diff options
Diffstat (limited to 'layout/mathml/nsMathMLmpaddedFrame.cpp')
| -rw-r--r-- | layout/mathml/nsMathMLmpaddedFrame.cpp | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/layout/mathml/nsMathMLmpaddedFrame.cpp b/layout/mathml/nsMathMLmpaddedFrame.cpp new file mode 100644 index 0000000000..2c73d60ab9 --- /dev/null +++ b/layout/mathml/nsMathMLmpaddedFrame.cpp @@ -0,0 +1,441 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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 "nsMathMLmpaddedFrame.h" + +#include "mozilla/dom/MathMLElement.h" +#include "mozilla/gfx/2D.h" +#include "mozilla/PresShell.h" +#include "mozilla/TextUtils.h" +#include "nsLayoutUtils.h" +#include <algorithm> + +using namespace mozilla; + +// +// <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(PresShell* aPresShell, + ComputedStyle* aStyle) { + return new (aPresShell) + nsMathMLmpaddedFrame(aStyle, aPresShell->GetPresContext()); +} + +NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmpaddedFrame) + +nsMathMLmpaddedFrame::~nsMathMLmpaddedFrame() = default; + +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() { + // clang-format off + /* + 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) + */ + // clang-format on + + nsAutoString value; + + // width + mWidthSign = NS_MATHML_SIGN_INVALID; + mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::width, value); + if (!value.IsEmpty()) { + if (!ParseAttribute(value, mWidthSign, mWidth, mWidthPseudoUnit)) { + ReportParseError(nsGkAtoms::width->GetUTF16String(), value.get()); + } + } + + // height + mHeightSign = NS_MATHML_SIGN_INVALID; + mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::height, value); + if (!value.IsEmpty()) { + if (!ParseAttribute(value, mHeightSign, mHeight, mHeightPseudoUnit)) { + ReportParseError(nsGkAtoms::height->GetUTF16String(), value.get()); + } + } + + // depth + mDepthSign = NS_MATHML_SIGN_INVALID; + mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::depth_, value); + if (!value.IsEmpty()) { + if (!ParseAttribute(value, mDepthSign, mDepth, mDepthPseudoUnit)) { + ReportParseError(nsGkAtoms::depth_->GetUTF16String(), value.get()); + } + } + + // lspace + mLeadingSpaceSign = NS_MATHML_SIGN_INVALID; + mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::lspace_, value); + if (!value.IsEmpty()) { + if (!ParseAttribute(value, mLeadingSpaceSign, mLeadingSpace, + mLeadingSpacePseudoUnit)) { + ReportParseError(nsGkAtoms::lspace_->GetUTF16String(), value.get()); + } + } + + // voffset + mVerticalOffsetSign = NS_MATHML_SIGN_INVALID; + mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::voffset_, value); + if (!value.IsEmpty()) { + if (!ParseAttribute(value, mVerticalOffsetSign, mVerticalOffset, + mVerticalOffsetPseudoUnit)) { + ReportParseError(nsGkAtoms::voffset_->GetUTF16String(), value.get()); + } + } +} + +// 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, int32_t& aSign, + nsCSSValue& aCSSValue, + int32_t& aPseudoUnit) { + aCSSValue.Reset(); + aSign = NS_MATHML_SIGN_INVALID; + aPseudoUnit = NS_MATHML_PSEUDO_UNIT_UNSPECIFIED; + aString.CompressWhitespace(); // aString is not a const in this code + + int32_t stringLength = aString.Length(); + if (!stringLength) return false; + + nsAutoString number, unit; + + ////////////////////// + // see if the sign is there + + int32_t 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; + + // get the number + bool gotDot = false, gotPercent = false; + for (; i < stringLength; i++) { + char16_t c = aString[i]; + if (gotDot && c == '.') { + // error - two dots encountered + aSign = NS_MATHML_SIGN_INVALID; + return false; + } + + if (c == '.') + gotDot = true; + else if (!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()) { + aSign = NS_MATHML_SIGN_INVALID; + return false; + } + + nsresult errorCode; + float floatValue = number.ToFloat(&errorCode); + if (NS_FAILED(errorCode)) { + aSign = NS_MATHML_SIGN_INVALID; + return false; + } + + // see if this is a percentage-based value + if (i < stringLength && aString[i] == '%') { + i++; + gotPercent = true; + } + + // the remainder now should be a css-unit, or a pseudo-unit, or a named-space + aString.Right(unit, stringLength - i); + + if (unit.IsEmpty()) { + if (gotPercent) { + // case ["+"|"-"] unsigned-number "%" + aCSSValue.SetPercentValue(floatValue / 100.0f); + aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF; + return true; + } else { + // case ["+"|"-"] unsigned-number + // XXXfredw: should we allow non-zero unitless values? See bug 757703. + if (!floatValue) { + aCSSValue.SetFloatValue(floatValue, eCSSUnit_Number); + aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF; + return true; + } + } + } 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 + if (dom::MathMLElement::ParseNamedSpaceValue( + unit, aCSSValue, dom::MathMLElement::PARSE_ALLOW_NEGATIVE, + *mContent->OwnerDoc())) { + // 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 + // We are not supposed to have a unitless, percent, negative or namedspace + // value here. + number.Append(unit); // leave the sign out if it was there + if (dom::MathMLElement::ParseNumericValue( + number, aCSSValue, dom::MathMLElement::PARSE_SUPPRESS_WARNINGS, + nullptr)) + 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 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(int32_t aSign, int32_t aPseudoUnit, + const nsCSSValue& aCSSValue, + const ReflowOutput& aDesiredSize, + nscoord& aValueToUpdate, + float aFontSizeInflation) 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 = aDesiredSize.Width(); + break; + + case NS_MATHML_PSEUDO_UNIT_HEIGHT: + scaler = aDesiredSize.BlockStartAscent(); + break; + + case NS_MATHML_PSEUDO_UNIT_DEPTH: + scaler = aDesiredSize.Height() - aDesiredSize.BlockStartAscent(); + 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(), mComputedStyle, aCSSValue, + aFontSizeInflation); + + if (NS_MATHML_SIGN_PLUS == aSign) + aValueToUpdate += amount; + else if (NS_MATHML_SIGN_MINUS == aSign) + aValueToUpdate -= amount; + else + aValueToUpdate = amount; + } +} + +void nsMathMLmpaddedFrame::Reflow(nsPresContext* aPresContext, + ReflowOutput& aDesiredSize, + const ReflowInput& aReflowInput, + nsReflowStatus& aStatus) { + MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!"); + + mPresentationData.flags &= ~NS_MATHML_ERROR; + ProcessAttributes(); + + /////////////// + // Let the base class format our content like an inferred mrow + nsMathMLContainerFrame::Reflow(aPresContext, aDesiredSize, aReflowInput, + aStatus); + // NS_ASSERTION(aStatus.IsComplete(), "bad status"); +} + +/* virtual */ +nsresult nsMathMLmpaddedFrame::Place(DrawTarget* aDrawTarget, bool aPlaceOrigin, + ReflowOutput& aDesiredSize) { + nsresult rv = nsMathMLContainerFrame::Place(aDrawTarget, false, aDesiredSize); + if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) { + DidReflowChildren(PrincipalChildList().FirstChild()); + return rv; + } + + nscoord height = aDesiredSize.BlockStartAscent(); + nscoord depth = aDesiredSize.Height() - aDesiredSize.BlockStartAscent(); + // 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 = aDesiredSize.Width(); + nscoord voffset = 0; + + int32_t pseudoUnit; + nscoord initialWidth = width; + float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this); + + // update width + pseudoUnit = (mWidthPseudoUnit == NS_MATHML_PSEUDO_UNIT_ITSELF) + ? NS_MATHML_PSEUDO_UNIT_WIDTH + : mWidthPseudoUnit; + UpdateValue(mWidthSign, pseudoUnit, mWidth, aDesiredSize, width, + fontSizeInflation); + width = std::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, aDesiredSize, height, + fontSizeInflation); + height = std::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, aDesiredSize, depth, + fontSizeInflation); + depth = std::max(0, depth); + + // update lspace + if (mLeadingSpacePseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) { + pseudoUnit = mLeadingSpacePseudoUnit; + UpdateValue(mLeadingSpaceSign, pseudoUnit, mLeadingSpace, aDesiredSize, + lspace, fontSizeInflation); + } + + // update voffset + if (mVerticalOffsetPseudoUnit != NS_MATHML_PSEUDO_UNIT_ITSELF) { + pseudoUnit = mVerticalOffsetPseudoUnit; + UpdateValue(mVerticalOffsetSign, pseudoUnit, mVerticalOffset, aDesiredSize, + voffset, fontSizeInflation); + } + // 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. + + const bool isRTL = StyleVisibility()->mDirection == StyleDirection::Rtl; + if ((isRTL ? 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 ((isRTL ? 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 dx = (isRTL ? width - initialWidth - lspace : lspace); + + aDesiredSize.SetBlockStartAscent(height); + aDesiredSize.Width() = mBoundingMetrics.width; + aDesiredSize.Height() = depth + aDesiredSize.BlockStartAscent(); + mBoundingMetrics.ascent = height; + mBoundingMetrics.descent = depth; + aDesiredSize.mBoundingMetrics = mBoundingMetrics; + + mReference.x = 0; + mReference.y = aDesiredSize.BlockStartAscent(); + + if (aPlaceOrigin) { + // Finish reflowing child frames, positioning their origins. + PositionRowChildFrames(dx, aDesiredSize.BlockStartAscent() - voffset); + } + + return NS_OK; +} + +/* virtual */ +nsresult nsMathMLmpaddedFrame::MeasureForWidth(DrawTarget* aDrawTarget, + ReflowOutput& aDesiredSize) { + ProcessAttributes(); + return Place(aDrawTarget, false, aDesiredSize); +} |