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

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