mediawiki-extensions-PdfHandler/PdfHandler.image.php

<?php
/**
 *
 * Copyright © 2007 Xarax <jodeldi@gmx.de>
 *
 * 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
 */

/**
 * inspired by djvuimage from Brion Vibber
 * modified and written by xarax
 */

class PdfImage {

	/**
	 * @param $filename
	 */
	function __construct( $filename ) {
		$this->mFilename = $filename;
	}

	/**
	 * @return bool
	 */
	public function isValid() {
		return true;
	}

	/**
	 * @return array|bool
	 */
	public function getImageSize() {
		$data = $this->retrieveMetadata();
		$size = self::getPageSize( $data, 1 );

		if( $size ) {
			$width = $size['width'];
			$height = $size['height'];
			return array( $width, $height, 'Pdf',
				"width=\"$width\" height=\"$height\"" );
		}
		return false;
	}

	/**
	 * @param $data array
	 * @param $page
	 * @return array|bool
	 */
	public static function getPageSize( $data, $page ) {
		global $wgPdfHandlerDpi;

		if( isset( $data['pages'][$page]['Page size'] ) ) {
			$o = $data['pages'][$page]['Page size'];
		} elseif( isset( $data['Page size'] ) ) {
			$o = $data['Page size'];
		} else {
			$o = false;
		}

		if ( $o ) {
			if( isset( $data['pages'][$page]['Page rot'] ) ) {
				$r = $data['pages'][$page]['Page rot'];
			} elseif( isset( $data['Page rot'] ) ) {
				$r = $data['Page rot'];
			} else {
				$r = 0;
			}
			$size = explode( 'x', $o, 2 );

			if ( $size ) {
				$width  = intval( trim( $size[0] ) / 72 * $wgPdfHandlerDpi );
				$height = explode( ' ', trim( $size[1] ), 2 );
				$height = intval( trim( $height[0] ) / 72 * $wgPdfHandlerDpi );
				if ( ( $r/90 ) & 1 ) {
					// Swap width and height for landscape pages
					$t = $width;
					$width = $height;
					$height = $t;
				}

				return array(
					'width' => $width,
					'height' => $height
				);
			}
		}

		return false;
	}

	/**
	 * @return array|bool|null
	 */
	public function retrieveMetaData() {
		global $wgPdfInfo, $wgPdftoText;

		if ( $wgPdfInfo ) {
			wfProfileIn( 'pdfinfo' );
			$cmd = wfEscapeShellArg( $wgPdfInfo ) .
				" -enc UTF-8 " . # Report metadata as UTF-8 text...
				" -l 9999999 " . # Report page sizes for all pages
				wfEscapeShellArg( $this->mFilename );
			$retval = '';
			$dump = wfShellExec( $cmd, $retval );
			$data = $this->convertDumpToArray( $dump );
			wfProfileOut( 'pdfinfo' );
		} else {
			$data = null;
		}

		# Read text layer
		if ( isset( $wgPdftoText ) ) {
			wfProfileIn( 'pdftotext' );
			$cmd = wfEscapeShellArg( $wgPdftoText ) . ' '. wfEscapeShellArg( $this->mFilename ) . ' - ';
			wfDebug( __METHOD__.": $cmd\n" );
			$retval = '';
			$txt = wfShellExec( $cmd, $retval );
			wfProfileOut( 'pdftotext' );
			if( $retval == 0 ) {
				$txt = str_replace( "\r\n", "\n", $txt );
				$pages = explode( "\f", $txt );
				foreach( $pages as $page => $pageText ) {
					# Get rid of invalid UTF-8, strip control characters
					# Note we need to do this per page, as \f page feed would be stripped.
					$pages[$page] = UtfNormal::cleanUp( $pageText );
				}
				$data['text'] = $pages;
			}
		}
		return $data;
	}

	/**
	 * @param $dump string
	 * @return array|bool
	 */
	protected function convertDumpToArray( $dump ) {
		if ( strval( $dump ) == '' ) {
			return false;
		}

		$lines = explode( "\n", $dump );
		$data = array();

		foreach( $lines as $line ) {
			$bits = explode( ':', $line, 2 );
			if( count( $bits ) > 1 ) {
				$key = trim( $bits[0] );
				$value = trim( $bits[1] );
				$matches = array();
				// "Page xx rot" will be in poppler 0.20's pdfinfo output
				// See https://bugs.freedesktop.org/show_bug.cgi?id=41867
				if( preg_match( '/^Page +(\d+) (size|rot)$/', $key, $matches ) ) {
					$data['pages'][$matches[1]][$matches[2] == 'size' ? 'Page size' : 'Page rot'] = $value;
				} else {
					$data[$key] = $value;
				}
			}
		}
		return $data;
	}
}