LCOV - code coverage report
Current view: directory - layout/mathml - nsMathMLmsupFrame.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 79 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                 : #include "nsCOMPtr.h"
      42                 : #include "nsFrame.h"
      43                 : #include "nsPresContext.h"
      44                 : #include "nsStyleContext.h"
      45                 : #include "nsStyleConsts.h"
      46                 : 
      47                 : #include "nsMathMLmsupFrame.h"
      48                 : 
      49                 : //
      50                 : // <msup> -- attach a superscript to a base - implementation
      51                 : //
      52                 : 
      53                 : nsIFrame*
      54               0 : NS_NewMathMLmsupFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
      55                 : {
      56               0 :   return new (aPresShell) nsMathMLmsupFrame(aContext);
      57                 : }
      58                 : 
      59               0 : NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmsupFrame)
      60                 : 
      61               0 : nsMathMLmsupFrame::~nsMathMLmsupFrame()
      62                 : {
      63               0 : }
      64                 : 
      65                 : NS_IMETHODIMP
      66               0 : nsMathMLmsupFrame::TransmitAutomaticData()
      67                 : {
      68                 :   // if our base is an embellished operator, its flags bubble to us
      69               0 :   mPresentationData.baseFrame = mFrames.FirstChild();
      70               0 :   GetEmbellishDataFrom(mPresentationData.baseFrame, mEmbellishData);
      71                 : 
      72                 :   // 1. The REC says:
      73                 :   // The <msup> element increments scriptlevel by 1, and sets displaystyle to
      74                 :   // "false", within superscript, but leaves both attributes unchanged within base.
      75                 :   // 2. The TeXbook (Ch 17. p.141) says the superscript *inherits* the compression,
      76                 :   // so we don't set the compression flag. Our parent will propagate its own.
      77                 :   UpdatePresentationDataFromChildAt(1, -1,
      78                 :     ~NS_MATHML_DISPLAYSTYLE,
      79               0 :      NS_MATHML_DISPLAYSTYLE);
      80                 : 
      81               0 :   return NS_OK;
      82                 : }
      83                 : 
      84                 : /* virtual */ nsresult
      85               0 : nsMathMLmsupFrame::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 superscriptshift attribute is there
      93               0 :   nsAutoString value;
      94               0 :   nscoord supScriptShift = 0;
      95                 :   GetAttribute(mContent, mPresentationData.mstyle,
      96               0 :                nsGkAtoms::superscriptshift_, value);
      97               0 :   if (!value.IsEmpty()) {
      98               0 :     nsCSSValue cssValue;
      99               0 :     if (ParseNumericValue(value, cssValue) && cssValue.IsLengthUnit()) {
     100               0 :       supScriptShift = CalcLength(PresContext(), mStyleContext, cssValue);
     101                 :     }
     102                 :   }
     103                 : 
     104                 :   return nsMathMLmsupFrame::PlaceSuperScript(PresContext(), 
     105                 :                                              aRenderingContext,
     106                 :                                              aPlaceOrigin,
     107                 :                                              aDesiredSize,
     108                 :                                              this,
     109                 :                                              supScriptShift,
     110               0 :                                              scriptSpace);
     111                 : }
     112                 : 
     113                 : // exported routine that both mover and msup share.
     114                 : // mover uses this when movablelimits is set.
     115                 : nsresult
     116               0 : nsMathMLmsupFrame::PlaceSuperScript(nsPresContext*      aPresContext,
     117                 :                                     nsRenderingContext& aRenderingContext,
     118                 :                                     bool                 aPlaceOrigin,
     119                 :                                     nsHTMLReflowMetrics& aDesiredSize,
     120                 :                                     nsMathMLContainerFrame* aFrame,
     121                 :                                     nscoord              aUserSupScriptShift,
     122                 :                                     nscoord              aScriptSpace)
     123                 : {
     124                 :   // force the scriptSpace to be at least 1 pixel 
     125               0 :   nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
     126               0 :   aScriptSpace = NS_MAX(onePixel, aScriptSpace);
     127                 : 
     128                 :   ////////////////////////////////////
     129                 :   // Get the children's desired sizes
     130                 : 
     131               0 :   nsHTMLReflowMetrics baseSize;
     132               0 :   nsHTMLReflowMetrics supScriptSize;
     133               0 :   nsBoundingMetrics bmBase, bmSupScript;
     134               0 :   nsIFrame* supScriptFrame = nsnull;
     135               0 :   nsIFrame* baseFrame = aFrame->GetFirstPrincipalChild();
     136               0 :   if (baseFrame)
     137               0 :     supScriptFrame = baseFrame->GetNextSibling();
     138               0 :   if (!baseFrame || !supScriptFrame || supScriptFrame->GetNextSibling()) {
     139                 :     // report an error, encourage people to get their markups in order
     140               0 :     return aFrame->ReflowError(aRenderingContext, aDesiredSize);
     141                 :   }
     142               0 :   GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
     143               0 :   GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, bmSupScript);
     144                 : 
     145                 :   // get the supdrop from the supscript font
     146                 :   nscoord supDrop;
     147               0 :   GetSupDropFromChild(supScriptFrame, supDrop);
     148                 :   // parameter u, Rule 18a, App. G, TeXbook
     149               0 :   nscoord minSupScriptShift = bmBase.ascent - supDrop;
     150                 : 
     151                 :   //////////////////
     152                 :   // Place Children 
     153                 :   
     154                 :   // get min supscript shift limit from x-height
     155                 :   // = d(x) + 1/4 * sigma_5, Rule 18c, App. G, TeXbook
     156               0 :   nscoord xHeight = 0;
     157               0 :   nsRefPtr<nsFontMetrics> fm;
     158               0 :   nsLayoutUtils::GetFontMetricsForFrame(baseFrame, getter_AddRefs(fm));
     159                 : 
     160               0 :   xHeight = fm->XHeight();
     161                 :   nscoord minShiftFromXHeight = (nscoord) 
     162               0 :     (bmSupScript.descent + (1.0f/4.0f) * xHeight);
     163                 :   nscoord italicCorrection;
     164               0 :   GetItalicCorrection(bmBase, italicCorrection);
     165                 : 
     166                 :   // supScriptShift{1,2,3}
     167                 :   // = minimum amount to shift the supscript up
     168                 :   // = sup{1,2,3} in TeX
     169                 :   // supScriptShift1 = superscriptshift attribute * x-height
     170                 :   // Note that there are THREE values for supscript shifts depending
     171                 :   // on the current style
     172                 :   nscoord supScriptShift1, supScriptShift2, supScriptShift3;
     173                 :   // Set supScriptShift{1,2,3} default from font
     174               0 :   GetSupScriptShifts (fm, supScriptShift1, supScriptShift2, supScriptShift3);
     175                 : 
     176               0 :   if (0 < aUserSupScriptShift) {
     177                 :     // the user has set the superscriptshift attribute
     178               0 :     float scaler2 = ((float) supScriptShift2) / supScriptShift1;
     179               0 :     float scaler3 = ((float) supScriptShift3) / supScriptShift1;
     180                 :     supScriptShift1 = 
     181               0 :       NS_MAX(supScriptShift1, aUserSupScriptShift);
     182               0 :     supScriptShift2 = NSToCoordRound(scaler2 * supScriptShift1);
     183               0 :     supScriptShift3 = NSToCoordRound(scaler3 * supScriptShift1);
     184                 :   }
     185                 : 
     186                 :   // get sup script shift depending on current script level and display style
     187                 :   // Rule 18c, App. G, TeXbook
     188                 :   nscoord supScriptShift;
     189               0 :   nsPresentationData presentationData;
     190               0 :   aFrame->GetPresentationData (presentationData);
     191               0 :   if ( aFrame->GetStyleFont()->mScriptLevel == 0 && 
     192                 :        NS_MATHML_IS_DISPLAYSTYLE(presentationData.flags) &&
     193               0 :       !NS_MATHML_IS_COMPRESSED(presentationData.flags)) {
     194                 :     // Style D in TeXbook
     195               0 :     supScriptShift = supScriptShift1;
     196                 :   }
     197               0 :   else if (NS_MATHML_IS_COMPRESSED(presentationData.flags)) {
     198                 :     // Style C' in TeXbook = D',T',S',SS'
     199               0 :     supScriptShift = supScriptShift3;
     200                 :   }
     201                 :   else {
     202                 :     // everything else = T,S,SS
     203               0 :     supScriptShift = supScriptShift2;
     204                 :   }
     205                 : 
     206                 :   // get actual supscriptshift to be used
     207                 :   // Rule 18c, App. G, TeXbook
     208                 :   nscoord actualSupScriptShift = 
     209               0 :     NS_MAX(minSupScriptShift,NS_MAX(supScriptShift,minShiftFromXHeight));
     210                 : 
     211                 :   // bounding box
     212               0 :   nsBoundingMetrics boundingMetrics;
     213                 :   boundingMetrics.ascent =
     214               0 :     NS_MAX(bmBase.ascent, (bmSupScript.ascent + actualSupScriptShift));
     215                 :   boundingMetrics.descent =
     216               0 :     NS_MAX(bmBase.descent, (bmSupScript.descent - actualSupScriptShift));
     217                 : 
     218                 :   // leave aScriptSpace after superscript
     219                 :   // add italicCorrection between base and superscript
     220                 :   // add "a little to spare" as well (see TeXbook Ch.11, p.64), as we
     221                 :   // estimate the italic creation ourselves and it isn't the same as TeX 
     222               0 :   italicCorrection += onePixel;
     223                 :   boundingMetrics.width = bmBase.width + italicCorrection +
     224               0 :                           bmSupScript.width + aScriptSpace;
     225               0 :   boundingMetrics.leftBearing = bmBase.leftBearing;
     226                 :   boundingMetrics.rightBearing = bmBase.width + italicCorrection +
     227               0 :                                  bmSupScript.rightBearing;
     228               0 :   aFrame->SetBoundingMetrics(boundingMetrics);
     229                 : 
     230                 :   // reflow metrics
     231                 :   aDesiredSize.ascent =
     232               0 :     NS_MAX(baseSize.ascent, (supScriptSize.ascent + actualSupScriptShift));
     233                 :   aDesiredSize.height = aDesiredSize.ascent +
     234                 :     NS_MAX(baseSize.height - baseSize.ascent,
     235               0 :            (supScriptSize.height - supScriptSize.ascent - actualSupScriptShift));
     236               0 :   aDesiredSize.width = boundingMetrics.width;
     237               0 :   aDesiredSize.mBoundingMetrics = boundingMetrics;
     238                 : 
     239               0 :   aFrame->SetReference(nsPoint(0, aDesiredSize.ascent));
     240                 : 
     241               0 :   if (aPlaceOrigin) {
     242                 :     nscoord dx, dy;
     243                 :     // now place the base ...
     244               0 :     dx = aFrame->MirrorIfRTL(aDesiredSize.width, baseSize.width, 0);
     245               0 :     dy = aDesiredSize.ascent - baseSize.ascent;
     246               0 :     FinishReflowChild (baseFrame, aPresContext, nsnull, baseSize, dx, dy, 0);
     247                 :     // ... and supscript
     248                 :     dx = aFrame->MirrorIfRTL(aDesiredSize.width, supScriptSize.width,
     249               0 :                              bmBase.width + italicCorrection);
     250               0 :     dy = aDesiredSize.ascent - (supScriptSize.ascent + actualSupScriptShift);
     251               0 :     FinishReflowChild (supScriptFrame, aPresContext, nsnull, supScriptSize, dx, dy, 0);
     252                 :   }
     253                 : 
     254               0 :   return NS_OK;
     255                 : }

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