gecko-dev/layout/mathml/nsMathMLmfencedFrame.cpp
2012-05-21 12:12:37 +01:00

710 lines
23 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 "nsCOMPtr.h"
#include "nsFrame.h"
#include "nsPresContext.h"
#include "nsStyleContext.h"
#include "nsStyleConsts.h"
#include "nsRenderingContext.h"
#include "nsMathMLmfencedFrame.h"
//
// <mfenced> -- surround content with a pair of fences
//
nsIFrame*
NS_NewMathMLmfencedFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsMathMLmfencedFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmfencedFrame)
nsMathMLmfencedFrame::~nsMathMLmfencedFrame()
{
RemoveFencesAndSeparators();
}
NS_IMETHODIMP
nsMathMLmfencedFrame::InheritAutomaticData(nsIFrame* aParent)
{
// let the base class get the default from our parent
nsMathMLContainerFrame::InheritAutomaticData(aParent);
mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;
RemoveFencesAndSeparators();
CreateFencesAndSeparators(PresContext());
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmfencedFrame::SetInitialChildList(ChildListID aListID,
nsFrameList& aChildList)
{
// First, let the base class do its work
nsresult rv = nsMathMLContainerFrame::SetInitialChildList(aListID, aChildList);
if (NS_FAILED(rv)) return rv;
// InheritAutomaticData will not get called if our parent is not a mathml
// frame, so initialize NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY for
// GetPreferredStretchSize() from Reflow().
mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;
// No need to track the style contexts given to our MathML chars.
// The Style System will use Get/SetAdditionalStyleContext() to keep them
// up-to-date if dynamic changes arise.
CreateFencesAndSeparators(PresContext());
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmfencedFrame::AttributeChanged(PRInt32 aNameSpaceID,
nsIAtom* aAttribute,
PRInt32 aModType)
{
RemoveFencesAndSeparators();
CreateFencesAndSeparators(PresContext());
return nsMathMLContainerFrame::
AttributeChanged(aNameSpaceID, aAttribute, aModType);
}
nsresult
nsMathMLmfencedFrame::ChildListChanged(PRInt32 aModType)
{
RemoveFencesAndSeparators();
CreateFencesAndSeparators(PresContext());
return nsMathMLContainerFrame::ChildListChanged(aModType);
}
void
nsMathMLmfencedFrame::RemoveFencesAndSeparators()
{
delete mOpenChar;
delete mCloseChar;
if (mSeparatorsChar) delete[] mSeparatorsChar;
mOpenChar = nsnull;
mCloseChar = nsnull;
mSeparatorsChar = nsnull;
mSeparatorsCount = 0;
}
void
nsMathMLmfencedFrame::CreateFencesAndSeparators(nsPresContext* aPresContext)
{
nsAutoString value;
bool isMutable = false;
//////////////
// see if the opening fence is there ...
if (!GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::open,
value)) {
value = PRUnichar('('); // default as per the MathML REC
} else {
value.CompressWhitespace();
}
if (!value.IsEmpty()) {
mOpenChar = new nsMathMLChar;
mOpenChar->SetData(aPresContext, value);
isMutable = nsMathMLOperators::IsMutableOperator(value);
ResolveMathMLCharStyle(aPresContext, mContent, mStyleContext, mOpenChar, isMutable);
}
//////////////
// see if the closing fence is there ...
if(!GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::close, value)) {
value = PRUnichar(')'); // default as per the MathML REC
} else {
value.CompressWhitespace();
}
if (!value.IsEmpty()) {
mCloseChar = new nsMathMLChar;
mCloseChar->SetData(aPresContext, value);
isMutable = nsMathMLOperators::IsMutableOperator(value);
ResolveMathMLCharStyle(aPresContext, mContent, mStyleContext, mCloseChar, isMutable);
}
//////////////
// see if separators are there ...
if (!GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::separators_, value)) {
value = PRUnichar(','); // default as per the MathML REC
} else {
value.StripWhitespace();
}
mSeparatorsCount = value.Length();
if (0 < mSeparatorsCount) {
PRInt32 sepCount = mFrames.GetLength() - 1;
if (0 < sepCount) {
mSeparatorsChar = new nsMathMLChar[sepCount];
nsAutoString sepChar;
for (PRInt32 i = 0; i < sepCount; i++) {
if (i < mSeparatorsCount) {
sepChar = value[i];
isMutable = nsMathMLOperators::IsMutableOperator(sepChar);
}
else {
sepChar = value[mSeparatorsCount-1];
// keep the value of isMutable that was set earlier
}
mSeparatorsChar[i].SetData(aPresContext, sepChar);
ResolveMathMLCharStyle(aPresContext, mContent, mStyleContext, &mSeparatorsChar[i], isMutable);
}
mSeparatorsCount = sepCount;
} else {
// No separators. Note that sepCount can be -1 here, so don't
// set mSeparatorsCount to it.
mSeparatorsCount = 0;
}
}
}
NS_IMETHODIMP
nsMathMLmfencedFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
/////////////
// display the content
nsresult rv = nsMathMLContainerFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
NS_ENSURE_SUCCESS(rv, rv);
////////////
// display fences and separators
PRUint32 count = 0;
if (mOpenChar) {
rv = mOpenChar->Display(aBuilder, this, aLists, count++);
NS_ENSURE_SUCCESS(rv, rv);
}
if (mCloseChar) {
rv = mCloseChar->Display(aBuilder, this, aLists, count++);
NS_ENSURE_SUCCESS(rv, rv);
}
for (PRInt32 i = 0; i < mSeparatorsCount; i++) {
rv = mSeparatorsChar[i].Display(aBuilder, this, aLists, count++);
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmfencedFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
nsresult rv;
aDesiredSize.width = aDesiredSize.height = 0;
aDesiredSize.ascent = 0;
aDesiredSize.mBoundingMetrics = nsBoundingMetrics();
PRInt32 i;
const nsStyleFont* font = GetStyleFont();
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
aReflowState.rendContext->SetFont(fm);
nscoord axisHeight, em;
GetAxisHeight(*aReflowState.rendContext, fm, axisHeight);
GetEmHeight(fm, em);
// leading to be left at the top and the bottom of stretched chars
nscoord leading = NSToCoordRound(0.2f * em);
/////////////
// Reflow children
// Asking each child to cache its bounding metrics
// Note that we don't use the base method nsMathMLContainerFrame::Reflow()
// because we want to stretch our fences, separators and stretchy frames using
// the *same* initial aDesiredSize.mBoundingMetrics. If we were to use the base
// method here, our stretchy frames will be stretched and placed, and we may
// end up stretching our fences/separators with a different aDesiredSize.
// XXX The above decision was revisited in bug 121748 and this code can be
// refactored to use nsMathMLContainerFrame::Reflow() at some stage.
nsReflowStatus childStatus;
nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
nsIFrame* firstChild = GetFirstPrincipalChild();
nsIFrame* childFrame = firstChild;
nscoord ascent = 0, descent = 0;
if (firstChild || mOpenChar || mCloseChar || mSeparatorsCount > 0) {
// We use the ASCII metrics to get our minimum height. This way,
// if we have borders or a background, they will fit better with
// other elements on the line.
ascent = fm->MaxAscent();
descent = fm->MaxDescent();
}
while (childFrame) {
nsHTMLReflowMetrics childDesiredSize(aDesiredSize.mFlags
| NS_REFLOW_CALC_BOUNDING_METRICS);
nsHTMLReflowState childReflowState(aPresContext, aReflowState,
childFrame, availSize);
rv = ReflowChild(childFrame, aPresContext, childDesiredSize,
childReflowState, childStatus);
//NS_ASSERTION(NS_FRAME_IS_COMPLETE(childStatus), "bad status");
if (NS_FAILED(rv)) {
// Call DidReflow() for the child frames we successfully did reflow.
DidReflowChildren(firstChild, childFrame);
return rv;
}
SaveReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
childDesiredSize.mBoundingMetrics);
nscoord childDescent = childDesiredSize.height - childDesiredSize.ascent;
if (descent < childDescent)
descent = childDescent;
if (ascent < childDesiredSize.ascent)
ascent = childDesiredSize.ascent;
childFrame = childFrame->GetNextSibling();
}
/////////////
// Ask stretchy children to stretch themselves
nsBoundingMetrics containerSize;
nsStretchDirection stretchDir = NS_STRETCH_DIRECTION_VERTICAL;
GetPreferredStretchSize(*aReflowState.rendContext,
0, /* i.e., without embellishments */
stretchDir, containerSize);
childFrame = firstChild;
while (childFrame) {
nsIMathMLFrame* mathmlChild = do_QueryFrame(childFrame);
if (mathmlChild) {
nsHTMLReflowMetrics childDesiredSize;
// retrieve the metrics that was stored at the previous pass
GetReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
childDesiredSize.mBoundingMetrics);
mathmlChild->Stretch(*aReflowState.rendContext,
stretchDir, containerSize, childDesiredSize);
// store the updated metrics
SaveReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
childDesiredSize.mBoundingMetrics);
nscoord childDescent = childDesiredSize.height - childDesiredSize.ascent;
if (descent < childDescent)
descent = childDescent;
if (ascent < childDesiredSize.ascent)
ascent = childDesiredSize.ascent;
}
childFrame = childFrame->GetNextSibling();
}
// bug 121748: for surrounding fences & separators, use a size that covers everything
GetPreferredStretchSize(*aReflowState.rendContext,
STRETCH_CONSIDER_EMBELLISHMENTS,
stretchDir, containerSize);
//////////////////////////////////////////
// Prepare the opening fence, separators, and closing fence, and
// adjust the origin of children.
// we need to center around the axis
nscoord delta = NS_MAX(containerSize.ascent - axisHeight,
containerSize.descent + axisHeight);
containerSize.ascent = delta + axisHeight;
containerSize.descent = delta - axisHeight;
bool isRTL = NS_MATHML_IS_RTL(mPresentationData.flags);
/////////////////
// opening fence ...
ReflowChar(aPresContext, *aReflowState.rendContext, mOpenChar,
NS_MATHML_OPERATOR_FORM_PREFIX, font->mScriptLevel,
axisHeight, leading, em, containerSize, ascent, descent, isRTL);
/////////////////
// separators ...
for (i = 0; i < mSeparatorsCount; i++) {
ReflowChar(aPresContext, *aReflowState.rendContext, &mSeparatorsChar[i],
NS_MATHML_OPERATOR_FORM_INFIX, font->mScriptLevel,
axisHeight, leading, em, containerSize, ascent, descent, isRTL);
}
/////////////////
// closing fence ...
ReflowChar(aPresContext, *aReflowState.rendContext, mCloseChar,
NS_MATHML_OPERATOR_FORM_POSTFIX, font->mScriptLevel,
axisHeight, leading, em, containerSize, ascent, descent, isRTL);
//////////////////
// Adjust the origins of each child.
// and update our bounding metrics
i = 0;
nscoord dx = 0;
nsBoundingMetrics bm;
bool firstTime = true;
nsMathMLChar *leftChar, *rightChar;
if (isRTL) {
leftChar = mCloseChar;
rightChar = mOpenChar;
} else {
leftChar = mOpenChar;
rightChar = mCloseChar;
}
if (leftChar) {
PlaceChar(leftChar, ascent, bm, dx);
aDesiredSize.mBoundingMetrics = bm;
firstTime = false;
}
if (isRTL) {
childFrame = this->GetLastChild(nsIFrame::kPrincipalList);
} else {
childFrame = firstChild;
}
while (childFrame) {
nsHTMLReflowMetrics childSize;
GetReflowAndBoundingMetricsFor(childFrame, childSize, bm);
if (firstTime) {
firstTime = false;
aDesiredSize.mBoundingMetrics = bm;
}
else
aDesiredSize.mBoundingMetrics += bm;
FinishReflowChild(childFrame, aPresContext, nsnull, childSize,
dx, ascent - childSize.ascent, 0);
dx += childSize.width;
if (i < mSeparatorsCount) {
PlaceChar(&mSeparatorsChar[isRTL ? mSeparatorsCount - 1 - i : i],
ascent, bm, dx);
aDesiredSize.mBoundingMetrics += bm;
}
i++;
if (isRTL) {
childFrame = childFrame->GetPrevSibling();
} else {
childFrame = childFrame->GetNextSibling();
}
}
if (rightChar) {
PlaceChar(rightChar, ascent, bm, dx);
if (firstTime)
aDesiredSize.mBoundingMetrics = bm;
else
aDesiredSize.mBoundingMetrics += bm;
}
aDesiredSize.width = aDesiredSize.mBoundingMetrics.width;
aDesiredSize.height = ascent + descent;
aDesiredSize.ascent = ascent;
SetBoundingMetrics(aDesiredSize.mBoundingMetrics);
SetReference(nsPoint(0, aDesiredSize.ascent));
// see if we should fix the spacing
FixInterFrameSpacing(aDesiredSize);
// Finished with these:
ClearSavedChildMetrics();
// Set our overflow area
GatherAndStoreOverflow(&aDesiredSize);
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
static void
GetCharSpacing(nsMathMLChar* aMathMLChar,
nsOperatorFlags aForm,
PRInt32 aScriptLevel,
nscoord em,
nscoord& aLeftSpace,
nscoord& aRightSpace)
{
nsAutoString data;
aMathMLChar->GetData(data);
nsOperatorFlags flags = 0;
float lspace = 0.0f;
float rspace = 0.0f;
bool found = nsMathMLOperators::LookupOperator(data, aForm,
&flags, &lspace, &rspace);
// We don't want extra space when we are a script
if (found && aScriptLevel > 0) {
lspace /= 2.0f;
rspace /= 2.0f;
}
aLeftSpace = NSToCoordRound(lspace * em);
aRightSpace = NSToCoordRound(rspace * em);
}
// helper functions to perform the common task of formatting our chars
/*static*/ nsresult
nsMathMLmfencedFrame::ReflowChar(nsPresContext* aPresContext,
nsRenderingContext& aRenderingContext,
nsMathMLChar* aMathMLChar,
nsOperatorFlags aForm,
PRInt32 aScriptLevel,
nscoord axisHeight,
nscoord leading,
nscoord em,
nsBoundingMetrics& aContainerSize,
nscoord& aAscent,
nscoord& aDescent,
bool aRTL)
{
if (aMathMLChar && 0 < aMathMLChar->Length()) {
nscoord leftSpace;
nscoord rightSpace;
GetCharSpacing(aMathMLChar, aForm, aScriptLevel, em, leftSpace, rightSpace);
// stretch the char to the appropriate height if it is not big enough.
nsBoundingMetrics charSize;
nsresult res = aMathMLChar->Stretch(aPresContext, aRenderingContext,
NS_STRETCH_DIRECTION_VERTICAL,
aContainerSize, charSize,
NS_STRETCH_NORMAL, aRTL);
if (NS_STRETCH_DIRECTION_UNSUPPORTED != aMathMLChar->GetStretchDirection()) {
// has changed... so center the char around the axis
nscoord height = charSize.ascent + charSize.descent;
charSize.ascent = height/2 + axisHeight;
charSize.descent = height - charSize.ascent;
}
else {
// either it hasn't changed or stretching the char failed (i.e.,
// GetBoundingMetrics failed)
leading = 0;
if (NS_FAILED(res)) {
nsAutoString data;
aMathMLChar->GetData(data);
nsBoundingMetrics metrics =
aRenderingContext.GetBoundingMetrics(data.get(), data.Length());
charSize.ascent = metrics.ascent;
charSize.descent = metrics.descent;
charSize.width = metrics.width;
// Set this as the bounding metrics of the MathMLChar to leave
// the necessary room to paint the char.
aMathMLChar->SetBoundingMetrics(charSize);
}
}
if (aAscent < charSize.ascent + leading)
aAscent = charSize.ascent + leading;
if (aDescent < charSize.descent + leading)
aDescent = charSize.descent + leading;
// account the spacing
charSize.width += leftSpace + rightSpace;
// x-origin is used to store lspace ...
// y-origin is used to stored the ascent ...
aMathMLChar->SetRect(nsRect(leftSpace,
charSize.ascent, charSize.width,
charSize.ascent + charSize.descent));
}
return NS_OK;
}
/*static*/ void
nsMathMLmfencedFrame::PlaceChar(nsMathMLChar* aMathMLChar,
nscoord aDesiredAscent,
nsBoundingMetrics& bm,
nscoord& dx)
{
aMathMLChar->GetBoundingMetrics(bm);
// the char's x-origin was used to store lspace ...
// the char's y-origin was used to store the ascent ...
// the char's width was used to store the advance with (with spacing) ...
nsRect rect;
aMathMLChar->GetRect(rect);
nscoord dy = aDesiredAscent - rect.y;
if (aMathMLChar->GetStretchDirection() != NS_STRETCH_DIRECTION_UNSUPPORTED) {
// the stretchy char will be centered around the axis
// so we adjust the returned bounding metrics accordingly
bm.descent = (bm.ascent + bm.descent) - rect.y;
bm.ascent = rect.y;
}
aMathMLChar->SetRect(nsRect(dx + rect.x, dy, bm.width, rect.height));
bm.leftBearing += rect.x;
bm.rightBearing += rect.x;
// return rect.width since it includes lspace and rspace
bm.width = rect.width;
dx += rect.width;
}
static nscoord
GetMaxCharWidth(nsPresContext* aPresContext,
nsRenderingContext* aRenderingContext,
nsMathMLChar* aMathMLChar,
nsOperatorFlags aForm,
PRInt32 aScriptLevel,
nscoord em)
{
nscoord width = aMathMLChar->GetMaxWidth(aPresContext, *aRenderingContext);
if (0 < aMathMLChar->Length()) {
nscoord leftSpace;
nscoord rightSpace;
GetCharSpacing(aMathMLChar, aForm, aScriptLevel, em, leftSpace, rightSpace);
width += leftSpace + rightSpace;
}
return width;
}
/* virtual */ nscoord
nsMathMLmfencedFrame::GetIntrinsicWidth(nsRenderingContext* aRenderingContext)
{
nscoord width = 0;
nsPresContext* presContext = PresContext();
const nsStyleFont* font = GetStyleFont();
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
nscoord em;
GetEmHeight(fm, em);
if (mOpenChar) {
width +=
GetMaxCharWidth(presContext, aRenderingContext, mOpenChar,
NS_MATHML_OPERATOR_FORM_PREFIX, font->mScriptLevel, em);
}
PRInt32 i = 0;
nsIFrame* childFrame = GetFirstPrincipalChild();
while (childFrame) {
// XXX This includes margin while Reflow currently doesn't consider
// margin, so we may end up with too much space, but, with stretchy
// characters, this is an approximation anyway.
width += nsLayoutUtils::IntrinsicForContainer(aRenderingContext, childFrame,
nsLayoutUtils::PREF_WIDTH);
if (i < mSeparatorsCount) {
width +=
GetMaxCharWidth(presContext, aRenderingContext, &mSeparatorsChar[i],
NS_MATHML_OPERATOR_FORM_INFIX, font->mScriptLevel, em);
}
i++;
childFrame = childFrame->GetNextSibling();
}
if (mCloseChar) {
width +=
GetMaxCharWidth(presContext, aRenderingContext, mCloseChar,
NS_MATHML_OPERATOR_FORM_POSTFIX, font->mScriptLevel, em);
}
return width;
}
nscoord
nsMathMLmfencedFrame::FixInterFrameSpacing(nsHTMLReflowMetrics& aDesiredSize)
{
nscoord gap = nsMathMLContainerFrame::FixInterFrameSpacing(aDesiredSize);
if (!gap) return 0;
nsRect rect;
if (mOpenChar) {
mOpenChar->GetRect(rect);
rect.MoveBy(gap, 0);
mOpenChar->SetRect(rect);
}
if (mCloseChar) {
mCloseChar->GetRect(rect);
rect.MoveBy(gap, 0);
mCloseChar->SetRect(rect);
}
for (PRInt32 i = 0; i < mSeparatorsCount; i++) {
mSeparatorsChar[i].GetRect(rect);
rect.MoveBy(gap, 0);
mSeparatorsChar[i].SetRect(rect);
}
return gap;
}
// ----------------------
// the Style System will use these to pass the proper style context to our MathMLChar
nsStyleContext*
nsMathMLmfencedFrame::GetAdditionalStyleContext(PRInt32 aIndex) const
{
PRInt32 openIndex = -1;
PRInt32 closeIndex = -1;
PRInt32 lastIndex = mSeparatorsCount-1;
if (mOpenChar) {
lastIndex++;
openIndex = lastIndex;
}
if (mCloseChar) {
lastIndex++;
closeIndex = lastIndex;
}
if (aIndex < 0 || aIndex > lastIndex) {
return nsnull;
}
if (aIndex < mSeparatorsCount) {
return mSeparatorsChar[aIndex].GetStyleContext();
}
else if (aIndex == openIndex) {
return mOpenChar->GetStyleContext();
}
else if (aIndex == closeIndex) {
return mCloseChar->GetStyleContext();
}
return nsnull;
}
void
nsMathMLmfencedFrame::SetAdditionalStyleContext(PRInt32 aIndex,
nsStyleContext* aStyleContext)
{
PRInt32 openIndex = -1;
PRInt32 closeIndex = -1;
PRInt32 lastIndex = mSeparatorsCount-1;
if (mOpenChar) {
lastIndex++;
openIndex = lastIndex;
}
if (mCloseChar) {
lastIndex++;
closeIndex = lastIndex;
}
if (aIndex < 0 || aIndex > lastIndex) {
return;
}
if (aIndex < mSeparatorsCount) {
mSeparatorsChar[aIndex].SetStyleContext(aStyleContext);
}
else if (aIndex == openIndex) {
mOpenChar->SetStyleContext(aStyleContext);
}
else if (aIndex == closeIndex) {
mCloseChar->SetStyleContext(aStyleContext);
}
}