chrome/browser/resources/pdf/browser_api.js

   1 // Copyright 2015 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 'use strict';
   6
   7 /**
   8  * Returns a promise that will resolve to the default zoom factor.
   9  * @param {!Object} streamInfo The stream object pointing to the data contained
  10  *     in the PDF.
  11  * @return {Promise<number>} A promise that will resolve to the default zoom
  12  *     factor.
  13  */
  14 function lookupDefaultZoom(streamInfo) {
  15   // Webviews don't run in tabs so |streamInfo.tabId| is -1 when running within
  16   // a webview.
  17   if (!chrome.tabs || streamInfo.tabId < 0)
  18     return Promise.resolve(1);
  19
  20   return new Promise(function(resolve, reject) {
  21     chrome.tabs.getZoomSettings(streamInfo.tabId, function(zoomSettings) {
  22       resolve(zoomSettings.defaultZoomFactor);
  23     });
  24   });
  25 }
  26
  27 /**
  28  * A class providing an interface to the browser.
  29  */
  30 class BrowserApi {
  31   /**
  32    * @constructor
  33    * @param {!Object} streamInfo The stream object which points to the data
  34    *     contained in the PDF.
  35    * @param {number} defaultZoom The default browser zoom.
  36    * @param {boolean} manageZoom Whether to manage zoom.
  37    */
  38   constructor(streamInfo, defaultZoom, manageZoom) {
  39     this.streamInfo_ = streamInfo;
  40     this.defaultZoom_ = defaultZoom;
  41     this.manageZoom_ = manageZoom;
  42   }
  43
  44   /**
  45    * Returns a promise to a BrowserApi.
  46    * @param {!Object} streamInfo The stream object pointing to the data
  47    *     contained in the PDF.
  48    * @param {boolean} manageZoom Whether to manage zoom.
  49    */
  50   static create(streamInfo, manageZoom) {
  51     return lookupDefaultZoom(streamInfo).then(function(defaultZoom) {
  52       return new BrowserApi(streamInfo, defaultZoom, manageZoom);
  53     });
  54   }
  55
  56   /**
  57    * Returns the stream info pointing to the data contained in the PDF.
  58    * @return {Object} The stream info object.
  59    */
  60   getStreamInfo() {
  61     return this.streamInfo_;
  62   }
  63
  64   /**
  65    * Aborts the stream.
  66    */
  67   abortStream() {
  68     if (chrome.mimeHandlerPrivate)
  69       chrome.mimeHandlerPrivate.abortStream();
  70   }
  71
  72   /**
  73    * Sets the browser zoom.
  74    * @param {number} zoom The zoom factor to send to the browser.
  75    * @return {Promise} A promise that will be resolved when the browser zoom
  76    *     has been updated.
  77    */
  78   setZoom(zoom) {
  79     if (!this.manageZoom_)
  80       return Promise.resolve();
  81     return new Promise(function(resolve, reject) {
  82       chrome.tabs.setZoom(this.streamInfo_.tabId, zoom, resolve);
  83     }.bind(this));
  84   }
  85
  86   /**
  87    * Returns the default browser zoom factor.
  88    * @return {number} The default browser zoom factor.
  89    */
  90   getDefaultZoom() {
  91     return this.defaultZoom_;
  92   }
  93
  94   /**
  95    * Adds an event listener to be notified when the browser zoom changes.
  96    * @param {function} listener The listener to be called with the new zoom
  97    *     factor.
  98    */
  99   addZoomEventListener(listener) {
 100     if (!this.manageZoom_)
 101       return;
 102
 103     chrome.tabs.onZoomChange.addListener(function(zoomChangeInfo) {
 104       if (zoomChangeInfo.tabId != this.streamInfo_.tabId)
 105         return;
 106       listener(zoomChangeInfo.newZoomFactor);
 107     }.bind(this));
 108   }
 109 };
 110
 111 /**
 112  * Creates a BrowserApi for an extension running as a mime handler.
 113  * @return {Promise<BrowserApi>} A promise to a BrowserApi instance constructed
 114  *     using the mimeHandlerPrivate API.
 115  */
 116 function createBrowserApiForMimeHandlerView() {
 117   return new Promise(function(resolve, reject) {
 118     chrome.mimeHandlerPrivate.getStreamInfo(resolve);
 119   }).then(function(streamInfo) {
 120     let manageZoom = !streamInfo.embedded && streamInfo.tabId != -1;
 121     return new Promise(function(resolve, reject) {
 122       if (!manageZoom) {
 123         resolve();
 124         return;
 125       }
 126       chrome.tabs.setZoomSettings(
 127           streamInfo.tabId, {mode: 'manual', scope: 'per-tab'}, resolve);
 128     }).then(function() { return BrowserApi.create(streamInfo, manageZoom); });
 129   });
 130 }
 131
 132 /**
 133  * Creates a BrowserApi instance for an extension not running as a mime handler.
 134  * @return {Promise<BrowserApi>} A promise to a BrowserApi instance constructed
 135  *     from the URL.
 136  */
 137 function createBrowserApiForStandaloneExtension() {
 138   let url = window.location.search.substring(1);
 139   let streamInfo = {
 140     streamUrl: url,
 141     originalUrl: url,
 142     responseHeaders: {},
 143     embedded: window.parent != window,
 144     tabId: -1,
 145   };
 146   return new Promise(function(resolve, reject) {
 147     if (!chrome.tabs) {
 148       resolve();
 149       return;
 150     }
 151     chrome.tabs.getCurrent(function(tab) {
 152       streamInfo.tabId = tab.id;
 153       resolve();
 154     });
 155   }).then(function() { return BrowserApi.create(streamInfo, false); });
 156 }
 157
 158 /**
 159  * Returns a promise that will resolve to a BrowserApi instance.
 160  * @return {Promise<BrowserApi>} A promise to a BrowserApi instance for the
 161  *     current environment.
 162  */
 163 function createBrowserApi() {
 164   if (window.location.search)
 165     return createBrowserApiForStandaloneExtension();
 166
 167   return createBrowserApiForMimeHandlerView();
 168 }