| // 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 ResizeObserver_h |
| #define ResizeObserver_h |
| |
| #include "core/CoreExport.h" |
| #include "platform/bindings/ScriptWrappable.h" |
| #include "platform/bindings/TraceWrapperMember.h" |
| #include "platform/heap/Handle.h" |
| |
| namespace blink { |
| |
| class Document; |
| class Element; |
| class ResizeObserverController; |
| class ResizeObserverEntry; |
| class ResizeObservation; |
| class V8ResizeObserverCallback; |
| |
| // ResizeObserver represents ResizeObserver javascript api: |
| // https://github.com/WICG/ResizeObserver/ |
| class CORE_EXPORT ResizeObserver final : public ScriptWrappable { |
| DEFINE_WRAPPERTYPEINFO(); |
| |
| public: |
| // This delegate is an internal (non-web-exposed) version of ResizeCallback. |
| class Delegate : public GarbageCollectedFinalized<Delegate> { |
| public: |
| virtual ~Delegate() = default; |
| virtual void OnResize( |
| const HeapVector<Member<ResizeObserverEntry>>& entries) = 0; |
| virtual void Trace(blink::Visitor* visitor) {} |
| }; |
| |
| static ResizeObserver* Create(Document&, V8ResizeObserverCallback*); |
| static ResizeObserver* Create(Document&, Delegate*); |
| |
| virtual ~ResizeObserver() = default; |
| ; |
| |
| // API methods |
| void observe(Element*); |
| void unobserve(Element*); |
| void disconnect(); |
| |
| // Returns depth of shallowest observed node, kDepthLimit if none. |
| size_t GatherObservations(size_t deeper_than); |
| bool SkippedObservations() { return skipped_observations_; } |
| void DeliverObservations(); |
| void ClearObservations(); |
| void ElementSizeChanged(); |
| bool HasElementSizeChanged() { return element_size_changed_; } |
| void Trace(blink::Visitor*); |
| void TraceWrappers(const ScriptWrappableVisitor*) const; |
| |
| private: |
| ResizeObserver(V8ResizeObserverCallback*, Document&); |
| ResizeObserver(Delegate*, Document&); |
| |
| using ObservationList = HeapLinkedHashSet<WeakMember<ResizeObservation>>; |
| |
| // Either of |callback_| and |delegate_| should be non-null. |
| const TraceWrapperMember<V8ResizeObserverCallback> callback_; |
| const Member<Delegate> delegate_; |
| |
| // List of Elements we are observing. These Elements make the ResizeObserver |
| // and most-importantly |callback_| alive. If |observations_| is empty, no one |
| // is performing wrapper-tracing and |callback_| might already be gone. |
| ObservationList observations_; |
| // List of elements that have changes |
| HeapVector<Member<ResizeObservation>> active_observations_; |
| // True if observations were skipped gatherObservations |
| bool skipped_observations_; |
| // True if any ResizeObservation reported size change |
| bool element_size_changed_; |
| WeakMember<ResizeObserverController> controller_; |
| }; |
| |
| } // namespace blink |
| |
| #endif // ResizeObserver_h |