summaryrefslogtreecommitdiffstats
path: root/dom/animation/PendingAnimationTracker.cpp
blob: 9993f0888a773bb87717acc78147e105421c715b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "PendingAnimationTracker.h"

#include "mozilla/PresShell.h"
#include "mozilla/dom/AnimationEffect.h"
#include "mozilla/dom/AnimationTimeline.h"
#include "mozilla/dom/Nullable.h"
#include "nsIFrame.h"
#include "nsTransitionManager.h"  // For CSSTransition

using mozilla::dom::Nullable;

namespace mozilla {

NS_IMPL_CYCLE_COLLECTION(PendingAnimationTracker, mPlayPendingSet,
                         mPausePendingSet, mDocument)

PendingAnimationTracker::PendingAnimationTracker(dom::Document* aDocument)
    : mDocument(aDocument) {}

void PendingAnimationTracker::AddPending(dom::Animation& aAnimation,
                                         AnimationSet& aSet) {
  aSet.Insert(&aAnimation);

  // Schedule a paint. Otherwise animations that don't trigger a paint by
  // themselves (e.g. CSS animations with an empty keyframes rule) won't
  // start until something else paints.
  EnsurePaintIsScheduled();
}

void PendingAnimationTracker::RemovePending(dom::Animation& aAnimation,
                                            AnimationSet& aSet) {
  aSet.Remove(&aAnimation);
}

bool PendingAnimationTracker::IsWaiting(const dom::Animation& aAnimation,
                                        const AnimationSet& aSet) const {
  return aSet.Contains(const_cast<dom::Animation*>(&aAnimation));
}

void PendingAnimationTracker::TriggerPendingAnimationsOnNextTick(
    const TimeStamp& aReadyTime) {
  auto triggerAnimationsAtReadyTime = [aReadyTime](
                                          AnimationSet& aAnimationSet) {
    for (auto iter = aAnimationSet.begin(), end = aAnimationSet.end();
         iter != end; ++iter) {
      dom::Animation* animation = *iter;
      dom::AnimationTimeline* timeline = animation->GetTimeline();

      // If the animation does not have a timeline, just drop it from the map.
      // The animation will detect that it is not being tracked and will trigger
      // itself on the next tick where it has a timeline.
      if (!timeline) {
        aAnimationSet.Remove(iter);
        continue;
      }

      MOZ_ASSERT(timeline->IsMonotonicallyIncreasing(),
                 "The non-monotonicially-increasing timeline should be in "
                 "ScrollTimelineAnimationTracker");

      // When the timeline's refresh driver is under test control, its values
      // have no correspondance to wallclock times so we shouldn't try to
      // convert aReadyTime (which is a wallclock time) to a timeline value.
      // Instead, the animation will be started/paused when the refresh driver
      // is next advanced since this will trigger a call to
      // TriggerPendingAnimationsNow.
      if (!timeline->TracksWallclockTime()) {
        continue;
      }

      Nullable<TimeDuration> readyTime = timeline->ToTimelineTime(aReadyTime);
      animation->TriggerOnNextTick(readyTime);

      aAnimationSet.Remove(iter);
    }
  };

  triggerAnimationsAtReadyTime(mPlayPendingSet);
  triggerAnimationsAtReadyTime(mPausePendingSet);

  mHasPlayPendingGeometricAnimations =
      mPlayPendingSet.Count() ? CheckState::Indeterminate : CheckState::Absent;
}

void PendingAnimationTracker::TriggerPendingAnimationsNow() {
  auto triggerAndClearAnimations = [](AnimationSet& aAnimationSet) {
    for (const auto& animation : aAnimationSet) {
      animation->TriggerNow();
    }
    aAnimationSet.Clear();
  };

  triggerAndClearAnimations(mPlayPendingSet);
  triggerAndClearAnimations(mPausePendingSet);

  mHasPlayPendingGeometricAnimations = CheckState::Absent;
}

static bool IsTransition(const dom::Animation& aAnimation) {
  const dom::CSSTransition* transition = aAnimation.AsCSSTransition();
  return transition && transition->IsTiedToMarkup();
}

void PendingAnimationTracker::MarkAnimationsThatMightNeedSynchronization() {
  // We only set mHasPlayPendingGeometricAnimations to "present" in this method
  // and nowhere else. After setting the state to "present", if there is any
  // change to the set of play-pending animations we will reset
  // mHasPlayPendingGeometricAnimations to either "indeterminate" or "absent".
  //
  // As a result, if mHasPlayPendingGeometricAnimations is "present", we can
  // assume that this method has already been called for the current set of
  // play-pending animations and it is not necessary to run this method again.
  //
  // If mHasPlayPendingGeometricAnimations is "absent", then we can also skip
  // the body of this method since there are no notifications to be sent.
  //
  // Therefore, the only case we need to be concerned about is the
  // "indeterminate" case. For all other cases we can return early.
  //
  // Note that *without* this optimization, starting animations would become
  // O(n^2) in the case where each animation is on a different element and
  // contains a compositor-animatable property since we would end up iterating
  // over all animations in the play-pending set for each target element.
  if (mHasPlayPendingGeometricAnimations != CheckState::Indeterminate) {
    return;
  }

  // We only synchronize CSS transitions with other CSS transitions (and we only
  // synchronize non-transition animations with non-transition animations)
  // since typically the author will not trigger both CSS animations and
  // CSS transitions simultaneously and expect them to be synchronized.
  //
  // If we try to synchronize CSS transitions with non-transitions then for some
  // content we will end up degrading performance by forcing animations to run
  // on the main thread that really don't need to.

  mHasPlayPendingGeometricAnimations = CheckState::Absent;
  for (const auto& animation : mPlayPendingSet) {
    if (animation->GetEffect() && animation->GetEffect()->AffectsGeometry()) {
      mHasPlayPendingGeometricAnimations &= ~CheckState::Absent;
      mHasPlayPendingGeometricAnimations |= IsTransition(*animation)
                                                ? CheckState::TransitionsPresent
                                                : CheckState::AnimationsPresent;

      // If we have both transitions and animations we don't need to look any
      // further.
      if (mHasPlayPendingGeometricAnimations ==
          (CheckState::TransitionsPresent | CheckState::AnimationsPresent)) {
        break;
      }
    }
  }

  if (mHasPlayPendingGeometricAnimations == CheckState::Absent) {
    return;
  }

  for (const auto& animation : mPlayPendingSet) {
    bool isTransition = IsTransition(*animation);
    if ((isTransition &&
         mHasPlayPendingGeometricAnimations & CheckState::TransitionsPresent) ||
        (!isTransition &&
         mHasPlayPendingGeometricAnimations & CheckState::AnimationsPresent)) {
      animation->NotifyGeometricAnimationsStartingThisFrame();
    }
  }
}

void PendingAnimationTracker::EnsurePaintIsScheduled() {
  if (!mDocument) {
    return;
  }

  PresShell* presShell = mDocument->GetPresShell();
  if (!presShell) {
    return;
  }

  nsIFrame* rootFrame = presShell->GetRootFrame();
  if (!rootFrame) {
    return;
  }

  rootFrame->SchedulePaintWithoutInvalidatingObservers();
}

}  // namespace mozilla