| // Copyright 2011 The Closure Library Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS-IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| /** |
| * @fileoverview A wrapper for the HTML5 FileWriter object. |
| * |
| * When adding or modifying functionality in this namespace, be sure to update |
| * the mock counterparts in goog.testing.fs. |
| * |
| */ |
| |
| goog.provide('goog.fs.FileWriter'); |
| |
| goog.require('goog.fs.Error'); |
| goog.require('goog.fs.FileSaver'); |
| |
| |
| |
| /** |
| * An object for monitoring the saving of files, as well as other fine-grained |
| * writing operations. |
| * |
| * This should not be instantiated directly. Instead, it should be accessed via |
| * {@link goog.fs.FileEntry#createWriter}. |
| * |
| * @param {!FileWriter} writer The underlying FileWriter object. |
| * @constructor |
| * @extends {goog.fs.FileSaver} |
| * @final |
| */ |
| goog.fs.FileWriter = function(writer) { |
| goog.fs.FileWriter.base(this, 'constructor', writer); |
| |
| /** |
| * The underlying FileWriter object. |
| * |
| * @type {!FileWriter} |
| * @private |
| */ |
| this.writer_ = writer; |
| }; |
| goog.inherits(goog.fs.FileWriter, goog.fs.FileSaver); |
| |
| |
| /** |
| * @return {number} The byte offset at which the next write will occur. |
| */ |
| goog.fs.FileWriter.prototype.getPosition = function() { |
| return this.writer_.position; |
| }; |
| |
| |
| /** |
| * @return {number} The length of the file. |
| */ |
| goog.fs.FileWriter.prototype.getLength = function() { |
| return this.writer_.length; |
| }; |
| |
| |
| /** |
| * Write data to the file. |
| * |
| * @param {!Blob} blob The data to write. |
| */ |
| goog.fs.FileWriter.prototype.write = function(blob) { |
| try { |
| this.writer_.write(blob); |
| } catch (e) { |
| throw new goog.fs.Error(e, 'writing file'); |
| } |
| }; |
| |
| |
| /** |
| * Set the file position at which the next write will occur. |
| * |
| * @param {number} offset An absolute byte offset into the file. |
| */ |
| goog.fs.FileWriter.prototype.seek = function(offset) { |
| try { |
| this.writer_.seek(offset); |
| } catch (e) { |
| throw new goog.fs.Error(e, 'seeking in file'); |
| } |
| }; |
| |
| |
| /** |
| * Changes the length of the file to that specified. |
| * |
| * @param {number} size The new size of the file, in bytes. |
| */ |
| goog.fs.FileWriter.prototype.truncate = function(size) { |
| try { |
| this.writer_.truncate(size); |
| } catch (e) { |
| throw new goog.fs.Error(e, 'truncating file'); |
| } |
| }; |