michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: const Cu = Components.utils;
michael@0: const Cr = Components.results;
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.import("resource://gre/modules/DOMRequestHelper.jsm");
michael@0: Cu.import("resource://gre/modules/DownloadsIPC.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
michael@0:                                    "@mozilla.org/childprocessmessagemanager;1",
michael@0:                                    "nsIMessageSender");
michael@0: 
michael@0: function debug(aStr) {
michael@0: #ifdef MOZ_DEBUG
michael@0:   dump("-*- DownloadsAPI.js : " + aStr + "\n");
michael@0: #endif
michael@0: }
michael@0: 
michael@0: function DOMDownloadManagerImpl() {
michael@0:   debug("DOMDownloadManagerImpl constructor");
michael@0: }
michael@0: 
michael@0: DOMDownloadManagerImpl.prototype = {
michael@0:   __proto__: DOMRequestIpcHelper.prototype,
michael@0: 
michael@0:   // nsIDOMGlobalPropertyInitializer implementation
michael@0:   init: function(aWindow) {
michael@0:     debug("DownloadsManager init");
michael@0:     this.initDOMRequestHelper(aWindow,
michael@0:                               ["Downloads:Added",
michael@0:                                "Downloads:Removed"]);
michael@0:   },
michael@0: 
michael@0:   uninit: function() {
michael@0:     debug("uninit");
michael@0:     downloadsCache.evict(this._window);
michael@0:   },
michael@0: 
michael@0:   set ondownloadstart(aHandler) {
michael@0:     this.__DOM_IMPL__.setEventHandler("ondownloadstart", aHandler);
michael@0:   },
michael@0: 
michael@0:   get ondownloadstart() {
michael@0:     return this.__DOM_IMPL__.getEventHandler("ondownloadstart");
michael@0:   },
michael@0: 
michael@0:   getDownloads: function() {
michael@0:     debug("getDownloads()");
michael@0: 
michael@0:     return this.createPromise(function (aResolve, aReject) {
michael@0:       DownloadsIPC.getDownloads().then(
michael@0:         function(aDownloads) {
michael@0:           // Turn the list of download objects into DOM objects and
michael@0:           // send them.
michael@0:           let array = new this._window.Array();
michael@0:           for (let id in aDownloads) {
michael@0:             let dom = createDOMDownloadObject(this._window, aDownloads[id]);
michael@0:             array.push(this._prepareForContent(dom));
michael@0:           }
michael@0:           aResolve(array);
michael@0:         }.bind(this),
michael@0:         function() {
michael@0:           aReject("GetDownloadsError");
michael@0:         }
michael@0:       );
michael@0:     }.bind(this));
michael@0:   },
michael@0: 
michael@0:   clearAllDone: function() {
michael@0:     debug("clearAllDone()");
michael@0:     return this.createPromise(function (aResolve, aReject) {
michael@0:       DownloadsIPC.clearAllDone().then(
michael@0:         function(aDownloads) {
michael@0:           // Turn the list of download objects into DOM objects and
michael@0:           // send them.
michael@0:           let array = new this._window.Array();
michael@0:           for (let id in aDownloads) {
michael@0:             let dom = createDOMDownloadObject(this._window, aDownloads[id]);
michael@0:             array.push(this._prepareForContent(dom));
michael@0:           }
michael@0:           aResolve(array);
michael@0:         }.bind(this),
michael@0:         function() {
michael@0:           aReject("ClearAllDoneError");
michael@0:         }
michael@0:       );
michael@0:     }.bind(this));
michael@0:   },
michael@0: 
michael@0:   remove: function(aDownload) {
michael@0:     debug("remove " + aDownload.url + " " + aDownload.id);
michael@0:     return this.createPromise(function (aResolve, aReject) {
michael@0:       if (!downloadsCache.has(this._window, aDownload.id)) {
michael@0:         debug("no download " + aDownload.id);
michael@0:         aReject("InvalidDownload");
michael@0:         return;
michael@0:       }
michael@0: 
michael@0:       DownloadsIPC.remove(aDownload.id).then(
michael@0:         function(aResult) {
michael@0:           let dom = createDOMDownloadObject(this._window, aResult);
michael@0:           // Change the state right away to not race against the update message.
michael@0:           dom.wrappedJSObject.state = "finalized";
michael@0:           aResolve(this._prepareForContent(dom));
michael@0:         }.bind(this),
michael@0:         function() {
michael@0:           aReject("RemoveError");
michael@0:         }
michael@0:       );
michael@0:     }.bind(this));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:     * Turns a chrome download object into a content accessible one.
michael@0:     * When we have __DOM_IMPL__ available we just use that, otherwise
michael@0:     * we run _create() with the wrapped js object.
michael@0:     */
michael@0:   _prepareForContent: function(aChromeObject) {
michael@0:     if (aChromeObject.__DOM_IMPL__) {
michael@0:       return aChromeObject.__DOM_IMPL__;
michael@0:     }
michael@0:     let res = this._window.DOMDownload._create(this._window,
michael@0:                                             aChromeObject.wrappedJSObject);
michael@0:     return res;
michael@0:   },
michael@0: 
michael@0:   receiveMessage: function(aMessage) {
michael@0:     let data = aMessage.data;
michael@0:     switch(aMessage.name) {
michael@0:       case "Downloads:Added":
michael@0:         debug("Adding " + uneval(data));
michael@0:         let event = new this._window.DownloadEvent("downloadstart", {
michael@0:           download:
michael@0:             this._prepareForContent(createDOMDownloadObject(this._window, data))
michael@0:         });
michael@0:         this.__DOM_IMPL__.dispatchEvent(event);
michael@0:         break;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   classID: Components.ID("{c6587afa-0696-469f-9eff-9dac0dd727fe}"),
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports,
michael@0:                                          Ci.nsISupportsWeakReference,
michael@0:                                          Ci.nsIObserver,
michael@0:                                          Ci.nsIDOMGlobalPropertyInitializer]),
michael@0: 
michael@0: };
michael@0: 
michael@0: /**
michael@0:   * Keep track of download objects per window.
michael@0:   */
michael@0: let downloadsCache = {
michael@0:   init: function() {
michael@0:     this.cache = new WeakMap();
michael@0:   },
michael@0: 
michael@0:   has: function(aWindow, aId) {
michael@0:     let downloads = this.cache.get(aWindow);
michael@0:     return !!(downloads && downloads[aId]);
michael@0:   },
michael@0: 
michael@0:   get: function(aWindow, aDownload) {
michael@0:     let downloads = this.cache.get(aWindow);
michael@0:     if (!(downloads && downloads[aDownload.id])) {
michael@0:       debug("Adding download " + aDownload.id + " to cache.");
michael@0:       if (!downloads) {
michael@0:         this.cache.set(aWindow, {});
michael@0:         downloads = this.cache.get(aWindow);
michael@0:       }
michael@0:       // Create the object and add it to the cache.
michael@0:       let impl = Cc["@mozilla.org/downloads/download;1"]
michael@0:                    .createInstance(Ci.nsISupports);
michael@0:       impl.wrappedJSObject._init(aWindow, aDownload);
michael@0:       downloads[aDownload.id] = impl;
michael@0:     }
michael@0:     return downloads[aDownload.id];
michael@0:   },
michael@0: 
michael@0:   evict: function(aWindow) {
michael@0:     this.cache.delete(aWindow);
michael@0:   }
michael@0: };
michael@0: 
michael@0: downloadsCache.init();
michael@0: 
michael@0: /**
michael@0:   * The DOM facade of a download object.
michael@0:   */
michael@0: 
michael@0: function createDOMDownloadObject(aWindow, aDownload) {
michael@0:   return downloadsCache.get(aWindow, aDownload);
michael@0: }
michael@0: 
michael@0: function DOMDownloadImpl() {
michael@0:   debug("DOMDownloadImpl constructor ");
michael@0: 
michael@0:   this.wrappedJSObject = this;
michael@0:   this.totalBytes = 0;
michael@0:   this.currentBytes = 0;
michael@0:   this.url = null;
michael@0:   this.path = null;
michael@0:   this.contentType = null;
michael@0: 
michael@0:   /* fields that require getters/setters */
michael@0:   this._error = null;
michael@0:   this._startTime = new Date();
michael@0:   this._state = "stopped";
michael@0: 
michael@0:   /* private fields */
michael@0:   this.id = null;
michael@0: }
michael@0: 
michael@0: DOMDownloadImpl.prototype = {
michael@0: 
michael@0:   createPromise: function(aPromiseInit) {
michael@0:     return new this._window.Promise(aPromiseInit);
michael@0:   },
michael@0: 
michael@0:   pause: function() {
michael@0:     debug("DOMDownloadImpl pause");
michael@0:     let id = this.id;
michael@0:     // We need to wrap the Promise.jsm promise in a "real" DOM promise...
michael@0:     return this.createPromise(function(aResolve, aReject) {
michael@0:       DownloadsIPC.pause(id).then(aResolve, aReject);
michael@0:     });
michael@0:   },
michael@0: 
michael@0:   resume: function() {
michael@0:     debug("DOMDownloadImpl resume");
michael@0:     let id = this.id;
michael@0:     // We need to wrap the Promise.jsm promise in a "real" DOM promise...
michael@0:     return this.createPromise(function(aResolve, aReject) {
michael@0:       DownloadsIPC.resume(id).then(aResolve, aReject);
michael@0:     });
michael@0:   },
michael@0: 
michael@0:   set onstatechange(aHandler) {
michael@0:     this.__DOM_IMPL__.setEventHandler("onstatechange", aHandler);
michael@0:   },
michael@0: 
michael@0:   get onstatechange() {
michael@0:     return this.__DOM_IMPL__.getEventHandler("onstatechange");
michael@0:   },
michael@0: 
michael@0:   get error() {
michael@0:     return this._error;
michael@0:   },
michael@0: 
michael@0:   set error(aError) {
michael@0:     this._error = aError;
michael@0:   },
michael@0: 
michael@0:   get startTime() {
michael@0:     return this._startTime;
michael@0:   },
michael@0: 
michael@0:   set startTime(aStartTime) {
michael@0:     if (aStartTime instanceof Date) {
michael@0:       this._startTime = aStartTime;
michael@0:     }
michael@0:     else {
michael@0:       this._startTime = new Date(aStartTime);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   get state() {
michael@0:     return this._state;
michael@0:   },
michael@0: 
michael@0:   // We require a setter here to simplify the internals of the Download Manager
michael@0:   // since we actually pass dummy JSON objects to the child process and update
michael@0:   // them. This is the case for all other setters for read-only attributes
michael@0:   // implemented in this object.
michael@0:   set state(aState) {
michael@0:     // We need to ensure that XPCOM consumers of this API respect the enum
michael@0:     // values as well.
michael@0:     if (["downloading",
michael@0:          "stopped",
michael@0:          "succeeded",
michael@0:          "finalized"].indexOf(aState) != -1) {
michael@0:       this._state = aState;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   _init: function(aWindow, aDownload) {
michael@0:     this._window = aWindow;
michael@0:     this.id = aDownload.id;
michael@0:     this._update(aDownload);
michael@0:     Services.obs.addObserver(this, "downloads-state-change-" + this.id,
michael@0:                              /* ownsWeak */ true);
michael@0:     debug("observer set for " + this.id);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:     * Updates the state of the object and fires the statechange event.
michael@0:     */
michael@0:   _update: function(aDownload) {
michael@0:     debug("update " + uneval(aDownload));
michael@0:     if (this.id != aDownload.id) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     let props = ["totalBytes", "currentBytes", "url", "path", "state",
michael@0:                  "contentType", "startTime"];
michael@0:     let changed = false;
michael@0: 
michael@0:     props.forEach((prop) => {
michael@0:       if (aDownload[prop] && (aDownload[prop] != this[prop])) {
michael@0:         this[prop] = aDownload[prop];
michael@0:         changed = true;
michael@0:       }
michael@0:     });
michael@0: 
michael@0:     if (aDownload.error) {
michael@0:       //
michael@0:       // When we get a generic error failure back from the js downloads api
michael@0:       // we will verify the status of device storage to see if we can't provide
michael@0:       // a better error result value.
michael@0:       //
michael@0:       // XXX If these checks expand further, consider moving them into their
michael@0:       // own function.
michael@0:       //
michael@0:       let result = aDownload.error.result;
michael@0:       let storage = this._window.navigator.getDeviceStorage("sdcard");
michael@0: 
michael@0:       // If we don't have access to device storage we'll opt out of these
michael@0:       // extra checks as they are all dependent on the state of the storage.
michael@0:       if (result == Cr.NS_ERROR_FAILURE && storage) {
michael@0:         // We will delay sending the notification until we've inferred which
michael@0:         // error is really happening.
michael@0:         changed = false;
michael@0:         debug("Attempting to infer error via device storage sanity checks.");
michael@0:         // Get device storage and request availability status.
michael@0:         let available = storage.available();
michael@0:         available.onsuccess = (function() {
michael@0:           debug("Storage Status = '" + available.result + "'");
michael@0:           let inferredError = result;
michael@0:           switch (available.result) {
michael@0:             case "unavailable":
michael@0:               inferredError = Cr.NS_ERROR_FILE_NOT_FOUND;
michael@0:               break;
michael@0:             case "shared":
michael@0:               inferredError = Cr.NS_ERROR_FILE_ACCESS_DENIED;
michael@0:               break;
michael@0:           }
michael@0:           this._updateWithError(aDownload, inferredError);
michael@0:         }).bind(this);
michael@0:         available.onerror = (function() {
michael@0:           this._updateWithError(aDownload, result);
michael@0:         }).bind(this);
michael@0:       }
michael@0: 
michael@0:       this.error =
michael@0:         new this._window.DOMError("DownloadError", result);
michael@0:     } else {
michael@0:       this.error = null;
michael@0:     }
michael@0: 
michael@0:     // The visible state has not changed, so no need to fire an event.
michael@0:     if (!changed) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     this._sendStateChange();
michael@0:   },
michael@0: 
michael@0:   _updateWithError: function(aDownload, aError) {
michael@0:     this.error =
michael@0:       new this._window.DOMError("DownloadError", aError);
michael@0:     this._sendStateChange();
michael@0:   },
michael@0: 
michael@0:   _sendStateChange: function() {
michael@0:     // __DOM_IMPL__ may not be available at first update.
michael@0:     if (this.__DOM_IMPL__) {
michael@0:       let event = new this._window.DownloadEvent("statechange", {
michael@0:         download: this.__DOM_IMPL__
michael@0:       });
michael@0:       debug("Dispatching statechange event. state=" + this.state);
michael@0:       this.__DOM_IMPL__.dispatchEvent(event);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   observe: function(aSubject, aTopic, aData) {
michael@0:     debug("DOMDownloadImpl observe " + aTopic);
michael@0:     if (aTopic !== "downloads-state-change-" + this.id) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     try {
michael@0:       let download = JSON.parse(aData);
michael@0:       // We get the start time as milliseconds, not as a Date object.
michael@0:       if (download.startTime) {
michael@0:         download.startTime = new Date(download.startTime);
michael@0:       }
michael@0:       this._update(download);
michael@0:     } catch(e) {}
michael@0:   },
michael@0: 
michael@0:   classID: Components.ID("{96b81b99-aa96-439d-8c59-92eeed34705f}"),
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports,
michael@0:                                          Ci.nsIObserver,
michael@0:                                          Ci.nsISupportsWeakReference])
michael@0: };
michael@0: 
michael@0: this.NSGetFactory = XPCOMUtils.generateNSGetFactory([DOMDownloadManagerImpl,
michael@0:                                                      DOMDownloadImpl]);