gecko/layout/mathml/nsMathMLTokenFrame.cpp

352 lines
12 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 "nsMathMLTokenFrame.h"
#include "nsPresContext.h"
#include "nsContentUtils.h"
#include "nsTextFrame.h"
#include "RestyleManager.h"
#include <algorithm>
nsIFrame*
NS_NewMathMLTokenFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsMathMLTokenFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLTokenFrame)
nsMathMLTokenFrame::~nsMathMLTokenFrame()
{
}
NS_IMETHODIMP
nsMathMLTokenFrame::InheritAutomaticData(nsIFrame* aParent)
{
// let the base class get the default from our parent
nsMathMLContainerFrame::InheritAutomaticData(aParent);
ProcessTextData();
return NS_OK;
}
eMathMLFrameType
nsMathMLTokenFrame::GetMathMLFrameType()
{
// treat everything other than <mi> as ordinary...
if (mContent->Tag() != nsGkAtoms::mi_) {
return eMathMLFrameType_Ordinary;
}
// for <mi>, distinguish between italic and upright...
nsAutoString style;
// mathvariant overrides fontstyle
// http://www.w3.org/TR/2003/REC-MathML2-20031021/chapter3.html#presm.deprecatt
mContent->GetAttr(kNameSpaceID_None,
nsGkAtoms::_moz_math_fontstyle_, style) ||
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::mathvariant_,
style) ||
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::fontstyle_,
style);
if (style.EqualsLiteral("italic") || style.EqualsLiteral("bold-italic") ||
style.EqualsLiteral("script") || style.EqualsLiteral("bold-script") ||
style.EqualsLiteral("sans-serif-italic") ||
style.EqualsLiteral("sans-serif-bold-italic")) {
return eMathMLFrameType_ItalicIdentifier;
}
else if(style.EqualsLiteral("invariant")) {
nsAutoString data;
nsContentUtils::GetNodeTextContent(mContent, false, data);
data.CompressWhitespace();
eMATHVARIANT variant = nsMathMLOperators::LookupInvariantChar(data);
switch (variant) {
case eMATHVARIANT_italic:
case eMATHVARIANT_bold_italic:
case eMATHVARIANT_script:
case eMATHVARIANT_bold_script:
case eMATHVARIANT_sans_serif_italic:
case eMATHVARIANT_sans_serif_bold_italic:
return eMathMLFrameType_ItalicIdentifier;
default:
; // fall through to upright
}
}
return eMathMLFrameType_UprightIdentifier;
}
void
nsMathMLTokenFrame::MarkTextFramesAsTokenMathML()
{
// Set flags on child text frames to force them to trim their leading and
// trailing whitespaces.
for (nsIFrame* childFrame = GetFirstPrincipalChild(); childFrame;
childFrame = childFrame->GetNextSibling()) {
for (nsIFrame* childFrame2 = childFrame->GetFirstPrincipalChild();
childFrame2; childFrame2 = childFrame2->GetNextSibling()) {
if (childFrame2->GetType() == nsGkAtoms::textFrame) {
childFrame2->AddStateBits(TEXT_IS_IN_TOKEN_MATHML);
}
}
}
}
NS_IMETHODIMP
nsMathMLTokenFrame::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;
MarkTextFramesAsTokenMathML();
ProcessTextData();
return rv;
}
NS_IMETHODIMP
nsMathMLTokenFrame::AppendFrames(ChildListID aListID,
nsFrameList& aChildList)
{
nsresult rv = nsMathMLContainerFrame::AppendFrames(aListID, aChildList);
if (NS_FAILED(rv))
return rv;
MarkTextFramesAsTokenMathML();
return rv;
}
NS_IMETHODIMP
nsMathMLTokenFrame::InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aChildList)
{
nsresult rv = nsMathMLContainerFrame::InsertFrames(aListID, aPrevFrame,
aChildList);
if (NS_FAILED(rv))
return rv;
MarkTextFramesAsTokenMathML();
return rv;
}
nsresult
nsMathMLTokenFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
nsresult rv = NS_OK;
// initializations needed for empty markup like <mtag></mtag>
aDesiredSize.width = aDesiredSize.height = 0;
aDesiredSize.ascent = 0;
aDesiredSize.mBoundingMetrics = nsBoundingMetrics();
nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
nsIFrame* childFrame = GetFirstPrincipalChild();
while (childFrame) {
// ask our children to compute their bounding metrics
nsHTMLReflowMetrics childDesiredSize(aDesiredSize.mFlags
| NS_REFLOW_CALC_BOUNDING_METRICS);
nsHTMLReflowState childReflowState(aPresContext, aReflowState,
childFrame, availSize);
rv = ReflowChild(childFrame, aPresContext, childDesiredSize,
childReflowState, aStatus);
//NS_ASSERTION(NS_FRAME_IS_COMPLETE(aStatus), "bad status");
if (NS_FAILED(rv)) {
// Call DidReflow() for the child frames we successfully did reflow.
DidReflowChildren(GetFirstPrincipalChild(), childFrame);
return rv;
}
SaveReflowAndBoundingMetricsFor(childFrame, childDesiredSize,
childDesiredSize.mBoundingMetrics);
childFrame = childFrame->GetNextSibling();
}
// place and size children
FinalizeReflow(*aReflowState.rendContext, aDesiredSize);
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
// For token elements, mBoundingMetrics is computed at the ReflowToken
// pass, it is not computed here because our children may be text frames
// that do not implement the GetBoundingMetrics() interface.
/* virtual */ nsresult
nsMathMLTokenFrame::Place(nsRenderingContext& aRenderingContext,
bool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
mBoundingMetrics = nsBoundingMetrics();
for (nsIFrame* childFrame = GetFirstPrincipalChild(); childFrame;
childFrame = childFrame->GetNextSibling()) {
nsHTMLReflowMetrics childSize;
GetReflowAndBoundingMetricsFor(childFrame, childSize,
childSize.mBoundingMetrics, nullptr);
// compute and cache the bounding metrics
mBoundingMetrics += childSize.mBoundingMetrics;
}
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
nscoord ascent = fm->MaxAscent();
nscoord descent = fm->MaxDescent();
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.ascent = std::max(mBoundingMetrics.ascent, ascent);
aDesiredSize.height = aDesiredSize.ascent +
std::max(mBoundingMetrics.descent, descent);
if (aPlaceOrigin) {
nscoord dy, dx = 0;
for (nsIFrame* childFrame = GetFirstPrincipalChild(); childFrame;
childFrame = childFrame->GetNextSibling()) {
nsHTMLReflowMetrics childSize;
GetReflowAndBoundingMetricsFor(childFrame, childSize,
childSize.mBoundingMetrics);
// place and size the child; (dx,0) makes the caret happy - bug 188146
dy = childSize.height == 0 ? 0 : aDesiredSize.ascent - childSize.ascent;
FinishReflowChild(childFrame, PresContext(), nullptr, childSize, dx, dy, 0);
dx += childSize.width;
}
}
SetReference(nsPoint(0, aDesiredSize.ascent));
return NS_OK;
}
/* virtual */ void
nsMathMLTokenFrame::MarkIntrinsicWidthsDirty()
{
// this could be called due to changes in the nsTextFrame beneath us
// when something changed in the text content. So re-process our text
ProcessTextData();
nsMathMLContainerFrame::MarkIntrinsicWidthsDirty();
}
void
nsMathMLTokenFrame::ProcessTextData()
{
// see if the style changes from normal to italic or vice-versa
if (!SetTextStyle())
return;
// explicitly request a re-resolve to pick up the change of style
PresContext()->RestyleManager()->
PostRestyleEvent(mContent->AsElement(), eRestyle_Subtree, NS_STYLE_HINT_NONE);
}
///////////////////////////////////////////////////////////////////////////
// For <mi>, if the content is not a single character, turn the font to
// normal (this function will also query attributes from the mstyle hierarchy)
// Returns true if there is a style change.
//
// http://www.w3.org/TR/2003/REC-MathML2-20031021/chapter3.html#presm.commatt
//
// "It is important to note that only certain combinations of
// character data and mathvariant attribute values make sense.
// ...
// By design, the only cases that have an unambiguous
// interpretation are exactly the ones that correspond to SMP Math
// Alphanumeric Symbol characters, which are enumerated in Section
// 6.2.3 Mathematical Alphanumeric Symbols Characters. In all other
// cases, it is suggested that renderers ignore the value of the
// mathvariant attribute if it is present."
//
// There are no corresponding characters for mathvariant=normal, suggesting
// that this value should be ignored, but this (from the same section of
// Chapter 3) implies that font-style should not be inherited, but set to
// normal for mathvariant=normal:
//
// "In particular, inheritance of the mathvariant attribute does not follow
// the CSS model. The default value for this attribute is "normal"
// (non-slanted) for all tokens except mi. ... (The deprecated fontslant
// attribute also behaves this way.)"
bool
nsMathMLTokenFrame::SetTextStyle()
{
if (mContent->Tag() != nsGkAtoms::mi_)
return false;
if (!mFrames.FirstChild())
return false;
// Get the text content that we enclose and its length
nsAutoString data;
nsContentUtils::GetNodeTextContent(mContent, false, data);
data.CompressWhitespace();
int32_t length = data.Length();
if (!length)
return false;
nsAutoString fontstyle;
bool isSingleCharacter =
length == 1 ||
(length == 2 && NS_IS_HIGH_SURROGATE(data[0]));
if (isSingleCharacter &&
nsMathMLOperators::LookupInvariantChar(data) != eMATHVARIANT_NONE) {
// bug 65951 - a non-stylable character has its own intrinsic appearance
fontstyle.AssignLiteral("invariant");
}
else {
// Attributes override the default behavior.
nsAutoString value;
if (!(GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::mathvariant_, value) ||
GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::fontstyle_, value))) {
if (!isSingleCharacter) {
fontstyle.AssignLiteral("normal");
}
else if (length == 1 && // BMP
!nsMathMLOperators::
TransformVariantChar(data[0], eMATHVARIANT_italic).
Equals(data)) {
// Transformation exists. Try to make the BMP character look like the
// styled character using the style system until bug 114365 is resolved.
fontstyle.AssignLiteral("italic");
}
// else single character but there is no corresponding Math Alphanumeric
// Symbol character: "ignore the value of the [default] mathvariant
// attribute".
}
}
// set the _moz-math-font-style attribute without notifying that we want a reflow
if (fontstyle.IsEmpty()) {
if (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::_moz_math_fontstyle_)) {
mContent->UnsetAttr(kNameSpaceID_None, nsGkAtoms::_moz_math_fontstyle_,
false);
return true;
}
}
else if (!mContent->AttrValueIs(kNameSpaceID_None,
nsGkAtoms::_moz_math_fontstyle_,
fontstyle, eCaseMatters)) {
mContent->SetAttr(kNameSpaceID_None, nsGkAtoms::_moz_math_fontstyle_,
fontstyle, false);
return true;
}
return false;
}