layout/mathml/nsMathMLmspaceFrame.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsMathMLmspaceFrame.h"
   7 #include "nsMathMLElement.h"
   8 #include "mozilla/gfx/2D.h"
   9 #include <algorithm>
  10
  11
  12 //
  13 // <mspace> -- space - implementation
  14 //
  15
  16 nsIFrame*
  17 NS_NewMathMLmspaceFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
  18 {
  19   return new (aPresShell) nsMathMLmspaceFrame(aContext);
  20 }
  21
  22 NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmspaceFrame)
  23
  24 nsMathMLmspaceFrame::~nsMathMLmspaceFrame()
  25 {
  26 }
  27
  28 bool
  29 nsMathMLmspaceFrame::IsLeaf() const
  30 {
  31   return true;
  32 }
  33
  34 void
  35 nsMathMLmspaceFrame::ProcessAttributes(nsPresContext* aPresContext)
  36 {
  37   nsAutoString value;
  38
  39   // width
  40   //
  41   // "Specifies the desired width of the space."
  42   //
  43   // values: length
  44   // default: 0em
  45   //
  46   // The default value is "0em", so unitless values can be ignored.
  47   // <mspace/> is listed among MathML elements allowing negative spacing and
  48   // the MathML test suite contains "Presentation/TokenElements/mspace/mspace2"
  49   // as an example. Hence we allow negative values.
  50   //
  51   mWidth = 0;
  52   mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::width, value);
  53   if (!value.IsEmpty()) {
  54     ParseNumericValue(value, &mWidth,
  55                       nsMathMLElement::PARSE_ALLOW_NEGATIVE,
  56                       aPresContext, mStyleContext);
  57   }
  58
  59   // height
  60   //
  61   // "Specifies the desired height (above the baseline) of the space."
  62   //
  63   // values: length
  64   // default: 0ex
  65   //
  66   // The default value is "0ex", so unitless values can be ignored.
  67   // We do not allow negative values. See bug 716349.
  68   //
  69   mHeight = 0;
  70   mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::height, value);
  71   if (!value.IsEmpty()) {
  72     ParseNumericValue(value, &mHeight, 0,
  73                       aPresContext, mStyleContext);
  74   }
  75
  76   // depth
  77   //
  78   // "Specifies the desired depth (below the baseline) of the space."
  79   //
  80   // values: length
  81   // default: 0ex
  82   //
  83   // The default value is "0ex", so unitless values can be ignored.
  84   // We do not allow negative values. See bug 716349.
  85   //
  86   mDepth = 0;
  87   mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::depth_, value);
  88   if (!value.IsEmpty()) {
  89     ParseNumericValue(value, &mDepth, 0,
  90                       aPresContext, mStyleContext);
  91   }
  92 }
  93
  94 void
  95 nsMathMLmspaceFrame::Reflow(nsPresContext*          aPresContext,
  96                             nsHTMLReflowMetrics&     aDesiredSize,
  97                             const nsHTMLReflowState& aReflowState,
  98                             nsReflowStatus&          aStatus)
  99 {
 100   ProcessAttributes(aPresContext);
 101
 102   mBoundingMetrics = nsBoundingMetrics();
 103   mBoundingMetrics.width = mWidth;
 104   mBoundingMetrics.ascent = mHeight;
 105   mBoundingMetrics.descent = mDepth;
 106   mBoundingMetrics.leftBearing = 0;
 107   mBoundingMetrics.rightBearing = mBoundingMetrics.width;
 108
 109   aDesiredSize.SetBlockStartAscent(mHeight);
 110   aDesiredSize.Width() = std::max(0, mBoundingMetrics.width);
 111   aDesiredSize.Height() = aDesiredSize.BlockStartAscent() + mDepth;
 112   // Also return our bounding metrics
 113   aDesiredSize.mBoundingMetrics = mBoundingMetrics;
 114
 115   aStatus = NS_FRAME_COMPLETE;
 116   NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
 117 }
 118
 119 /* virtual */ nsresult
 120 nsMathMLmspaceFrame::MeasureForWidth(nsRenderingContext& aRenderingContext,
 121                                      nsHTMLReflowMetrics& aDesiredSize)
 122 {
 123   ProcessAttributes(PresContext());
 124   mBoundingMetrics = nsBoundingMetrics();
 125   mBoundingMetrics.width = mWidth;
 126   aDesiredSize.Width() = std::max(0, mBoundingMetrics.width);
 127   aDesiredSize.mBoundingMetrics = mBoundingMetrics;
 128   return NS_OK;
 129 }