/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* 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/. */ #ifndef nsMathMLmfracFrame_h___ #define nsMathMLmfracFrame_h___ #include "mozilla/Attributes.h" #include "nsMathMLContainerFrame.h" // // <mfrac> -- form a fraction from two subexpressions // /* The MathML REC describes: The <mfrac> element is used for fractions. It can also be used to mark up fraction-like objects such as binomial coefficients and Legendre symbols. The syntax for <mfrac> is: <mfrac> numerator denominator </mfrac> Attributes of <mfrac>: Name values default linethickness number [ v-unit ] | thin | medium | thick 1 E.g., linethickness=2 actually means that linethickness=2*DEFAULT_THICKNESS (DEFAULT_THICKNESS is not specified by MathML, see below.) The linethickness attribute indicates the thickness of the horizontal "fraction bar", or "rule", typically used to render fractions. A fraction with linethickness="0" renders without the bar, and might be used within binomial coefficients. A linethickness greater than one might be used with nested fractions. In general, the value of linethickness can be a number, as a multiplier of the default thickness of the fraction bar (the default thickness is not specified by MathML), or a number with a unit of vertical length (see Section 2.3.3), or one of the keywords medium (same as 1), thin (thinner than 1, otherwise up to the renderer), or thick (thicker than 1, otherwise up to the renderer). The <mfrac> element sets displaystyle to "false", or if it was already false increments scriptlevel by 1, within numerator and denominator. These attributes are inherited by every element from its rendering environment, but can be set explicitly only on the <mstyle> element. */ class nsMathMLmfracFrame : public nsMathMLContainerFrame { public: NS_DECL_FRAMEARENA_HELPERS friend nsIFrame* NS_NewMathMLmfracFrame(nsIPresShell* aPresShell, nsStyleContext* aContext); virtual eMathMLFrameType GetMathMLFrameType() override; virtual nsresult MeasureForWidth(DrawTarget* aDrawTarget, ReflowOutput& aDesiredSize) override; virtual nsresult Place(DrawTarget* aDrawTarget, bool aPlaceOrigin, ReflowOutput& aDesiredSize) override; virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder, const nsRect& aDirtyRect, const nsDisplayListSet& aLists) override; virtual nsresult AttributeChanged(int32_t aNameSpaceID, nsIAtom* aAttribute, int32_t aModType) override; NS_IMETHOD TransmitAutomaticData() override; // override the base method so that we can deal with the fraction line virtual nscoord FixInterFrameSpacing(ReflowOutput& aDesiredSize) override; // helper to translate the thickness attribute into a usable form static nscoord CalcLineThickness(nsPresContext* aPresContext, nsStyleContext* aStyleContext, nsString& aThicknessAttribute, nscoord onePixel, nscoord aDefaultRuleThickness, float aFontSizeInflation); uint8_t ScriptIncrement(nsIFrame* aFrame) override; protected: explicit nsMathMLmfracFrame(nsStyleContext* aContext) : nsMathMLContainerFrame(aContext) {} virtual ~nsMathMLmfracFrame(); nsresult PlaceInternal(DrawTarget* aDrawTarget, bool aPlaceOrigin, ReflowOutput& aDesiredSize, bool aWidthOnly); // Display a slash void DisplaySlash(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, const nsRect& aRect, nscoord aThickness, const nsDisplayListSet& aLists); nsRect mLineRect; nsMathMLChar* mSlashChar; nscoord mLineThickness; bool mIsBevelled; }; #endif /* nsMathMLmfracFrame_h___ */