/* -*- 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 NSIFRAMETRAVERSAL_H
#define NSIFRAMETRAVERSAL_H

#include "nsISupports.h"

class nsIFrame;
class nsPresContext;

#define NS_IFRAMEENUMERATOR_IID                      \
  {                                                  \
    0x7c633f5d, 0x91eb, 0x494e, {                    \
      0xa1, 0x40, 0x17, 0x46, 0x17, 0x4c, 0x23, 0xd3 \
    }                                                \
  }

class nsIFrameEnumerator : public nsISupports {
 public:
  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IFRAMEENUMERATOR_IID)

  virtual void First() = 0;
  virtual void Next() = 0;
  virtual nsIFrame* CurrentItem() = 0;
  virtual bool IsDone() = 0;

  virtual void Last() = 0;
  virtual void Prev() = 0;

  inline nsIFrame* Traverse(bool aForward) {
    if (aForward) {
      Next();
    } else {
      Prev();
    }
    return CurrentItem();
  };
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIFrameEnumerator, NS_IFRAMEENUMERATOR_IID)

enum nsIteratorType { eLeaf, ePreOrder, ePostOrder };

// {d33fe76c-207c-4359-a315-8eb1eecf80e5}
#define NS_IFRAMETRAVERSAL_IID                       \
  {                                                  \
    0xd33fe76c, 0x207c, 0x4359, {                    \
      0xa3, 0x15, 0x8e, 0xb1, 0xee, 0xcf, 0x80, 0xe5 \
    }                                                \
  }

class nsIFrameTraversal : public nsISupports {
 public:
  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IFRAMETRAVERSAL_IID)

  /**
   * Create a frame iterator with the specified properties.
   * @param aEnumerator [out] the created iterator
   * @param aPresContext [in]
   * @param aStart [in] the frame to start iterating from
   * @param aType [in] the type of the iterator: leaf, pre-order, or post-order
   * @param aVisual [in] whether the iterator should traverse frames in visual
   *        bidi order
   * @param aLockInScrollView [in] whether to stop iterating when exiting a
   *        scroll view
   * @param aFollowOOFs [in] whether the iterator should follow out-of-flows.
   *        If true, when reaching a placeholder frame while going down will get
   *        the real frame. Going back up will go on past the placeholder,
   *        so the placeholders are logically part of the frame tree.
   * @param aSkipPopupChecks [in] if false, then don't iterate into or out of a
   *        popup frame. If true, skip any popup related checks.
   */
  NS_IMETHOD NewFrameTraversal(nsIFrameEnumerator** aEnumerator,
                               nsPresContext* aPresContext, nsIFrame* aStart,
                               int32_t aType, bool aVisual,
                               bool aLockInScrollView, bool aFollowOOFs,
                               bool aSkipPopupChecks) = 0;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIFrameTraversal, NS_IFRAMETRAVERSAL_IID)

#endif  // NSIFRAMETRAVERSAL_H
