1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/mathml/nsMathMLmfracFrame.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,112 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsMathMLmfracFrame_h___
1.10 +#define nsMathMLmfracFrame_h___
1.11 +
1.12 +#include "mozilla/Attributes.h"
1.13 +#include "nsMathMLContainerFrame.h"
1.14 +
1.15 +//
1.16 +// <mfrac> -- form a fraction from two subexpressions
1.17 +//
1.18 +
1.19 +/*
1.20 +The MathML REC describes:
1.21 +
1.22 +The <mfrac> element is used for fractions. It can also be used to mark up
1.23 +fraction-like objects such as binomial coefficients and Legendre symbols.
1.24 +The syntax for <mfrac> is:
1.25 + <mfrac> numerator denominator </mfrac>
1.26 +
1.27 +Attributes of <mfrac>:
1.28 + Name values default
1.29 + linethickness number [ v-unit ] | thin | medium | thick 1
1.30 +
1.31 +E.g.,
1.32 +linethickness=2 actually means that linethickness=2*DEFAULT_THICKNESS
1.33 +(DEFAULT_THICKNESS is not specified by MathML, see below.)
1.34 +
1.35 +The linethickness attribute indicates the thickness of the horizontal
1.36 +"fraction bar", or "rule", typically used to render fractions. A fraction
1.37 +with linethickness="0" renders without the bar, and might be used within
1.38 +binomial coefficients. A linethickness greater than one might be used with
1.39 +nested fractions.
1.40 +
1.41 +In general, the value of linethickness can be a number, as a multiplier
1.42 +of the default thickness of the fraction bar (the default thickness is
1.43 +not specified by MathML), or a number with a unit of vertical length (see
1.44 +Section 2.3.3), or one of the keywords medium (same as 1), thin (thinner
1.45 +than 1, otherwise up to the renderer), or thick (thicker than 1, otherwise
1.46 +up to the renderer).
1.47 +
1.48 +The <mfrac> element sets displaystyle to "false", or if it was already
1.49 +false increments scriptlevel by 1, within numerator and denominator.
1.50 +These attributes are inherited by every element from its rendering
1.51 +environment, but can be set explicitly only on the <mstyle>
1.52 +element.
1.53 +*/
1.54 +
1.55 +class nsMathMLmfracFrame : public nsMathMLContainerFrame {
1.56 +public:
1.57 + NS_DECL_FRAMEARENA_HELPERS
1.58 +
1.59 + friend nsIFrame* NS_NewMathMLmfracFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
1.60 +
1.61 + virtual eMathMLFrameType GetMathMLFrameType() MOZ_OVERRIDE;
1.62 +
1.63 + virtual nsresult
1.64 + MeasureForWidth(nsRenderingContext& aRenderingContext,
1.65 + nsHTMLReflowMetrics& aDesiredSize) MOZ_OVERRIDE;
1.66 +
1.67 + virtual nsresult
1.68 + Place(nsRenderingContext& aRenderingContext,
1.69 + bool aPlaceOrigin,
1.70 + nsHTMLReflowMetrics& aDesiredSize) MOZ_OVERRIDE;
1.71 +
1.72 + virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder,
1.73 + const nsRect& aDirtyRect,
1.74 + const nsDisplayListSet& aLists) MOZ_OVERRIDE;
1.75 +
1.76 + NS_IMETHOD
1.77 + TransmitAutomaticData() MOZ_OVERRIDE;
1.78 +
1.79 + // override the base method so that we can deal with the fraction line
1.80 + virtual nscoord
1.81 + FixInterFrameSpacing(nsHTMLReflowMetrics& aDesiredSize) MOZ_OVERRIDE;
1.82 +
1.83 + // helper to translate the thickness attribute into a usable form
1.84 + static nscoord
1.85 + CalcLineThickness(nsPresContext* aPresContext,
1.86 + nsStyleContext* aStyleContext,
1.87 + nsString& aThicknessAttribute,
1.88 + nscoord onePixel,
1.89 + nscoord aDefaultRuleThickness);
1.90 +
1.91 + uint8_t
1.92 + ScriptIncrement(nsIFrame* aFrame) MOZ_OVERRIDE;
1.93 +
1.94 +protected:
1.95 + nsMathMLmfracFrame(nsStyleContext* aContext) : nsMathMLContainerFrame(aContext) {}
1.96 + virtual ~nsMathMLmfracFrame();
1.97 +
1.98 + nsresult PlaceInternal(nsRenderingContext& aRenderingContext,
1.99 + bool aPlaceOrigin,
1.100 + nsHTMLReflowMetrics& aDesiredSize,
1.101 + bool aWidthOnly);
1.102 +
1.103 + // Display a slash
1.104 + void DisplaySlash(nsDisplayListBuilder* aBuilder,
1.105 + nsIFrame* aFrame, const nsRect& aRect,
1.106 + nscoord aThickness,
1.107 + const nsDisplayListSet& aLists);
1.108 +
1.109 + nsRect mLineRect;
1.110 + nsMathMLChar* mSlashChar;
1.111 + nscoord mLineThickness;
1.112 + bool mIsBevelled;
1.113 +};
1.114 +
1.115 +#endif /* nsMathMLmfracFrame_h___ */
