pjs/layout/mathml/nsMathMLFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* 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 Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Roger B. Sidje <rbs@maths.uq.edu.au>
* Frederic Wang <fred.wang@free.fr>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsINameSpaceManager.h"
#include "nsMathMLFrame.h"
#include "nsMathMLChar.h"
#include "nsCSSPseudoElements.h"
// used to map attributes into CSS rules
#include "nsStyleSet.h"
#include "nsAutoPtr.h"
#include "nsDisplayList.h"
#include "nsRenderingContext.h"
eMathMLFrameType
nsMathMLFrame::GetMathMLFrameType()
{
// see if it is an embellished operator (mapped to 'Op' in TeX)
if (mEmbellishData.coreFrame)
return GetMathMLFrameTypeFor(mEmbellishData.coreFrame);
// if it has a prescribed base, fetch the type from there
if (mPresentationData.baseFrame)
return GetMathMLFrameTypeFor(mPresentationData.baseFrame);
// everything else is treated as ordinary (mapped to 'Ord' in TeX)
return eMathMLFrameType_Ordinary;
}
// snippet of code used by <mstyle>, <mtable> and <math> which are the only
// three tags where the displaystyle attribute is allowed by the spec.
/* static */ void
nsMathMLFrame::FindAttrDisplaystyle(nsIContent* aContent,
nsPresentationData& aPresentationData)
{
NS_ASSERTION(aContent->Tag() == nsGkAtoms::mstyle_ ||
aContent->Tag() == nsGkAtoms::mtable_ ||
aContent->Tag() == nsGkAtoms::math, "bad caller");
static nsIContent::AttrValuesArray strings[] =
{&nsGkAtoms::_false, &nsGkAtoms::_true, nsnull};
// see if the explicit displaystyle attribute is there
switch (aContent->FindAttrValueIn(kNameSpaceID_None,
nsGkAtoms::displaystyle_, strings, eCaseMatters)) {
case 0:
aPresentationData.flags &= ~NS_MATHML_DISPLAYSTYLE;
aPresentationData.flags |= NS_MATHML_EXPLICIT_DISPLAYSTYLE;
break;
case 1:
aPresentationData.flags |= NS_MATHML_DISPLAYSTYLE;
aPresentationData.flags |= NS_MATHML_EXPLICIT_DISPLAYSTYLE;
break;
}
// no reset if the attr isn't found. so be sure to call it on inherited flags
}
// snippet of code used by the tags where the dir attribute is allowed.
/* static */ void
nsMathMLFrame::FindAttrDirectionality(nsIContent* aContent,
nsPresentationData& aPresentationData)
{
NS_ASSERTION(aContent->Tag() == nsGkAtoms::math ||
aContent->Tag() == nsGkAtoms::mrow_ ||
aContent->Tag() == nsGkAtoms::mstyle_ ||
aContent->Tag() == nsGkAtoms::mi_ ||
aContent->Tag() == nsGkAtoms::mn_ ||
aContent->Tag() == nsGkAtoms::mo_ ||
aContent->Tag() == nsGkAtoms::mtext_ ||
aContent->Tag() == nsGkAtoms::ms_, "bad caller");
static nsIContent::AttrValuesArray strings[] =
{&nsGkAtoms::ltr, &nsGkAtoms::rtl, nsnull};
// see if the explicit dir attribute is there
switch (aContent->FindAttrValueIn(kNameSpaceID_None,
nsGkAtoms::dir, strings, eCaseMatters))
{
case 0:
aPresentationData.flags &= ~NS_MATHML_RTL;
break;
case 1:
aPresentationData.flags |= NS_MATHML_RTL;
break;
}
// no reset if the attr isn't found. so be sure to call it on inherited flags
}
NS_IMETHODIMP
nsMathMLFrame::InheritAutomaticData(nsIFrame* aParent)
{
mEmbellishData.flags = 0;
mEmbellishData.coreFrame = nsnull;
mEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
mEmbellishData.leadingSpace = 0;
mEmbellishData.trailingSpace = 0;
mPresentationData.flags = 0;
mPresentationData.baseFrame = nsnull;
mPresentationData.mstyle = nsnull;
// by default, just inherit the display of our parent
nsPresentationData parentData;
GetPresentationDataFrom(aParent, parentData);
mPresentationData.mstyle = parentData.mstyle;
if (NS_MATHML_IS_DISPLAYSTYLE(parentData.flags)) {
mPresentationData.flags |= NS_MATHML_DISPLAYSTYLE;
}
if (NS_MATHML_IS_RTL(parentData.flags)) {
mPresentationData.flags |= NS_MATHML_RTL;
}
#if defined(NS_DEBUG) && defined(SHOW_BOUNDING_BOX)
mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
#endif
return NS_OK;
}
NS_IMETHODIMP
nsMathMLFrame::UpdatePresentationData(PRUint32 aFlagsValues,
PRUint32 aWhichFlags)
{
NS_ASSERTION(NS_MATHML_IS_DISPLAYSTYLE(aWhichFlags) ||
NS_MATHML_IS_COMPRESSED(aWhichFlags),
"aWhichFlags should only be displaystyle or compression flag");
// update flags that are relevant to this call
if (NS_MATHML_IS_DISPLAYSTYLE(aWhichFlags)) {
// updating the displaystyle flag is allowed
if (NS_MATHML_IS_DISPLAYSTYLE(aFlagsValues)) {
mPresentationData.flags |= NS_MATHML_DISPLAYSTYLE;
}
else {
mPresentationData.flags &= ~NS_MATHML_DISPLAYSTYLE;
}
}
if (NS_MATHML_IS_COMPRESSED(aWhichFlags)) {
// updating the compression flag is allowed
if (NS_MATHML_IS_COMPRESSED(aFlagsValues)) {
// 'compressed' means 'prime' style in App. G, TeXbook
mPresentationData.flags |= NS_MATHML_COMPRESSED;
}
// no else. the flag is sticky. it retains its value once it is set
}
return NS_OK;
}
// Helper to give a style context suitable for doing the stretching of
// a MathMLChar. Frame classes that use this should ensure that the
// extra leaf style contexts given to the MathMLChars are accessible to
// the Style System via the Get/Set AdditionalStyleContext() APIs.
/* static */ void
nsMathMLFrame::ResolveMathMLCharStyle(nsPresContext* aPresContext,
nsIContent* aContent,
nsStyleContext* aParentStyleContext,
nsMathMLChar* aMathMLChar,
bool aIsMutableChar)
{
nsCSSPseudoElements::Type pseudoType = (aIsMutableChar) ?
nsCSSPseudoElements::ePseudo_mozMathStretchy :
nsCSSPseudoElements::ePseudo_mozMathAnonymous; // savings
nsRefPtr<nsStyleContext> newStyleContext;
newStyleContext = aPresContext->StyleSet()->
ResolvePseudoElementStyle(aContent->AsElement(), pseudoType,
aParentStyleContext);
if (newStyleContext)
aMathMLChar->SetStyleContext(newStyleContext);
}
/* static */ void
nsMathMLFrame::GetEmbellishDataFrom(nsIFrame* aFrame,
nsEmbellishData& aEmbellishData)
{
// initialize OUT params
aEmbellishData.flags = 0;
aEmbellishData.coreFrame = nsnull;
aEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
aEmbellishData.leadingSpace = 0;
aEmbellishData.trailingSpace = 0;
if (aFrame && aFrame->IsFrameOfType(nsIFrame::eMathML)) {
nsIMathMLFrame* mathMLFrame = do_QueryFrame(aFrame);
if (mathMLFrame) {
mathMLFrame->GetEmbellishData(aEmbellishData);
}
}
}
// helper to get the presentation data of a frame, by possibly walking up
// the frame hierarchy if we happen to be surrounded by non-MathML frames.
/* static */ void
nsMathMLFrame::GetPresentationDataFrom(nsIFrame* aFrame,
nsPresentationData& aPresentationData,
bool aClimbTree)
{
// initialize OUT params
aPresentationData.flags = 0;
aPresentationData.baseFrame = nsnull;
aPresentationData.mstyle = nsnull;
nsIFrame* frame = aFrame;
while (frame) {
if (frame->IsFrameOfType(nsIFrame::eMathML)) {
nsIMathMLFrame* mathMLFrame = do_QueryFrame(frame);
if (mathMLFrame) {
mathMLFrame->GetPresentationData(aPresentationData);
break;
}
}
// stop if the caller doesn't want to lookup beyond the frame
if (!aClimbTree) {
break;
}
// stop if we reach the root <math> tag
nsIContent* content = frame->GetContent();
NS_ASSERTION(content || !frame->GetParent(), // no assert for the root
"dangling frame without a content node");
if (!content)
break;
if (content->Tag() == nsGkAtoms::math) {
const nsStyleDisplay* display = frame->GetStyleDisplay();
if (display->mDisplay == NS_STYLE_DISPLAY_BLOCK) {
aPresentationData.flags |= NS_MATHML_DISPLAYSTYLE;
}
FindAttrDisplaystyle(content, aPresentationData);
FindAttrDirectionality(content, aPresentationData);
aPresentationData.mstyle = frame->GetFirstContinuation();
break;
}
frame = frame->GetParent();
}
NS_WARN_IF_FALSE(frame && frame->GetContent(),
"bad MathML markup - could not find the top <math> element");
}
// helper to get an attribute from the content or the surrounding <mstyle> hierarchy
/* static */ bool
nsMathMLFrame::GetAttribute(nsIContent* aContent,
nsIFrame* aMathMLmstyleFrame,
nsIAtom* aAttributeAtom,
nsString& aValue)
{
// see if we can get the attribute from the content
if (aContent && aContent->GetAttr(kNameSpaceID_None, aAttributeAtom,
aValue)) {
return true;
}
// see if we can get the attribute from the mstyle frame
if (!aMathMLmstyleFrame) {
return false;
}
nsIFrame* mstyleParent = aMathMLmstyleFrame->GetParent();
nsPresentationData mstyleParentData;
mstyleParentData.mstyle = nsnull;
if (mstyleParent) {
nsIMathMLFrame* mathMLFrame = do_QueryFrame(mstyleParent);
if (mathMLFrame) {
mathMLFrame->GetPresentationData(mstyleParentData);
}
}
// recurse all the way up into the <mstyle> hierarchy
return GetAttribute(aMathMLmstyleFrame->GetContent(),
mstyleParentData.mstyle, aAttributeAtom, aValue);
}
/* static */ void
nsMathMLFrame::GetRuleThickness(nsRenderingContext& aRenderingContext,
nsFontMetrics* aFontMetrics,
nscoord& aRuleThickness)
{
// get the bounding metrics of the overbar char, the rendering context
// is assumed to have been set with the font of the current style context
NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
Equals(aFontMetrics->Font()),
"unexpected state");
nscoord xHeight = aFontMetrics->XHeight();
PRUnichar overBar = 0x00AF;
nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&overBar, 1);
aRuleThickness = bm.ascent + bm.descent;
if (aRuleThickness <= 0 || aRuleThickness >= xHeight) {
// fall-back to the other version
GetRuleThickness(aFontMetrics, aRuleThickness);
}
}
/* static */ void
nsMathMLFrame::GetAxisHeight(nsRenderingContext& aRenderingContext,
nsFontMetrics* aFontMetrics,
nscoord& aAxisHeight)
{
// get the bounding metrics of the minus sign, the rendering context
// is assumed to have been set with the font of the current style context
NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
Equals(aFontMetrics->Font()),
"unexpected state");
nscoord xHeight = aFontMetrics->XHeight();
PRUnichar minus = 0x2212; // not '-', but official Unicode minus sign
nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&minus, 1);
aAxisHeight = bm.ascent - (bm.ascent + bm.descent)/2;
if (aAxisHeight <= 0 || aAxisHeight >= xHeight) {
// fall-back to the other version
GetAxisHeight(aFontMetrics, aAxisHeight);
}
}
/* static */ nscoord
nsMathMLFrame::CalcLength(nsPresContext* aPresContext,
nsStyleContext* aStyleContext,
const nsCSSValue& aCSSValue)
{
NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");
if (aCSSValue.IsFixedLengthUnit()) {
return aCSSValue.GetFixedLength(aPresContext);
}
if (aCSSValue.IsPixelLengthUnit()) {
return aCSSValue.GetPixelLength();
}
nsCSSUnit unit = aCSSValue.GetUnit();
if (eCSSUnit_EM == unit) {
const nsStyleFont* font = aStyleContext->GetStyleFont();
return NSToCoordRound(aCSSValue.GetFloatValue() * (float)font->mFont.size);
}
else if (eCSSUnit_XHeight == unit) {
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForStyleContext(aStyleContext,
getter_AddRefs(fm));
nscoord xHeight = fm->XHeight();
return NSToCoordRound(aCSSValue.GetFloatValue() * (float)xHeight);
}
// MathML doesn't specify other CSS units such as rem or ch
NS_ERROR("Unsupported unit");
return 0;
}
/* static */ bool
nsMathMLFrame::ParseNamedSpaceValue(nsIFrame* aMathMLmstyleFrame,
nsString& aString,
nsCSSValue& aCSSValue)
{
aCSSValue.Reset();
aString.CompressWhitespace(); // aString is not a const in this code...
if (!aString.Length()) return false;
// See if it is one of the 'namedspace' (ranging 1/18em...7/18em)
PRInt32 i = 0;
nsIAtom* namedspaceAtom = nsnull;
if (aString.EqualsLiteral("veryverythinmathspace")) {
i = 1;
namedspaceAtom = nsGkAtoms::veryverythinmathspace_;
}
else if (aString.EqualsLiteral("verythinmathspace")) {
i = 2;
namedspaceAtom = nsGkAtoms::verythinmathspace_;
}
else if (aString.EqualsLiteral("thinmathspace")) {
i = 3;
namedspaceAtom = nsGkAtoms::thinmathspace_;
}
else if (aString.EqualsLiteral("mediummathspace")) {
i = 4;
namedspaceAtom = nsGkAtoms::mediummathspace_;
}
else if (aString.EqualsLiteral("thickmathspace")) {
i = 5;
namedspaceAtom = nsGkAtoms::thickmathspace_;
}
else if (aString.EqualsLiteral("verythickmathspace")) {
i = 6;
namedspaceAtom = nsGkAtoms::verythickmathspace_;
}
else if (aString.EqualsLiteral("veryverythickmathspace")) {
i = 7;
namedspaceAtom = nsGkAtoms::veryverythickmathspace_;
}
else if (aString.EqualsLiteral("negativeveryverythinmathspace")) {
i = -1;
namedspaceAtom = nsGkAtoms::negativeveryverythinmathspace_;
}
else if (aString.EqualsLiteral("negativeverythinmathspace")) {
i = -2;
namedspaceAtom = nsGkAtoms::negativeverythinmathspace_;
}
else if (aString.EqualsLiteral("negativethinmathspace")) {
i = -3;
namedspaceAtom = nsGkAtoms::negativethinmathspace_;
}
else if (aString.EqualsLiteral("negativemediummathspace")) {
i = -4;
namedspaceAtom = nsGkAtoms::negativemediummathspace_;
}
else if (aString.EqualsLiteral("negativethickmathspace")) {
i = -5;
namedspaceAtom = nsGkAtoms::negativethickmathspace_;
}
else if (aString.EqualsLiteral("negativeverythickmathspace")) {
i = -6;
namedspaceAtom = nsGkAtoms::negativeverythickmathspace_;
}
else if (aString.EqualsLiteral("negativeveryverythickmathspace")) {
i = -7;
namedspaceAtom = nsGkAtoms::negativeveryverythickmathspace_;
}
if (0 != i) {
if (aMathMLmstyleFrame) {
// see if there is a <mstyle> that has overriden the default value
// GetAttribute() will recurse all the way up into the <mstyle> hierarchy
nsAutoString value;
GetAttribute(nsnull, aMathMLmstyleFrame, namedspaceAtom, value);
if (!value.IsEmpty()) {
if (ParseNumericValue(value, aCSSValue) &&
aCSSValue.IsLengthUnit()) {
return true;
}
}
}
// fall back to the default value
aCSSValue.SetFloatValue(float(i)/float(18), eCSSUnit_EM);
return true;
}
return false;
}
// ================
// Utils to map attributes into CSS rules (work-around to bug 69409 which
// is not scheduled to be fixed anytime soon)
//
static const PRInt32 kMathMLversion1 = 1;
static const PRInt32 kMathMLversion2 = 2;
struct
nsCSSMapping {
PRInt32 compatibility;
const nsIAtom* attrAtom;
const char* cssProperty;
};
#if defined(NS_DEBUG) && defined(SHOW_BOUNDING_BOX)
class nsDisplayMathMLBoundingMetrics : public nsDisplayItem {
public:
nsDisplayMathMLBoundingMetrics(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const nsRect& aRect)
: nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
MOZ_COUNT_CTOR(nsDisplayMathMLBoundingMetrics);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayMathMLBoundingMetrics() {
MOZ_COUNT_DTOR(nsDisplayMathMLBoundingMetrics);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx);
NS_DISPLAY_DECL_NAME("MathMLBoundingMetrics", TYPE_MATHML_BOUNDING_METRICS)
private:
nsRect mRect;
};
void nsDisplayMathMLBoundingMetrics::Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx)
{
aCtx->SetColor(NS_RGB(0,0,255));
aCtx->DrawRect(mRect + ToReferenceFrame());
}
nsresult
nsMathMLFrame::DisplayBoundingMetrics(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const nsPoint& aPt,
const nsBoundingMetrics& aMetrics,
const nsDisplayListSet& aLists) {
if (!NS_MATHML_PAINT_BOUNDING_METRICS(mPresentationData.flags))
return NS_OK;
nscoord x = aPt.x + aMetrics.leftBearing;
nscoord y = aPt.y - aMetrics.ascent;
nscoord w = aMetrics.rightBearing - aMetrics.leftBearing;
nscoord h = aMetrics.ascent + aMetrics.descent;
return aLists.Content()->AppendNewToTop(new (aBuilder)
nsDisplayMathMLBoundingMetrics(aBuilder, this, nsRect(x,y,w,h)));
}
#endif
class nsDisplayMathMLBar : public nsDisplayItem {
public:
nsDisplayMathMLBar(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const nsRect& aRect)
: nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
MOZ_COUNT_CTOR(nsDisplayMathMLBar);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayMathMLBar() {
MOZ_COUNT_DTOR(nsDisplayMathMLBar);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx);
NS_DISPLAY_DECL_NAME("MathMLBar", TYPE_MATHML_BAR)
private:
nsRect mRect;
};
void nsDisplayMathMLBar::Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx)
{
// paint the bar with the current text color
aCtx->SetColor(mFrame->GetVisitedDependentColor(eCSSProperty_color));
aCtx->FillRect(mRect + ToReferenceFrame());
}
nsresult
nsMathMLFrame::DisplayBar(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const nsRect& aRect,
const nsDisplayListSet& aLists) {
if (!aFrame->GetStyleVisibility()->IsVisible() || aRect.IsEmpty())
return NS_OK;
return aLists.Content()->AppendNewToTop(new (aBuilder)
nsDisplayMathMLBar(aBuilder, aFrame, aRect));
}