Bug 957592. Expose download API properties based on permission. r=bz

b2g/app/b2g.js

@@ -865,9 +865,6 @@ pref("media.webspeech.synth.enabled", true);
 pref("dom.mozDownloads.enabled", true);
 pref("dom.downloads.max_retention_days", 7);
 
-// Downloads API
-pref("dom.mozDownloads.enabled", true);
-
 // Inactivity time in milliseconds after which we shut down the OS.File worker.
 pref("osfile.reset_worker_delay", 5000);
 

dom/base/Navigator.cpp

@@ -1916,6 +1916,27 @@ Navigator::HasDataStoreSupport(JSContext* cx, JSObject* aGlobal)
   return status == nsIPrincipal::APP_STATUS_CERTIFIED;
 }
 
+/* static */
+bool
+Navigator::HasDownloadsSupport(JSContext* aCx, JSObject* aGlobal)
+{
+  // We'll need a rooted object so that GC doesn't make it go away while
+  // we're calling CheckIsChrome.
+  JS::Rooted<JSObject*> global(aCx, aGlobal);
+
+  // Because of the way this API must be implemented, it will interact with
+  // objects attached to a chrome window. We always want to allow this.
+  if (ThreadsafeCheckIsChrome(aCx, global)) {
+    return true;
+  }
+
+  nsCOMPtr<nsPIDOMWindow> win = GetWindowFromGlobal(global);
+
+  return win &&
+         CheckPermission(win, "downloads")  &&
+         Preferences::GetBool("dom.mozDownloads.enabled");
+}
+
 /* static */
 already_AddRefed<nsPIDOMWindow>
 Navigator::GetWindowFromGlobal(JSObject* aGlobal)

dom/base/Navigator.h

@@ -290,6 +290,8 @@ public:
 
   static bool HasDataStoreSupport(JSContext* cx, JSObject* aGlobal);
 
+  static bool HasDownloadsSupport(JSContext* aCx, JSObject* aGlobal);
+
   nsPIDOMWindow* GetParentObject() const
   {
     return GetWindow();

dom/downloads/src/DownloadsAPI.js

@@ -206,12 +206,12 @@ function DOMDownloadImpl() {
   this.currentBytes = 0;
   this.url = null;
   this.path = null;
-  this.state = "stopped";
   this.contentType = null;
 
   /* fields that require getters/setters */
   this._error = null;
   this._startTime = new Date();
+  this._state = "stopped";
 
   /* private fields */
   this.id = null;
@@ -270,6 +270,25 @@ DOMDownloadImpl.prototype = {
     }
   },
 
+  get state() {
+    return this._state;
+  },
+
+  // We require a setter here to simplify the internals of the Download Manager
+  // since we actually pass dummy JSON objects to the child process and update
+  // them. This is the case for all other setters for read-only attributes
+  // implemented in this object.
+  set state(aState) {
+    // We need to ensure that XPCOM consumers of this API respect the enum
+    // values as well.
+    if (["downloading",
+         "stopped",
+         "succeeded",
+         "finalized"].indexOf(aState) != -1) {
+      this._state = aState;
+    }
+  },
+
   _init: function(aWindow, aDownload) {
     this._window = aWindow;
     this.id = aDownload.id;

dom/downloads/tests/serve_file.sjs

@@ -9,9 +9,6 @@ function getQuery(request) {
   return query;
 }
 
-// Timer used to handle the request response.
-var timer = null;
-
 function handleResponse() {
   // Is this a rate limited response?
   if (this.state.rate > 0) {
@@ -26,7 +23,24 @@ function handleResponse() {
         (bytesToWrite > this.state.rate) ? this.state.rate : bytesToWrite;
 
       for (let i = 0; i < bytesToWrite; i++) {
-        this.response.write("0");
+        try {
+          this.response.bodyOutputStream.write("0", 1);
+        } catch (e) {
+          // Connection was closed by client.
+          if (e == Components.results.NS_ERROR_NOT_AVAILABLE) {
+            // There's no harm in calling this multiple times.
+            this.response.finish();
+
+            // It's possible that our timer wasn't cancelled in time
+            // and we'll be called again.
+            if (this.timer) {
+              this.timer.cancel();
+              this.timer = null;
+            }
+
+            return;
+          }
+        }
       }
 
       // Update the number of bytes we've sent to the client.
@@ -47,12 +61,19 @@ function handleResponse() {
   this.response.finish();
 
   // All done sending, go ahead and cancel our repeating timer.
-  timer.cancel();
+  this.timer.cancel();
+
+  // Clear the timer.
+  this.timer = null;
 }
 
 function handleRequest(request, response) {
   var query = getQuery(request);
 
+  // sending at a specific rate requires our response to be asynchronous so
+  // we handle all requests asynchronously. See handleResponse().
+  response.processAsync();
+
   // Default status when responding.
   var version = "1.1";
   var statusCode = 200;
@@ -120,20 +141,17 @@ function handleRequest(request, response) {
       totalBytes: size,
       sentBytes: 0,
       rate: rate
-    }
+    },
+    timer: null
   };
 
   // The notify implementation for the timer.
   context.notify = handleResponse.bind(context);
 
-  timer =
+  context.timer =
     Components.classes["@mozilla.org/timer;1"]
               .createInstance(Components.interfaces.nsITimer);
 
-  // sending at a specific rate requires our response to be asynchronous so
-  // we handle all requests asynchronously. See handleResponse().
-  response.processAsync();
-
   // generate the content.
   response.setStatusLine(version, statusCode, description);
   response.setHeader("Content-Type", contentType, false);
@@ -143,8 +161,10 @@ function handleRequest(request, response) {
   response.setHeader("Content-Length", size.toString(), false);
 
   // initialize the timer and start writing out the response.
-  timer.initWithCallback(context,
-                         1000,
-                         Components.interfaces.nsITimer.TYPE_REPEATING_SLACK);
+  context.timer.initWithCallback(
+    context,
+    1000,
+    Components.interfaces.nsITimer.TYPE_REPEATING_SLACK
+  );
 
 }

dom/tests/mochitest/general/test_interfaces.html

@@ -326,12 +326,6 @@ var interfaceNamesInGlobalScope =
     "DOMTokenList",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "DOMTransactionEvent",
-// IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "DOMDownload", b2g: true, pref: "dom.mozDownloads.enabled"},
-// IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "DOMDownloadManager", b2g: true, pref: "dom.mozDownloads.enabled"},
-// IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "DownloadEvent", b2g: true, pref: "dom.mozDownloads.enabled"},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "DragEvent",
 // IMPORTANT: Do not change this list without review from a DOM peer!

dom/webidl/DownloadEvent.webidl

@@ -5,7 +5,7 @@
  */
 
 [Constructor(DOMString type, optional DownloadEventInit eventInitDict),
- Pref="dom.mozDownloads.enabled"]
+ Func="Navigator::HasDownloadsSupport"]
 interface DownloadEvent : Event
 {
   readonly attribute DOMDownload? download;

dom/webidl/Downloads.webidl

@@ -4,7 +4,26 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-[NavigatorProperty="mozDownloadManager",
+// Represents the state of a download.
+// "downloading": The resource is actively transfering.
+// "stopped"    : No network tranfer is happening.
+// "succeeded"  : The resource has been downloaded successfully.
+// "finalized"  : We won't try to download this resource, but the DOM
+//                object is still alive.
+enum DownloadState {
+  "downloading",
+  "stopped",
+  "succeeded",
+  "finalized"
+};
+
+//
+// XXXTODO: When we have a generic way to do feature detection in marketplace
+//          we will *STOP* using the pref and use the function like DOMDownload
+//          and DownloadEvent.
+//
+[NoInterfaceObject,
+ NavigatorProperty="mozDownloadManager",
  JSImplementation="@mozilla.org/downloads/manager;1",
  Pref="dom.mozDownloads.enabled"]
 interface DOMDownloadManager : EventTarget {
@@ -24,7 +43,7 @@ interface DOMDownloadManager : EventTarget {
 };
 
 [JSImplementation="@mozilla.org/downloads/download;1",
- Pref="dom.mozDownloads.enabled"]
+ Func="Navigator::HasDownloadsSupport"]
 interface DOMDownload : EventTarget {
   // The full size of the resource.
   readonly attribute long totalBytes;
@@ -39,13 +58,8 @@ interface DOMDownload : EventTarget {
   // is complete.
   readonly attribute DOMString path;
 
-  // The state of the download. Can be any of:
-  // "downloading": The resource is actively transfering.
-  // "stopped"    : No network tranfer is happening.
-  // "succeeded"  : The resource has been downloaded successfully.
-  // "finalized"  : We won't try to download this resource, but the DOM
-  //                object is still alive.
-  readonly attribute DOMString state;
+  // The state of the download.
+  readonly attribute DownloadState state;
 
   // The mime type for this resource.
   readonly attribute DOMString contentType;