/* -*- 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 RETAINEDDISPLAYLISTBUILDER_H_

#define RETAINEDDISPLAYLISTBUILDER_H_

#include "nsDisplayList.h"

#include "mozilla/Maybe.h"

#include "mozilla/TypedEnumBits.h"

namespace mozilla {

class DisplayListChecker;

} // namespace mozilla

/**

 * RetainedDisplayListData contains frame invalidation information. It is stored

 * in root frames, and used by RetainedDisplayListBuilder.

 * Currently this is implemented as a map of frame pointers to flags.

 */

struct RetainedDisplayListData

{

  NS_DECLARE_FRAME_PROPERTY_DELETABLE(DisplayListData, RetainedDisplayListData)

  enum class FrameFlags : uint8_t

  {

    None = 0,

    Modified = 1 << 0,

    HasProps = 1 << 1,

    HadWillChange = 1 << 2

  };

  /**

   * Removes all the frames from this RetainedDisplayListData.

   */

  void Clear() { mFrames.Clear(); }

  /**

   * Returns a mutable reference to flags set for the given |aFrame|. If the

   * frame does not exist in this RetainedDisplayListData, it is added with

   * default constructible flags FrameFlags::None.

   */

  FrameFlags& Flags(nsIFrame* aFrame) { return mFrames.GetOrInsert(aFrame); }

  /**

   * Returns flags set for the given |aFrame|, or FrameFlags::None if the frame

   * is not in this RetainedDisplayListData.

   */

  FrameFlags GetFlags(nsIFrame* aFrame) const { return mFrames.Get(aFrame); }

  /**

   * Returns an iterator to the underlying frame storage.

   */

  auto Iterator() { return mFrames.Iter(); }

  /**

   * Removes the given |aFrame| from this RetainedDisplayListData.

   */

  bool Remove(nsIFrame* aFrame) { return mFrames.Remove(aFrame); }

private:

  nsDataHashtable<nsPtrHashKey<nsIFrame>, FrameFlags> mFrames;

};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(RetainedDisplayListData::FrameFlags)

/**

 * Returns RetainedDisplayListData property for the given |aRootFrame|, or

 * nullptr if the property is not set.

 */

RetainedDisplayListData*

GetRetainedDisplayListData(nsIFrame* aRootFrame);

/**

 * Returns RetainedDisplayListData property for the given |aRootFrame|. Creates

 * and sets a new RetainedDisplayListData property if it is not already set.

 */

RetainedDisplayListData*

GetOrSetRetainedDisplayListData(nsIFrame* aRootFrame);

struct RetainedDisplayListBuilder

{

  RetainedDisplayListBuilder(nsIFrame* aReferenceFrame,

                             nsDisplayListBuilderMode aMode,

                             bool aBuildCaret)

    : mBuilder(aReferenceFrame, aMode, aBuildCaret, true)

  {

  }

  ~RetainedDisplayListBuilder() { mList.DeleteAll(&mBuilder); }

  nsDisplayListBuilder* Builder() { return &mBuilder; }

  nsDisplayList* List() { return &mList; }

  enum class PartialUpdateResult

  {

    Failed,

    NoChange,

    Updated

  };

  PartialUpdateResult AttemptPartialUpdate(

    nscolor aBackstop,

    mozilla::DisplayListChecker* aChecker);

  /**

   * Iterates through the display list builder reference frame document and

   * subdocuments, and clears the modified frame lists from the root frames.

   * Also clears the frame properties set by RetainedDisplayListBuilder for all

   * the frames in the modified frame lists.

   */

  void ClearFramesWithProps();

  NS_DECLARE_FRAME_PROPERTY_DELETABLE(Cached, RetainedDisplayListBuilder)

private:

  bool PreProcessDisplayList(RetainedDisplayList* aList,

                             AnimatedGeometryRoot* aAGR,

                             uint32_t aCallerKey = 0,

                             uint32_t aNestingDepth = 0);

  bool MergeDisplayLists(

    nsDisplayList* aNewList,

    RetainedDisplayList* aOldList,

    RetainedDisplayList* aOutList,

    mozilla::Maybe<const mozilla::ActiveScrolledRoot*>& aOutContainerASR,

    uint32_t aOuterKey = 0);

  bool ComputeRebuildRegion(nsTArray<nsIFrame*>& aModifiedFrames,

                            nsRect* aOutDirty,

                            AnimatedGeometryRoot** aOutModifiedAGR,

                            nsTArray<nsIFrame*>& aOutFramesWithProps);

  bool ProcessFrame(nsIFrame* aFrame,

                    nsDisplayListBuilder& aBuilder,

                    nsIFrame* aStopAtFrame,

                    nsTArray<nsIFrame*>& aOutFramesWithProps,

                    const bool aStopAtStackingContext,

                    nsRect* aOutDirty,

                    AnimatedGeometryRoot** aOutModifiedAGR);

  void IncrementSubDocPresShellPaintCount(nsDisplayItem* aItem);

  friend class MergeState;

  nsDisplayListBuilder mBuilder;

  RetainedDisplayList mList;

  WeakFrame mPreviousCaret;

};

#endif // RETAINEDDISPLAYLISTBUILDER_H_