New custom wallpaper picker UI

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_directories.js

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Wallpaper file system quota.
+ */
+/** #const */ var WallpaperQuota = 1024 * 1024 * 100;
+
+/**
+ * Wallpaper directories enum.
+ */
+/** #const */ var WallpaperDirNameEnum = {
+                  ORIGINAL: 'original',
+                  THUMBNAIL: 'thumbnail'
+              };
+
+var wallpaperDirectories = null;
+
+/**
+ * Manages custom wallpaper related directories in wallpaper's sandboxed
+ * FileSystem.
+ * @constructor
+ */
+function WallpaperDirectories() {
+  this.wallpaperDirs_ = {};
+  this.wallpaperDirs_[WallpaperDirNameEnum.ORIGINAL] = null;
+  this.wallpaperDirs_[WallpaperDirNameEnum.THUMBNAIL] = null;
+}
+
+/**
+ * Gets WallpaperDirectories instance. In case is hasn't been initialized, a new
+ * instance is created.
+ * @return {WallpaperDirectories} A WallpaperDirectories instance.
+ */
+WallpaperDirectories.getInstance = function() {
+  if (wallpaperDirectories === null)
+    wallpaperDirectories = new WallpaperDirectories();
+  return wallpaperDirectories;
+};
+
+WallpaperDirectories.prototype = {
+  /**
+   * Returns all custom wallpaper related directory entries.
+   */
+  get wallpaperDirs() {
+    return this.wallpaperDirs_;
+  },
+
+  /**
+   * If dirName is not requested, gets the directory entry of dirName and cache
+   * the result. Calls success callback if success.
+   * @param {string} dirName The directory name of requested directory entry.
+   * @param {function(DirectoryEntry):void} success Call success with requested
+   *     DirectoryEntry.
+   * @param {function(e):void} failure Call failure when failed to get the
+   *     requested directory.
+   */
+  requestDir: function(dirName, success, failure) {
+    if (dirName != WallpaperDirNameEnum.ORIGINAL &&
+        dirName != WallpaperDirNameEnum.THUMBNAIL) {
+      console.error('Error: Unknow directory name.');
+      var e = new Error();
+      e.code = FileError.NOT_FOUND_ERR;
+      failure(e);
+      return;
+    }
+    var self = this;
+    window.webkitRequestFileSystem(window.PERSISTENT, WallpaperQuota,
+                                   function(fs) {
+      fs.root.getDirectory(dirName, {create: true}, function(dirEntry) {
+        self.wallpaperDirs_[dirName] = dirEntry;
+        success(dirEntry);
+      }, failure);
+    }, failure);
+  },
+
+  /**
+   * Gets DirectoryEntry associated with dirName from cache. If not in cache try
+   * to request it from FileSystem.
+   * @param {string} dirName The directory name of requested directory entry.
+   * @param {function(DirectoryEntry):void} success Call success with requested
+   *     DirectoryEntry.
+   * @param {function(e):void} failure Call failure when failed to get the
+   *     requested directory.
+   */
+  getDirectory: function(dirName, success, failure) {
+    if (this.wallpaperDirs[dirName])
+      success(this.wallpaperDirs[dirName]);
+    else
+      this.requestDir(dirName, success, failure);
+  }
+};