gecko-dev/layout/mathml/nsMathMLFrame.cpp
L. David Baron d2b6891283 Switch lots of callers to using nsLayoutUtils::GetFontMetricsForFrame and nsLayoutUtils::GetFontMetricsForStyleContext. (Bug 678671, patch 1) r=roc
This changes a number of callers that were previously bypassing the use
of the correct language (with either no language or the charset-detected
language on the pres context via nsPresContext::GetMetricsFor) and/or
the correct user font set to pass the correct values, which should
improve the correctness of the behavior of whatever they were using the
fonts for, and also reduce the number of unique sets of font metrics
requested (which helps nsFontCache effectiveness).
2011-08-14 10:08:04 -07:00

533 lines
18 KiB
C++

/* -*- 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>
*
* 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
}
NS_IMETHODIMP
nsMathMLFrame::InheritAutomaticData(nsIFrame* aParent)
{
mEmbellishData.flags = 0;
mEmbellishData.coreFrame = nsnull;
mEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
mEmbellishData.leftSpace = 0;
mEmbellishData.rightSpace = 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 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)
{
// 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,
PRBool 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.leftSpace = 0;
aEmbellishData.rightSpace = 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,
PRBool 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);
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 */ PRBool
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 PR_TRUE;
}
// see if we can get the attribute from the mstyle frame
if (!aMathMLmstyleFrame) {
return PR_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 */ PRBool
nsMathMLFrame::ParseNamedSpaceValue(nsIFrame* aMathMLmstyleFrame,
nsString& aString,
nsCSSValue& aCSSValue)
{
aCSSValue.Reset();
aString.CompressWhitespace(); // aString is not a const in this code...
if (!aString.Length()) return PR_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 PR_TRUE;
}
}
}
// fall back to the default value
aCSSValue.SetFloatValue(float(i)/float(18), eCSSUnit_EM);
return PR_TRUE;
}
return PR_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->GetStyleColor()->mColor);
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));
}