ImageMap.php

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<?php
class ImageMap {
    public static $id = 0;
 
    const TOP_RIGHT = 0;
    const BOTTOM_RIGHT = 1;
    const BOTTOM_LEFT = 2;
    const TOP_LEFT = 3;
    const NONE = 4;
 
    public static function onParserFirstCallInit( Parser &$parser ) {
        $parser->setHook( 'imagemap', [ 'ImageMap', 'render' ] );
    }
 
    public static function render( $input, $params, $parser ) {
        global $wgUrlProtocols, $wgNoFollowLinks;
        $config = ConfigFactory::getDefaultInstance()->makeConfig( 'main' );
 
        $lines = explode( "\n", $input );
 
        $first = true;
        $scale = 1;
        $imageNode = null;
        $domDoc = null;
        $thumbWidth = 0;
        $thumbHeight = 0;
        $imageTitle = null;
        $lineNum = 0;
        $mapHTML = '';
        $links = [];
 
        // Define canonical desc types to allow i18n of 'imagemap_desc_types'
        $descTypesCanonical = 'top-right, bottom-right, bottom-left, top-left, none';
        $descType = self::BOTTOM_RIGHT;
        $defaultLinkAttribs = false;
        $realmap = true;
        $extLinks = [];
        foreach ( $lines as $line ) {
            ++$lineNum;
            $externLink = false;
 
            $line = trim( $line );
            if ( $line == '' || $line[0] == '#' ) {
                continue;
            }
 
            if ( $first ) {
                $first = false;
 
                // The first line should have an image specification on it
                // Extract it and render the HTML
                $bits = explode( '|', $line, 2 );
                if ( count( $bits ) == 1 ) {
                    $image = $bits[0];
                    $options = '';
                } else {
                    list( $image, $options ) = $bits;
                }
                $imageTitle = Title::newFromText( $image );
                if ( !$imageTitle || !$imageTitle->inNamespace( NS_FILE ) ) {
                    return self::error( 'imagemap_no_image' );
                }
                if ( wfIsBadImage( $imageTitle->getDBkey(), $parser->mTitle ) ) {
                    return self::error( 'imagemap_bad_image' );
                }
                // Parse the options so we can use links and the like in the caption
                $parsedOptions = $parser->recursiveTagParse( $options );
                $imageHTML = $parser->makeImage( $imageTitle, $parsedOptions );
                $parser->replaceLinkHolders( $imageHTML );
                $imageHTML = $parser->mStripState->unstripBoth( $imageHTML );
                $imageHTML = Sanitizer::normalizeCharReferences( $imageHTML );
 
                $domDoc = new DOMDocument();
                Wikimedia\suppressWarnings();
                $ok = $domDoc->loadXML( $imageHTML );
                Wikimedia\restoreWarnings();
                if ( !$ok ) {
                    return self::error( 'imagemap_invalid_image' );
                }
                $xpath = new DOMXPath( $domDoc );
                $imgs = $xpath->query( '//img' );
                if ( !$imgs->length ) {
                    return self::error( 'imagemap_invalid_image' );
                }
                $imageNode = $imgs->item( 0 );
                $thumbWidth = $imageNode->getAttribute( 'width' );
                $thumbHeight = $imageNode->getAttribute( 'height' );
 
                $imageObj = wfFindFile( $imageTitle );
                if ( !$imageObj || !$imageObj->exists() ) {
                    return self::error( 'imagemap_invalid_image' );
                }
                // Add the linear dimensions to avoid inaccuracy in the scale
                // factor when one is much larger than the other
                // (sx+sy)/(x+y) = s
                $denominator = $imageObj->getWidth() + $imageObj->getHeight();
                $numerator = $thumbWidth + $thumbHeight;
                if ( $denominator <= 0 || $numerator <= 0 ) {
                    return self::error( 'imagemap_invalid_image' );
                }
                $scale = $numerator / $denominator;
                continue;
            }
 
            // Handle desc spec
            $cmd = strtok( $line, " \t" );
            if ( $cmd == 'desc' ) {
                $typesText = wfMessage( 'imagemap_desc_types' )->inContentLanguage()->text();
                if ( $descTypesCanonical != $typesText ) {
                    // i18n desc types exists
                    $typesText = $descTypesCanonical . ', ' . $typesText;
                }
                $types = array_map( 'trim', explode( ',', $typesText ) );
                $type = trim( strtok( '' ) );
                $descType = array_search( $type, $types );
                if ( $descType > 4 ) {
                    // A localized descType is used. Subtract 5 to reach the canonical desc type.
                    $descType = $descType - 5;
                }
                // <0? In theory never, but paranoia...
                if ( $descType === false || $descType < 0 ) {
                    return self::error( 'imagemap_invalid_desc', $typesText );
                }
                continue;
            }
 
            $title = false;
            // Find the link
            $link = trim( strstr( $line, '[' ) );
            $m = [];
            if ( preg_match( '/^ \[\[  ([^|]*+)  \|  ([^\]]*+)  \]\] \w* $ /x', $link, $m ) ) {
                $title = Title::newFromText( $m[1] );
                $alt = trim( $m[2] );
            } elseif ( preg_match( '/^ \[\[  ([^\]]*+) \]\] \w* $ /x', $link, $m ) ) {
                $title = Title::newFromText( $m[1] );
                if ( is_null( $title ) ) {
                    return self::error( 'imagemap_invalid_title', $lineNum );
                }
                $alt = $title->getFullText();
            } elseif ( in_array( substr( $link, 1, strpos( $link, '//' ) + 1 ), $wgUrlProtocols )
                || in_array( substr( $link, 1, strpos( $link, ':' ) ), $wgUrlProtocols )
            ) {
                if ( preg_match( '/^ \[  ([^\s]*+)  \s  ([^\]]*+)  \] \w* $ /x', $link, $m ) ) {
                    $title = $m[1];
                    $alt = trim( $m[2] );
                    $externLink = true;
                } elseif ( preg_match( '/^ \[  ([^\]]*+) \] \w* $ /x', $link, $m ) ) {
                    $title = $alt = trim( $m[1] );
                    $externLink = true;
                }
            } else {
                return self::error( 'imagemap_no_link', $lineNum );
            }
            if ( !$title ) {
                return self::error( 'imagemap_invalid_title', $lineNum );
            }
 
            $shapeSpec = substr( $line, 0, -strlen( $link ) );
 
            // Tokenize shape spec
            $shape = strtok( $shapeSpec, " \t" );
            switch ( $shape ) {
                case 'default':
                    $coords = [];
                    break;
                case 'rect':
                    $coords = self::tokenizeCoords( 4, $lineNum );
                    if ( !is_array( $coords ) ) {
                        return $coords;
                    }
                    break;
                case 'circle':
                    $coords = self::tokenizeCoords( 3, $lineNum );
                    if ( !is_array( $coords ) ) {
                        return $coords;
                    }
                    break;
                case 'poly':
                    $coords = [];
                    $coord = strtok( " \t" );
                    while ( $coord !== false ) {
                        if ( !is_numeric( $coord ) || $coord > 1e9 || $coord < 0 ) {
                            return self::error( 'imagemap_invalid_coord', $lineNum );
                        }
                        $coords[] = $coord;
                        $coord = strtok( " \t" );
                    }
                    if ( !count( $coords ) ) {
                        return self::error( 'imagemap_missing_coord', $lineNum );
                    }
                    if ( count( $coords ) % 2 !== 0 ) {
                        return self::error( 'imagemap_poly_odd', $lineNum );
                    }
                    break;
                default:
                    return self::error( 'imagemap_unrecognised_shape', $lineNum );
            }
 
            // Scale the coords using the size of the source image
            foreach ( $coords as $i => $c ) {
                $coords[$i] = (int)round( $c * $scale );
            }
 
            // Construct the area tag
            $attribs = [];
            if ( $externLink ) {
                $attribs['href'] = $title;
                $attribs['class'] = 'plainlinks';
                if ( $wgNoFollowLinks ) {
                    $attribs['rel'] = 'nofollow';
                }
            } elseif ( $title->getFragment() != '' && $title->getPrefixedDBkey() == '' ) {
                // XXX: kluge to handle [[#Fragment]] links, should really fix getLocalURL()
                // in Title.php to return an empty string in this case
                $attribs['href'] = $title->getFragmentForURL();
            } else {
                $attribs['href'] = $title->getLocalURL() . $title->getFragmentForURL();
            }
            if ( $shape != 'default' ) {
                $attribs['shape'] = $shape;
            }
            if ( $coords ) {
                $attribs['coords'] = implode( ',', $coords );
            }
            if ( $alt != '' ) {
                if ( $shape != 'default' ) {
                    $attribs['alt'] = $alt;
                }
                $attribs['title'] = $alt;
            }
            if ( $shape == 'default' ) {
                $defaultLinkAttribs = $attribs;
            } else {
                $mapHTML .= Xml::element( 'area', $attribs ) . "\n";
            }
            if ( $externLink ) {
                $extLinks[] = $title;
            } else {
                $links[] = $title;
            }
        }
 
        if ( $first || !$imageNode ) {
            return self::error( 'imagemap_no_image' );
        }
 
        if ( $mapHTML == '' ) {
            // no areas defined, default only. It's not a real imagemap, so we do not need some tags
            $realmap = false;
        }
 
        if ( $realmap ) {
            // Construct the map
            // Add random number to avoid breaking cached HTML fragments that are
            // later joined together on the one page (bug 16471)
            $mapName = "ImageMap_" . ++self::$id . '_' . mt_rand( 0, 0x7fffffff );
            $mapHTML = "<map name=\"$mapName\">\n$mapHTML</map>\n";
 
            // Alter the image tag
            $imageNode->setAttribute( 'usemap', "#$mapName" );
        }
 
        // Add a surrounding div, remove the default link to the description page
        $anchor = $imageNode->parentNode;
        $parent = $anchor->parentNode;
        $div = $parent->insertBefore( new DOMElement( 'div' ), $anchor );
        $div->setAttribute( 'class', 'noresize' );
        if ( $defaultLinkAttribs ) {
            $defaultAnchor = $div->appendChild( new DOMElement( 'a' ) );
            foreach ( $defaultLinkAttribs as $name => $value ) {
                $defaultAnchor->setAttribute( $name, $value );
            }
            $imageParent = $defaultAnchor;
        } else {
            $imageParent = $div;
        }
 
        // Add the map HTML to the div
        // We used to add it before the div, but that made tidy unhappy
        if ( $mapHTML != '' ) {
            $mapDoc = new DOMDocument();
            $mapDoc->loadXML( $mapHTML );
            $mapNode = $domDoc->importNode( $mapDoc->documentElement, true );
            $div->appendChild( $mapNode );
        }
 
        $imageParent->appendChild( $imageNode->cloneNode( true ) );
        $parent->removeChild( $anchor );
 
        // Determine whether a "magnify" link is present
        $xpath = new DOMXPath( $domDoc );
        $magnify = $xpath->query( '//div[@class="magnify"]' );
        if ( !$magnify->length && $descType != self::NONE ) {
            // Add image description link
            if ( $descType == self::TOP_LEFT || $descType == self::BOTTOM_LEFT ) {
                $marginLeft = 0;
            } else {
                $marginLeft = $thumbWidth - 20;
            }
            if ( $descType == self::TOP_LEFT || $descType == self::TOP_RIGHT ) {
                $marginTop = -$thumbHeight;
                // 1px hack for IE, to stop it poking out the top
                $marginTop += 1;
            } else {
                $marginTop = -20;
            }
            $div->setAttribute( 'style', "height: {$thumbHeight}px; width: {$thumbWidth}px; " );
            $descWrapper = $div->appendChild( new DOMElement( 'div' ) );
            $descWrapper->setAttribute( 'style',
                "margin-left: {$marginLeft}px; " .
                    "margin-top: {$marginTop}px; " .
                    "text-align: left;"
            );
 
            $descAnchor = $descWrapper->appendChild( new DOMElement( 'a' ) );
            $descAnchor->setAttribute( 'href', $imageTitle->getLocalURL() );
            $descAnchor->setAttribute(
                'title',
                wfMessage( 'imagemap_description' )->inContentLanguage()->text()
            );
            $descImg = $descAnchor->appendChild( new DOMElement( 'img' ) );
            $descImg->setAttribute(
                'alt',
                wfMessage( 'imagemap_description' )->inContentLanguage()->text()
            );
            $url = $config->get( 'ExtensionAssetsPath' ) . '/ImageMap/resources/desc-20.png';
            $descImg->setAttribute(
                'src',
                OutputPage::transformResourcePath( $config, $url )
            );
            $descImg->setAttribute( 'style', 'border: none;' );
        }
 
        // Output the result
        // We use saveXML() not saveHTML() because then we get XHTML-compliant output.
        // The disadvantage is that we have to strip out the DTD
        $output = preg_replace( '/<\?xml[^?]*\?>/', '', $domDoc->saveXML( null, LIBXML_NOEMPTYTAG ) );
 
        // Register links
        foreach ( $links as $title ) {
            if ( $title->isExternal() || $title->getNamespace() == NS_SPECIAL ) {
                // Don't register special or interwiki links...
            } elseif ( $title->getNamespace() == NS_MEDIA ) {
                // Regular Media: links are recorded as image usages
                $parser->mOutput->addImage( $title->getDBkey() );
            } else {
                // Plain ol' link
                $parser->mOutput->addLink( $title );
            }
        }
        foreach ( $extLinks as $title ) {
            $parser->mOutput->addExternalLink( $title );
        }
        // Armour output against broken parser
        $output = str_replace( "\n", '', $output );
        return $output;
    }
 
    private static function tokenizeCoords( $count, $lineNum ) {
        $coords = [];
        for ( $i = 0; $i < $count; $i++ ) {
            $coord = strtok( " \t" );
            if ( $coord === false ) {
                return self::error( 'imagemap_missing_coord', $lineNum );
            }
            if ( !is_numeric( $coord ) || $coord > 1e9 || $coord < 0 ) {
                return self::error( 'imagemap_invalid_coord', $lineNum );
            }
            $coords[$i] = $coord;
        }
        return $coords;
    }
 
    private static function error( $name, $line = false ) {
        return '<p class="error">' . wfMessage( $name, $line )->parse() . '</p>';
    }
}