/* -*- 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/. */

#ifndef DOMIntersectionObserver_h

#define DOMIntersectionObserver_h

#include "mozilla/dom/IntersectionObserverBinding.h"

#include "nsStyleCoord.h"

#include "nsTArray.h"

using mozilla::dom::DOMRect;

using mozilla::dom::Element;

namespace mozilla {

namespace dom {

class DOMIntersectionObserver;

class DOMIntersectionObserverEntry final : public nsISupports,

                                           public nsWrapperCache

{

  ~DOMIntersectionObserverEntry() {}

public:

  DOMIntersectionObserverEntry(nsISupports* aOwner,

                               DOMHighResTimeStamp aTime,

                               RefPtr<DOMRect> aRootBounds,

                               RefPtr<DOMRect> aBoundingClientRect,

                               RefPtr<DOMRect> aIntersectionRect,

                               bool aIsIntersecting,

                               Element* aTarget,

                               double aIntersectionRatio)

  : mOwner(aOwner),

    mTime(aTime),

    mRootBounds(aRootBounds),

    mBoundingClientRect(aBoundingClientRect),

    mIntersectionRect(aIntersectionRect),

    mIsIntersecting(aIsIntersecting),

    mTarget(aTarget),

    mIntersectionRatio(aIntersectionRatio)

  {

  }

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMIntersectionObserverEntry)

  nsISupports* GetParentObject() const

  {

    return mOwner;

  }

  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override

  {

    return mozilla::dom::IntersectionObserverEntry_Binding::Wrap(aCx, this, aGivenProto);

  }

  DOMHighResTimeStamp Time()

  {

    return mTime;

  }

  DOMRect* GetRootBounds()

  {

    return mRootBounds;

  }

  DOMRect* BoundingClientRect()

  {

    return mBoundingClientRect;

  }

  DOMRect* IntersectionRect()

  {

    return mIntersectionRect;

  }

  bool IsIntersecting()

  {

    return mIsIntersecting;

  }

  double IntersectionRatio()

  {

    return mIntersectionRatio;

  }

  Element* Target()

  {

    return mTarget;

  }

protected:

  nsCOMPtr<nsISupports> mOwner;

  DOMHighResTimeStamp   mTime;

  RefPtr<DOMRect>       mRootBounds;

  RefPtr<DOMRect>       mBoundingClientRect;

  RefPtr<DOMRect>       mIntersectionRect;

  bool                  mIsIntersecting;

  RefPtr<Element>       mTarget;

  double                mIntersectionRatio;

};

#define NS_DOM_INTERSECTION_OBSERVER_IID \

{ 0x8570a575, 0xe303, 0x4d18, \

  { 0xb6, 0xb1, 0x4d, 0x2b, 0x49, 0xd8, 0xef, 0x94 } }

class DOMIntersectionObserver final : public nsISupports,

                                      public nsWrapperCache

{

  virtual ~DOMIntersectionObserver() {

    Disconnect();

  }

public:

  DOMIntersectionObserver(already_AddRefed<nsPIDOMWindowInner>&& aOwner,

                          mozilla::dom::IntersectionCallback& aCb)

  : mOwner(aOwner), mDocument(mOwner->GetExtantDoc()), mCallback(&aCb), mConnected(false)

  {

  }

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMIntersectionObserver)

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_INTERSECTION_OBSERVER_IID)

  static already_AddRefed<DOMIntersectionObserver>

  Constructor(const mozilla::dom::GlobalObject& aGlobal,

              mozilla::dom::IntersectionCallback& aCb,

              mozilla::ErrorResult& aRv);

  static already_AddRefed<DOMIntersectionObserver>

  Constructor(const mozilla::dom::GlobalObject& aGlobal,

              mozilla::dom::IntersectionCallback& aCb,

              const mozilla::dom::IntersectionObserverInit& aOptions,

              mozilla::ErrorResult& aRv);

  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override

  {

    return mozilla::dom::IntersectionObserver_Binding::Wrap(aCx, this, aGivenProto);

  }

  nsISupports* GetParentObject() const

  {

    return mOwner;

  }

  Element* GetRoot() const {

    return mRoot;

  }

  void GetRootMargin(mozilla::dom::DOMString& aRetVal);

  void GetThresholds(nsTArray<double>& aRetVal);

  void Observe(Element& aTarget);

  void Unobserve(Element& aTarget);

  void UnlinkTarget(Element& aTarget);

  void Disconnect();

  void TakeRecords(nsTArray<RefPtr<DOMIntersectionObserverEntry>>& aRetVal);

  mozilla::dom::IntersectionCallback* IntersectionCallback() { return mCallback; }

  bool SetRootMargin(const nsAString& aString);

  void Update(nsIDocument* aDocument, DOMHighResTimeStamp time);

  void Notify();

protected:

  void Connect();

  void QueueIntersectionObserverEntry(Element* aTarget,

                                      DOMHighResTimeStamp time,

                                      const Maybe<nsRect>& aRootRect,

                                      const nsRect& aTargetRect,

                                      const Maybe<nsRect>& aIntersectionRect,

                                      double aIntersectionRatio);

  nsCOMPtr<nsPIDOMWindowInner>                    mOwner;

  RefPtr<nsIDocument>                             mDocument;

  RefPtr<mozilla::dom::IntersectionCallback>      mCallback;

  RefPtr<Element>                                 mRoot;

  nsStyleSides                                    mRootMargin;

  nsTArray<double>                                mThresholds;

  // Holds raw pointers which are explicitly cleared by UnlinkTarget().

  nsTArray<Element*>                              mObservationTargets;

  nsTArray<RefPtr<DOMIntersectionObserverEntry>>  mQueuedEntries;

  bool                                            mConnected;

};

NS_DEFINE_STATIC_IID_ACCESSOR(DOMIntersectionObserver, NS_DOM_INTERSECTION_OBSERVER_IID)

} // namespace dom

} // namespace mozilla

#endif