resources/mediawiki.special/mediawiki.special.upload.js

   1 /*
   2  * JavaScript for Special:Upload
   3  * Note that additional code still lives in skins/common/upload.js
   4  */
   5
   6 jQuery( function( $ ) {
   7         /**
   8          * Is the FileAPI available with sufficient functionality?
   9          */
  10         function hasFileAPI(){
  11                 return typeof window.FileReader !== 'undefined';
  12         }
  13
  14         /**
  15          * Check if this is a recognizable image type...
  16          * Also excludes files over 10M to avoid going insane on memory usage.
  17          *
  18          * @todo is there a way we can ask the browser what's supported in <img>s?
  19          *
  20          * @param {File} file
  21          * @return boolean
  22          */
  23         function fileIsPreviewable( file ) {
  24                 var     known = ['image/png', 'image/gif', 'image/jpeg', 'image/svg+xml'],
  25                         tooHuge = 10 * 1024 * 1024;
  26                 return ( $.inArray( file.type, known ) !== -1 ) && file.size > 0 && file.size < tooHuge;
  27         }
  28
  29         /**
  30          * Show a thumbnail preview of PNG, JPEG, GIF, and SVG files prior to upload
  31          * in browsers supporting HTML5 FileAPI.
  32          *
  33          * As of this writing, known good:
  34          * - Firefox 3.6+
  35          * - Chrome 7.something
  36          *
  37          * @todo check file size limits and warn of likely failures
  38          *
  39          * @param {File} file
  40          */
  41         function showPreview( file ) {
  42                 var     previewSize = 180,
  43                         thumb = $( '<div id="mw-upload-thumbnail" class="thumb tright">' +
  44                                                 '<div class="thumbinner">' +
  45                                                         '<canvas width="' + previewSize + '" height="' + previewSize + '" ></canvas>' +
  46                                                         '<div class="thumbcaption"><div class="filename"></div><div class="fileinfo"></div></div>' +
  47                                                 '</div>' +
  48                                         '</div>' );
  49                 thumb.find( '.filename' ).text( file.name ).end()
  50                         .find( '.fileinfo' ).text( prettySize( file.size ) ).end();
  51
  52                 var     ctx = thumb.find( 'canvas' )[0].getContext( '2d' ),
  53                         spinner = new Image();
  54                 spinner.onload = function() {
  55                         ctx.drawImage( spinner, (previewSize - spinner.width) / 2,
  56                                         (previewSize - spinner.height) / 2 );
  57                 };
  58                 spinner.src = mw.config.get( 'wgScriptPath' ) + '/skins/common/images/spinner.gif';
  59                 $( '#mw-htmlform-source' ).parent().prepend( thumb );
  60
  61                 var meta;
  62                 fetchPreview( file, function( dataURL ) {
  63                         var     img = new Image(),
  64                                 rotation = 0;
  65
  66                         if ( meta && meta.tiff && meta.tiff.Orientation ) {
  67                                 rotation = (360 - function () {
  68                                         // See includes/media/Bitmap.php
  69                                         switch ( meta.tiff.Orientation.value ) {
  70                                                 case 8:
  71                                                         return 90;
  72                                                 case 3:
  73                                                         return 180;
  74                                                 case 6:
  75                                                         return 270;
  76                                                 default:
  77                                                         return 0;
  78                                         }
  79                                 }() ) % 360;
  80                         }
  81
  82                         img.onload = function() {
  83                                 // Fit the image within the previewSizexpreviewSize box
  84                                 if ( img.width > img.height ) {
  85                                         width = previewSize;
  86                                         height = img.height / img.width * previewSize;
  87                                 } else {
  88                                         height = previewSize;
  89                                         width = img.width / img.height * previewSize;
  90                                 }
  91                                 // Determine the offset required to center the image
  92                                 dx = (180 - width) / 2;
  93                                 dy = (180 - height) / 2;
  94                                 switch ( rotation ) {
  95                                         // If a rotation is applied, the direction of the axis
  96                                         // changes as well. You can derive the values below by
  97                                         // drawing on paper an axis system, rotate it and see
  98                                         // where the positive axis direction is
  99                                         case 0:
 100                                                 x = dx;
 101                                                 y = dy;
 102                                                 break;
 103                                         case 90:
 104
 105                                                 x = dx;
 106                                                 y = dy - previewSize;
 107                                                 break;
 108                                         case 180:
 109                                                 x = dx - previewSize;
 110                                                 y = dy - previewSize;
 111                                                 break;
 112                                         case 270:
 113                                                 x = dx - previewSize;
 114                                                 y = dy;
 115                                                 break;
 116                                 }
 117
 118                                 ctx.clearRect( 0, 0, 180, 180 );
 119                                 ctx.rotate( rotation / 180 * Math.PI );
 120                                 ctx.drawImage( img, x, y, width, height );
 121
 122                                 // Image size
 123                                 var info = mw.msg( 'widthheight', img.width, img.height ) +
 124                                         ', ' + prettySize( file.size );
 125                                 $( '#mw-upload-thumbnail .fileinfo' ).text( info );
 126                         };
 127                         img.src = dataURL;
 128                 }, mediaWiki.config.get( 'wgFileCanRotate' ) ? function ( data ) {
 129                         try {
 130                                 meta = mediaWiki.util.jpegmeta( data, file.fileName );
 131                                 meta._binary_data = null;
 132                         } catch ( e ) {
 133                                 meta = null;
 134                         }
 135                 } : null );
 136         }
 137
 138         /**
 139          * Start loading a file into memory; when complete, pass it as a
 140          * data URL to the callback function. If the callbackBinary is set it will
 141          * first be read as binary and afterwards as data URL. Useful if you want
 142          * to do preprocessing on the binary data first.
 143          *
 144          * @param {File} file
 145          * @param {function} callback
 146          * @param {function} callbackBinary
 147          */
 148         function fetchPreview( file, callback, callbackBinary ) {
 149                 var reader = new FileReader();
 150                 reader.onload = function() {
 151                         if ( callbackBinary ) {
 152                                 callbackBinary( reader.result );
 153                                 reader.onload = function() {
 154                                         callback( reader.result );
 155                                 };
 156                                 reader.readAsDataURL( file );
 157                         } else {
 158                                 callback( reader.result );
 159                         }
 160                 };
 161                 if ( callbackBinary ) {
 162                         reader.readAsBinaryString( file );
 163                 } else {
 164                         reader.readAsDataURL( file );
 165                 }
 166         }
 167
 168         /**
 169          * Format a file size attractively.
 170          * @todo match numeric formatting
 171          *
 172          * @param {number} s
 173          * @return string
 174          */
 175         function prettySize( s ) {
 176                 var sizes = ['size-bytes', 'size-kilobytes', 'size-megabytes', 'size-gigabytes'];
 177                 while ( s >= 1024 && sizes.length > 1 ) {
 178                         s /= 1024;
 179                         sizes = sizes.slice( 1 );
 180                 }
 181                 return mw.msg( sizes[0], Math.round( s ) );
 182         }
 183
 184         /**
 185          * Clear the file upload preview area.
 186          */
 187         function clearPreview() {
 188                 $( '#mw-upload-thumbnail' ).remove();
 189         }
 190
 191
 192         if ( hasFileAPI() ) {
 193                 // Update thumbnail when the file selection control is updated.
 194                 $( '#wpUploadFile' ).change( function() {
 195                         clearPreview();
 196                         if ( this.files && this.files.length ) {
 197                                 // Note: would need to be updated to handle multiple files.
 198                                 var file = this.files[0];
 199                                 if ( fileIsPreviewable( file ) ) {
 200                                         showPreview( file );
 201                                 }
 202                         }
 203                 } );
 204         }
 205 } );