| /* |
| * Copyright (C) 2010 Alex Milowski (alex@milowski.com). All rights reserved. |
| * Copyright (C) 2013 The MathJax Consortium. |
| * Copyright (C) 2016 Igalia S.L. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "RenderMathMLScripts.h" |
| |
| #if ENABLE(MATHML) |
| |
| #include "MathMLElement.h" |
| #include "MathMLScriptsElement.h" |
| #include "RenderMathMLOperator.h" |
| #include <wtf/IsoMallocInlines.h> |
| |
| namespace WebCore { |
| |
| WTF_MAKE_ISO_ALLOCATED_IMPL(RenderMathMLScripts); |
| |
| static bool isPrescriptDelimiter(const RenderObject& renderObject) |
| { |
| return renderObject.node() && renderObject.node()->hasTagName(MathMLNames::mprescriptsTag); |
| } |
| |
| RenderMathMLScripts::RenderMathMLScripts(MathMLScriptsElement& element, RenderStyle&& style) |
| : RenderMathMLBlock(element, WTFMove(style)) |
| { |
| } |
| |
| MathMLScriptsElement& RenderMathMLScripts::element() const |
| { |
| return static_cast<MathMLScriptsElement&>(nodeForNonAnonymous()); |
| } |
| |
| MathMLScriptsElement::ScriptType RenderMathMLScripts::scriptType() const |
| { |
| return element().scriptType(); |
| } |
| |
| RenderMathMLOperator* RenderMathMLScripts::unembellishedOperator() const |
| { |
| auto base = firstChildBox(); |
| if (!is<RenderMathMLBlock>(base)) |
| return nullptr; |
| return downcast<RenderMathMLBlock>(base)->unembellishedOperator(); |
| } |
| |
| Optional<RenderMathMLScripts::ReferenceChildren> RenderMathMLScripts::validateAndGetReferenceChildren() |
| { |
| // All scripted elements must have at least one child. |
| // The first child is the base. |
| auto base = firstChildBox(); |
| if (!base) |
| return WTF::nullopt; |
| |
| ReferenceChildren reference; |
| reference.base = base; |
| reference.firstPostScript = nullptr; |
| reference.firstPreScript = nullptr; |
| reference.prescriptDelimiter = nullptr; |
| |
| switch (scriptType()) { |
| case MathMLScriptsElement::ScriptType::Sub: |
| case MathMLScriptsElement::ScriptType::Super: |
| case MathMLScriptsElement::ScriptType::Under: |
| case MathMLScriptsElement::ScriptType::Over: { |
| // These elements must have exactly two children. |
| // The second child is a postscript and there are no prescripts. |
| // <msub> base subscript </msub> |
| // <msup> base superscript </msup> |
| // <munder> base underscript </munder> |
| // <mover> base overscript </mover> |
| auto script = base->nextSiblingBox(); |
| if (!script || isPrescriptDelimiter(*script) || script->nextSiblingBox()) |
| return WTF::nullopt; |
| reference.firstPostScript = script; |
| return reference; |
| } |
| case MathMLScriptsElement::ScriptType::SubSup: |
| case MathMLScriptsElement::ScriptType::UnderOver: { |
| // These elements must have exactly three children. |
| // The second and third children are postscripts and there are no prescripts. |
| // <msubsup> base subscript superscript </msubsup> |
| // <munderover> base subscript superscript </munderover> |
| auto subScript = base->nextSiblingBox(); |
| if (!subScript || isPrescriptDelimiter(*subScript)) |
| return WTF::nullopt; |
| auto superScript = subScript->nextSiblingBox(); |
| if (!superScript || isPrescriptDelimiter(*superScript) || superScript->nextSiblingBox()) |
| return WTF::nullopt; |
| reference.firstPostScript = subScript; |
| return reference; |
| } |
| case MathMLScriptsElement::ScriptType::Multiscripts: { |
| // This element accepts the following syntax: |
| // |
| // <mmultiscripts> |
| // base |
| // (subscript superscript)* |
| // [ <mprescripts/> (presubscript presuperscript)* ] |
| // </mmultiscripts> |
| // |
| // https://www.w3.org/TR/MathML3/chapter3.html#presm.mmultiscripts |
| // |
| // We set the first postscript, unless (subscript superscript)* is empty. |
| if (base->nextSiblingBox() && !isPrescriptDelimiter(*base->nextSiblingBox())) |
| reference.firstPostScript = base->nextSiblingBox(); |
| |
| // We browse the children in order to |
| // 1) Set the first prescript, unless (presubscript presuperscript)* is empty. |
| // 2) Ensure the validity of the element i.e. |
| // a) That the list of postscripts can be grouped into pairs of subscript/superscript. |
| // b) That the list of prescripts can be grouped into pairs of subscript/superscript. |
| // c) That there is at most one <mprescripts/>. |
| bool numberOfScriptIsEven = true; |
| for (auto script = base->nextSiblingBox(); script; script = script->nextSiblingBox()) { |
| if (isPrescriptDelimiter(*script)) { |
| // This is a <mprescripts/>. Let's check 2a) and 2c). |
| if (!numberOfScriptIsEven || reference.firstPreScript) |
| return WTF::nullopt; |
| reference.firstPreScript = script->nextSiblingBox(); // We do 1). |
| reference.prescriptDelimiter = script; |
| continue; |
| } |
| numberOfScriptIsEven = !numberOfScriptIsEven; |
| } |
| return numberOfScriptIsEven ? Optional<ReferenceChildren>(reference) : WTF::nullopt; // We verify 2b). |
| } |
| } |
| |
| ASSERT_NOT_REACHED(); |
| return WTF::nullopt; |
| } |
| |
| LayoutUnit RenderMathMLScripts::spaceAfterScript() |
| { |
| const auto& primaryFont = style().fontCascade().primaryFont(); |
| if (auto* mathData = primaryFont.mathData()) |
| return LayoutUnit(mathData->getMathConstant(primaryFont, OpenTypeMathData::SpaceAfterScript)); |
| return LayoutUnit(style().fontCascade().size() / 5); |
| } |
| |
| LayoutUnit RenderMathMLScripts::italicCorrection(const ReferenceChildren& reference) |
| { |
| if (is<RenderMathMLBlock>(*reference.base)) { |
| if (auto* renderOperator = downcast<RenderMathMLBlock>(*reference.base).unembellishedOperator()) |
| return renderOperator->italicCorrection(); |
| } |
| return 0; |
| } |
| |
| void RenderMathMLScripts::computePreferredLogicalWidths() |
| { |
| ASSERT(preferredLogicalWidthsDirty()); |
| |
| m_minPreferredLogicalWidth = 0; |
| m_maxPreferredLogicalWidth = 0; |
| |
| auto possibleReference = validateAndGetReferenceChildren(); |
| if (!possibleReference) { |
| setPreferredLogicalWidthsDirty(false); |
| return; |
| } |
| auto& reference = possibleReference.value(); |
| |
| LayoutUnit baseItalicCorrection = std::min(reference.base->maxPreferredLogicalWidth(), italicCorrection(reference)); |
| LayoutUnit space = spaceAfterScript(); |
| |
| switch (scriptType()) { |
| case MathMLScriptsElement::ScriptType::Sub: |
| case MathMLScriptsElement::ScriptType::Under: |
| m_maxPreferredLogicalWidth += reference.base->maxPreferredLogicalWidth(); |
| m_maxPreferredLogicalWidth += std::max(0_lu, reference.firstPostScript->maxPreferredLogicalWidth() - baseItalicCorrection + space); |
| break; |
| case MathMLScriptsElement::ScriptType::Super: |
| case MathMLScriptsElement::ScriptType::Over: |
| m_maxPreferredLogicalWidth += reference.base->maxPreferredLogicalWidth(); |
| m_maxPreferredLogicalWidth += std::max(0_lu, reference.firstPostScript->maxPreferredLogicalWidth() + space); |
| break; |
| case MathMLScriptsElement::ScriptType::SubSup: |
| case MathMLScriptsElement::ScriptType::UnderOver: |
| case MathMLScriptsElement::ScriptType::Multiscripts: { |
| auto subScript = reference.firstPreScript; |
| while (subScript) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subSupPairWidth = std::max(subScript->maxPreferredLogicalWidth(), supScript->maxPreferredLogicalWidth()); |
| m_maxPreferredLogicalWidth += subSupPairWidth + space; |
| subScript = supScript->nextSiblingBox(); |
| } |
| m_maxPreferredLogicalWidth += reference.base->maxPreferredLogicalWidth(); |
| subScript = reference.firstPostScript; |
| while (subScript && subScript != reference.prescriptDelimiter) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subSupPairWidth = std::max(std::max(0_lu, subScript->maxPreferredLogicalWidth() - baseItalicCorrection), supScript->maxPreferredLogicalWidth()); |
| m_maxPreferredLogicalWidth += subSupPairWidth + space; |
| subScript = supScript->nextSiblingBox(); |
| } |
| } |
| } |
| |
| m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth; |
| |
| setPreferredLogicalWidthsDirty(false); |
| } |
| |
| auto RenderMathMLScripts::verticalParameters() const -> VerticalParameters |
| { |
| VerticalParameters parameters; |
| const auto& primaryFont = style().fontCascade().primaryFont(); |
| if (auto* mathData = primaryFont.mathData()) { |
| parameters.subscriptShiftDown = mathData->getMathConstant(primaryFont, OpenTypeMathData::SubscriptShiftDown); |
| parameters.superscriptShiftUp = mathData->getMathConstant(primaryFont, OpenTypeMathData::SuperscriptShiftUp); |
| parameters.subscriptBaselineDropMin = mathData->getMathConstant(primaryFont, OpenTypeMathData::SubscriptBaselineDropMin); |
| parameters.superScriptBaselineDropMax = mathData->getMathConstant(primaryFont, OpenTypeMathData::SuperscriptBaselineDropMax); |
| parameters.subSuperscriptGapMin = mathData->getMathConstant(primaryFont, OpenTypeMathData::SubSuperscriptGapMin); |
| parameters.superscriptBottomMin = mathData->getMathConstant(primaryFont, OpenTypeMathData::SuperscriptBottomMin); |
| parameters.subscriptTopMax = mathData->getMathConstant(primaryFont, OpenTypeMathData::SubscriptTopMax); |
| parameters.superscriptBottomMaxWithSubscript = mathData->getMathConstant(primaryFont, OpenTypeMathData::SuperscriptBottomMaxWithSubscript); |
| } else { |
| // Default heuristic values when you do not have a font. |
| parameters.subscriptShiftDown = style().fontMetrics().xHeight() / 3; |
| parameters.superscriptShiftUp = style().fontMetrics().xHeight(); |
| parameters.subscriptBaselineDropMin = style().fontMetrics().xHeight() / 2; |
| parameters.superScriptBaselineDropMax = style().fontMetrics().xHeight() / 2; |
| parameters.subSuperscriptGapMin = style().fontCascade().size() / 5; |
| parameters.superscriptBottomMin = style().fontMetrics().xHeight() / 4; |
| parameters.subscriptTopMax = 4 * style().fontMetrics().xHeight() / 5; |
| parameters.superscriptBottomMaxWithSubscript = 4 * style().fontMetrics().xHeight() / 5; |
| } |
| return parameters; |
| } |
| |
| RenderMathMLScripts::VerticalMetrics RenderMathMLScripts::verticalMetrics(const ReferenceChildren& reference) |
| { |
| VerticalParameters parameters = verticalParameters(); |
| VerticalMetrics metrics = { 0, 0, 0, 0 }; |
| |
| LayoutUnit baseAscent = ascentForChild(*reference.base); |
| LayoutUnit baseDescent = reference.base->logicalHeight() - baseAscent; |
| if (scriptType() == MathMLScriptsElement::ScriptType::Sub || scriptType() == MathMLScriptsElement::ScriptType::SubSup || scriptType() == MathMLScriptsElement::ScriptType::Multiscripts || scriptType() == MathMLScriptsElement::ScriptType::Under || scriptType() == MathMLScriptsElement::ScriptType::UnderOver) { |
| metrics.subShift = std::max(parameters.subscriptShiftDown, baseDescent + parameters.subscriptBaselineDropMin); |
| if (!isRenderMathMLUnderOver()) { |
| // It is not clear how to interpret the default shift and it is not available yet anyway. |
| // Hence we just pass 0 as the default value used by toUserUnits. |
| LayoutUnit specifiedMinSubShift = toUserUnits(element().subscriptShift(), style(), 0); |
| metrics.subShift = std::max(metrics.subShift, specifiedMinSubShift); |
| } |
| } |
| if (scriptType() == MathMLScriptsElement::ScriptType::Super || scriptType() == MathMLScriptsElement::ScriptType::SubSup || scriptType() == MathMLScriptsElement::ScriptType::Multiscripts || scriptType() == MathMLScriptsElement::ScriptType::Over || scriptType() == MathMLScriptsElement::ScriptType::UnderOver) { |
| metrics.supShift = std::max(parameters.superscriptShiftUp, baseAscent - parameters.superScriptBaselineDropMax); |
| if (!isRenderMathMLUnderOver()) { |
| // It is not clear how to interpret the default shift and it is not available yet anyway. |
| // Hence we just pass 0 as the default value used by toUserUnits. |
| LayoutUnit specifiedMinSupShift = toUserUnits(element().superscriptShift(), style(), 0); |
| metrics.supShift = std::max(metrics.supShift, specifiedMinSupShift); |
| } |
| } |
| |
| switch (scriptType()) { |
| case MathMLScriptsElement::ScriptType::Sub: |
| case MathMLScriptsElement::ScriptType::Under: { |
| LayoutUnit subAscent = ascentForChild(*reference.firstPostScript); |
| LayoutUnit subDescent = reference.firstPostScript->logicalHeight() - subAscent; |
| metrics.descent = subDescent; |
| metrics.subShift = std::max(metrics.subShift, subAscent - parameters.subscriptTopMax); |
| } |
| break; |
| case MathMLScriptsElement::ScriptType::Super: |
| case MathMLScriptsElement::ScriptType::Over: { |
| LayoutUnit supAscent = ascentForChild(*reference.firstPostScript); |
| LayoutUnit supDescent = reference.firstPostScript->logicalHeight() - supAscent; |
| metrics.ascent = supAscent; |
| metrics.supShift = std::max(metrics.supShift, parameters.superscriptBottomMin + supDescent); |
| } |
| break; |
| case MathMLScriptsElement::ScriptType::SubSup: |
| case MathMLScriptsElement::ScriptType::UnderOver: |
| case MathMLScriptsElement::ScriptType::Multiscripts: { |
| // FIXME: We should move the code updating VerticalMetrics for each sub/sup pair in a helper |
| // function. That way, SubSup/UnderOver can just make one call and the loop for Multiscripts |
| // can be rewritten in a more readable. |
| auto subScript = reference.firstPostScript ? reference.firstPostScript : reference.firstPreScript; |
| while (subScript) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subAscent = ascentForChild(*subScript); |
| LayoutUnit subDescent = subScript->logicalHeight() - subAscent; |
| LayoutUnit supAscent = ascentForChild(*supScript); |
| LayoutUnit supDescent = supScript->logicalHeight() - supAscent; |
| metrics.ascent = std::max(metrics.ascent, supAscent); |
| metrics.descent = std::max(metrics.descent, subDescent); |
| LayoutUnit subScriptShift = std::max(parameters.subscriptShiftDown, baseDescent + parameters.subscriptBaselineDropMin); |
| subScriptShift = std::max(subScriptShift, subAscent - parameters.subscriptTopMax); |
| LayoutUnit supScriptShift = std::max(parameters.superscriptShiftUp, baseAscent - parameters.superScriptBaselineDropMax); |
| supScriptShift = std::max(supScriptShift, parameters.superscriptBottomMin + supDescent); |
| |
| LayoutUnit subSuperscriptGap = (subScriptShift - subAscent) + (supScriptShift - supDescent); |
| if (subSuperscriptGap < parameters.subSuperscriptGapMin) { |
| // First, we try and push the superscript up. |
| LayoutUnit delta = parameters.superscriptBottomMaxWithSubscript - (supScriptShift - supDescent); |
| if (delta > 0) { |
| delta = std::min(delta, parameters.subSuperscriptGapMin - subSuperscriptGap); |
| supScriptShift += delta; |
| subSuperscriptGap += delta; |
| } |
| // If that is not enough, we push the subscript down. |
| if (subSuperscriptGap < parameters.subSuperscriptGapMin) |
| subScriptShift += parameters.subSuperscriptGapMin - subSuperscriptGap; |
| } |
| |
| metrics.subShift = std::max(metrics.subShift, subScriptShift); |
| metrics.supShift = std::max(metrics.supShift, supScriptShift); |
| |
| subScript = supScript->nextSiblingBox(); |
| if (subScript == reference.prescriptDelimiter) |
| subScript = reference.firstPreScript; |
| } |
| } |
| } |
| |
| return metrics; |
| } |
| |
| void RenderMathMLScripts::layoutBlock(bool relayoutChildren, LayoutUnit) |
| { |
| ASSERT(needsLayout()); |
| |
| if (!relayoutChildren && simplifiedLayout()) |
| return; |
| |
| auto possibleReference = validateAndGetReferenceChildren(); |
| if (!possibleReference) { |
| layoutInvalidMarkup(relayoutChildren); |
| return; |
| } |
| auto& reference = possibleReference.value(); |
| |
| recomputeLogicalWidth(); |
| for (auto child = firstChildBox(); child; child = child->nextSiblingBox()) |
| child->layoutIfNeeded(); |
| |
| LayoutUnit space = spaceAfterScript(); |
| |
| // We determine the minimal shift/size of each script and take the maximum of the values. |
| VerticalMetrics metrics = verticalMetrics(reference); |
| |
| LayoutUnit baseAscent = ascentForChild(*reference.base); |
| LayoutUnit baseDescent = reference.base->logicalHeight() - baseAscent; |
| LayoutUnit baseItalicCorrection = std::min(reference.base->logicalWidth(), italicCorrection(reference)); |
| LayoutUnit horizontalOffset; |
| |
| LayoutUnit ascent = std::max(baseAscent, metrics.ascent + metrics.supShift); |
| LayoutUnit descent = std::max(baseDescent, metrics.descent + metrics.subShift); |
| setLogicalHeight(ascent + descent); |
| |
| switch (scriptType()) { |
| case MathMLScriptsElement::ScriptType::Sub: |
| case MathMLScriptsElement::ScriptType::Under: { |
| setLogicalWidth(reference.base->logicalWidth() + std::max(0_lu, reference.firstPostScript->logicalWidth() - baseItalicCorrection + space)); |
| LayoutPoint baseLocation(mirrorIfNeeded(horizontalOffset, *reference.base), ascent - baseAscent); |
| reference.base->setLocation(baseLocation); |
| horizontalOffset += reference.base->logicalWidth(); |
| LayoutUnit scriptAscent = ascentForChild(*reference.firstPostScript); |
| LayoutPoint scriptLocation(mirrorIfNeeded(horizontalOffset - baseItalicCorrection, *reference.firstPostScript), ascent + metrics.subShift - scriptAscent); |
| reference.firstPostScript->setLocation(scriptLocation); |
| } |
| break; |
| case MathMLScriptsElement::ScriptType::Super: |
| case MathMLScriptsElement::ScriptType::Over: { |
| setLogicalWidth(reference.base->logicalWidth() + std::max(0_lu, reference.firstPostScript->logicalWidth() + space)); |
| LayoutPoint baseLocation(mirrorIfNeeded(horizontalOffset, *reference.base), ascent - baseAscent); |
| reference.base->setLocation(baseLocation); |
| horizontalOffset += reference.base->logicalWidth(); |
| LayoutUnit scriptAscent = ascentForChild(*reference.firstPostScript); |
| LayoutPoint scriptLocation(mirrorIfNeeded(horizontalOffset, *reference.firstPostScript), ascent - metrics.supShift - scriptAscent); |
| reference.firstPostScript->setLocation(scriptLocation); |
| } |
| break; |
| case MathMLScriptsElement::ScriptType::SubSup: |
| case MathMLScriptsElement::ScriptType::UnderOver: |
| case MathMLScriptsElement::ScriptType::Multiscripts: { |
| // Calculate the logical width. |
| LayoutUnit logicalWidth; |
| auto subScript = reference.firstPreScript; |
| while (subScript) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subSupPairWidth = std::max(subScript->logicalWidth(), supScript->logicalWidth()); |
| logicalWidth += subSupPairWidth + space; |
| subScript = supScript->nextSiblingBox(); |
| } |
| logicalWidth += reference.base->logicalWidth(); |
| subScript = reference.firstPostScript; |
| while (subScript && subScript != reference.prescriptDelimiter) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subSupPairWidth = std::max(std::max(0_lu, subScript->logicalWidth() - baseItalicCorrection), supScript->logicalWidth()); |
| logicalWidth += subSupPairWidth + space; |
| subScript = supScript->nextSiblingBox(); |
| } |
| setLogicalWidth(logicalWidth); |
| |
| subScript = reference.firstPreScript; |
| while (subScript) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subSupPairWidth = std::max(subScript->logicalWidth(), supScript->logicalWidth()); |
| horizontalOffset += space + subSupPairWidth; |
| LayoutUnit subAscent = ascentForChild(*subScript); |
| LayoutPoint subScriptLocation(mirrorIfNeeded(horizontalOffset - subScript->logicalWidth(), *subScript), ascent + metrics.subShift - subAscent); |
| subScript->setLocation(subScriptLocation); |
| LayoutUnit supAscent = ascentForChild(*supScript); |
| LayoutPoint supScriptLocation(mirrorIfNeeded(horizontalOffset - supScript->logicalWidth(), *supScript), ascent - metrics.supShift - supAscent); |
| supScript->setLocation(supScriptLocation); |
| subScript = supScript->nextSiblingBox(); |
| } |
| LayoutPoint baseLocation(mirrorIfNeeded(horizontalOffset, *reference.base), ascent - baseAscent); |
| reference.base->setLocation(baseLocation); |
| horizontalOffset += reference.base->logicalWidth(); |
| subScript = reference.firstPostScript; |
| while (subScript && subScript != reference.prescriptDelimiter) { |
| auto supScript = subScript->nextSiblingBox(); |
| ASSERT(supScript); |
| LayoutUnit subAscent = ascentForChild(*subScript); |
| LayoutPoint subScriptLocation(mirrorIfNeeded(horizontalOffset - baseItalicCorrection, *subScript), ascent + metrics.subShift - subAscent); |
| subScript->setLocation(subScriptLocation); |
| LayoutUnit supAscent = ascentForChild(*supScript); |
| LayoutPoint supScriptLocation(mirrorIfNeeded(horizontalOffset, *supScript), ascent - metrics.supShift - supAscent); |
| supScript->setLocation(supScriptLocation); |
| |
| LayoutUnit subSupPairWidth = std::max(subScript->logicalWidth(), supScript->logicalWidth()); |
| horizontalOffset += subSupPairWidth + space; |
| subScript = supScript->nextSiblingBox(); |
| } |
| } |
| } |
| |
| layoutPositionedObjects(relayoutChildren); |
| |
| updateScrollInfoAfterLayout(); |
| |
| clearNeedsLayout(); |
| } |
| |
| Optional<int> RenderMathMLScripts::firstLineBaseline() const |
| { |
| auto* base = firstChildBox(); |
| if (!base) |
| return Optional<int>(); |
| return Optional<int>(static_cast<int>(lroundf(ascentForChild(*base) + base->logicalTop()))); |
| } |
| |
| } |
| |
| #endif // ENABLE(MATHML) |
