ui/file_manager/gallery/js/gallery_item.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * Object representing an image item (a photo).
   7  *
   8  * @param {FileEntry} entry Image entry.
   9  * @param {EntryLocation} locationInfo Entry location information.
  10  * @param {Object} metadata Metadata for the entry.
  11  * @param {MetadataCache} metadataCache Metadata cache instance.
  12  * @param {boolean} original Whether the entry is original or edited.
  13  * @constructor
  14  */
  15 Gallery.Item = function(
  16     entry, locationInfo, metadata, metadataCache, original) {
  17   /**
  18    * @type {FileEntry}
  19    * @private
  20    */
  21   this.entry_ = entry;
  22
  23   /**
  24    * @type {EntryLocation}
  25    * @private
  26    */
  27   this.locationInfo_ = locationInfo;
  28
  29   /**
  30    * @type {Object}
  31    * @private
  32    */
  33   this.metadata_ = Object.freeze(metadata);
  34
  35   /**
  36    * @type {MetadataCache}
  37    * @private
  38    */
  39   this.metadataCache_ = metadataCache;
  40
  41   /**
  42    * The content cache is used for prefetching the next image when going through
  43    * the images sequentially. The real life photos can be large (18Mpix = 72Mb
  44    * pixel array) so we want only the minimum amount of caching.
  45    * @type {HTMLCanvasElement}
  46    */
  47   this.screenImage = null;
  48
  49   /**
  50    * We reuse previously generated screen-scale images so that going back to a
  51    * recently loaded image looks instant even if the image is not in the content
  52    * cache any more. Screen-scale images are small (~1Mpix) so we can afford to
  53    * cache more of them.
  54    * @type {HTMLCanvasElement}
  55    */
  56   this.contentImage = null;
  57
  58   /**
  59    * Last accessed date to be used for selecting items whose cache are evicted.
  60    * @type {number}
  61    * @private
  62    */
  63   this.lastAccessed_ = Date.now();
  64
  65   /**
  66    * @type {boolean}
  67    * @private
  68    */
  69   this.original_ = original;
  70
  71   Object.seal(this);
  72 };
  73
  74 /**
  75  * @return {FileEntry} Image entry.
  76  */
  77 Gallery.Item.prototype.getEntry = function() { return this.entry_; };
  78
  79 /**
  80  * @return {EntryLocation} Entry location information.
  81  */
  82 Gallery.Item.prototype.getLocationInfo = function() {
  83   return this.locationInfo_;
  84 };
  85
  86 /**
  87  * @return {Object} Metadata.
  88  */
  89 Gallery.Item.prototype.getMetadata = function() { return this.metadata_; };
  90
  91 /**
  92  * Obtains the latest media metadata.
  93  *
  94  * This is a heavy operation since it forces to load the image data to obtain
  95  * the metadata.
  96  * @return {Promise} Promise to be fulfilled with fetched metadata.
  97  */
  98 Gallery.Item.prototype.getFetchedMedia = function() {
  99   return new Promise(function(fulfill, reject) {
 100     this.metadataCache_.getLatest(
 101         [this.entry_],
 102         'fetchedMedia',
 103         function(metadata) {
 104           if (metadata[0])
 105             fulfill(metadata[0]);
 106           else
 107             reject('Failed to load metadata.');
 108         });
 109   }.bind(this));
 110 };
 111
 112 /**
 113  * Sets the metadata.
 114  * @param {Object} metadata New metadata.
 115  */
 116 Gallery.Item.prototype.setMetadata = function(metadata) {
 117   this.metadata_ = Object.freeze(metadata);
 118 };
 119
 120 /**
 121  * @return {string} File name.
 122  */
 123 Gallery.Item.prototype.getFileName = function() {
 124   return this.entry_.name;
 125 };
 126
 127 /**
 128  * @return {boolean} True if this image has not been created in this session.
 129  */
 130 Gallery.Item.prototype.isOriginal = function() { return this.original_; };
 131
 132 /**
 133  * Obtains the last accessed date.
 134  * @return {number} Last accessed date.
 135  */
 136 Gallery.Item.prototype.getLastAccessedDate = function() {
 137   return this.lastAccessed_;
 138 };
 139
 140 /**
 141  * Updates the last accessed date.
 142  */
 143 Gallery.Item.prototype.touch = function() {
 144   this.lastAccessed_ = Date.now();
 145 };
 146
 147 // TODO: Localize?
 148 /**
 149  * @type {string} Suffix for a edited copy file name.
 150  */
 151 Gallery.Item.COPY_SIGNATURE = ' - Edited';
 152
 153 /**
 154  * Regular expression to match '... - Edited'.
 155  * @type {RegExp}
 156  */
 157 Gallery.Item.REGEXP_COPY_0 =
 158     new RegExp('^(.+)' + Gallery.Item.COPY_SIGNATURE + '$');
 159
 160 /**
 161  * Regular expression to match '... - Edited (N)'.
 162  * @type {RegExp}
 163  */
 164 Gallery.Item.REGEXP_COPY_N =
 165     new RegExp('^(.+)' + Gallery.Item.COPY_SIGNATURE + ' \\((\\d+)\\)$');
 166
 167 /**
 168  * Creates a name for an edited copy of the file.
 169  *
 170  * @param {DirectoryEntry} dirEntry Entry.
 171  * @param {function(string)} callback Callback.
 172  * @private
 173  */
 174 Gallery.Item.prototype.createCopyName_ = function(dirEntry, callback) {
 175   var name = this.getFileName();
 176
 177   // If the item represents a file created during the current Gallery session
 178   // we reuse it for subsequent saves instead of creating multiple copies.
 179   if (!this.original_) {
 180     callback(name);
 181     return;
 182   }
 183
 184   var ext = '';
 185   var index = name.lastIndexOf('.');
 186   if (index != -1) {
 187     ext = name.substr(index);
 188     name = name.substr(0, index);
 189   }
 190
 191   if (!ext.match(/jpe?g/i)) {
 192     // Chrome can natively encode only two formats: JPEG and PNG.
 193     // All non-JPEG images are saved in PNG, hence forcing the file extension.
 194     ext = '.png';
 195   }
 196
 197   function tryNext(tries) {
 198     // All the names are used. Let's overwrite the last one.
 199     if (tries == 0) {
 200       setTimeout(callback, 0, name + ext);
 201       return;
 202     }
 203
 204     // If the file name contains the copy signature add/advance the sequential
 205     // number.
 206     var matchN = Gallery.Item.REGEXP_COPY_N.exec(name);
 207     var match0 = Gallery.Item.REGEXP_COPY_0.exec(name);
 208     if (matchN && matchN[1] && matchN[2]) {
 209       var copyNumber = parseInt(matchN[2], 10) + 1;
 210       name = matchN[1] + Gallery.Item.COPY_SIGNATURE + ' (' + copyNumber + ')';
 211     } else if (match0 && match0[1]) {
 212       name = match0[1] + Gallery.Item.COPY_SIGNATURE + ' (1)';
 213     } else {
 214       name += Gallery.Item.COPY_SIGNATURE;
 215     }
 216
 217     dirEntry.getFile(name + ext, {create: false, exclusive: false},
 218         tryNext.bind(null, tries - 1),
 219         callback.bind(null, name + ext));
 220   }
 221
 222   tryNext(10);
 223 };
 224
 225 /**
 226  * Writes the new item content to either the existing or a new file.
 227  *
 228  * @param {VolumeManager} volumeManager Volume manager instance.
 229  * @param {string} fallbackDir Fallback directory in case the current directory
 230  *     is read only.
 231  * @param {boolean} overwrite Whether to overwrite the image to the item or not.
 232  * @param {HTMLCanvasElement} canvas Source canvas.
 233  * @param {ImageEncoder.MetadataEncoder} metadataEncoder MetadataEncoder.
 234  * @param {function(boolean)=} opt_callback Callback accepting true for success.
 235  */
 236 Gallery.Item.prototype.saveToFile = function(
 237     volumeManager, fallbackDir, overwrite, canvas, metadataEncoder,
 238     opt_callback) {
 239   ImageUtil.metrics.startInterval(ImageUtil.getMetricName('SaveTime'));
 240
 241   var name = this.getFileName();
 242
 243   var onSuccess = function(entry, locationInfo) {
 244     ImageUtil.metrics.recordEnum(ImageUtil.getMetricName('SaveResult'), 1, 2);
 245     ImageUtil.metrics.recordInterval(ImageUtil.getMetricName('SaveTime'));
 246
 247     this.entry_ = entry;
 248     this.locationInfo_ = locationInfo;
 249
 250     this.metadataCache_.clear([this.entry_], 'fetchedMedia');
 251     if (opt_callback)
 252       opt_callback(true);
 253   }.bind(this);
 254
 255   var onError = function(error) {
 256     console.error('Error saving from gallery', name, error);
 257     ImageUtil.metrics.recordEnum(ImageUtil.getMetricName('SaveResult'), 0, 2);
 258     if (opt_callback)
 259       opt_callback(false);
 260   }
 261
 262   var doSave = function(newFile, fileEntry) {
 263     fileEntry.createWriter(function(fileWriter) {
 264       function writeContent() {
 265         fileWriter.onwriteend = onSuccess.bind(null, fileEntry);
 266         fileWriter.write(ImageEncoder.getBlob(canvas, metadataEncoder));
 267       }
 268       fileWriter.onerror = function(error) {
 269         onError(error);
 270         // Disable all callbacks on the first error.
 271         fileWriter.onerror = null;
 272         fileWriter.onwriteend = null;
 273       };
 274       if (newFile) {
 275         writeContent();
 276       } else {
 277         fileWriter.onwriteend = writeContent;
 278         fileWriter.truncate(0);
 279       }
 280     }, onError);
 281   }
 282
 283   var getFile = function(dir, newFile) {
 284     dir.getFile(name, {create: newFile, exclusive: newFile},
 285         function(fileEntry) {
 286           var locationInfo = volumeManager.getLocationInfo(fileEntry);
 287           // If the volume is gone, then abort the saving operation.
 288           if (!locationInfo) {
 289             onError('NotFound');
 290             return;
 291           }
 292           doSave(newFile, fileEntry, locationInfo);
 293         }.bind(this), onError);
 294   }.bind(this);
 295
 296   var checkExistence = function(dir) {
 297     dir.getFile(name, {create: false, exclusive: false},
 298         getFile.bind(null, dir, false /* existing file */),
 299         getFile.bind(null, dir, true /* create new file */));
 300   }
 301
 302   var saveToDir = function(dir) {
 303     if (overwrite && !this.locationInfo_.isReadOnly) {
 304       checkExistence(dir);
 305     } else {
 306       this.createCopyName_(dir, function(copyName) {
 307         this.original_ = false;
 308         name = copyName;
 309         checkExistence(dir);
 310       }.bind(this));
 311     }
 312   }.bind(this);
 313
 314   if (this.locationInfo_.isReadOnly) {
 315     saveToDir(fallbackDir);
 316   } else {
 317     this.entry_.getParent(saveToDir, onError);
 318   }
 319 };
 320
 321 /**
 322  * Renames the item.
 323  *
 324  * @param {string} displayName New display name (without the extension).
 325  * @return {Promise} Promise fulfilled with when renaming completes, or rejected
 326  *     with the error message.
 327  */
 328 Gallery.Item.prototype.rename = function(displayName) {
 329   var newFileName = this.entry_.name.replace(
 330       ImageUtil.getDisplayNameFromName(this.entry_.name), displayName);
 331
 332   if (newFileName === this.entry_.name)
 333     return Promise.reject('NOT_CHANGED');
 334
 335   if (/^\s*$/.test(displayName))
 336     return Promise.reject(str('ERROR_WHITESPACE_NAME'));
 337
 338   var parentDirectoryPromise = new Promise(
 339       this.entry_.getParent.bind(this.entry_));
 340   return parentDirectoryPromise.then(function(parentDirectory) {
 341     var nameValidatingPromise =
 342         util.validateFileName(parentDirectory, newFileName, true);
 343     return nameValidatingPromise.then(function() {
 344       var existingFilePromise = new Promise(parentDirectory.getFile.bind(
 345           parentDirectory, newFileName, {create: false, exclusive: false}));
 346       return existingFilePromise.then(function() {
 347         return Promise.reject(str('GALLERY_FILE_EXISTS'));
 348       }, function() {
 349         return new Promise(
 350             this.entry_.moveTo.bind(this.entry_, parentDirectory, newFileName));
 351       }.bind(this));
 352     }.bind(this));
 353   }.bind(this)).then(function(entry) {
 354     this.entry_ = entry;
 355   }.bind(this));
 356 };