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gecko-dev/layout/mathml/nsMathMLmpaddedFrame.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>
* David J. Fiddes <D.J.Fiddes@hw.ac.uk>
* Karl Tomlinson <karlt+@karlt.net>, Mozilla Corporation
*
* 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 "nsCOMPtr.h"
#include "nsCRT.h" // to get NS_IS_SPACE
#include "nsFrame.h"
#include "nsPresContext.h"
#include "nsStyleContext.h"
#include "nsStyleConsts.h"
#include "nsMathMLmpaddedFrame.h"
//
// <mpadded> -- adjust space around content - implementation
//
#define NS_MATHML_SIGN_INVALID -1 // if the attribute is not there
#define NS_MATHML_SIGN_UNSPECIFIED 0
#define NS_MATHML_SIGN_MINUS 1
#define NS_MATHML_SIGN_PLUS 2
#define NS_MATHML_PSEUDO_UNIT_UNSPECIFIED 0
#define NS_MATHML_PSEUDO_UNIT_ITSELF 1 // special
#define NS_MATHML_PSEUDO_UNIT_WIDTH 2
#define NS_MATHML_PSEUDO_UNIT_HEIGHT 3
#define NS_MATHML_PSEUDO_UNIT_DEPTH 4
#define NS_MATHML_PSEUDO_UNIT_NAMEDSPACE 5
nsIFrame*
NS_NewMathMLmpaddedFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsMathMLmpaddedFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmpaddedFrame)
nsMathMLmpaddedFrame::~nsMathMLmpaddedFrame()
{
}
NS_IMETHODIMP
nsMathMLmpaddedFrame::InheritAutomaticData(nsIFrame* aParent)
{
// let the base class get the default from our parent
nsMathMLContainerFrame::InheritAutomaticData(aParent);
mPresentationData.flags |= NS_MATHML_STRETCH_ALL_CHILDREN_VERTICALLY;
return NS_OK;
}
void
nsMathMLmpaddedFrame::ProcessAttributes()
{
/*
parse the attributes
width = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | h-unit | namedspace)
height = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | v-unit | namedspace)
depth = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | v-unit | namedspace)
lspace = [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | h-unit | namedspace)
voffset= [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | v-unit | namedspace)
*/
nsAutoString value;
/* The REC says:
There is one exceptional element, <mpadded>, whose attributes cannot be
set with <mstyle>. When the attributes width, height and depth are specified
on an <mstyle> element, they apply only to the <mspace/> element. Similarly,
when lspace is set with <mstyle>, it applies only to the <mo> element.
*/
// See if attributes are local, don't access mstyle !
// width
mWidthSign = NS_MATHML_SIGN_INVALID;
GetAttribute(mContent, nsnull, nsGkAtoms::width, value);
if (!value.IsEmpty()) {
ParseAttribute(value, mWidthSign, mWidth, mWidthPseudoUnit);
}
// height
mHeightSign = NS_MATHML_SIGN_INVALID;
GetAttribute(mContent, nsnull, nsGkAtoms::height, value);
if (!value.IsEmpty()) {
ParseAttribute(value, mHeightSign, mHeight, mHeightPseudoUnit);
}
// depth
mDepthSign = NS_MATHML_SIGN_INVALID;
GetAttribute(mContent, nsnull, nsGkAtoms::depth_, value);
if (!value.IsEmpty()) {
ParseAttribute(value, mDepthSign, mDepth, mDepthPseudoUnit);
}
// lspace
mLeadingSpaceSign = NS_MATHML_SIGN_INVALID;
GetAttribute(mContent, nsnull, nsGkAtoms::lspace_, value);
if (!value.IsEmpty()) {
ParseAttribute(value, mLeadingSpaceSign, mLeadingSpace,
mLeadingSpacePseudoUnit);
}
// voffset
mVerticalOffsetSign = NS_MATHML_SIGN_INVALID;
GetAttribute(mContent, nsnull, nsGkAtoms::voffset_, value);
if (!value.IsEmpty()) {
ParseAttribute(value, mVerticalOffsetSign, mVerticalOffset,
mVerticalOffsetPseudoUnit);
}
}
// parse an input string in the following format (see bug 148326 for testcases):
// [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | css-unit | namedspace)
bool
nsMathMLmpaddedFrame::ParseAttribute(nsString& aString,
PRInt32& aSign,
nsCSSValue& aCSSValue,
PRInt32& aPseudoUnit)
{
aCSSValue.Reset();
aSign = NS_MATHML_SIGN_INVALID;
aPseudoUnit = NS_MATHML_PSEUDO_UNIT_UNSPECIFIED;
aString.CompressWhitespace(); // aString is not a const in this code
PRInt32 stringLength = aString.Length();
if (!stringLength)
return false;
nsAutoString number, unit;
//////////////////////
// see if the sign is there
PRInt32 i = 0;
if (aString[0] == '+') {
aSign = NS_MATHML_SIGN_PLUS;
i++;
}
else if (aString[0] == '-') {
aSign = NS_MATHML_SIGN_MINUS;
i++;
}
else
aSign = NS_MATHML_SIGN_UNSPECIFIED;
// skip any space after the sign
if (i < stringLength && nsCRT::IsAsciiSpace(aString[i]))
i++;
// get the number
bool gotDot = false, gotPercent = false;
for (; i < stringLength; i++) {
PRUnichar c = aString[i];
if (gotDot && c == '.') {
// error - two dots encountered
aSign = NS_MATHML_SIGN_INVALID;
return false;
}
if (c == '.')
gotDot = true;
else if (!nsCRT::IsAsciiDigit(c)) {
break;
}
number.Append(c);
}
// catch error if we didn't enter the loop above... we could simply initialize
// floatValue = 1, to cater for cases such as width="height", but that wouldn't
// be in line with the spec which requires an explicit number
if (number.IsEmpty()) {
#ifdef NS_DEBUG
printf("mpadded: attribute with bad numeric value: %s\n",
NS_LossyConvertUTF16toASCII(aString).get());
#endif
aSign = NS_MATHML_SIGN_INVALID;
return false;
}
PRInt32 errorCode;
float floatValue = number.ToFloat(&errorCode);
if (errorCode) {
aSign = NS_MATHML_SIGN_INVALID;
return false;
}
// skip any space after the number
if (i < stringLength && nsCRT::IsAsciiSpace(aString[i]))
i++;
// see if this is a percentage-based value
if (i < stringLength && aString[i] == '%') {
i++;
gotPercent = true;
// skip any space after the '%' sign
if (i < stringLength && nsCRT::IsAsciiSpace(aString[i]))
i++;
}
// the remainder now should be a css-unit, or a pseudo-unit, or a named-space
aString.Right(unit, stringLength - i);
if (unit.IsEmpty()) {
// also cater for the edge case of "0" for which the unit is optional
if (gotPercent || !floatValue) {
aCSSValue.SetPercentValue(floatValue / 100.0f);
aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF;
return true;
}
/*
else {
// no explicit CSS unit and no explicit pseudo-unit...
// In this case, the MathML REC suggests taking ems for
// h-unit (width, lspace) or exs for v-unit (height, depth).
// Here, however, we explicitly request authors to specify
// the unit. This is more in line with the CSS REC (and
// it allows keeping the code simpler...)
}
*/
}
else if (unit.EqualsLiteral("width")) aPseudoUnit = NS_MATHML_PSEUDO_UNIT_WIDTH;
else if (unit.EqualsLiteral("height")) aPseudoUnit = NS_MATHML_PSEUDO_UNIT_HEIGHT;
else if (unit.EqualsLiteral("depth")) aPseudoUnit = NS_MATHML_PSEUDO_UNIT_DEPTH;
else if (!gotPercent) { // percentage can only apply to a pseudo-unit
// see if the unit is a named-space
// XXX nsnull in ParseNamedSpacedValue()? don't access mstyle?
if (ParseNamedSpaceValue(nsnull, unit, aCSSValue)) {
// re-scale properly, and we know that the unit of the named-space is 'em'
floatValue *= aCSSValue.GetFloatValue();
aCSSValue.SetFloatValue(floatValue, eCSSUnit_EM);
aPseudoUnit = NS_MATHML_PSEUDO_UNIT_NAMEDSPACE;
return true;
}
// see if the input was just a CSS value
number.Append(unit); // leave the sign out if it was there
if (ParseNumericValue(number, aCSSValue))
return true;
}
// if we enter here, we have a number that will act as a multiplier on a pseudo-unit
if (aPseudoUnit != NS_MATHML_PSEUDO_UNIT_UNSPECIFIED) {
if (gotPercent)
aCSSValue.SetPercentValue(floatValue / 100.0f);
else
aCSSValue.SetFloatValue(floatValue, eCSSUnit_Number);
return true;
}
#ifdef NS_DEBUG
printf("mpadded: attribute with bad numeric value: %s\n",
NS_LossyConvertUTF16toASCII(aString).get());
#endif
// if we reach here, it means we encounter an unexpected input
aSign = NS_MATHML_SIGN_INVALID;
return false;
}
void
nsMathMLmpaddedFrame::UpdateValue(PRInt32 aSign,
PRInt32 aPseudoUnit,
const nsCSSValue& aCSSValue,
const nsBoundingMetrics& aBoundingMetrics,
nscoord& aValueToUpdate) const
{
nsCSSUnit unit = aCSSValue.GetUnit();
if (NS_MATHML_SIGN_INVALID != aSign && eCSSUnit_Null != unit) {
nscoord scaler = 0, amount = 0;
if (eCSSUnit_Percent == unit || eCSSUnit_Number == unit) {
switch(aPseudoUnit) {
case NS_MATHML_PSEUDO_UNIT_WIDTH:
scaler = aBoundingMetrics.width;
break;
case NS_MATHML_PSEUDO_UNIT_HEIGHT:
scaler = aBoundingMetrics.ascent;
break;
case NS_MATHML_PSEUDO_UNIT_DEPTH:
scaler = aBoundingMetrics.descent;
break;
default:
// if we ever reach here, it would mean something is wrong
// somewhere with the setup and/or the caller
NS_ERROR("Unexpected Pseudo Unit");
return;
}
}
if (eCSSUnit_Number == unit)
amount = NSToCoordRound(float(scaler) * aCSSValue.GetFloatValue());
else if (eCSSUnit_Percent == unit)
amount = NSToCoordRound(float(scaler) * aCSSValue.GetPercentValue());
else
amount = CalcLength(PresContext(), mStyleContext, aCSSValue);
if (NS_MATHML_SIGN_PLUS == aSign)
aValueToUpdate += amount;
else if (NS_MATHML_SIGN_MINUS == aSign)
aValueToUpdate -= amount;
else
aValueToUpdate = amount;
}
}
NS_IMETHODIMP
nsMathMLmpaddedFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
ProcessAttributes();
///////////////
// Let the base class format our content like an inferred mrow
nsresult rv = nsMathMLContainerFrame::Reflow(aPresContext, aDesiredSize,
aReflowState, aStatus);
//NS_ASSERTION(NS_FRAME_IS_COMPLETE(aStatus), "bad status");
return rv;
}
/* virtual */ nsresult
nsMathMLmpaddedFrame::Place(nsRenderingContext& aRenderingContext,
bool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
nsresult rv =
nsMathMLContainerFrame::Place(aRenderingContext, false, aDesiredSize);
if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
DidReflowChildren(GetFirstPrincipalChild());
return rv;
}
nscoord height = mBoundingMetrics.ascent;
nscoord depth = mBoundingMetrics.descent;
// The REC says:
//
// "The lspace attribute ('leading' space) specifies the horizontal location
// of the positioning point of the child content with respect to the
// positioning point of the mpadded element. By default they coincide, and
// therefore absolute values for lspace have the same effect as relative
// values."
//
// "MathML renderers should ensure that, except for the effects of the
// attributes, the relative spacing between the contents of the mpadded
// element and surrounding MathML elements would not be modified by replacing
// an mpadded element with an mrow element with the same content, even if
// linebreaking occurs within the mpadded element."
//
// (http://www.w3.org/TR/MathML/chapter3.html#presm.mpadded)
//
// "In those discussions, the terms leading and trailing are used to specify
// a side of an object when which side to use depends on the directionality;
// ie. leading means left in LTR but right in RTL."
// (http://www.w3.org/TR/MathML/chapter3.html#presm.bidi.math)
nscoord lspace = 0;
// In MathML3, "width" will be the bounding box width and "advancewidth" will
// refer "to the horizontal distance between the positioning point of the
// mpadded and the positioning point for the following content". MathML2
// doesn't make the distinction.
nscoord width = mBoundingMetrics.width;
nscoord voffset = 0;
PRInt32 pseudoUnit;
nscoord initialWidth = width;
// update width
pseudoUnit = (mWidthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
? NS_MATHML_PSEUDO_UNIT_WIDTH : mWidthPseudoUnit;
UpdateValue(mWidthSign, pseudoUnit, mWidth,
mBoundingMetrics, width);
width = NS_MAX(0, width);
// update "height" (this is the ascent in the terminology of the REC)
pseudoUnit = (mHeightPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
? NS_MATHML_PSEUDO_UNIT_HEIGHT : mHeightPseudoUnit;
UpdateValue(mHeightSign, pseudoUnit, mHeight,
mBoundingMetrics, height);
height = NS_MAX(0, height);
// update "depth" (this is the descent in the terminology of the REC)
pseudoUnit = (mDepthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF)
? NS_MATHML_PSEUDO_UNIT_DEPTH : mDepthPseudoUnit;
UpdateValue(mDepthSign, pseudoUnit, mDepth,
mBoundingMetrics, depth);
depth = NS_MAX(0, depth);
// update lspace
if (mLeadingSpacePseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) {
pseudoUnit = mLeadingSpacePseudoUnit;
UpdateValue(mLeadingSpaceSign, pseudoUnit, mLeadingSpace,
mBoundingMetrics, lspace);
}
// update voffset
if (mVerticalOffsetPseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) {
pseudoUnit = mVerticalOffsetPseudoUnit;
UpdateValue(mVerticalOffsetSign, pseudoUnit, mVerticalOffset,
mBoundingMetrics, voffset);
}
// do the padding now that we have everything
// The idea here is to maintain the invariant that <mpadded>...</mpadded> (i.e.,
// with no attributes) looks the same as <mrow>...</mrow>. But when there are
// attributes, tweak our metrics and move children to achieve the desired visual
// effects.
if ((NS_MATHML_IS_RTL(mPresentationData.flags) ?
mWidthSign : mLeadingSpaceSign) != NS_MATHML_SIGN_INVALID) {
// there was padding on the left. dismiss the left italic correction now
// (so that our parent won't correct us)
mBoundingMetrics.leftBearing = 0;
}
if ((NS_MATHML_IS_RTL(mPresentationData.flags) ?
mLeadingSpaceSign : mWidthSign) != NS_MATHML_SIGN_INVALID) {
// there was padding on the right. dismiss the right italic correction now
// (so that our parent won't correct us)
mBoundingMetrics.width = width;
mBoundingMetrics.rightBearing = mBoundingMetrics.width;
}
nscoord dy = height - mBoundingMetrics.ascent;
nscoord dx = NS_MATHML_IS_RTL(mPresentationData.flags) ?
width - initialWidth - lspace : lspace;
aDesiredSize.ascent += dy;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.height += dy + depth - mBoundingMetrics.descent;
mBoundingMetrics.ascent = height;
mBoundingMetrics.descent = depth;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
// Finish reflowing child frames, positioning their origins.
PositionRowChildFrames(dx, aDesiredSize.ascent - voffset);
}
return NS_OK;
}
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