dom/base/ScrollingMetrics.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_ScrollingMetrics_h
   8 #define mozilla_dom_ScrollingMetrics_h
   9
  10 #include "Units.h"
  11 #include "mozilla/MozPromise.h"
  12 #include "mozilla/RefPtr.h"
  13 #include "mozilla/StaticPtr.h"
  14
  15 namespace mozilla {
  16
  17 /**
  18  * ScrollingMetrics records user-intiated scrolling interactions. These are
  19  * aggregrated along with other user interactions (e.g. typing, view time), in
  20  * the history metadata.
  21  */
  22 class ScrollingMetrics {
  23  public:
  24   using ScrollingMetricsPromise =
  25       MozPromise<std::tuple<uint32_t, uint32_t>, bool, true>;
  26
  27   static RefPtr<ScrollingMetricsPromise> CollectScrollingMetrics() {
  28     return GetSingleton()->CollectScrollingMetricsInternal();
  29   }
  30
  31   // Return the tuple of <scrollingTimeInMilliseconds,
  32   // ScrollingDistanceInPixels>
  33   static std::tuple<uint32_t, uint32_t> CollectLocalScrollingMetrics() {
  34     return GetSingleton()->CollectLocalScrollingMetricsInternal();
  35   }
  36
  37   // Report a new user-initiated scrolling interaction
  38   static void OnScrollingInteraction(CSSCoord distanceScrolled);
  39
  40   static void OnScrollingInteractionEnded();
  41
  42  private:
  43   static ScrollingMetrics* GetSingleton();
  44   static StaticAutoPtr<ScrollingMetrics> sSingleton;
  45   RefPtr<ScrollingMetricsPromise> CollectScrollingMetricsInternal();
  46   std::tuple<uint32_t, uint32_t> CollectLocalScrollingMetricsInternal();
  47 };
  48
  49 }  // namespace mozilla
  50
  51 #endif /* mozilla_dom_ScrollingMetrics_h */