LCOV - code coverage report
Current view: directory - layout/mathml - nsMathMLmsubFrame.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 63 0 0.0 %
Date: 2012-06-02 Functions: 8 0 0.0 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2                 : /* ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is Mozilla MathML Project.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is
      18                 :  * The University Of Queensland.
      19                 :  * Portions created by the Initial Developer are Copyright (C) 1999
      20                 :  * the Initial Developer. All Rights Reserved.
      21                 :  *
      22                 :  * Contributor(s):
      23                 :  *   Roger B. Sidje <rbs@maths.uq.edu.au>
      24                 :  *   David J. Fiddes <D.J.Fiddes@hw.ac.uk>
      25                 :  *   Shyjan Mahamud <mahamud@cs.cmu.edu> (added TeX rendering rules)
      26                 :  *
      27                 :  * Alternatively, the contents of this file may be used under the terms of
      28                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      29                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      30                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      31                 :  * of those above. If you wish to allow use of your version of this file only
      32                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      33                 :  * use your version of this file under the terms of the MPL, indicate your
      34                 :  * decision by deleting the provisions above and replace them with the notice
      35                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      36                 :  * the provisions above, a recipient may use your version of this file under
      37                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      38                 :  *
      39                 :  * ***** END LICENSE BLOCK ***** */
      40                 : 
      41                 : 
      42                 : #include "nsCOMPtr.h"
      43                 : #include "nsFrame.h"
      44                 : #include "nsPresContext.h"
      45                 : #include "nsStyleContext.h"
      46                 : #include "nsStyleConsts.h"
      47                 : 
      48                 : #include "nsMathMLmsubFrame.h"
      49                 : 
      50                 : //
      51                 : // <msub> -- attach a subscript to a base - implementation
      52                 : //
      53                 : 
      54                 : nsIFrame*
      55               0 : NS_NewMathMLmsubFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
      56                 : {
      57               0 :   return new (aPresShell) nsMathMLmsubFrame(aContext);
      58                 : }
      59                 : 
      60               0 : NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmsubFrame)
      61                 : 
      62               0 : nsMathMLmsubFrame::~nsMathMLmsubFrame()
      63                 : {
      64               0 : }
      65                 : 
      66                 : NS_IMETHODIMP
      67               0 : nsMathMLmsubFrame::TransmitAutomaticData()
      68                 : {
      69                 :   // if our base is an embellished operator, let its state bubble to us
      70               0 :   mPresentationData.baseFrame = mFrames.FirstChild();
      71               0 :   GetEmbellishDataFrom(mPresentationData.baseFrame, mEmbellishData);
      72                 : 
      73                 :   // 1. The REC says:
      74                 :   // The <msub> element increments scriptlevel by 1, and sets displaystyle to
      75                 :   // "false", within subscript, but leaves both attributes unchanged within base.
      76                 :   // 2. The TeXbook (Ch 17. p.141) says the subscript is compressed
      77                 :   UpdatePresentationDataFromChildAt(1, -1,
      78                 :     ~NS_MATHML_DISPLAYSTYLE | NS_MATHML_COMPRESSED,
      79               0 :      NS_MATHML_DISPLAYSTYLE | NS_MATHML_COMPRESSED);
      80                 : 
      81               0 :   return NS_OK;
      82                 : }
      83                 : 
      84                 : /* virtual */ nsresult
      85               0 : nsMathMLmsubFrame::Place (nsRenderingContext& aRenderingContext,
      86                 :                           bool                 aPlaceOrigin,
      87                 :                           nsHTMLReflowMetrics& aDesiredSize)
      88                 : {
      89                 :   // extra spacing after sup/subscript
      90               0 :   nscoord scriptSpace = nsPresContext::CSSPointsToAppUnits(0.5f); // 0.5pt as in plain TeX
      91                 : 
      92                 :   // check if the subscriptshift attribute is there
      93               0 :   nscoord subScriptShift = 0;
      94               0 :   nsAutoString value;
      95                 :   GetAttribute(mContent, mPresentationData.mstyle,
      96               0 :                nsGkAtoms::subscriptshift_, value);
      97               0 :   if (!value.IsEmpty()) {
      98               0 :     nsCSSValue cssValue;
      99               0 :     if (ParseNumericValue(value, cssValue) && cssValue.IsLengthUnit()) {
     100               0 :       subScriptShift = CalcLength(PresContext(), mStyleContext, cssValue);
     101                 :     }
     102                 :   }
     103                 : 
     104                 :   return nsMathMLmsubFrame::PlaceSubScript(PresContext(), 
     105                 :                                            aRenderingContext,
     106                 :                                            aPlaceOrigin,
     107                 :                                            aDesiredSize,
     108                 :                                            this,
     109                 :                                            subScriptShift,
     110               0 :                                            scriptSpace);
     111                 : }
     112                 : 
     113                 : // exported routine that both munder and msub share.
     114                 : // munder uses this when movablelimits is set.
     115                 : nsresult
     116               0 : nsMathMLmsubFrame::PlaceSubScript (nsPresContext*      aPresContext,
     117                 :                                    nsRenderingContext& aRenderingContext,
     118                 :                                    bool                 aPlaceOrigin,
     119                 :                                    nsHTMLReflowMetrics& aDesiredSize,
     120                 :                                    nsMathMLContainerFrame* aFrame,
     121                 :                                    nscoord              aUserSubScriptShift,
     122                 :                                    nscoord              aScriptSpace)
     123                 : {
     124                 :   // force the scriptSpace to be atleast 1 pixel 
     125               0 :   aScriptSpace = NS_MAX(nsPresContext::CSSPixelsToAppUnits(1), aScriptSpace);
     126                 : 
     127                 :   ////////////////////////////////////
     128                 :   // Get the children's desired sizes
     129                 : 
     130               0 :   nsBoundingMetrics bmBase, bmSubScript;
     131               0 :   nsHTMLReflowMetrics baseSize;
     132               0 :   nsHTMLReflowMetrics subScriptSize;
     133               0 :   nsIFrame* baseFrame = aFrame->GetFirstPrincipalChild();
     134               0 :   nsIFrame* subScriptFrame = nsnull;
     135               0 :   if (baseFrame)
     136               0 :     subScriptFrame = baseFrame->GetNextSibling();
     137               0 :   if (!baseFrame || !subScriptFrame || subScriptFrame->GetNextSibling()) {
     138                 :     // report an error, encourage people to get their markups in order
     139               0 :     return aFrame->ReflowError(aRenderingContext, aDesiredSize);
     140                 :   }
     141               0 :   GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
     142               0 :   GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
     143                 : 
     144                 :   // get the subdrop from the subscript font
     145                 :   nscoord subDrop;
     146               0 :   GetSubDropFromChild(subScriptFrame, subDrop);
     147                 :   // parameter v, Rule 18a, App. G, TeXbook
     148               0 :   nscoord minSubScriptShift = bmBase.descent + subDrop;
     149                 : 
     150                 :   //////////////////
     151                 :   // Place Children
     152                 :   
     153                 :   // get min subscript shift limit from x-height
     154                 :   // = h(x) - 4/5 * sigma_5, Rule 18b, App. G, TeXbook
     155               0 :   nscoord xHeight = 0;
     156               0 :   nsRefPtr<nsFontMetrics> fm;
     157               0 :   nsLayoutUtils::GetFontMetricsForFrame(baseFrame, getter_AddRefs(fm));
     158                 : 
     159               0 :   xHeight = fm->XHeight();
     160                 :   nscoord minShiftFromXHeight = (nscoord) 
     161               0 :     (bmSubScript.ascent - (4.0f/5.0f) * xHeight);
     162                 : 
     163                 :   // subScriptShift
     164                 :   // = minimum amount to shift the subscript down set by user or from the font
     165                 :   // = sub1 in TeX
     166                 :   // = subscriptshift attribute * x-height
     167                 :   nscoord subScriptShift, dummy;
     168                 :   // get subScriptShift default from font
     169               0 :   GetSubScriptShifts (fm, subScriptShift, dummy);
     170                 : 
     171                 :   subScriptShift = 
     172               0 :     NS_MAX(subScriptShift, aUserSubScriptShift);
     173                 : 
     174                 :   // get actual subscriptshift to be used
     175                 :   // Rule 18b, App. G, TeXbook
     176                 :   nscoord actualSubScriptShift = 
     177               0 :     NS_MAX(minSubScriptShift,NS_MAX(subScriptShift,minShiftFromXHeight));
     178                 :   // get bounding box for base + subscript
     179               0 :   nsBoundingMetrics boundingMetrics;
     180                 :   boundingMetrics.ascent = 
     181               0 :     NS_MAX(bmBase.ascent, bmSubScript.ascent - actualSubScriptShift);
     182                 :   boundingMetrics.descent = 
     183               0 :     NS_MAX(bmBase.descent, bmSubScript.descent + actualSubScriptShift);
     184                 : 
     185                 :   // add aScriptSpace to the subscript's width
     186               0 :   boundingMetrics.width = bmBase.width + bmSubScript.width + aScriptSpace;
     187               0 :   boundingMetrics.leftBearing = bmBase.leftBearing;
     188                 :   boundingMetrics.rightBearing = NS_MAX(bmBase.rightBearing, bmBase.width +
     189               0 :     NS_MAX(bmSubScript.width + aScriptSpace, bmSubScript.rightBearing));
     190               0 :   aFrame->SetBoundingMetrics (boundingMetrics);
     191                 : 
     192                 :   // reflow metrics
     193                 :   aDesiredSize.ascent = 
     194               0 :     NS_MAX(baseSize.ascent, subScriptSize.ascent - actualSubScriptShift);
     195                 :   aDesiredSize.height = aDesiredSize.ascent +
     196                 :     NS_MAX(baseSize.height - baseSize.ascent,
     197               0 :            subScriptSize.height - subScriptSize.ascent + actualSubScriptShift);
     198               0 :   aDesiredSize.width = boundingMetrics.width;
     199               0 :   aDesiredSize.mBoundingMetrics = boundingMetrics;
     200                 : 
     201               0 :   aFrame->SetReference(nsPoint(0, aDesiredSize.ascent));
     202                 : 
     203               0 :   if (aPlaceOrigin) {
     204                 :     nscoord dx, dy;
     205                 :     // now place the base ...
     206               0 :     dx = aFrame->MirrorIfRTL(aDesiredSize.width, baseSize.width, 0);
     207               0 :     dy = aDesiredSize.ascent - baseSize.ascent;
     208               0 :     FinishReflowChild (baseFrame, aPresContext, nsnull, baseSize, dx, dy, 0);
     209                 :     // ... and subscript
     210                 :     dx = aFrame->MirrorIfRTL(aDesiredSize.width, subScriptSize.width,
     211               0 :                              bmBase.width);
     212               0 :     dy = aDesiredSize.ascent - (subScriptSize.ascent - actualSubScriptShift);
     213               0 :     FinishReflowChild (subScriptFrame, aPresContext, nsnull, subScriptSize, dx, dy, 0);
     214                 :   }
     215                 : 
     216               0 :   return NS_OK;
     217                 : }

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