107 lines
3.2 KiB
JavaScript
107 lines
3.2 KiB
JavaScript
// Copyright 2015 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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* @fileoverview Wrapper for URL and its createObjectUrl and revokeObjectUrl
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* methods that are part of the HTML5 File API.
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*/
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goog.provide('goog.fs.url');
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/**
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* Creates a blob URL for a blob object.
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* Throws an error if the browser does not support Object Urls.
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*
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* @param {!Blob} blob The object for which to create the URL.
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* @return {string} The URL for the object.
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*/
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goog.fs.url.createObjectUrl = function(blob) {
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return goog.fs.url.getUrlObject_().createObjectURL(blob);
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};
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/**
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* Revokes a URL created by {@link goog.fs.url.createObjectUrl}.
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* Throws an error if the browser does not support Object Urls.
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*
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* @param {string} url The URL to revoke.
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*/
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goog.fs.url.revokeObjectUrl = function(url) {
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goog.fs.url.getUrlObject_().revokeObjectURL(url);
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};
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/**
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* @typedef {{createObjectURL: (function(!Blob): string),
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* revokeObjectURL: function(string): void}}
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*/
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goog.fs.url.UrlObject_;
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/**
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* Get the object that has the createObjectURL and revokeObjectURL functions for
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* this browser.
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*
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* @return {goog.fs.url.UrlObject_} The object for this browser.
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* @private
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*/
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goog.fs.url.getUrlObject_ = function() {
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var urlObject = goog.fs.url.findUrlObject_();
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if (urlObject != null) {
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return urlObject;
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} else {
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throw Error('This browser doesn\'t seem to support blob URLs');
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}
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};
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/**
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* Finds the object that has the createObjectURL and revokeObjectURL functions
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* for this browser.
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*
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* @return {?goog.fs.url.UrlObject_} The object for this browser or null if the
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* browser does not support Object Urls.
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* @private
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*/
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goog.fs.url.findUrlObject_ = function() {
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// This is what the spec says to do
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// http://dev.w3.org/2006/webapi/FileAPI/#dfn-createObjectURL
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if (goog.isDef(goog.global.URL) &&
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goog.isDef(goog.global.URL.createObjectURL)) {
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return /** @type {goog.fs.url.UrlObject_} */ (goog.global.URL);
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// This is what Chrome does (as of 10.0.648.6 dev)
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} else if (
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goog.isDef(goog.global.webkitURL) &&
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goog.isDef(goog.global.webkitURL.createObjectURL)) {
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return /** @type {goog.fs.url.UrlObject_} */ (goog.global.webkitURL);
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// This is what the spec used to say to do
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} else if (goog.isDef(goog.global.createObjectURL)) {
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return /** @type {goog.fs.url.UrlObject_} */ (goog.global);
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} else {
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return null;
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}
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};
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/**
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* Checks whether this browser supports Object Urls. If not, calls to
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* createObjectUrl and revokeObjectUrl will result in an error.
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*
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* @return {boolean} True if this browser supports Object Urls.
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*/
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goog.fs.url.browserSupportsObjectUrls = function() {
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return goog.fs.url.findUrlObject_() != null;
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};
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