Mozilla/mozilla/layout/mathml/base/src/nsMathMLmfracFrame.h

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5.4 KiB
C++

/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Mozilla MathML Project.
*
* The Initial Developer of the Original Code is The University Of
* Queensland. Portions created by The University Of Queensland are
* Copyright (C) 1999 The University Of Queensland. All Rights Reserved.
*
* Contributor(s):
* Roger B. Sidje <rbs@maths.uq.edu.au>
* David J. Fiddes <D.J.Fiddes@hw.ac.uk>
* Shyjan Mahamud <mahamud@cs.cmu.edu>
*/
#ifndef nsMathMLmfracFrame_h___
#define nsMathMLmfracFrame_h___
#include "nsCOMPtr.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:
friend nsresult NS_NewMathMLmfracFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
NS_IMETHOD
SetAdditionalStyleContext(PRInt32 aIndex,
nsIStyleContext* aStyleContext);
NS_IMETHOD
GetAdditionalStyleContext(PRInt32 aIndex,
nsIStyleContext** aStyleContext) const;
NS_IMETHOD
AttributeChanged(nsIPresContext* aPresContext,
nsIContent* aChild,
PRInt32 aNameSpaceID,
nsIAtom* aAttribute,
PRInt32 aModType,
PRInt32 aHint);
NS_IMETHOD
Init(nsIPresContext* aPresContext,
nsIContent* aContent,
nsIFrame* aParent,
nsIStyleContext* aContext,
nsIFrame* aPrevInFlow);
NS_IMETHOD
Reflow(nsIPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus);
NS_IMETHOD
Place(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize);
NS_IMETHOD
Paint(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
const nsRect& aDirtyRect,
nsFramePaintLayer aWhichLayer,
PRUint32 aFlags = 0);
NS_IMETHOD
TransmitAutomaticData(nsIPresContext* aPresContext);
NS_IMETHOD
UpdatePresentationData(nsIPresContext* aPresContext,
PRInt32 aScriptLevelIncrement,
PRUint32 aFlagsValues,
PRUint32 aFlagsToUpdate);
NS_IMETHOD
UpdatePresentationDataFromChildAt(nsIPresContext* aPresContext,
PRInt32 aFirstIndex,
PRInt32 aLastIndex,
PRInt32 aScriptLevelIncrement,
PRUint32 aFlagsValues,
PRUint32 aFlagsToUpdate);
// helper to translate the thickness attribute into a usable form
static nscoord
CalcLineThickness(nsIPresContext* aPresContext,
nsIStyleContext* aStyleContext,
nsString& aThicknessAttribute,
nscoord onePixel,
nscoord aDefaultRuleThickness);
protected:
nsMathMLmfracFrame();
virtual ~nsMathMLmfracFrame();
virtual PRIntn GetSkipSides() const { return 0; }
PRBool
IsBevelled();
PRInt32 mInnerScriptLevel;
nsRect mLineRect;
nsMathMLChar* mSlashChar;
};
#endif /* nsMathMLmfracFrame_h___ */