Initial implementation of WorkletAnimation

third_party/WebKit/Source/modules/compositorworker/WorkletAnimation.cpp

Index: third_party/WebKit/Source/modules/compositorworker/WorkletAnimation.cpp
diff --git a/third_party/WebKit/Source/modules/compositorworker/WorkletAnimation.cpp b/third_party/WebKit/Source/modules/compositorworker/WorkletAnimation.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c59d9acbc17ed619dc2501ceb42724243bf3c4d4
--- /dev/null
+++ b/third_party/WebKit/Source/modules/compositorworker/WorkletAnimation.cpp
@@ -0,0 +1,201 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/compositorworker/WorkletAnimation.h"
+
+#include "core/animation/DocumentTimeline.h"
+#include "core/animation/ElementAnimations.h"
+#include "core/animation/KeyframeEffectModel.h"
+#include "core/animation/ScrollTimeline.h"
+#include "core/animation/Timing.h"
+#include "core/dom/Node.h"
+#include "core/dom/NodeComputedStyle.h"
+#include "platform/animation/CompositorAnimationPlayer.h"
+#include "platform/wtf/text/WTFString.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebCompositorSupport.h"
+
+namespace blink {
+
+namespace {
+bool ValidateEffects(const HeapVector<Member<KeyframeEffectReadOnly>>& effects,
+                     String* error_string) {

[alancutter (OOO until 2018), 2017/06/26 11:57:02]

Blink style is to use references instead of pointers for parameters that are
never null.

[smcgruer, 2017/06/26 21:14:08]

Done.

+  if (effects.IsEmpty()) {
+    *error_string = "Effects array must be non-empty";
+    return false;
+  }
+
+  Document& target_document = effects.at(0)->Target()->GetDocument();
+  for (const auto& effect : effects) {
+    if (effect->Target()->GetDocument() != target_document) {
+      *error_string = "All effects must target elements in the same document";
+      return false;
+    }
+  }
+  return true;
+}
+
+bool ValidateTimelines(HeapVector<DocumentTimelineOrScrollTimeline>& timelines,
+                       String* error_string) {
+  if (timelines.IsEmpty()) {
+    *error_string = "Timelines array must be non-empty";
+    return false;
+  }
+
+  for (const auto& timeline : timelines) {
+    if (timeline.isScrollTimeline()) {
+      DoubleOrScrollTimelineAutoKeyword time_range;
+      timeline.getAsScrollTimeline()->timeRange(time_range);
+      if (time_range.isScrollTimelineAutoKeyword()) {
+        *error_string = "ScrollTimeline timeRange must have non-auto value";
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+String AnimationPlayStateToString(
+    WorkletAnimation::AnimationPlayState play_state) {
+  switch (play_state) {
+    case WorkletAnimation::kIdle:
+      return "idle";
+    case WorkletAnimation::kPending:
+      return "pending";
+    case WorkletAnimation::kRunning:
+      return "running";
+    default:
+      NOTREACHED();
+      return "";
+  }
+}
+}  // namespace
+
+WorkletAnimation* WorkletAnimation::Create(
+    String animator_name,
+    const HeapVector<Member<KeyframeEffectReadOnly>>& effects,
+    HeapVector<DocumentTimelineOrScrollTimeline>& timelines,
+    RefPtr<SerializedScriptValue> options,
+    ExceptionState& exception_state) {
+  String error_string;
+  if (!ValidateEffects(effects, &error_string)) {
+    exception_state.ThrowDOMException(kNotSupportedError, error_string);
+    return nullptr;
+  }
+
+  if (!ValidateTimelines(timelines, &error_string)) {
+    exception_state.ThrowDOMException(kNotSupportedError, error_string);
+    return nullptr;
+  }
+
+  Document& document = effects.at(0)->Target()->GetDocument();
+  WorkletAnimation* animation = new WorkletAnimation(
+      animator_name, document, effects, timelines, std::move(options));
+  animation->AttachCompositorTimeline();
+
+  return animation;
+}
+
+WorkletAnimation::WorkletAnimation(
+    String animator_name,
+    Document& document,
+    const HeapVector<Member<KeyframeEffectReadOnly>>& effects,
+    HeapVector<DocumentTimelineOrScrollTimeline>& timelines,
+    RefPtr<SerializedScriptValue> options)
+    : animator_name_(animator_name),
+      document_(document),
+      effects_(effects),
+      timelines_(timelines),
+      options_(std::move(options)) {
+  DCHECK(Platform::Current()->IsThreadedAnimationEnabled());
+  DCHECK(Platform::Current()->CompositorSupport());
+  compositor_player_ = CompositorAnimationPlayerHolder::Create(this);
+  DCHECK(compositor_player_);
+}
+
+String WorkletAnimation::playState() {
+  return AnimationPlayStateToString(play_state_);
+}
+
+void WorkletAnimation::play() {
+  // TODO(smcgruer): Should this set NeedsCompositingUpdate?

[flackr, 2017/06/19 20:35:33]

The WorkletAnimationController should I think.

[smcgruer, 2017/07/24 14:48:58]

Ack added TODO on the WorkletAnimationController. I need to work out the best
way to get at the LocalFrameView (or ultimately PaintLayerCompositor).

+  document_->GetWorkletAnimationController().AttachAnimation(*this);
+  play_state_ = kPending;
+}
+
+void WorkletAnimation::cancel() {
+  document_->GetWorkletAnimationController().DetachAnimation(*this);
+  play_state_ = kIdle;
+}
+
+bool WorkletAnimation::StartOnCompositor() {
+  int group = 0;
+  double start_time = 0;
+  double current_time = 0;
+  double animation_playback_rate = 1;
+  Element& target = *effects_.at(0)->Target();
+  static_cast<KeyframeEffectModelBase*>(effects_.at(0)->Model())

[alancutter (OOO until 2018), 2017/06/26 11:57:02]

Use ToKeyframeEffectModelBase().

[smcgruer, 2017/06/26 21:14:08]

Done.

+      ->SnapshotAllCompositorKeyframes(target, target.ComputedStyleRef(),
+                                       target.ParentComputedStyle());
+  bool success = effects_.at(0)->MaybeStartAnimationOnCompositor(

[alancutter (OOO until 2018), 2017/06/26 11:57:02]

MaybeStartAnimationOnCompositor() is now
CanStartAnimationOnCompositor()/StartAnimationOnCompositor(). The former gives
an error message when an animation can't be started on the compositor.

[smcgruer, 2017/06/26 21:14:08]

Ack; I see that there is now a new cl to make them
Check{CanStartAnimationOnCompositor()/StartAnimationOnCompositor()} as well.
I'll rebase onto that one tomorrow and start using them properly. For now, just
fixed the code to compile with my current checkout.

[smcgruer, 2017/06/27 18:02:43]

Done.

+      group, start_time, current_time, animation_playback_rate,
+      compositor_player_->Player());

[flackr, 2017/06/19 20:35:33]

I'm a bit confused about what this is doing. We're just starting one of the
effects? Should we start all of them instead? Is plumbing needed on the cc side
to recognize that these are WorkletAnimation effects which shouldn't start
running immediately? 

[smcgruer, 2017/06/26 21:14:08]

As far as I understand it, a lot of plumbing is still needed on the cc side for
this CL to be worth anything. But I still don't understand either the proposed
or realized cc-side changes, so I think we need to sync offline about this.

[smcgruer, 2017/06/27 18:02:43]

A question was raised today as to why this doesn't currently do anything (even
just a single effect and normal CompositorPlayer) with the code so far. The
reason appears to be that for some reason element_animations_ is nullptr in
AnimationPlayer::AddAnimation.

[flackr, 2017/07/19 19:23:48]

I think we should just assume success (or failure?) with a TODO to actually
create the element animations on the compositor, rather than do something that
doesn't seem to work.

[smcgruer, 2017/07/24 14:48:58]

Done.

+  play_state_ = success ? kRunning : kIdle;
+  return success;
+}
+
+void WorkletAnimation::AttachCompositorTimeline() {
+  document_->Timeline().CompositorTimeline()->PlayerAttached(*this);
+}
+
+void WorkletAnimation::DetachCompositorTimeline() {
+  document_->Timeline().CompositorTimeline()->PlayerDestroyed(*this);
+}

[alancutter (OOO until 2018), 2017/06/26 11:57:02]

I'm not sure we need these two methods given they're one liners and only called
once.

[smcgruer, 2017/06/26 21:14:08]

Done.

+
+void WorkletAnimation::Dispose() {
+  DetachCompositorTimeline();
+  compositor_player_->Detach();
+  compositor_player_ = nullptr;
+}
+
+void WorkletAnimation::SetEffectInheritedTimeForTesting(
+    Member<KeyframeEffectReadOnly> effect,
+    double inherited_time) {}
+
+DEFINE_TRACE(WorkletAnimation) {
+  visitor->Trace(document_);
+  visitor->Trace(effects_);
+  visitor->Trace(timelines_);
+  visitor->Trace(compositor_player_);
+  WorkletAnimationBase::Trace(visitor);
+}
+
+WorkletAnimation::CompositorAnimationPlayerHolder*
+WorkletAnimation::CompositorAnimationPlayerHolder::Create(
+    WorkletAnimation* animation) {
+  return new CompositorAnimationPlayerHolder(animation);
+}
+
+WorkletAnimation::CompositorAnimationPlayerHolder::
+    CompositorAnimationPlayerHolder(WorkletAnimation* animation)
+    : animation_(animation) {
+  compositor_player_ = CompositorAnimationPlayer::Create();
+  compositor_player_->SetAnimationDelegate(animation_);
+}
+
+void WorkletAnimation::CompositorAnimationPlayerHolder::Dispose() {
+  if (!animation_)
+    return;
+  animation_->Dispose();
+  DCHECK(!animation_);
+  DCHECK(!compositor_player_);
+}
+
+void WorkletAnimation::CompositorAnimationPlayerHolder::Detach() {
+  compositor_player_->SetAnimationDelegate(nullptr);
+  animation_ = nullptr;
+  compositor_player_.reset();
+}
+
+}  // namespace blink