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gecko/layout/mathml/nsMathMLmoFrame.cpp

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/* -*- 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 "nsContentUtils.h"
#include "nsMathMLmoFrame.h"
#include <algorithm>
//
// <mo> -- operator, fence, or separator - implementation
//
// additional style context to be used by our MathMLChar.
#define NS_MATHML_CHAR_STYLE_CONTEXT_INDEX 0
nsIFrame*
NS_NewMathMLmoFrame(nsIPresShell* aPresShell, nsStyleContext *aContext)
{
return new (aPresShell) nsMathMLmoFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmoFrame)
nsMathMLmoFrame::~nsMathMLmoFrame()
{
}
static const PRUnichar kInvisibleComma = PRUnichar(0x200B); // a.k.a. ZERO WIDTH SPACE
static const PRUnichar kApplyFunction = PRUnichar(0x2061);
static const PRUnichar kInvisibleTimes = PRUnichar(0x2062);
static const PRUnichar kNullCh = PRUnichar('\0');
eMathMLFrameType
nsMathMLmoFrame::GetMathMLFrameType()
{
return NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags)
? eMathMLFrameType_OperatorInvisible
: eMathMLFrameType_OperatorOrdinary;
}
// since a mouse click implies selection, we cannot just rely on the
// frame's state bit in our child text frame. So we will first check
// its selected state bit, and use this little helper to double check.
bool
nsMathMLmoFrame::IsFrameInSelection(nsIFrame* aFrame)
{
NS_ASSERTION(aFrame, "null arg");
if (!aFrame || !aFrame->IsSelected())
return false;
const nsFrameSelection* frameSelection = aFrame->GetConstFrameSelection();
SelectionDetails* details =
frameSelection->LookUpSelection(aFrame->GetContent(), 0, 1, true);
if (!details)
return false;
while (details) {
SelectionDetails* next = details->mNext;
delete details;
details = next;
}
return true;
}
bool
nsMathMLmoFrame::UseMathMLChar()
{
return (NS_MATHML_OPERATOR_GET_FORM(mFlags) &&
NS_MATHML_OPERATOR_IS_MUTABLE(mFlags)) ||
NS_MATHML_OPERATOR_IS_CENTERED(mFlags) ||
NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags);
}
void
nsMathMLmoFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
bool useMathMLChar = UseMathMLChar();
if (!useMathMLChar) {
// let the base class do everything
nsMathMLTokenFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
} else {
DisplayBorderBackgroundOutline(aBuilder, aLists);
// make our char selected if our inner child text frame is selected
bool isSelected = false;
nsRect selectedRect;
nsIFrame* firstChild = mFrames.FirstChild();
if (IsFrameInSelection(firstChild)) {
mMathMLChar.GetRect(selectedRect);
// add a one pixel border (it renders better for operators like minus)
selectedRect.Inflate(nsPresContext::CSSPixelsToAppUnits(1));
isSelected = true;
}
mMathMLChar.Display(aBuilder, this, aLists, 0, isSelected ? &selectedRect : nullptr);
#if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
// for visual debug
DisplayBoundingMetrics(aBuilder, this, mReference, mBoundingMetrics, aLists);
#endif
}
}
// get the text that we enclose and setup our nsMathMLChar
void
nsMathMLmoFrame::ProcessTextData()
{
mFlags = 0;
nsAutoString data;
nsContentUtils::GetNodeTextContent(mContent, false, data);
data.CompressWhitespace();
int32_t length = data.Length();
PRUnichar ch = (length == 0) ? kNullCh : data[0];
if ((length == 1) &&
(ch == kInvisibleComma ||
ch == kApplyFunction ||
ch == kInvisibleTimes)) {
mFlags |= NS_MATHML_OPERATOR_INVISIBLE;
}
// don't bother doing anything special if we don't have a
// single child with a visible text content
nsPresContext* presContext = PresContext();
if (NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags) || mFrames.GetLength() != 1) {
data.Truncate(); // empty data to reset the char
mMathMLChar.SetData(presContext, data);
ResolveMathMLCharStyle(presContext, mContent, mStyleContext, &mMathMLChar, false);
return;
}
// special... in math mode, the usual minus sign '-' looks too short, so
// what we do here is to remap <mo>-</mo> to the official Unicode minus
// sign (U+2212) which looks much better. For background on this, see
// http://groups.google.com/groups?hl=en&th=66488daf1ade7635&rnum=1
if (1 == length && ch == '-') {
ch = 0x2212;
data = ch;
}
// cache the special bits: mutable, accent, movablelimits, centered.
// we need to do this in anticipation of other requirements, and these
// bits don't change. Do not reset these bits unless the text gets changed.
// lookup all the forms under which the operator is listed in the dictionary,
// and record whether the operator has accent="true" or movablelimits="true"
nsOperatorFlags flags[4];
float lspace[4], rspace[4];
nsMathMLOperators::LookupOperators(data, flags, lspace, rspace);
nsOperatorFlags allFlags =
flags[NS_MATHML_OPERATOR_FORM_INFIX] |
flags[NS_MATHML_OPERATOR_FORM_POSTFIX] |
flags[NS_MATHML_OPERATOR_FORM_PREFIX];
mFlags |= allFlags & NS_MATHML_OPERATOR_ACCENT;
mFlags |= allFlags & NS_MATHML_OPERATOR_MOVABLELIMITS;
bool isMutable =
NS_MATHML_OPERATOR_IS_STRETCHY(allFlags) ||
NS_MATHML_OPERATOR_IS_LARGEOP(allFlags);
if (isMutable)
mFlags |= NS_MATHML_OPERATOR_MUTABLE;
// see if this is an operator that should be centered to cater for
// fonts that are not math-aware
if (1 == length) {
if ((ch == '+') || (ch == '=') || (ch == '*') ||
(ch == 0x2212) || // &minus;
(ch == 0x2264) || // &le;
(ch == 0x2265) || // &ge;
(ch == 0x00D7)) { // &times;
mFlags |= NS_MATHML_OPERATOR_CENTERED;
}
}
// cache the operator
mMathMLChar.SetData(presContext, data);
ResolveMathMLCharStyle(presContext, mContent, mStyleContext, &mMathMLChar, isMutable);
// cache the native direction -- beware of bug 133429...
// mEmbellishData.direction must always retain our native direction, whereas
// mMathMLChar.GetStretchDirection() may change later, when Stretch() is called
mEmbellishData.direction = mMathMLChar.GetStretchDirection();
}
// get our 'form' and lookup in the Operator Dictionary to fetch
// our default data that may come from there. Then complete our setup
// using attributes that we may have. To stay in sync, this function is
// called very often. We depend on many things that may change around us.
// However, we re-use unchanged values.
void
nsMathMLmoFrame::ProcessOperatorData()
{
// if we have been here before, we will just use our cached form
nsOperatorFlags form = NS_MATHML_OPERATOR_GET_FORM(mFlags);
nsAutoString value;
// special bits are always kept in mFlags.
// remember the mutable bit from ProcessTextData().
// Some chars are listed under different forms in the dictionary,
// and there could be a form under which the char is mutable.
// If the char is the core of an embellished container, we will keep
// it mutable irrespective of the form of the embellished container.
// Also remember the other special bits that we want to carry forward.
mFlags &= NS_MATHML_OPERATOR_MUTABLE |
NS_MATHML_OPERATOR_ACCENT |
NS_MATHML_OPERATOR_MOVABLELIMITS |
NS_MATHML_OPERATOR_CENTERED |
NS_MATHML_OPERATOR_INVISIBLE;
if (!mEmbellishData.coreFrame) {
// i.e., we haven't been here before, the default form is infix
form = NS_MATHML_OPERATOR_FORM_INFIX;
// reset everything so that we don't keep outdated values around
// in case of dynamic changes
mEmbellishData.flags = 0;
mEmbellishData.coreFrame = nullptr;
mEmbellishData.leadingSpace = 0;
mEmbellishData.trailingSpace = 0;
if (mMathMLChar.Length() != 1)
mEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
// else... retain the native direction obtained in ProcessTextData()
if (!mFrames.FirstChild()) {
return;
}
mEmbellishData.flags |= NS_MATHML_EMBELLISH_OPERATOR;
mEmbellishData.coreFrame = this;
// there are two particular things that we also need to record so that if our
// parent is <mover>, <munder>, or <munderover>, they will treat us properly:
// 1) do we have accent="true"
// 2) do we have movablelimits="true"
// they need the extra information to decide how to treat their scripts/limits
// (note: <mover>, <munder>, or <munderover> need not necessarily be our
// direct parent -- case of embellished operators)
// default values from the Operator Dictionary were obtained in ProcessTextData()
// and these special bits are always kept in mFlags
if (NS_MATHML_OPERATOR_IS_ACCENT(mFlags))
mEmbellishData.flags |= NS_MATHML_EMBELLISH_ACCENT;
if (NS_MATHML_OPERATOR_IS_MOVABLELIMITS(mFlags))
mEmbellishData.flags |= NS_MATHML_EMBELLISH_MOVABLELIMITS;
// see if the accent attribute is there
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::accent_,
value);
if (value.EqualsLiteral("true"))
mEmbellishData.flags |= NS_MATHML_EMBELLISH_ACCENT;
else if (value.EqualsLiteral("false"))
mEmbellishData.flags &= ~NS_MATHML_EMBELLISH_ACCENT;
// see if the movablelimits attribute is there
GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::movablelimits_, value);
if (value.EqualsLiteral("true"))
mEmbellishData.flags |= NS_MATHML_EMBELLISH_MOVABLELIMITS;
else if (value.EqualsLiteral("false"))
mEmbellishData.flags &= ~NS_MATHML_EMBELLISH_MOVABLELIMITS;
// ---------------------------------------------------------------------
// we will be called again to re-sync the rest of our state next time...
// (nobody needs the other values below at this stage)
mFlags |= form;
return;
}
nsPresContext* presContext = PresContext();
// beware of bug 133814 - there is a two-way dependency in the
// embellished hierarchy: our embellished ancestors need to set
// their flags based on some of our state (set above), and here we
// need to re-sync our 'form' depending on our outermost embellished
// container. A null form here means that an earlier attempt to stretch
// our mMathMLChar failed, in which case we don't bother re-stretching again
if (form) {
// get our outermost embellished container and its parent.
// (we ensure that we are the core, not just a sibling of the core)
nsIFrame* embellishAncestor = this;
nsEmbellishData embellishData;
nsIFrame* parentAncestor = this;
do {
embellishAncestor = parentAncestor;
parentAncestor = embellishAncestor->GetParent();
GetEmbellishDataFrom(parentAncestor, embellishData);
} while (embellishData.coreFrame == this);
// flag if we have an embellished ancestor
if (embellishAncestor != this)
mFlags |= NS_MATHML_OPERATOR_EMBELLISH_ANCESTOR;
else
mFlags &= ~NS_MATHML_OPERATOR_EMBELLISH_ANCESTOR;
// find the position of our outermost embellished container w.r.t
// its siblings.
nsIFrame* nextSibling = embellishAncestor->GetNextSibling();
nsIFrame* prevSibling = embellishAncestor->GetPrevSibling();
// flag to distinguish from a real infix
if (!prevSibling && !nextSibling)
mFlags |= NS_MATHML_OPERATOR_EMBELLISH_ISOLATED;
else
mFlags &= ~NS_MATHML_OPERATOR_EMBELLISH_ISOLATED;
// find our form
form = NS_MATHML_OPERATOR_FORM_INFIX;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::form,
value);
if (!value.IsEmpty()) {
if (value.EqualsLiteral("prefix"))
form = NS_MATHML_OPERATOR_FORM_PREFIX;
else if (value.EqualsLiteral("postfix"))
form = NS_MATHML_OPERATOR_FORM_POSTFIX;
}
else {
// set our form flag depending on the position
if (!prevSibling && nextSibling)
form = NS_MATHML_OPERATOR_FORM_PREFIX;
else if (prevSibling && !nextSibling)
form = NS_MATHML_OPERATOR_FORM_POSTFIX;
}
mFlags &= ~NS_MATHML_OPERATOR_FORM; // clear the old form bits
mFlags |= form;
// Use the default value suggested by the MathML REC.
// http://www.w3.org/TR/MathML/chapter3.html#presm.mo.attrs
// thickmathspace = 5/18em
float lspace = 5.0f/18.0f;
float rspace = 5.0f/18.0f;
if (NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags)) {
// mMathMLChar has been reset in ProcessTextData so we can not find it
// in the operator dictionary. The operator dictionary always uses
// lspace = rspace = 0 for invisible operators.
lspace = rspace = 0;
} else {
// lookup the operator dictionary
nsAutoString data;
mMathMLChar.GetData(data);
nsMathMLOperators::LookupOperator(data, form, &mFlags, &lspace, &rspace);
}
if (lspace || rspace) {
// Cache the default values of lspace and rspace.
// since these values are relative to the 'em' unit, convert to twips now
nscoord em;
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
GetEmHeight(fm, em);
mEmbellishData.leadingSpace = NSToCoordRound(lspace * em);
mEmbellishData.trailingSpace = NSToCoordRound(rspace * em);
// tuning if we don't want too much extra space when we are a script.
// (with its fonts, TeX sets lspace=0 & rspace=0 as soon as scriptlevel>0.
// Our fonts can be anything, so...)
if (StyleFont()->mScriptLevel > 0) {
if (NS_MATHML_OPERATOR_EMBELLISH_IS_ISOLATED(mFlags)) {
// could be an isolated accent or script, e.g., x^{+}, just zero out
mEmbellishData.leadingSpace = 0;
mEmbellishData.trailingSpace = 0;
}
else if (!NS_MATHML_OPERATOR_HAS_EMBELLISH_ANCESTOR(mFlags)) {
mEmbellishData.leadingSpace /= 2;
mEmbellishData.trailingSpace /= 2;
}
}
}
}
// If we are an accent without explicit lspace="." or rspace=".",
// we will ignore our default leading/trailing space
// lspace
//
// "Specifies the leading space appearing before the operator"
//
// values: length
// default: set by dictionary (thickmathspace)
//
// XXXfredw Support for negative and relative values is not implemented
// (bug 805926).
// Relative values will give a multiple of the current leading space,
// which is not necessarily the default one.
//
nscoord leadingSpace = mEmbellishData.leadingSpace;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::lspace_,
value);
if (!value.IsEmpty()) {
nsCSSValue cssValue;
if (nsMathMLElement::ParseNumericValue(value, cssValue, 0,
mContent->OwnerDoc())) {
if ((eCSSUnit_Number == cssValue.GetUnit()) && !cssValue.GetFloatValue())
leadingSpace = 0;
else if (cssValue.IsLengthUnit())
leadingSpace = CalcLength(presContext, mStyleContext, cssValue);
mFlags |= NS_MATHML_OPERATOR_LSPACE_ATTR;
}
}
// rspace
//
// "Specifies the trailing space appearing after the operator"
//
// values: length
// default: set by dictionary (thickmathspace)
//
// XXXfredw Support for negative and relative values is not implemented
// (bug 805926).
// Relative values will give a multiple of the current leading space,
// which is not necessarily the default one.
//
nscoord trailingSpace = mEmbellishData.trailingSpace;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::rspace_,
value);
if (!value.IsEmpty()) {
nsCSSValue cssValue;
if (nsMathMLElement::ParseNumericValue(value, cssValue, 0,
mContent->OwnerDoc())) {
if ((eCSSUnit_Number == cssValue.GetUnit()) && !cssValue.GetFloatValue())
trailingSpace = 0;
else if (cssValue.IsLengthUnit())
trailingSpace = CalcLength(presContext, mStyleContext, cssValue);
mFlags |= NS_MATHML_OPERATOR_RSPACE_ATTR;
}
}
// little extra tuning to round lspace & rspace to at least a pixel so that
// operators don't look as if they are colliding with their operands
if (leadingSpace || trailingSpace) {
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
if (leadingSpace && leadingSpace < onePixel)
leadingSpace = onePixel;
if (trailingSpace && trailingSpace < onePixel)
trailingSpace = onePixel;
}
// the values that we get from our attributes override the dictionary
mEmbellishData.leadingSpace = leadingSpace;
mEmbellishData.trailingSpace = trailingSpace;
// Now see if there are user-defined attributes that override the dictionary.
// XXX If an attribute can be forced to be true when it is false in the
// dictionary, then the following code has to change...
// For each attribute overriden by the user, turn off its bit flag.
// symmetric|movablelimits|separator|largeop|accent|fence|stretchy|form
// special: accent and movablelimits are handled above,
// don't process them here
GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::stretchy_, value);
if (value.EqualsLiteral("false")) {
mFlags &= ~NS_MATHML_OPERATOR_STRETCHY;
} else if (value.EqualsLiteral("true")) {
mFlags |= NS_MATHML_OPERATOR_STRETCHY;
}
if (NS_MATHML_OPERATOR_IS_FENCE(mFlags)) {
GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::fence_, value);
if (value.EqualsLiteral("false"))
mFlags &= ~NS_MATHML_OPERATOR_FENCE;
}
GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::largeop_, value);
if (value.EqualsLiteral("false")) {
mFlags &= ~NS_MATHML_OPERATOR_LARGEOP;
} else if (value.EqualsLiteral("true")) {
mFlags |= NS_MATHML_OPERATOR_LARGEOP;
}
if (NS_MATHML_OPERATOR_IS_SEPARATOR(mFlags)) {
GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::separator_, value);
if (value.EqualsLiteral("false"))
mFlags &= ~NS_MATHML_OPERATOR_SEPARATOR;
}
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::symmetric_,
value);
if (value.EqualsLiteral("false"))
mFlags &= ~NS_MATHML_OPERATOR_SYMMETRIC;
else if (value.EqualsLiteral("true"))
mFlags |= NS_MATHML_OPERATOR_SYMMETRIC;
// minsize
//
// "Specifies the minimum size of the operator when stretchy"
//
// values: length
// default: set by dictionary (1em)
//
// We don't allow negative values.
// Note: Contrary to other "length" values, unitless and percentage do not
// give a multiple of the defaut value but a multiple of the operator at
// normal size.
//
mMinSize = 0;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::minsize_,
value);
if (!value.IsEmpty()) {
nsCSSValue cssValue;
if (nsMathMLElement::ParseNumericValue(value, cssValue,
nsMathMLElement::
PARSE_ALLOW_UNITLESS,
mContent->OwnerDoc())) {
nsCSSUnit unit = cssValue.GetUnit();
if (eCSSUnit_Number == unit)
mMinSize = cssValue.GetFloatValue();
else if (eCSSUnit_Percent == unit)
mMinSize = cssValue.GetPercentValue();
else if (eCSSUnit_Null != unit) {
mMinSize = float(CalcLength(presContext, mStyleContext, cssValue));
mFlags |= NS_MATHML_OPERATOR_MINSIZE_ABSOLUTE;
}
}
}
// maxsize
//
// "Specifies the maximum size of the operator when stretchy"
//
// values: length | "infinity"
// default: set by dictionary (infinity)
//
// We don't allow negative values.
// Note: Contrary to other "length" values, unitless and percentage do not
// give a multiple of the defaut value but a multiple of the operator at
// normal size.
//
mMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::maxsize_,
value);
if (!value.IsEmpty()) {
nsCSSValue cssValue;
if (nsMathMLElement::ParseNumericValue(value, cssValue,
nsMathMLElement::
PARSE_ALLOW_UNITLESS,
mContent->OwnerDoc())) {
nsCSSUnit unit = cssValue.GetUnit();
if (eCSSUnit_Number == unit)
mMaxSize = cssValue.GetFloatValue();
else if (eCSSUnit_Percent == unit)
mMaxSize = cssValue.GetPercentValue();
else if (eCSSUnit_Null != unit) {
mMaxSize = float(CalcLength(presContext, mStyleContext, cssValue));
mFlags |= NS_MATHML_OPERATOR_MAXSIZE_ABSOLUTE;
}
}
}
}
static uint32_t
GetStretchHint(nsOperatorFlags aFlags, nsPresentationData aPresentationData,
bool aIsVertical)
{
uint32_t stretchHint = NS_STRETCH_NONE;
// See if it is okay to stretch,
// starting from what the Operator Dictionary said
if (NS_MATHML_OPERATOR_IS_MUTABLE(aFlags)) {
// set the largeop or largeopOnly flags to suitably cover all the
// 8 possible cases depending on whether displaystyle, largeop,
// stretchy are true or false (see bug 69325).
// . largeopOnly is taken if largeop=true and stretchy=false
// . largeop is taken if largeop=true and stretchy=true
if (NS_MATHML_IS_DISPLAYSTYLE(aPresentationData.flags) &&
NS_MATHML_OPERATOR_IS_LARGEOP(aFlags)) {
stretchHint = NS_STRETCH_LARGEOP; // (largeopOnly, not mask!)
if (NS_MATHML_OPERATOR_IS_INTEGRAL(aFlags)) {
stretchHint |= NS_STRETCH_INTEGRAL;
}
if (NS_MATHML_OPERATOR_IS_STRETCHY(aFlags)) {
stretchHint |= NS_STRETCH_NEARER | NS_STRETCH_LARGER;
}
}
else if(NS_MATHML_OPERATOR_IS_STRETCHY(aFlags)) {
if (aIsVertical) {
// TeX hint. Can impact some sloppy markups missing <mrow></mrow>
stretchHint = NS_STRETCH_NEARER;
}
else {
stretchHint = NS_STRETCH_NORMAL;
}
}
// else if the stretchy and largeop attributes have been disabled,
// the operator is not mutable
}
return stretchHint;
}
// NOTE: aDesiredStretchSize is an IN/OUT parameter
// On input - it contains our current size
// On output - the same size or the new size that we want
NS_IMETHODIMP
nsMathMLmoFrame::Stretch(nsRenderingContext& aRenderingContext,
nsStretchDirection aStretchDirection,
nsBoundingMetrics& aContainerSize,
nsHTMLReflowMetrics& aDesiredStretchSize)
{
if (NS_MATHML_STRETCH_WAS_DONE(mPresentationData.flags)) {
NS_WARNING("it is wrong to fire stretch more than once on a frame");
return NS_OK;
}
mPresentationData.flags |= NS_MATHML_STRETCH_DONE;
nsIFrame* firstChild = mFrames.FirstChild();
// get the axis height;
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
aRenderingContext.SetFont(fm);
nscoord axisHeight, height;
GetAxisHeight(aRenderingContext, fm, axisHeight);
// get the leading to be left at the top and the bottom of the stretched char
// this seems more reliable than using fm->GetLeading() on suspicious fonts
nscoord em;
GetEmHeight(fm, em);
nscoord leading = NSToCoordRound(0.2f * em);
// Operators that are stretchy, or those that are to be centered
// to cater for fonts that are not math-aware, are handled by the MathMLChar
// ('form' is reset if stretch fails -- i.e., we don't bother to stretch next time)
bool useMathMLChar = UseMathMLChar();
nsBoundingMetrics charSize;
nsBoundingMetrics container = aDesiredStretchSize.mBoundingMetrics;
bool isVertical = false;
if (((aStretchDirection == NS_STRETCH_DIRECTION_VERTICAL) ||
(aStretchDirection == NS_STRETCH_DIRECTION_DEFAULT)) &&
(mEmbellishData.direction == NS_STRETCH_DIRECTION_VERTICAL)) {
isVertical = true;
}
uint32_t stretchHint =
GetStretchHint(mFlags, mPresentationData, isVertical);
if (useMathMLChar) {
nsBoundingMetrics initialSize = aDesiredStretchSize.mBoundingMetrics;
if (stretchHint != NS_STRETCH_NONE) {
container = aContainerSize;
// some adjustments if the operator is symmetric and vertical
if (isVertical && NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags)) {
// we need to center about the axis
nscoord delta = std::max(container.ascent - axisHeight,
container.descent + axisHeight);
container.ascent = delta + axisHeight;
container.descent = delta - axisHeight;
// get ready in case we encounter user-desired min-max size
delta = std::max(initialSize.ascent - axisHeight,
initialSize.descent + axisHeight);
initialSize.ascent = delta + axisHeight;
initialSize.descent = delta - axisHeight;
}
// check for user-desired min-max size
if (mMaxSize != NS_MATHML_OPERATOR_SIZE_INFINITY && mMaxSize > 0.0f) {
// if we are here, there is a user defined maxsize ...
//XXX Set stretchHint = NS_STRETCH_NORMAL? to honor the maxsize as close as possible?
if (NS_MATHML_OPERATOR_MAXSIZE_IS_ABSOLUTE(mFlags)) {
// there is an explicit value like maxsize="20pt"
// try to maintain the aspect ratio of the char
float aspect = mMaxSize / float(initialSize.ascent + initialSize.descent);
container.ascent =
std::min(container.ascent, nscoord(initialSize.ascent * aspect));
container.descent =
std::min(container.descent, nscoord(initialSize.descent * aspect));
// below we use a type cast instead of a conversion to avoid a VC++ bug
// see http://support.microsoft.com/support/kb/articles/Q115/7/05.ASP
container.width =
std::min(container.width, (nscoord)mMaxSize);
}
else { // multiplicative value
container.ascent =
std::min(container.ascent, nscoord(initialSize.ascent * mMaxSize));
container.descent =
std::min(container.descent, nscoord(initialSize.descent * mMaxSize));
container.width =
std::min(container.width, nscoord(initialSize.width * mMaxSize));
}
if (isVertical && !NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags)) {
// re-adjust to align the char with the bottom of the initial container
height = container.ascent + container.descent;
container.descent = aContainerSize.descent;
container.ascent = height - container.descent;
}
}
if (mMinSize > 0.0f) {
// if we are here, there is a user defined minsize ...
// always allow the char to stretch in its natural direction,
// even if it is different from the caller's direction
if (aStretchDirection != NS_STRETCH_DIRECTION_DEFAULT &&
aStretchDirection != mEmbellishData.direction) {
aStretchDirection = NS_STRETCH_DIRECTION_DEFAULT;
// but when we are not honoring the requested direction
// we should not use the caller's container size either
container = initialSize;
}
if (NS_MATHML_OPERATOR_MINSIZE_IS_ABSOLUTE(mFlags)) {
// there is an explicit value like minsize="20pt"
// try to maintain the aspect ratio of the char
float aspect = mMinSize / float(initialSize.ascent + initialSize.descent);
container.ascent =
std::max(container.ascent, nscoord(initialSize.ascent * aspect));
container.descent =
std::max(container.descent, nscoord(initialSize.descent * aspect));
container.width =
std::max(container.width, (nscoord)mMinSize);
}
else { // multiplicative value
container.ascent =
std::max(container.ascent, nscoord(initialSize.ascent * mMinSize));
container.descent =
std::max(container.descent, nscoord(initialSize.descent * mMinSize));
container.width =
std::max(container.width, nscoord(initialSize.width * mMinSize));
}
if (isVertical && !NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags)) {
// re-adjust to align the char with the bottom of the initial container
height = container.ascent + container.descent;
container.descent = aContainerSize.descent;
container.ascent = height - container.descent;
}
}
}
// let the MathMLChar stretch itself...
nsresult res = mMathMLChar.Stretch(PresContext(), aRenderingContext,
aStretchDirection, container, charSize,
stretchHint,
NS_MATHML_IS_RTL(mPresentationData.
flags));
if (NS_FAILED(res)) {
// gracefully handle cases where stretching the char failed (i.e., GetBoundingMetrics failed)
// clear our 'form' to behave as if the operator wasn't in the dictionary
mFlags &= ~NS_MATHML_OPERATOR_FORM;
useMathMLChar = false;
}
}
// Child frames of invisble operators are not reflowed
if (!NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags)) {
// Place our children using the default method
// This will allow our child text frame to get its DidReflow()
nsresult rv = Place(aRenderingContext, true, aDesiredStretchSize);
if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
// Make sure the child frames get their DidReflow() calls.
DidReflowChildren(mFrames.FirstChild());
}
}
if (useMathMLChar) {
// update our bounding metrics... it becomes that of our MathML char
mBoundingMetrics = charSize;
// if the returned direction is 'unsupported', the char didn't actually change.
// So we do the centering only if necessary
if (mMathMLChar.GetStretchDirection() != NS_STRETCH_DIRECTION_UNSUPPORTED ||
NS_MATHML_OPERATOR_IS_CENTERED(mFlags)) {
bool largeopOnly =
(NS_STRETCH_LARGEOP & stretchHint) != 0 &&
(NS_STRETCH_VARIABLE_MASK & stretchHint) == 0;
if (isVertical || NS_MATHML_OPERATOR_IS_CENTERED(mFlags)) {
// the desired size returned by mMathMLChar maybe different
// from the size of the container.
// the mMathMLChar.mRect.y calculation is subtle, watch out!!!
height = mBoundingMetrics.ascent + mBoundingMetrics.descent;
if (NS_MATHML_OPERATOR_IS_SYMMETRIC(mFlags) ||
NS_MATHML_OPERATOR_IS_CENTERED(mFlags)) {
// For symmetric and vertical operators, or for operators that are always
// centered ('+', '*', etc) we want to center about the axis of the container
mBoundingMetrics.descent = height/2 - axisHeight;
} else if (!largeopOnly) {
// Align the center of the char with the center of the container
mBoundingMetrics.descent = height/2 +
(container.ascent + container.descent)/2 - container.ascent;
} // else align the baselines
mBoundingMetrics.ascent = height - mBoundingMetrics.descent;
}
}
}
// Fixup for the final height.
// On one hand, our stretchy height can sometimes be shorter than surrounding
// ASCII chars, e.g., arrow symbols have |mBoundingMetrics.ascent + leading|
// that is smaller than the ASCII's ascent, hence when painting the background
// later, it won't look uniform along the line.
// On the other hand, sometimes we may leave too much gap when our glyph happens
// to come from a font with tall glyphs. For example, since CMEX10 has very tall
// glyphs, its natural font metrics are large, even if we pick a small glyph
// whose size is comparable to the size of a normal ASCII glyph.
// So to avoid uneven spacing in either of these two cases, we use the height
// of the ASCII font as a reference and try to match it if possible.
// special case for accents... keep them short to improve mouse operations...
// an accent can only be the non-first child of <mover>, <munder>, <munderover>
bool isAccent =
NS_MATHML_EMBELLISH_IS_ACCENT(mEmbellishData.flags);
if (isAccent) {
nsEmbellishData parentData;
GetEmbellishDataFrom(mParent, parentData);
isAccent =
(NS_MATHML_EMBELLISH_IS_ACCENTOVER(parentData.flags) ||
NS_MATHML_EMBELLISH_IS_ACCENTUNDER(parentData.flags)) &&
parentData.coreFrame != this;
}
if (isAccent && firstChild) {
// see bug 188467 for what is going on here
nscoord dy = aDesiredStretchSize.ascent - (mBoundingMetrics.ascent + leading);
aDesiredStretchSize.ascent = mBoundingMetrics.ascent + leading;
aDesiredStretchSize.height = aDesiredStretchSize.ascent + mBoundingMetrics.descent;
firstChild->SetPosition(firstChild->GetPosition() - nsPoint(0, dy));
}
else if (useMathMLChar) {
nscoord ascent = fm->MaxAscent();
nscoord descent = fm->MaxDescent();
aDesiredStretchSize.ascent = std::max(mBoundingMetrics.ascent + leading, ascent);
aDesiredStretchSize.height = aDesiredStretchSize.ascent +
std::max(mBoundingMetrics.descent + leading, descent);
}
aDesiredStretchSize.width = mBoundingMetrics.width;
aDesiredStretchSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredStretchSize.ascent;
// Place our mMathMLChar, its origin is in our coordinate system
if (useMathMLChar) {
nscoord dy = aDesiredStretchSize.ascent - mBoundingMetrics.ascent;
mMathMLChar.SetRect(nsRect(0, dy, charSize.width, charSize.ascent + charSize.descent));
}
// Before we leave... there is a last item in the check-list:
// If our parent is not embellished, it means we are the outermost embellished
// container and so we put the spacing, otherwise we don't include the spacing,
// the outermost embellished container will take care of it.
if (!NS_MATHML_OPERATOR_HAS_EMBELLISH_ANCESTOR(mFlags)) {
// Account the spacing if we are not an accent with explicit attributes
nscoord leadingSpace = mEmbellishData.leadingSpace;
if (isAccent && !NS_MATHML_OPERATOR_HAS_LSPACE_ATTR(mFlags)) {
leadingSpace = 0;
}
nscoord trailingSpace = mEmbellishData.trailingSpace;
if (isAccent && !NS_MATHML_OPERATOR_HAS_RSPACE_ATTR(mFlags)) {
trailingSpace = 0;
}
mBoundingMetrics.width += leadingSpace + trailingSpace;
aDesiredStretchSize.width = mBoundingMetrics.width;
aDesiredStretchSize.mBoundingMetrics.width = mBoundingMetrics.width;
nscoord dx = (NS_MATHML_IS_RTL(mPresentationData.flags) ?
trailingSpace : leadingSpace);
if (dx) {
// adjust the offsets
mBoundingMetrics.leftBearing += dx;
mBoundingMetrics.rightBearing += dx;
aDesiredStretchSize.mBoundingMetrics.leftBearing += dx;
aDesiredStretchSize.mBoundingMetrics.rightBearing += dx;
if (useMathMLChar) {
nsRect rect;
mMathMLChar.GetRect(rect);
mMathMLChar.SetRect(nsRect(rect.x + dx, rect.y,
rect.width, rect.height));
}
else {
nsIFrame* childFrame = firstChild;
while (childFrame) {
childFrame->SetPosition(childFrame->GetPosition() +
nsPoint(dx, 0));
childFrame = childFrame->GetNextSibling();
}
}
}
}
// Finished with these:
ClearSavedChildMetrics();
// Set our overflow area
GatherAndStoreOverflow(&aDesiredStretchSize);
// There used to be code here to change the height of the child frame to
// change the caret height, but the text frame that manages the caret is now
// not a direct child but wrapped in a block frame. See also bug 412033.
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmoFrame::InheritAutomaticData(nsIFrame* aParent)
{
// retain our native direction, it only changes if our text content changes
nsStretchDirection direction = mEmbellishData.direction;
nsMathMLTokenFrame::InheritAutomaticData(aParent);
mEmbellishData.direction = direction;
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmoFrame::TransmitAutomaticData()
{
// this will cause us to re-sync our flags from scratch
// but our returned 'form' is still not final (bug 133429), it will
// be recomputed to its final value during the next call in Reflow()
mEmbellishData.coreFrame = nullptr;
ProcessOperatorData();
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmoFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
// certain values use units that depend on our style context, so
// it is safer to just process the whole lot here
ProcessOperatorData();
// play safe by not passing invisible operators to the font subsystem because
// some platforms risk selecting strange glyphs for them and give bad inter-space
if (NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags)) {
// return empty space for now, but this is not yet final since there
// can be lspace and rspace attributes that reclaim some room.
// These will be dealt with later in Stretch().
aDesiredSize.width = 0;
aDesiredSize.height = 0;
aDesiredSize.ascent = 0;
aDesiredSize.mBoundingMetrics = nsBoundingMetrics();
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
return nsMathMLTokenFrame::Reflow(aPresContext, aDesiredSize,
aReflowState, aStatus);
}
/* virtual */ void
nsMathMLmoFrame::MarkIntrinsicWidthsDirty()
{
// if we get this, it may mean that something changed in the text
// content. So blow away everything an re-build the automatic data
// from the parent of our outermost embellished container (we ensure
// that we are the core, not just a sibling of the core)
ProcessTextData();
nsIFrame* target = this;
nsEmbellishData embellishData;
do {
target = target->GetParent();
GetEmbellishDataFrom(target, embellishData);
} while (embellishData.coreFrame == this);
// we have automatic data to update in the children of the target frame
// XXXldb This should really be marking dirty rather than rebuilding
// so that we don't rebuild multiple times for the same change.
RebuildAutomaticDataForChildren(target);
nsMathMLContainerFrame::MarkIntrinsicWidthsDirty();
}
/* virtual */ nscoord
nsMathMLmoFrame::GetIntrinsicWidth(nsRenderingContext *aRenderingContext)
{
ProcessOperatorData();
nscoord width;
if (UseMathMLChar()) {
uint32_t stretchHint = GetStretchHint(mFlags, mPresentationData, true);
width = mMathMLChar.
GetMaxWidth(PresContext(), *aRenderingContext,
stretchHint, mMaxSize,
NS_MATHML_OPERATOR_MAXSIZE_IS_ABSOLUTE(mFlags));
}
else {
width = nsMathMLTokenFrame::GetIntrinsicWidth(aRenderingContext);
}
// leadingSpace and trailingSpace are actually applied to the outermost
// embellished container but for determining total intrinsic width it should
// be safe to include it for the core here instead.
width += mEmbellishData.leadingSpace + mEmbellishData.trailingSpace;
return width;
}
NS_IMETHODIMP
nsMathMLmoFrame::AttributeChanged(int32_t aNameSpaceID,
nsIAtom* aAttribute,
int32_t aModType)
{
// check if this is an attribute that can affect the embellished hierarchy
// in a significant way and re-layout the entire hierarchy.
if (nsGkAtoms::accent_ == aAttribute ||
nsGkAtoms::movablelimits_ == aAttribute) {
// set the target as the parent of our outermost embellished container
// (we ensure that we are the core, not just a sibling of the core)
nsIFrame* target = this;
nsEmbellishData embellishData;
do {
target = target->GetParent();
GetEmbellishDataFrom(target, embellishData);
} while (embellishData.coreFrame == this);
// we have automatic data to update in the children of the target frame
return ReLayoutChildren(target);
}
return nsMathMLTokenFrame::
AttributeChanged(aNameSpaceID, aAttribute, aModType);
}
// ----------------------
// No need to track the style context given to our MathML char.
// the Style System will use these to pass the proper style context to our MathMLChar
nsStyleContext*
nsMathMLmoFrame::GetAdditionalStyleContext(int32_t aIndex) const
{
switch (aIndex) {
case NS_MATHML_CHAR_STYLE_CONTEXT_INDEX:
return mMathMLChar.GetStyleContext();
default:
return nullptr;
}
}
void
nsMathMLmoFrame::SetAdditionalStyleContext(int32_t aIndex,
nsStyleContext* aStyleContext)
{
switch (aIndex) {
case NS_MATHML_CHAR_STYLE_CONTEXT_INDEX:
mMathMLChar.SetStyleContext(aStyleContext);
break;
}
}
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