Mozilla/mozilla/layout/mathml/base/src/nsMathMLmsubFrame.cpp

134 lines
3.9 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>
*/
#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::Place(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
nscoord count = 0;
nsRect rect[2];
nsIFrame* child[2];
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
if (!IsOnlyWhitespace(childFrame) && 2 > count) {
childFrame->GetRect(rect[count]);
child[count] = childFrame;
count++;
}
childFrame->GetNextSibling(&childFrame);
}
aDesiredSize.ascent = rect[0].y;
// Get the subscript offset
nscoord subscriptOffset, leading;
nsCOMPtr<nsIFontMetrics> fm;
const nsStyleFont* aFont =
(const nsStyleFont*)mStyleContext->GetStyleData(eStyleStruct_Font);
aPresContext->GetMetricsFor(aFont->mFont, getter_AddRefs(fm));
fm->GetSubscriptOffset(subscriptOffset);
fm->GetLeading(leading);
// XXX temporary hack pending bug http://bugzilla.mozilla.org/show_bug.cgi?id=9640
//#if 0
nscoord fmAscent, xHeight;
fm->GetMaxAscent(fmAscent);
fm->GetXHeight(xHeight);
subscriptOffset = PR_MAX(subscriptOffset,fmAscent-(xHeight*4)/5);
//#endif
//for (int i=0; i<100; i++) {
//printf("Ascent:%d xHeight:%d subscriptOffset:%d leading: %d ",
//fmAscent, xHeight, subscriptOffset, leading);
//}
subscriptOffset += leading;
// logic derived after examining the boxes on three cases: h0==h1, h0>h1, h0<h1
aDesiredSize.height = rect[0].height + rect[1].height - subscriptOffset;
aDesiredSize.width = rect[0].width + rect[1].width;
rect[0].x = 0;
rect[0].y = 0;
rect[1].x = rect[0].width;
rect[1].y = aDesiredSize.height - rect[1].height;
aDesiredSize.descent = aDesiredSize.height - aDesiredSize.ascent;
if (aPlaceOrigin) {
// child[0]->SetRect(aPresContext, rect[0]);
// child[1]->SetRect(aPresContext, rect[1]);
nsHTMLReflowMetrics childSize(nsnull);
for (PRInt32 i=0; i<count; i++) {
childSize.width = rect[i].width;
childSize.height = rect[i].height;
FinishReflowChild(child[i], aPresContext, childSize, rect[i].x, rect[i].y, 0);
}
}
return NS_OK;
}