title->getDBkey();
 115                                         } else {
 116                                                 $exceptions[$title->getPrefixedDBkey()] = true;
 117                                         }
 118                                 }
 119                         }
 120
 121                         if ( $imageDBkey !== false ) {
 122                                 $badImages[$imageDBkey] = $exceptions;
 123                         }
 124                 }
 125         }
 126
 127         $contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
 128         $bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
 129         wfProfileOut( __METHOD__ );
 130         return $bad;
 131 }
 132
 133 /**
 134  * Calculate the largest thumbnail width for a given original file size
 135  * such that the thumbnail's height is at most $maxHeight.
 136  * @param $boxWidth Integer Width of the thumbnail box.
 137  * @param $boxHeight Integer Height of the thumbnail box.
 138  * @param $maxHeight Integer Maximum height expected for the thumbnail.
 139  * @return Integer.
 140  */
 141 function wfFitBoxWidth( $boxWidth, $boxHeight, $maxHeight ) {
 142         $idealWidth = $boxWidth * $maxHeight / $boxHeight;
 143         $roundedUp = ceil( $idealWidth );
 144         if( round( $roundedUp * $boxHeight / $boxWidth ) > $maxHeight )
 145                 return floor( $idealWidth );
 146         else
 147                 return $roundedUp;
 148 }