wikimedia/mediawiki-core

<?php
/**
 * Handler for PNG images.
 *
 * 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
 */

use MediaWiki\Context\IContextSource;
use Wikimedia\RequestTimeout\TimeoutException;

/**
 * Handler for PNG images.
 *
 * @ingroup Media
 */
class PNGHandler extends BitmapHandler {
    private const BROKEN_FILE = '0';

    /**
     * @param MediaHandlerState $state
     * @param string $filename
     * @return array
     */
    public function getSizeAndMetadata( $state, $filename ) {
        try {
            $metadata = BitmapMetadataHandler::PNG( $filename );
        } catch ( TimeoutException $e ) {
            throw $e;
        } catch ( Exception $e ) {
            // Broken file?
            wfDebug( __METHOD__ . ': ' . $e->getMessage() );

            return [ 'metadata' => [ '_error' => self::BROKEN_FILE ] ];
        }

        return [
            'width' => $metadata['width'],
            'height' => $metadata['height'],
            'bits' => $metadata['bitDepth'],
            'metadata' => array_diff_key(
                $metadata,
                [ 'width' => true, 'height' => true, 'bits' => true ]
            )
        ];
    }

    /**
     * @param File $image
     * @param IContextSource|false $context
     * @return array[]|false
     */
    public function formatMetadata( $image, $context = false ) {
        $meta = $this->getCommonMetaArray( $image );
        if ( !$meta ) {
            return false;
        }

        return $this->formatMetadataHelper( $meta, $context );
    }

    /**
     * Get a file type independent array of metadata.
     *
     * @param File $image
     * @return array The metadata array
     */
    public function getCommonMetaArray( File $image ) {
        $meta = $image->getMetadataArray();

        if ( !isset( $meta['metadata'] ) ) {
            return [];
        }
        unset( $meta['metadata']['_MW_PNG_VERSION'] );

        return $meta['metadata'];
    }

    /**
     * @param File $image
     * @return bool
     */
    public function isAnimatedImage( $image ) {
        $metadata = $image->getMetadataArray();
        return isset( $metadata['frameCount'] ) && $metadata['frameCount'] > 1;
    }

    /**
     * We do not support making APNG thumbnails, so always false
     * @param File $image
     * @return bool False
     */
    public function canAnimateThumbnail( $image ) {
        return false;
    }

    public function getMetadataType( $image ) {
        return 'parsed-png';
    }

    public function isFileMetadataValid( $image ) {
        $data = $image->getMetadataArray();
        if ( $data === [ '_error' => self::BROKEN_FILE ] ) {
            // Do not repetitively regenerate metadata on broken file.
            return self::METADATA_GOOD;
        }

        if ( !$data || isset( $data['_error'] ) ) {
            wfDebug( __METHOD__ . " invalid png metadata" );

            return self::METADATA_BAD;
        }

        if ( !isset( $data['metadata']['_MW_PNG_VERSION'] )
            || $data['metadata']['_MW_PNG_VERSION'] !== PNGMetadataExtractor::VERSION
        ) {
            wfDebug( __METHOD__ . " old but compatible png metadata" );

            return self::METADATA_COMPATIBLE;
        }

        return self::METADATA_GOOD;
    }

    /**
     * @param File $image
     * @return string
     */
    public function getLongDesc( $image ) {
        global $wgLang;
        $original = parent::getLongDesc( $image );

        $metadata = $image->getMetadataArray();

        if ( !$metadata || isset( $metadata['_error'] ) || $metadata['frameCount'] <= 0 ) {
            return $original;
        }

        $info = [];
        $info[] = $original;

        if ( $metadata['loopCount'] == 0 ) {
            $info[] = wfMessage( 'file-info-png-looped' )->parse();
        } elseif ( $metadata['loopCount'] > 1 ) {
            $info[] = wfMessage( 'file-info-png-repeat' )->numParams( $metadata['loopCount'] )->parse();
        }

        if ( $metadata['frameCount'] > 0 ) {
            $info[] = wfMessage( 'file-info-png-frames' )->numParams( $metadata['frameCount'] )->parse();
        }

        if ( $metadata['duration'] ) {
            $info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
        }

        return $wgLang->commaList( $info );
    }

    /**
     * Return the duration of an APNG file.
     *
     * Shown in the &query=imageinfo&iiprop=size api query.
     *
     * @param File $file
     * @return float The duration of the file.
     */
    public function getLength( $file ) {
        $metadata = $file->getMetadataArray();

        if ( !$metadata || !isset( $metadata['duration'] ) || !$metadata['duration'] ) {
            return 0.0;
        }

        return (float)$metadata['duration'];
    }

    // PNGs should be easy to support, but it will need some sharpening applied
    // and another user test to check if the perceived quality change is noticeable
    public function supportsBucketing() {
        return false;
    }
}