dom/media/autoplay/GVAutoplayPermissionRequest.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   3  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef DOM_MEDIA_GVAUTOPLAYPERMISSIONREQUEST_H_
   6 #define DOM_MEDIA_GVAUTOPLAYPERMISSIONREQUEST_H_
   7
   8 #include "GVAutoplayRequestUtils.h"
   9 #include "nsContentPermissionHelper.h"
  10
  11 class nsGlobalWindowInner;
  12
  13 namespace mozilla::dom {
  14
  15 /**
  16  * This class is used to provide an ability for GeckoView (GV) to allow its
  17  * embedder (application) to decide whether the autoplay media should be allowed
  18  * or denied on the page. We have two types of request, one for audible media,
  19  * another one for inaudible media. Each page would at most have one request per
  20  * type at a time, and the result of request would be effective on that page
  21  * until the page gets reloaded or closed.
  22  */
  23 class GVAutoplayPermissionRequest : public ContentPermissionRequestBase {
  24  public:
  25   NS_DECL_ISUPPORTS_INHERITED
  26   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(GVAutoplayPermissionRequest,
  27                                            ContentPermissionRequestBase)
  28
  29   // nsIContentPermissionRequest methods
  30   NS_IMETHOD Cancel(void) override;
  31   NS_IMETHOD Allow(JS::Handle<JS::Value> choices) override;
  32
  33  private:
  34   // Only allow to create this request from the requestor.
  35   friend class GVAutoplayPermissionRequestor;
  36   static void CreateRequest(nsGlobalWindowInner* aWindow,
  37                             BrowsingContext* aContext,
  38                             GVAutoplayRequestType aType);
  39
  40   GVAutoplayPermissionRequest(nsGlobalWindowInner* aWindow,
  41                               BrowsingContext* aContext,
  42                               GVAutoplayRequestType aType);
  43   ~GVAutoplayPermissionRequest();
  44
  45   void SetRequestStatus(GVAutoplayRequestStatus aStatus);
  46
  47   GVAutoplayRequestType mType;
  48   RefPtr<BrowsingContext> mContext;
  49 };
  50
  51 /**
  52  * This class provides a method to request autoplay permission for a page, which
  53  * would be used to be a factor to determine if media is allowed to autoplay or
  54  * not on GeckoView.
  55  *
  56  * A page could only have at most one audible request and one inaudible request,
  57  * and once a page has been closed or reloaded, those requests would be dropped.
  58  * In order to achieve that all media existing in the same page can share the
  59  * result of those requests, the request status would only be stored in the
  60  * top-level browsing context, which allows them to be synchronized among
  61  * different processes when Fission is enabled.
  62  *
  63  * The current way we choose is to request for a permission when creating media
  64  * element, in order to get the response from the embedding app before media
  65  * starts playing if the app can response the request quickly enough. However,
  66  * the request might be pending if the app doesn't response to it, we might
  67  * never get the response. As that is just one factor of determining the
  68  * autoplay result, even if we don't get the response for the request, we still
  69  * have a chance to play media. Check AutoplayPolicy to see more details about
  70  * how we decide the final autoplay decision.
  71  */
  72 class GVAutoplayPermissionRequestor final {
  73  public:
  74   static void AskForPermissionIfNeeded(nsPIDOMWindowInner* aWindow);
  75
  76  private:
  77   static bool HasEverAskForRequest(BrowsingContext* aContext,
  78                                    GVAutoplayRequestType aType);
  79   static void CreateAsyncRequest(nsPIDOMWindowInner* aWindow,
  80                                  BrowsingContext* aContext,
  81                                  GVAutoplayRequestType aType);
  82 };
  83
  84 }  // namespace mozilla::dom
  85
  86 #endif