gecko-dev/layout/mathml/nsMathMLmspaceFrame.cpp

134 lines
3.8 KiB
C++

/* -*- 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 "nsMathMLmspaceFrame.h"
#include "nsMathMLElement.h"
#include "mozilla/gfx/2D.h"
#include <algorithm>
//
// <mspace> -- space - implementation
//
nsIFrame*
NS_NewMathMLmspaceFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsMathMLmspaceFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmspaceFrame)
nsMathMLmspaceFrame::~nsMathMLmspaceFrame()
{
}
bool
nsMathMLmspaceFrame::IsLeaf() const
{
return true;
}
void
nsMathMLmspaceFrame::ProcessAttributes(nsPresContext* aPresContext)
{
nsAutoString value;
// width
//
// "Specifies the desired width of the space."
//
// values: length
// default: 0em
//
// The default value is "0em", so unitless values can be ignored.
// <mspace/> is listed among MathML elements allowing negative spacing and
// the MathML test suite contains "Presentation/TokenElements/mspace/mspace2"
// as an example. Hence we allow negative values.
//
mWidth = 0;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::width,
value);
if (!value.IsEmpty()) {
ParseNumericValue(value, &mWidth,
nsMathMLElement::PARSE_ALLOW_NEGATIVE,
aPresContext, mStyleContext);
}
// height
//
// "Specifies the desired height (above the baseline) of the space."
//
// values: length
// default: 0ex
//
// The default value is "0ex", so unitless values can be ignored.
// We do not allow negative values. See bug 716349.
//
mHeight = 0;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::height,
value);
if (!value.IsEmpty()) {
ParseNumericValue(value, &mHeight, 0,
aPresContext, mStyleContext);
}
// depth
//
// "Specifies the desired depth (below the baseline) of the space."
//
// values: length
// default: 0ex
//
// The default value is "0ex", so unitless values can be ignored.
// We do not allow negative values. See bug 716349.
//
mDepth = 0;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::depth_,
value);
if (!value.IsEmpty()) {
ParseNumericValue(value, &mDepth, 0,
aPresContext, mStyleContext);
}
}
NS_IMETHODIMP
nsMathMLmspaceFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
ProcessAttributes(aPresContext);
mBoundingMetrics = nsBoundingMetrics();
mBoundingMetrics.width = mWidth;
mBoundingMetrics.ascent = mHeight;
mBoundingMetrics.descent = mDepth;
mBoundingMetrics.leftBearing = 0;
mBoundingMetrics.rightBearing = mBoundingMetrics.width;
aDesiredSize.SetTopAscent(mHeight);
aDesiredSize.Width() = std::max(0, mBoundingMetrics.width);
aDesiredSize.Height() = aDesiredSize.TopAscent() + mDepth;
// Also return our bounding metrics
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
/* virtual */ nsresult
nsMathMLmspaceFrame::MeasureForWidth(nsRenderingContext& aRenderingContext,
nsHTMLReflowMetrics& aDesiredSize)
{
ProcessAttributes(PresContext());
mBoundingMetrics = nsBoundingMetrics();
mBoundingMetrics.width = mWidth;
aDesiredSize.Width() = std::max(0, mBoundingMetrics.width);
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
return NS_OK;
}