summaryrefslogtreecommitdiffstats
path: root/layout/mathml/nsMathMLmfracFrame.h
diff options
context:
space:
mode:
Diffstat (limited to 'layout/mathml/nsMathMLmfracFrame.h')
-rw-r--r--layout/mathml/nsMathMLmfracFrame.h118
1 files changed, 118 insertions, 0 deletions
diff --git a/layout/mathml/nsMathMLmfracFrame.h b/layout/mathml/nsMathMLmfracFrame.h
new file mode 100644
index 000000000..330a31180
--- /dev/null
+++ b/layout/mathml/nsMathMLmfracFrame.h
@@ -0,0 +1,118 @@
+/* -*- 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___ */