223 lines
6.9 KiB
C++
223 lines
6.9 KiB
C++
/*
|
|
* The contents of this file are subject to the Mozilla Public
|
|
* License Version 1.1 (the "License"); you may not use this file
|
|
* except in compliance with the License. You may obtain a copy of
|
|
* the License at http://www.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS
|
|
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
|
|
* implied. See the License for the specific language governing
|
|
* rights and limitations under the License.
|
|
*
|
|
* The Original Code is Mozilla MathML Project.
|
|
*
|
|
* The Initial Developer of the Original Code is The University Of
|
|
* Queensland. Portions created by The University Of Queensland are
|
|
* Copyright (C) 1999 The University Of Queensland. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* Roger B. Sidje <rbs@maths.uq.edu.au>
|
|
* David J. Fiddes <D.J.Fiddes@hw.ac.uk>
|
|
* Shyjan Mahamud <mahamud@cs.cmu.edu> (added TeX rendering rules)
|
|
*/
|
|
|
|
|
|
#include "nsCOMPtr.h"
|
|
#include "nsHTMLParts.h"
|
|
#include "nsIHTMLContent.h"
|
|
#include "nsFrame.h"
|
|
#include "nsLineLayout.h"
|
|
#include "nsHTMLIIDs.h"
|
|
#include "nsIPresContext.h"
|
|
#include "nsHTMLAtoms.h"
|
|
#include "nsUnitConversion.h"
|
|
#include "nsIStyleContext.h"
|
|
#include "nsStyleConsts.h"
|
|
#include "nsINameSpaceManager.h"
|
|
#include "nsIRenderingContext.h"
|
|
#include "nsIFontMetrics.h"
|
|
#include "nsStyleUtil.h"
|
|
|
|
#include "nsMathMLmsubFrame.h"
|
|
|
|
//
|
|
// <msub> -- attach a subscript to a base - implementation
|
|
//
|
|
|
|
nsresult
|
|
NS_NewMathMLmsubFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame)
|
|
{
|
|
NS_PRECONDITION(aNewFrame, "null OUT ptr");
|
|
if (nsnull == aNewFrame) {
|
|
return NS_ERROR_NULL_POINTER;
|
|
}
|
|
nsMathMLmsubFrame* it = new (aPresShell) nsMathMLmsubFrame;
|
|
if (nsnull == it) {
|
|
return NS_ERROR_OUT_OF_MEMORY;
|
|
}
|
|
*aNewFrame = it;
|
|
return NS_OK;
|
|
}
|
|
|
|
nsMathMLmsubFrame::nsMathMLmsubFrame()
|
|
{
|
|
}
|
|
|
|
nsMathMLmsubFrame::~nsMathMLmsubFrame()
|
|
{
|
|
}
|
|
|
|
NS_IMETHODIMP
|
|
nsMathMLmsubFrame::Init(nsIPresContext* aPresContext,
|
|
nsIContent* aContent,
|
|
nsIFrame* aParent,
|
|
nsIStyleContext* aContext,
|
|
nsIFrame* aPrevInFlow)
|
|
{
|
|
nsresult rv = nsMathMLContainerFrame::Init
|
|
(aPresContext, aContent, aParent, aContext, aPrevInFlow);
|
|
|
|
mSubScriptShiftFactor = 0.0;
|
|
mScriptSpace = NSFloatPointsToTwips(0.5f); // 0.5pt as in plain TeX
|
|
|
|
// check for subscriptshift attribute in ex units
|
|
nsAutoString value;
|
|
mUserSetFlag = PR_FALSE;
|
|
if (NS_CONTENT_ATTR_HAS_VALUE == mContent->GetAttribute
|
|
(kNameSpaceID_None, nsMathMLAtoms::subscriptshift_, value)) {
|
|
PRInt32 aErrorCode;
|
|
float aUserValue = value.ToFloat(&aErrorCode);
|
|
if (NS_SUCCEEDED(aErrorCode)) {
|
|
mUserSetFlag = PR_TRUE;
|
|
mSubScriptShiftFactor = aUserValue;
|
|
}
|
|
}
|
|
|
|
mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
|
|
return rv;
|
|
}
|
|
|
|
NS_IMETHODIMP
|
|
nsMathMLmsubFrame::Place(nsIPresContext* aPresContext,
|
|
nsIRenderingContext& aRenderingContext,
|
|
PRBool aPlaceOrigin,
|
|
nsHTMLReflowMetrics& aDesiredSize)
|
|
{
|
|
nsresult rv = NS_OK;
|
|
|
|
////////////////////////////////////
|
|
// Get the children's desired sizes
|
|
|
|
PRInt32 count = 0;
|
|
nsHTMLReflowMetrics baseSize (nsnull);
|
|
nsHTMLReflowMetrics subScriptSize (nsnull);
|
|
nsIFrame* baseFrame;
|
|
nsIFrame* subScriptFrame;
|
|
// parameter v, Rule 18a, Appendix G of the TeXbook
|
|
nscoord minSubScriptShift = 0;
|
|
|
|
nsBoundingMetrics bmBase, bmSubScript;
|
|
|
|
nsIFrame* aChildFrame = mFrames.FirstChild();
|
|
while (nsnull != aChildFrame)
|
|
{
|
|
if (!IsOnlyWhitespace(aChildFrame)) {
|
|
if (0 == count) {
|
|
// base
|
|
baseFrame = aChildFrame;
|
|
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
|
|
}
|
|
else if (1 == count) {
|
|
// subscript
|
|
subScriptFrame = aChildFrame;
|
|
GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
|
|
// get the subdrop from the subscript font
|
|
nscoord aSubDrop;
|
|
GetSubDropFromChild (aPresContext, subScriptFrame, aSubDrop);
|
|
// parameter v, Rule 18a, App. G, TeXbook
|
|
minSubScriptShift = bmBase.descent + aSubDrop;
|
|
}
|
|
else {
|
|
NS_ASSERTION((count < 2),"nsMathMLmsubFrame : invalid markup");
|
|
}
|
|
count++;
|
|
}
|
|
|
|
rv = aChildFrame->GetNextSibling(&aChildFrame);
|
|
NS_ASSERTION(NS_SUCCEEDED(rv),"failed to get next child");
|
|
}
|
|
|
|
//////////////////
|
|
// Place Children
|
|
|
|
// get min subscript shift limit from x-height
|
|
// = h(x) - 4/5 * sigma_5, Rule 18b, App. G, TeXbook
|
|
nscoord xHeight = 0;
|
|
nsCOMPtr<nsIFontMetrics> fm;
|
|
|
|
// const nsStyleFont* aFont =
|
|
// (const nsStyleFont*) mStyleContext->GetStyleData (eStyleStruct_Font);
|
|
|
|
const nsStyleFont* aFont;
|
|
baseFrame->GetStyleData(eStyleStruct_Font, (const nsStyleStruct *&)aFont);
|
|
|
|
aPresContext->GetMetricsFor (aFont->mFont, getter_AddRefs(fm));
|
|
fm->GetXHeight (xHeight);
|
|
nscoord minShiftFromXHeight = (nscoord)
|
|
(bmSubScript.ascent - (4.0f/5.0f) * xHeight);
|
|
|
|
// aSubScriptShift
|
|
// = minimum amount to shift the subscript down set by user or from the font
|
|
// = sub1 in TeX
|
|
// = subscriptshift attribute * x-height
|
|
nscoord aSubScriptShift, dummy;
|
|
// get aSubScriptShift default from font
|
|
GetSubScriptShifts (fm, aSubScriptShift, dummy);
|
|
if (mUserSetFlag) {
|
|
// the user has set the subscriptshift attribute
|
|
aSubScriptShift = NSToCoordRound(mSubScriptShiftFactor * xHeight);
|
|
//XXX shouldn't this be
|
|
// aSubScriptShift =
|
|
// PR_MAX(aSubScriptShift, NSToCoordRound(mSubScriptShiftFactor * xHeight));
|
|
}
|
|
|
|
// get actual subscriptshift to be used
|
|
// Rule 18b, App. G, TeXbook
|
|
nscoord actualSubScriptShift =
|
|
PR_MAX(minSubScriptShift,PR_MAX(aSubScriptShift,minShiftFromXHeight));
|
|
// get bounding box for base + subscript
|
|
mBoundingMetrics.ascent =
|
|
PR_MAX(bmBase.ascent, bmSubScript.ascent - actualSubScriptShift);
|
|
mBoundingMetrics.descent =
|
|
PR_MAX(bmBase.descent, bmSubScript.descent + actualSubScriptShift);
|
|
// add mScriptSpace between base and supscript
|
|
mBoundingMetrics.width = bmBase.width + mScriptSpace + bmSubScript.width;
|
|
mBoundingMetrics.leftBearing = bmBase.leftBearing;
|
|
mBoundingMetrics.rightBearing = baseSize.width + mScriptSpace + bmSubScript.rightBearing;
|
|
|
|
// reflow metrics
|
|
aDesiredSize.ascent =
|
|
PR_MAX(baseSize.ascent, subScriptSize.ascent - actualSubScriptShift);
|
|
aDesiredSize.descent =
|
|
PR_MAX(baseSize.descent, subScriptSize.descent + actualSubScriptShift);
|
|
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
|
|
aDesiredSize.width = baseSize.width + mScriptSpace + subScriptSize.width;
|
|
|
|
mReference.x = 0;
|
|
mReference.y = aDesiredSize.ascent - mBoundingMetrics.ascent;
|
|
|
|
if (aPlaceOrigin) {
|
|
nscoord dx, dy;
|
|
// now place the base ...
|
|
dx = 0; dy = aDesiredSize.ascent - baseSize.ascent;
|
|
FinishReflowChild (baseFrame, aPresContext, baseSize, dx, dy, 0);
|
|
// ... and subscript
|
|
dx = baseSize.width;
|
|
dy = aDesiredSize.ascent - (subScriptSize.ascent - actualSubScriptShift);
|
|
FinishReflowChild (subScriptFrame, aPresContext, subScriptSize, dx, dy, 0);
|
|
}
|
|
|
|
return NS_OK;
|
|
}
|
|
|