gecko-dev/layout/mathml/nsMathMLTokenFrame.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>
* Karl Tomlinson <karlt+@karlt.net>, Mozilla Corporation
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 "nsCOMPtr.h"
#include "nsFrame.h"
#include "nsPresContext.h"
#include "nsStyleContext.h"
#include "nsStyleConsts.h"
#include "nsIRenderingContext.h"
#include "nsIFontMetrics.h"
#include "nsContentUtils.h"
#include "nsCSSFrameConstructor.h"
#include "nsMathMLTokenFrame.h"
nsIFrame*
NS_NewMathMLTokenFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsMathMLTokenFrame(aContext);
}
nsMathMLTokenFrame::~nsMathMLTokenFrame()
{
}
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...
// Don't use nsMathMLFrame::GetAttribute for mathvariant or fontstyle as
// default values are not inherited.
nsAutoString style;
// mathvariant overrides fontstyle
// http://www.w3.org/TR/2003/REC-MathML2-20031021/chapter3.html#presm.deprecatt
mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::MOZfontstyle, style) ||
mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::mathvariant_, style) ||
mContent->GetAttr(kNameSpaceID_None, 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, PR_FALSE, data);
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;
}
static void
CompressWhitespace(nsIContent* aContent)
{
PRUint32 numKids = aContent->GetChildCount();
for (PRUint32 kid = 0; kid < numKids; kid++) {
nsIContent* cont = aContent->GetChildAt(kid);
if (cont && cont->IsNodeOfType(nsINode::eTEXT)) {
nsAutoString text;
cont->AppendTextTo(text);
text.CompressWhitespace();
cont->SetText(text, PR_FALSE); // not meant to be used if notify is needed
}
}
}
NS_IMETHODIMP
nsMathMLTokenFrame::Init(nsIContent* aContent,
nsIFrame* aParent,
nsIFrame* aPrevInFlow)
{
// leading and trailing whitespace doesn't count -- bug 15402
// brute force removal for people who do <mi> a </mi> instead of <mi>a</mi>
// XXX the best fix is to skip these in nsTextFrame
CompressWhitespace(aContent);
// let the base class do its Init()
return nsMathMLContainerFrame::Init(aContent, aParent, aPrevInFlow);
}
NS_IMETHODIMP
nsMathMLTokenFrame::SetInitialChildList(nsIAtom* aListName,
nsIFrame* aChildList)
{
// First, let the base class do its work
nsresult rv = nsMathMLContainerFrame::SetInitialChildList(aListName, aChildList);
if (NS_FAILED(rv))
return rv;
SetQuotes();
ProcessTextData();
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.Clear();
nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
nsIFrame* childFrame = GetFirstChild(nsnull);
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(GetFirstChild(nsnull), 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(nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
mBoundingMetrics.Clear();
for (nsIFrame* childFrame = GetFirstChild(nsnull); childFrame;
childFrame = childFrame->GetNextSibling()) {
nsHTMLReflowMetrics childSize;
GetReflowAndBoundingMetricsFor(childFrame, childSize,
childSize.mBoundingMetrics, nsnull);
// compute and cache the bounding metrics
mBoundingMetrics += childSize.mBoundingMetrics;
}
nsCOMPtr<nsIFontMetrics> fm =
PresContext()->GetMetricsFor(GetStyleFont()->mFont);
nscoord ascent, descent;
fm->GetMaxAscent(ascent);
fm->GetMaxDescent(descent);
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.ascent = PR_MAX(mBoundingMetrics.ascent, ascent);
aDesiredSize.height = aDesiredSize.ascent +
PR_MAX(mBoundingMetrics.descent, descent);
if (aPlaceOrigin) {
nscoord dy, dx = 0;
for (nsIFrame* childFrame = GetFirstChild(nsnull); 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(), nsnull, 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();
}
NS_IMETHODIMP
nsMathMLTokenFrame::AttributeChanged(PRInt32 aNameSpaceID,
nsIAtom* aAttribute,
PRInt32 aModType)
{
if (nsGkAtoms::lquote_ == aAttribute ||
nsGkAtoms::rquote_ == aAttribute) {
SetQuotes();
}
return nsMathMLContainerFrame::
AttributeChanged(aNameSpaceID, aAttribute, aModType);
}
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()->PresShell()->FrameConstructor()->
PostRestyleEvent(mContent, eReStyle_Self, 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 PR_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.)"
PRBool
nsMathMLTokenFrame::SetTextStyle()
{
if (mContent->Tag() != nsGkAtoms::mi_)
return PR_FALSE;
if (!mFrames.FirstChild())
return PR_FALSE;
// Get the text content that we enclose and its length
nsAutoString data;
nsContentUtils::GetNodeTextContent(mContent, PR_FALSE, data);
PRInt32 length = data.Length();
if (!length)
return PR_FALSE;
nsAutoString fontstyle;
PRBool 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.
if (!(mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::mathvariant_) ||
mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::fontstyle_))) {
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::MOZfontstyle)) {
mContent->UnsetAttr(kNameSpaceID_None, nsGkAtoms::MOZfontstyle, PR_FALSE);
return PR_TRUE;
}
}
else if (!mContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::MOZfontstyle,
fontstyle, eCaseMatters)) {
mContent->SetAttr(kNameSpaceID_None, nsGkAtoms::MOZfontstyle,
fontstyle, PR_FALSE);
return PR_TRUE;
}
return PR_FALSE;
}
///////////////////////////////////////////////////////////////////////////
// For <ms>, it is assumed that the mathml.css file contains two rules:
// ms:before { content: open-quote; }
// ms:after { content: close-quote; }
// With these two rules, the frame construction code will
// create inline frames that contain text frames which themselves
// contain the text content of the quotes.
// So the main idea in this code is to see if there are lquote and
// rquote attributes. If these are there, we ovewrite the default
// quotes in the text frames.
//
// But what if the mathml.css file wasn't loaded?
// We also check that we are not relying on null pointers...
static void
SetQuote(nsIFrame* aFrame,
nsString& aValue)
{
nsIFrame* textFrame;
do {
// walk down the hierarchy of first children because they could be wrapped
textFrame = aFrame->GetFirstChild(nsnull);
if (textFrame) {
if (textFrame->GetType() == nsGkAtoms::textFrame)
break;
}
aFrame = textFrame;
} while (textFrame);
if (textFrame) {
nsIContent* quoteContent = textFrame->GetContent();
if (quoteContent && quoteContent->IsNodeOfType(nsINode::eTEXT)) {
quoteContent->SetText(aValue, PR_FALSE); // no notify since we don't want a reflow yet
}
}
}
void
nsMathMLTokenFrame::SetQuotes()
{
if (mContent->Tag() != nsGkAtoms::ms_)
return;
nsIFrame* rightFrame = nsnull;
nsIFrame* baseFrame = nsnull;
nsIFrame* leftFrame = mFrames.FirstChild();
if (leftFrame)
baseFrame = leftFrame->GetNextSibling();
if (baseFrame)
rightFrame = baseFrame->GetNextSibling();
if (!leftFrame || !baseFrame || !rightFrame)
return;
nsAutoString value;
// lquote
if (GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::lquote_, value)) {
SetQuote(leftFrame, value);
}
// rquote
if (GetAttribute(mContent, mPresentationData.mstyle,
nsGkAtoms::rquote_, value)) {
SetQuote(rightFrame, value);
}
}