dom/animation/AnimationTimeline.cpp

   1 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "AnimationTimeline.h"
   7 #include "mozilla/dom/AnimationTimelineBinding.h"
   8 #include "AnimationUtils.h"
   9 #include "nsContentUtils.h"
  10 #include "nsIPresShell.h"
  11 #include "nsPresContext.h"
  12 #include "nsRefreshDriver.h"
  13 #include "nsDOMNavigationTiming.h"
  14
  15 namespace mozilla {
  16 namespace dom {
  17
  18 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(AnimationTimeline, mDocument)
  19
  20 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(AnimationTimeline, AddRef)
  21 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(AnimationTimeline, Release)
  22
  23 JSObject*
  24 AnimationTimeline::WrapObject(JSContext* aCx)
  25 {
  26   return AnimationTimelineBinding::Wrap(aCx, this);
  27 }
  28
  29 Nullable<TimeDuration>
  30 AnimationTimeline::GetCurrentTime() const
  31 {
  32   return ToTimelineTime(GetCurrentTimeStamp());
  33 }
  34
  35 Nullable<double>
  36 AnimationTimeline::GetCurrentTimeAsDouble() const
  37 {
  38   return AnimationUtils::TimeDurationToDouble(GetCurrentTime());
  39 }
  40
  41 TimeStamp
  42 AnimationTimeline::GetCurrentTimeStamp() const
  43 {
  44   nsRefreshDriver* refreshDriver = GetRefreshDriver();
  45   TimeStamp refreshTime = refreshDriver
  46                           ? refreshDriver->MostRecentRefresh()
  47                           : TimeStamp();
  48
  49   // Always return the same object to benefit from return-value optimization.
  50   TimeStamp result = !refreshTime.IsNull()
  51                      ? refreshTime
  52                      : mLastRefreshDriverTime;
  53
  54   // If we don't have a refresh driver and we've never had one use the
  55   // timeline's zero time.
  56   if (result.IsNull()) {
  57     nsRefPtr<nsDOMNavigationTiming> timing = mDocument->GetNavigationTiming();
  58     if (timing) {
  59       result = timing->GetNavigationStartTimeStamp();
  60       // Also, let this time represent the current refresh time. This way
  61       // we'll save it as the last refresh time and skip looking up
  62       // navigation timing each time.
  63       refreshTime = result;
  64     }
  65   }
  66
  67   if (!refreshTime.IsNull()) {
  68     mLastRefreshDriverTime = refreshTime;
  69   }
  70
  71   return result;
  72 }
  73
  74 Nullable<TimeDuration>
  75 AnimationTimeline::ToTimelineTime(const TimeStamp& aTimeStamp) const
  76 {
  77   Nullable<TimeDuration> result; // Initializes to null
  78   if (aTimeStamp.IsNull()) {
  79     return result;
  80   }
  81
  82   nsRefPtr<nsDOMNavigationTiming> timing = mDocument->GetNavigationTiming();
  83   if (MOZ_UNLIKELY(!timing)) {
  84     return result;
  85   }
  86
  87   result.SetValue(aTimeStamp - timing->GetNavigationStartTimeStamp());
  88   return result;
  89 }
  90
  91 TimeStamp
  92 AnimationTimeline::ToTimeStamp(const TimeDuration& aTimeDuration) const
  93 {
  94   TimeStamp result;
  95   nsRefPtr<nsDOMNavigationTiming> timing = mDocument->GetNavigationTiming();
  96   if (MOZ_UNLIKELY(!timing)) {
  97     return result;
  98   }
  99
 100   result = timing->GetNavigationStartTimeStamp() + aTimeDuration;
 101   return result;
 102 }
 103
 104 nsRefreshDriver*
 105 AnimationTimeline::GetRefreshDriver() const
 106 {
 107   nsIPresShell* presShell = mDocument->GetShell();
 108   if (MOZ_UNLIKELY(!presShell)) {
 109     return nullptr;
 110   }
 111
 112   nsPresContext* presContext = presShell->GetPresContext();
 113   if (MOZ_UNLIKELY(!presContext)) {
 114     return nullptr;
 115   }
 116
 117   return presContext->RefreshDriver();
 118 }
 119
 120 } // namespace dom
 121 } // namespace mozilla