/* static */ nscoord
nsMathMLFrame::CalcLength(nsPresContext*   aPresContext,
                          nsStyleContext*   aStyleContext,
                          const nsCSSValue& aCSSValue,
                          float             aFontSizeInflation)
{
  NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");

  if (aCSSValue.IsFixedLengthUnit()) {
    return aCSSValue.GetFixedLength(aPresContext);
  }
  if (aCSSValue.IsPixelLengthUnit()) {
    return aCSSValue.GetPixelLength();
  }

  nsCSSUnit unit = aCSSValue.GetUnit();

  if (eCSSUnit_EM == unit) {
    const nsStyleFont* font = aStyleContext->StyleFont();
    return NSToCoordRound(aCSSValue.GetFloatValue() * (float)font->mFont.size);
  }
  else if (eCSSUnit_XHeight == unit) {
    aPresContext->SetUsesExChUnits(true);
    RefPtr<nsFontMetrics> fm = nsLayoutUtils::
      GetFontMetricsForStyleContext(aStyleContext, aFontSizeInflation);
    nscoord xHeight = fm->XHeight();
    return NSToCoordRound(aCSSValue.GetFloatValue() * (float)xHeight);
  }

  // MathML doesn't specify other CSS units such as rem or ch
  NS_ERROR("Unsupported unit");
  return 0;
}
Beispiel #2
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/* static */ nscoord
nsMathMLFrame::CalcLength(nsPresContext*   aPresContext,
                          nsStyleContext*   aStyleContext,
                          const nsCSSValue& aCSSValue)
{
  NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");

  if (aCSSValue.IsFixedLengthUnit()) {
    return aCSSValue.GetLengthTwips();
  }

  nsCSSUnit unit = aCSSValue.GetUnit();

  if (eCSSUnit_Pixel == unit) {
    return NSFloatPixelsToTwips(aCSSValue.GetFloatValue(),
                                aPresContext->ScaledPixelsToTwips());
  }
  else if (eCSSUnit_EM == unit) {
    const nsStyleFont* font = aStyleContext->GetStyleFont();
    return NSToCoordRound(aCSSValue.GetFloatValue() * (float)font->mFont.size);
  }
  else if (eCSSUnit_XHeight == unit) {
    nscoord xHeight;
    const nsStyleFont* font = aStyleContext->GetStyleFont();
    nsCOMPtr<nsIFontMetrics> fm = aPresContext->GetMetricsFor(font->mFont);
    fm->GetXHeight(xHeight);
    return NSToCoordRound(aCSSValue.GetFloatValue() * (float)xHeight);
  }

  return 0;
}
Beispiel #3
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/* static */ PRBool
nsMathMLFrame::ParseNamedSpaceValue(nsIFrame*   aMathMLmstyleFrame,
                                    nsString&   aString,
                                    nsCSSValue& aCSSValue)
{
  aCSSValue.Reset();
  aString.CompressWhitespace(); //  aString is not a const in this code...
  if (!aString.Length()) return PR_FALSE;

  // See if it is one of the 'namedspace' (ranging 1/18em...7/18em)
  PRInt32 i = 0;
  nsIAtom* namedspaceAtom = nsnull;
  if (aString.EqualsLiteral("veryverythinmathspace")) {
    i = 1;
    namedspaceAtom = nsMathMLAtoms::veryverythinmathspace_;
  }
  else if (aString.EqualsLiteral("verythinmathspace")) {
    i = 2;
    namedspaceAtom = nsMathMLAtoms::verythinmathspace_;
  }
  else if (aString.EqualsLiteral("thinmathspace")) {
    i = 3;
    namedspaceAtom = nsMathMLAtoms::thinmathspace_;
  }
  else if (aString.EqualsLiteral("mediummathspace")) {
    i = 4;
    namedspaceAtom = nsMathMLAtoms::mediummathspace_;
  }
  else if (aString.EqualsLiteral("thickmathspace")) {
    i = 5;
    namedspaceAtom = nsMathMLAtoms::thickmathspace_;
  }
  else if (aString.EqualsLiteral("verythickmathspace")) {
    i = 6;
    namedspaceAtom = nsMathMLAtoms::verythickmathspace_;
  }
  else if (aString.EqualsLiteral("veryverythickmathspace")) {
    i = 7;
    namedspaceAtom = nsMathMLAtoms::veryverythickmathspace_;
  }

  if (0 != i) {
    if (aMathMLmstyleFrame) {
      // see if there is a <mstyle> that has overriden the default value
      // GetAttribute() will recurse all the way up into the <mstyle> hierarchy
      nsAutoString value;
      if (NS_CONTENT_ATTR_HAS_VALUE ==
          GetAttribute(nsnull, aMathMLmstyleFrame, namedspaceAtom, value)) {
        if (ParseNumericValue(value, aCSSValue) &&
            aCSSValue.IsLengthUnit()) {
          return PR_TRUE;
        }
      }
    }

    // fall back to the default value
    aCSSValue.SetFloatValue(float(i)/float(18), eCSSUnit_EM);
    return PR_TRUE;
  }

  return PR_FALSE;
}