gecko/layout/mathml/nsMathMLmsqrtFrame.h

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * 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/
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 * 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 Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Roger B. Sidje <rbs@maths.uq.edu.au>
 *   David J. Fiddes <D.J.Fiddes@hw.ac.uk>
 *   Vilya Harvey <vilya@nag.co.uk>
 *   Shyjan Mahamud <mahamud@cs.cmu.edu>
 *
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#ifndef nsMathMLmsqrtFrame_h___
#define nsMathMLmsqrtFrame_h___

#include "nsCOMPtr.h"
#include "nsMathMLContainerFrame.h"

//
// <msqrt> -- form a fraction from two subexpressions 
//

/*
The MathML REC describes:

The <msqrt> element is used to display square roots.
The syntax for <msqrt> is:
  <msqrt> base </msqrt>

Attributes of <msqrt> and <mroot>:

None (except the attributes allowed for all MathML elements, listed in Section
2.3.4). 

The <mroot> element increments scriptlevel by 2, and sets displaystyle to
"false", within index, but leaves both attributes unchanged within base. The
<msqrt> element leaves both attributes unchanged within all its arguments.
These attributes are inherited by every element from its rendering environment,
but can be set explicitly only on <mstyle>. (See Section 3.3.4.) 
*/

/*
TODO:
*/

class nsMathMLmsqrtFrame : public nsMathMLContainerFrame {
public:
  friend nsIFrame* NS_NewMathMLmsqrtFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);

  virtual void
  SetAdditionalStyleContext(PRInt32          aIndex, 
                            nsStyleContext*  aStyleContext);
  virtual nsStyleContext*
  GetAdditionalStyleContext(PRInt32 aIndex) const;

  NS_IMETHOD
  Init(nsIContent* aContent,
       nsIFrame*   aParent,
       nsIFrame*   aPrevInFlow);

  virtual nsresult
  Place(nsIRenderingContext& aRenderingContext,
        PRBool               aPlaceOrigin,
        nsHTMLReflowMetrics& aDesiredSize);

  virtual nscoord
  GetIntrinsicWidth(nsIRenderingContext* aRenderingContext);

  NS_IMETHOD BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                              const nsRect&           aDirtyRect,
                              const nsDisplayListSet& aLists);

  NS_IMETHOD
  InheritAutomaticData(nsIFrame* aParent);

  NS_IMETHOD
  TransmitAutomaticData();

  // the base method doesn't deal fully with <msqrt> because it only
  // slides child frames and has no idea that we have a sqrt glyph that
  // is part of the flow without being a frame. We need to shift our
  // sqrt glyph too. 
  virtual nscoord
  FixInterFrameSpacing(nsHTMLReflowMetrics& aDesiredSize);

protected:
  nsMathMLmsqrtFrame(nsStyleContext* aContext);
  virtual ~nsMathMLmsqrtFrame();
  
  virtual PRIntn GetSkipSides() const { return 0; }

  virtual nsresult
  MeasureChildFrames(nsIRenderingContext& aRenderingContext,
                     nsHTMLReflowMetrics& aDesiredSize);

  nsMathMLChar mSqrChar;
  nsRect       mBarRect;
};

#endif /* nsMathMLmsqrtFrame_h___ */