| // Copyright 2016 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. |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_INTERSECTION_OBSERVER_INTERSECTION_OBSERVER_CONTROLLER_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_INTERSECTION_OBSERVER_INTERSECTION_OBSERVER_CONTROLLER_H_ |
| |
| #include "third_party/blink/renderer/core/execution_context/context_lifecycle_observer.h" |
| #include "third_party/blink/renderer/core/intersection_observer/intersection_observer.h" |
| #include "third_party/blink/renderer/platform/bindings/name_client.h" |
| #include "third_party/blink/renderer/platform/bindings/trace_wrapper_member.h" |
| #include "third_party/blink/renderer/platform/heap/handle.h" |
| #include "third_party/blink/renderer/platform/wtf/hash_set.h" |
| |
| // Design doc for IntersectionObserver implementation: |
| // https://docs.google.com/a/google.com/document/d/1hLK0eyT5_BzyNS4OkjsnoqqFQDYCbKfyBinj94OnLiQ |
| |
| namespace blink { |
| |
| class Document; |
| |
| class IntersectionObserverController |
| : public GarbageCollectedFinalized<IntersectionObserverController>, |
| public ContextClient, |
| public NameClient { |
| USING_GARBAGE_COLLECTED_MIXIN(IntersectionObserverController); |
| |
| public: |
| static IntersectionObserverController* Create(Document*); |
| |
| explicit IntersectionObserverController(Document*); |
| virtual ~IntersectionObserverController(); |
| |
| void ScheduleIntersectionObserverForDelivery(IntersectionObserver&); |
| |
| // Immediately deliver all notifications for all observers for which |
| // (observer->GetDeliveryBehavior() == behavior). |
| void DeliverIntersectionObservations( |
| IntersectionObserver::DeliveryBehavior behavior); |
| |
| // The flags argument is composed of values from |
| // IntersectionObservation::ComputeFlags. They are dirty bits that control |
| // whether an IntersectionObserver needs to do any work. The return value |
| // communicates whether observer->trackVisibility() is true for any tracked |
| // observer. |
| bool ComputeTrackedIntersectionObservations(unsigned flags); |
| // The second argument indicates whether the Element is being tracked by any |
| // observers for which observer->trackVisibility() is true. |
| void AddTrackedTarget(Element&, bool); |
| void RemoveTrackedTarget(Element&); |
| |
| void Trace(blink::Visitor*) override; |
| const char* NameInHeapSnapshot() const override { |
| return "IntersectionObserverController"; |
| } |
| unsigned GetTrackedTargetCountForTesting() const { |
| return tracked_observation_targets_.size(); |
| } |
| |
| private: |
| void PostTaskToDeliverObservations(); |
| |
| private: |
| // Elements in this document which are the target of an |
| // IntersectionObservation. |
| HeapHashSet<WeakMember<Element>> tracked_observation_targets_; |
| // IntersectionObservers for which this is the execution context of the |
| // callback. |
| HeapHashSet<TraceWrapperMember<IntersectionObserver>> |
| pending_intersection_observers_; |
| // TODO(https://crbug.com/796145): Remove this hack once on-stack objects |
| // get supported by either of wrapper-tracing or unified GC. |
| HeapVector<TraceWrapperMember<IntersectionObserver>> |
| intersection_observers_being_invoked_; |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_CORE_INTERSECTION_OBSERVER_INTERSECTION_OBSERVER_CONTROLLER_H_ |