nsMathMLmunderoverFrame.h

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/* -*- 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 nsMathMLmunderoverFrame_h___

#define nsMathMLmunderoverFrame_h___

#include "nsIReflowCallback.h"

#include "nsMathMLContainerFrame.h"

namespace mozilla {

class PresShell;

}  // namespace mozilla

//

// <munderover> -- attach an underscript-overscript pair to a base

//

class nsMathMLmunderoverFrame final : public nsMathMLContainerFrame,

                                      public nsIReflowCallback {

 public:

  NS_DECL_FRAMEARENA_HELPERS(nsMathMLmunderoverFrame)

  friend nsIFrame* NS_NewMathMLmunderoverFrame(mozilla::PresShell* aPresShell,

                                               ComputedStyle* aStyle);

  void Place(DrawTarget* aDrawTarget, const PlaceFlags& aFlags,

             ReflowOutput& aDesiredSize) override;

  NS_IMETHOD InheritAutomaticData(nsIFrame* aParent) override;

  NS_IMETHOD TransmitAutomaticData() override;

  NS_IMETHOD UpdatePresentationData(uint32_t aFlagsValues,

                                    uint32_t aFlagsToUpdate) override;

  void Destroy(DestroyContext&) override;

  nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,

                            AttrModType aModType) override;

  uint8_t ScriptIncrement(nsIFrame* aFrame) override;

  // nsIReflowCallback.

  bool ReflowFinished() override;

  void ReflowCallbackCanceled() override;

 protected:

  explicit nsMathMLmunderoverFrame(ComputedStyle* aStyle,

                                   nsPresContext* aPresContext)

      : nsMathMLContainerFrame(aStyle, aPresContext, kClassID),

        mIncrementUnder(false),

        mIncrementOver(false) {}

  virtual ~nsMathMLmunderoverFrame();

 private:

  bool IsMathContentBoxHorizontallyCentered() const final;

  // Helper to set the "increment script level" flag on the element belonging

  // to a child frame given by aChildIndex.

//

  // When this flag is set, the style system will increment the scriptlevel for

  // the child element. This is needed for situations where the style system

  // cannot itself determine the scriptlevel (mfrac, munder, mover, munderover).

//

  // This should be called during reflow.

//

  // We set the flag and if it changed, we request appropriate restyling and

  // also queue a post-reflow callback to ensure that restyle and reflow happens

  // immediately after the current reflow.

  void SetIncrementScriptLevel(uint32_t aChildIndex, bool aIncrement);

  void SetPendingPostReflowIncrementScriptLevel();

  bool mIncrementUnder;

  bool mIncrementOver;

  struct SetIncrementScriptLevelCommand {

    uint32_t mChildIndex;

    bool mDoIncrement;

};

  nsTArray<SetIncrementScriptLevelCommand>

      mPostReflowIncrementScriptLevelCommands;

};

#endif /* nsMathMLmunderoverFrame_h___ */