portal/patient/fwk/libs/util/thumbnail.php

   1 <?php
   2
   3 /**
   4  *
   5  * Enter description here ...
   6  * @link http://www.electrictoolbox.com/php-generate-thumbnails/
   7  * @author Chris Hope
   8  *
   9  */
  10
  11 /**
  12  * thumbnail generator for creating smaller sized images and either saving them to disk
  13  * or streaming them directly to the browser
  14  *
  15  * @example <pre>
  16  *          // Create a thumbnail from /tmp/big.jpg and stream it to the browser with maximum dimensions of 100x100
  17  *          // this will default to jpg format and will send the necessary image type header:
  18  *          $tg = new thumbnailGenerator;
  19  *          $tg->generate('/tmp/big.jpg', 100, 100);
  20  *
  21  *          // Create a thumbnail from /tmp/big.png and save it to /tmp/small.png with maximum dimensions of 100x100:
  22  *          $tg = new thumbnailGenerator;
  23  *          $tg->generate('/tmp/big.jpg', 100, 100, '/tmp/small.jpg');
  24  *          </pre>
  25  */
  26 class thumbnail
  27 {
  28     var $allowableTypes = array (
  29             IMAGETYPE_GIF,
  30             IMAGETYPE_JPEG,
  31             IMAGETYPE_PNG
  32     );
  33     public function imageCreateFromFile($filename, $imageType)
  34     {
  35         switch ($imageType) {
  36             case IMAGETYPE_GIF:
  37                 return imagecreatefromgif($filename);
  38             case IMAGETYPE_JPEG:
  39                 return imagecreatefromjpeg($filename);
  40             case IMAGETYPE_PNG:
  41                 return imagecreatefrompng($filename);
  42             default:
  43                 return false;
  44         }
  45     }
  46
  47     /**
  48      * Generates a thumbnail image using the file at $sourceFilename and either writing it
  49      * out to a new file or directly to the browser.
  50      *
  51      * @param string $sourceFilename
  52      *          Filename for the image to have thumbnail made from
  53      * @param integer $maxWidth
  54      *          The maxium width for the resulting thumbnail
  55      * @param integer $maxHeight
  56      *          The maxium height for the resulting thumbnail
  57      * @param string $targetFormatOrFilename
  58      *          Either a filename extension (gif|jpg|png) or the
  59      * @param
  60      *          bool set to true to set the image to the exact size given (stretching if necessary)
  61      *          filename the resulting file should be written to. This is optional and if not specified
  62      *          will send a jpg to the browser.
  63      * @return boolean true if the image could be created, false if not
  64      */
  65     public function generate($sourceFilename, $maxWidth, $maxHeight, $targetFormatOrFilename = 'jpg', $useExactSize = false)
  66     {
  67         $size = getimagesize($sourceFilename); // 0 = width, 1 = height, 2 = type
  68
  69         // check to make sure source image is in allowable format
  70         if (! in_array($size [2], $this->allowableTypes)) {
  71             return false;
  72         }
  73
  74         // work out the extension, what target filename should be and output function to call
  75         $pathinfo = pathinfo($targetFormatOrFilename);
  76         if ($pathinfo ['basename'] == $pathinfo ['filename']) {
  77             $extension = strtolower($targetFormatOrFilename);
  78             // set target to null so writes out to browser
  79             $targetFormatOrFilename = null;
  80         } else {
  81             $extension = strtolower($pathinfo ['extension']);
  82         }
  83
  84         switch ($extension) {
  85             case 'gif':
  86                 $function = 'imagegif';
  87                 break;
  88             case 'png':
  89                 $function = 'imagepng';
  90                 break;
  91             default:
  92                 $function = 'imagejpeg';
  93                 break;
  94         }
  95
  96         // load the image and return false if didn't work
  97         $source = $this->imageCreateFromFile($sourceFilename, $size [2]);
  98         if (! $source) {
  99             return false;
 100         }
 101
 102         // write out the appropriate HTTP headers if going to browser
 103         if ($targetFormatOrFilename == null) {
 104             if ($extension == 'jpg') {
 105                 header("Content-Type: image/jpeg");
 106             } else {
 107                 header("Content-Type: image/$extension");
 108             }
 109         }
 110
 111         // if the source fits within the maximum then no need to resize
 112         if ($useExactSize == false && $size [0] <= $maxWidth && $size [1] <= $maxHeight) {
 113             $function($source, $targetFormatOrFilename);
 114         } else {
 115             $newWidth = 0;
 116             $newHeight = 0;
 117
 118             if ($useExactSize) {
 119                 $newWidth = $maxWidth;
 120                 $newHeight = $maxHeight;
 121             } else {
 122                 $ratioWidth = $maxWidth / $size [0];
 123                 $ratioHeight = $maxHeight / $size [1];
 124
 125                 // use smallest ratio
 126                 if ($ratioWidth < $ratioHeight) {
 127                     $newWidth = $maxWidth;
 128                     $newHeight = round($size [1] * $ratioWidth);
 129                 } else {
 130                     $newWidth = round($size [0] * $ratioHeight);
 131                     $newHeight = $maxHeight;
 132                 }
 133             }
 134
 135             $target = imagecreatetruecolor($newWidth, $newHeight);
 136             imagecopyresampled($target, $source, 0, 0, 0, 0, $newWidth, $newHeight, $size [0], $size [1]);
 137             $function($target, $targetFormatOrFilename);
 138         }
 139
 140         return true;
 141     }
 142 }