gecko-dev/layout/mathml/nsMathMLmstyleFrame.cpp

/* -*- 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/. */


#include "nsCOMPtr.h"
#include "nsFrame.h"
#include "nsStyleContext.h"
#include "nsStyleConsts.h"
#include "nsINameSpaceManager.h"

#include "nsMathMLmstyleFrame.h"

//
// <mstyle> -- style change
//

nsIFrame*
NS_NewMathMLmstyleFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
  return new (aPresShell) nsMathMLmstyleFrame(aContext);
}

NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmstyleFrame)

nsMathMLmstyleFrame::~nsMathMLmstyleFrame()
{
}

// mstyle needs special care for its scriptlevel and displaystyle attributes
NS_IMETHODIMP
nsMathMLmstyleFrame::InheritAutomaticData(nsIFrame* aParent) 
{
  // let the base class get the default from our parent
  nsMathMLContainerFrame::InheritAutomaticData(aParent);

  // sync with our current state
  mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;
  mPresentationData.mstyle = this;

  // see if the displaystyle attribute is there
  nsMathMLFrame::FindAttrDisplaystyle(mContent, mPresentationData);

  return NS_OK;
}

NS_IMETHODIMP
nsMathMLmstyleFrame::TransmitAutomaticData()
{
  return TransmitAutomaticDataForMrowLikeElement();
}

// displaystyle and scriptlevel are special in <mstyle>...
// Since UpdatePresentation() and UpdatePresentationDataFromChildAt() can be called
// by a parent, ensure that the explicit attributes of <mstyle> take precedence
NS_IMETHODIMP
nsMathMLmstyleFrame::UpdatePresentationData(uint32_t        aFlagsValues,
                                            uint32_t        aWhichFlags)
{
  if (NS_MATHML_HAS_EXPLICIT_DISPLAYSTYLE(mPresentationData.flags)) {
    // our current state takes precedence, disallow updating the displastyle
    aWhichFlags &= ~NS_MATHML_DISPLAYSTYLE;
    aFlagsValues &= ~NS_MATHML_DISPLAYSTYLE;
  }

  return nsMathMLContainerFrame::UpdatePresentationData(aFlagsValues, aWhichFlags);
}

NS_IMETHODIMP
nsMathMLmstyleFrame::UpdatePresentationDataFromChildAt(int32_t         aFirstIndex,
                                                       int32_t         aLastIndex,
                                                       uint32_t        aFlagsValues,
                                                       uint32_t        aWhichFlags)
{
  if (NS_MATHML_HAS_EXPLICIT_DISPLAYSTYLE(mPresentationData.flags)) {
    // our current state takes precedence, disallow updating the displastyle
    aWhichFlags &= ~NS_MATHML_DISPLAYSTYLE;
    aFlagsValues &= ~NS_MATHML_DISPLAYSTYLE;
  }

  // let the base class worry about the update
  return
    nsMathMLContainerFrame::UpdatePresentationDataFromChildAt(
      aFirstIndex, aLastIndex, aFlagsValues, aWhichFlags); 
}

NS_IMETHODIMP
nsMathMLmstyleFrame::AttributeChanged(int32_t         aNameSpaceID,
                                      nsIAtom*        aAttribute,
                                      int32_t         aModType)
{
  // Other attributes can affect too many things, ask our parent to re-layout
  // its children so that we can pick up changes in our attributes & transmit
  // them in our subtree. However, our siblings will be re-laid too. We used
  // to have a more speedier but more verbose alternative that didn't re-layout
  // our siblings. See bug 114909 - attachment 67668.
  return ReLayoutChildren(mParent);
}