/* 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 mozilla_a11y_EnumVariant_h_
#define mozilla_a11y_EnumVariant_h_

#include "IUnknownImpl.h"
#include "MsaaAccessible.h"

namespace mozilla {
namespace a11y {

/**
 * Used to fetch accessible children.
 */
class ChildrenEnumVariant final : public IEnumVARIANT {
 public:
  explicit ChildrenEnumVariant(MsaaAccessible* aAnchor)
      : mAnchorMsaa(aAnchor),
        mCurAcc(mAnchorMsaa->Acc()->ChildAt(0)),
        mCurIndex(0) {}

  // IUnknown
  DECL_IUNKNOWN

  // IEnumVariant
  virtual /* [local] */ HRESULT STDMETHODCALLTYPE Next(
      /* [in] */ ULONG aCount,
      /* [length_is][size_is][out] */ VARIANT* aItems,
      /* [out] */ ULONG* aCountFetched);

  virtual HRESULT STDMETHODCALLTYPE Skip(
      /* [in] */ ULONG aCount);

  virtual HRESULT STDMETHODCALLTYPE Reset();

  virtual HRESULT STDMETHODCALLTYPE Clone(
      /* [out] */ IEnumVARIANT** aEnumVaraint);

 private:
  ChildrenEnumVariant() = delete;
  ChildrenEnumVariant& operator=(const ChildrenEnumVariant&) = delete;

  ChildrenEnumVariant(const ChildrenEnumVariant& aEnumVariant)
      : mAnchorMsaa(aEnumVariant.mAnchorMsaa),
        mCurAcc(aEnumVariant.mCurAcc),
        mCurIndex(aEnumVariant.mCurIndex) {}
  virtual ~ChildrenEnumVariant() {}

 protected:
  RefPtr<MsaaAccessible> mAnchorMsaa;
  Accessible* mCurAcc;
  uint32_t mCurIndex;
};

}  // namespace a11y
}  // namespace mozilla

#endif
