gecko-dev/layout/mathml/nsMathMLmunderoverFrame.h

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2.7 KiB
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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "mozilla/Attributes.h"
#include "nsIReflowCallback.h"
#include "nsMathMLContainerFrame.h"
//
// <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(nsIPresShell* aPresShell, nsStyleContext* aContext);
nsresult Place(DrawTarget* aDrawTarget,
bool aPlaceOrigin,
ReflowOutput& aDesiredSize) override;
NS_IMETHOD InheritAutomaticData(nsIFrame* aParent) override;
NS_IMETHOD TransmitAutomaticData() override;
NS_IMETHOD UpdatePresentationData(uint32_t aFlagsValues,
uint32_t aFlagsToUpdate) override;
void DestroyFrom(nsIFrame* aRoot) override;
nsresult AttributeChanged(int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType) override;
uint8_t ScriptIncrement(nsIFrame* aFrame) override;
// nsIReflowCallback.
bool ReflowFinished() override;
void ReflowCallbackCanceled() override;
protected:
explicit nsMathMLmunderoverFrame(nsStyleContext* aContext)
: nsMathMLContainerFrame(aContext, kClassID)
, mIncrementUnder(false)
, mIncrementOver(false)
{}
virtual ~nsMathMLmunderoverFrame();
private:
// 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___ */