Attachment #356148 for bug #472195

Attachment #356148: CSS3 rem units support (work in progress) for bug #472195

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GK_ATOM(radio, "radio")
GK_ATOM(radiogroup, "radiogroup")
GK_ATOM(readonly, "readonly")
GK_ATOM(rect, "rect")
GK_ATOM(rectangle, "rectangle")
GK_ATOM(ref, "ref")
GK_ATOM(refresh, "refresh")
GK_ATOM(rel, "rel")
GK_ATOM(rem, "rem")
GK_ATOM(removeelement, "removeelement")
GK_ATOM(repeat, "repeat")
GK_ATOM(replace, "replace")
GK_ATOM(reset, "reset")
GK_ATOM(resizeafter, "resizeafter")
GK_ATOM(resizebefore, "resizebefore")
GK_ATOM(resizer, "resizer")
GK_ATOM(resolution, "resolution")

GK_ATOM(other_, "other")
GK_ATOM(partialdiff_, "partialdiff")
GK_ATOM(plus_, "plus")
GK_ATOM(power_, "power")
GK_ATOM(product_, "product")
GK_ATOM(prsubset_, "prsubset")
GK_ATOM(quotient_, "quotient")
GK_ATOM(reln_, "reln")
GK_ATOM(rem_, "rem")
GK_ATOM(root_, "root")
GK_ATOM(rowalign_, "rowalign")
GK_ATOM(rowlines_, "rowlines")
GK_ATOM(rowspacing_, "rowspacing")
GK_ATOM(rquote_, "rquote")
GK_ATOM(rspace_, "rspace")
GK_ATOM(scriptlevel_, "scriptlevel")
GK_ATOM(scriptminsize_, "scriptminsize")





    case eCSSUnit_Point:        aResult.AppendLiteral("pt");   break;
    case eCSSUnit_Pica:         aResult.AppendLiteral("pc");   break;
    case eCSSUnit_Didot:        aResult.AppendLiteral("dt");   break;
    case eCSSUnit_Cicero:       aResult.AppendLiteral("cc");   break;

    case eCSSUnit_EM:           aResult.AppendLiteral("em");   break;
    case eCSSUnit_XHeight:      aResult.AppendLiteral("ex");   break;
    case eCSSUnit_Char:         aResult.AppendLiteral("ch");   break;
    case eCSSUnit_RootEM:       aResult.AppendLiteral("rem");  break;

    case eCSSUnit_Pixel:        aResult.AppendLiteral("px");   break;

    case eCSSUnit_Degree:       aResult.AppendLiteral("deg");  break;
    case eCSSUnit_Grad:         aResult.AppendLiteral("grad"); break;
    case eCSSUnit_Radian:       aResult.AppendLiteral("rad");  break;

    case eCSSUnit_Hertz:        aResult.AppendLiteral("Hz");   break;





const UnitInfo UnitData[] = {
  { STR_WITH_LEN("px"), eCSSUnit_Pixel, VARIANT_LENGTH },
  { STR_WITH_LEN("em"), eCSSUnit_EM, VARIANT_LENGTH },
  { STR_WITH_LEN("ex"), eCSSUnit_XHeight, VARIANT_LENGTH },
  { STR_WITH_LEN("pt"), eCSSUnit_Point, VARIANT_LENGTH },
  { STR_WITH_LEN("in"), eCSSUnit_Inch, VARIANT_LENGTH },
  { STR_WITH_LEN("cm"), eCSSUnit_Centimeter, VARIANT_LENGTH },
  { STR_WITH_LEN("ch"), eCSSUnit_Char, VARIANT_LENGTH },
  { STR_WITH_LEN("rem"), eCSSUnit_RootEM, VARIANT_LENGTH },
  { STR_WITH_LEN("mm"), eCSSUnit_Millimeter, VARIANT_LENGTH },
  { STR_WITH_LEN("pc"), eCSSUnit_Pica, VARIANT_LENGTH },
  { STR_WITH_LEN("deg"), eCSSUnit_Degree, VARIANT_ANGLE },
  { STR_WITH_LEN("grad"), eCSSUnit_Grad, VARIANT_ANGLE },
  { STR_WITH_LEN("rad"), eCSSUnit_Radian, VARIANT_ANGLE },
  { STR_WITH_LEN("hz"), eCSSUnit_Hertz, VARIANT_FREQUENCY },
  { STR_WITH_LEN("khz"), eCSSUnit_Kilohertz, VARIANT_FREQUENCY },
  { STR_WITH_LEN("s"), eCSSUnit_Seconds, VARIANT_TIME },





  eCSSUnit_Didot        = 400,    // (float) 15 didots == 16 points
  eCSSUnit_Cicero       = 401,    // (float) 12 didots

  // Length units - relative
  // Font relative measure
  eCSSUnit_EM           = 800,    // (float) == current font size
  eCSSUnit_XHeight      = 801,    // (float) distance from top of lower case x to baseline
  eCSSUnit_Char         = 802,    // (float) number of characters, used for width with monospace font
  eCSSUnit_RootEM       = 803,    // (float) == root element font size

  // Screen relative measure
  eCSSUnit_Pixel        = 900,    // (float) CSS pixel unit

  // Angular units
  eCSSUnit_Degree       = 1000,    // (float) 360 per circle
  eCSSUnit_Grad         = 1001,    // (float) 400 per circle
  eCSSUnit_Radian       = 1002,    // (float) 2*pi per circle





       (start == PRUnichar('\'')))) {
    PRInt32 length = aString.Length();
    aString.Truncate(length - 1);
    aString.Cut(0, 1);
  }
  return aString;
}

static inline nscoord ScaleCoord(const nsCSSValue &aValue, float factor)
{
  return NSToCoordRoundWithClamp(aValue.GetFloatValue() * factor);
}

static nscoord CalcLengthWith(const nsCSSValue& aValue,
                              nscoord aFontSize,
                              const nsStyleFont* aStyleFont,
                              nsStyleContext* aStyleContext,
                              nsPresContext* aPresContext,
                              PRBool useProvidedRootEmSize,
                              PRBool& aInherited)
{
  NS_ASSERTION(aValue.IsLengthUnit(), "not a length unit");
  NS_ASSERTION(aStyleFont || aStyleContext, "Must have style data");
  NS_ASSERTION(aPresContext, "Must have prescontext");

  if (aValue.IsFixedLengthUnit()) {
    return aPresContext->TwipsToAppUnits(aValue.GetLengthTwips());

    aStyleFont = aStyleContext->GetStyleFont();
  }
  if (aFontSize == -1) {
    // XXX Should this be aStyleFont->mSize instead to avoid taking minfontsize
    // prefs into account?
    aFontSize = aStyleFont->mFont.size;
  }
  switch (unit) {
    case eCSSUnit_RootEM: {
      nscoord rootFontSize;

      if (useProvidedRootEmSize) {
        // We should use the provided aFontSize as the reference length to
        // scale. This only happens when we are calculating something on the
        // root element, in which case aFontSize is already the value we want.
        rootFontSize = aFontSize;
      } else {
        // This is not the root element or we are calculating something other
        // than font size, so rem is relative to the root element's font size.
        nsRefPtr<nsStyleContext> rootStyle;
        const nsStyleFont *rootStyleFont = aStyleFont;
        nsIContent* docElement = aPresContext->Document()->GetRootContent();

        rootStyle = aPresContext->StyleSet()->ResolveStyleFor(docElement,
                                                              nsnull);
        if (rootStyle) {
          rootStyleFont = rootStyle->GetStyleFont();
          rootFontSize = rootStyleFont->mFont.size;
        }
      }

      return ScaleCoord(aValue, float(rootFontSize));
    }
    case eCSSUnit_EM: {
      return ScaleCoord(aValue, float(aFontSize));
      // XXX scale against font metrics height instead?
    }
    case eCSSUnit_XHeight: {
      nsFont font = aStyleFont->mFont;
      font.size = aFontSize;
      nsCOMPtr<nsIFontMetrics> fm = aPresContext->GetMetricsFor(font);
      nscoord xHeight;
      fm->GetXHeight(xHeight);
      return ScaleCoord(aValue, float(xHeight));
    }
    case eCSSUnit_Char: {
      nsFont font = aStyleFont->mFont;
      font.size = aFontSize;
      nsCOMPtr<nsIFontMetrics> fm = aPresContext->GetMetricsFor(font);
      nsCOMPtr<nsIThebesFontMetrics> tfm(do_QueryInterface(fm));
      gfxFloat zeroWidth = (tfm->GetThebesFontGroup()->GetFontAt(0)
                            ->GetMetrics().zeroOrAveCharWidth);

      return ScaleCoord(aValue, NS_ceil(aPresContext->AppUnitsPerDevPixel() *
                                        zeroWidth));
                                    zeroWidth));
    }
    default:
      NS_NOTREACHED("unexpected unit");
      break;
  }
  return 0;
}

/* static */ nscoord
nsRuleNode::CalcLength(const nsCSSValue& aValue,
                       nsStyleContext* aStyleContext,
                       nsPresContext* aPresContext,
                       PRBool& aInherited)
{
  NS_ASSERTION(aStyleContext, "Must have style data");

  return CalcLengthWith(aValue, -1, nsnull, aStyleContext, aPresContext,
                        PR_FALSE, aInherited);
}

/* Inline helper function to redirect requests to CalcLength. */
static inline nscoord CalcLength(const nsCSSValue& aValue,
                                 nsStyleContext* aStyleContext,
                                 nsPresContext* aPresContext,
                                 PRBool& aInherited)
{


/* static */ nscoord
nsRuleNode::CalcLengthWithInitialFont(nsPresContext* aPresContext,
                                      const nsCSSValue& aValue)
{
  nsStyleFont defaultFont(aPresContext);
  PRBool inherited;
  return CalcLengthWith(aValue, -1, &defaultFont, nsnull, aPresContext,
                        PR_FALSE, inherited);
}

#define SETCOORD_NORMAL                 0x01   // N
#define SETCOORD_AUTO                   0x02   // A
#define SETCOORD_INHERIT                0x04   // H
#define SETCOORD_PERCENT                0x08   // P
#define SETCOORD_FACTOR                 0x10   // F
#define SETCOORD_LENGTH                 0x20   // L

                        const nsRuleDataFont& aFontData,
                        const nsStyleFont* aFont,
                        const nsStyleFont* aParentFont,
                        nscoord* aSize,
                        const nsFont& aSystemFont,
                        nscoord aParentSize,
                        nscoord aScriptLevelAdjustedParentSize,
                        PRBool aUsedStartStruct,
                        PRBool atRoot,
                        PRBool& aInherited)
{
  PRBool zoom = PR_FALSE;
  PRInt32 baseSize = (PRInt32) aPresContext->
    GetDefaultFont(aFont->mGenericID)->size;
  if (eCSSUnit_Enumerated == aFontData.mSize.GetUnit()) {
    PRInt32 value = aFontData.mSize.GetIntValue();
    PRInt32 scaler = aPresContext->FontScaler();

      NS_NOTREACHED("unexpected value");
    }
  }
  else if (aFontData.mSize.IsLengthUnit()) {
    // Note that font-based length units use the parent's size unadjusted
    // for scriptlevel changes. A scriptlevel change between us and the parent
    // is simply ignored.
    *aSize = CalcLengthWith(aFontData.mSize, aParentSize, aParentFont, nsnull,
                        aPresContext, atRoot, aInherited);
    zoom = aFontData.mSize.IsFixedLengthUnit() ||
           aFontData.mSize.GetUnit() == eCSSUnit_Pixel;
  }
  else if (eCSSUnit_Percent == aFontData.mSize.GetUnit()) {
    aInherited = PR_TRUE;
    // Note that % units use the parent's size unadjusted for scriptlevel
    // changes. A scriptlevel change between us and the parent is simply
    // ignored.

}

/* static */ void
nsRuleNode::SetFont(nsPresContext* aPresContext, nsStyleContext* aContext,
                    nscoord aMinFontSize,
                    PRUint8 aGenericFontID, const nsRuleDataFont& aFontData,
                    const nsStyleFont* aParentFont,
                    nsStyleFont* aFont, PRBool aUsedStartStruct,
                    PRBool atRoot, PRBool& aInherited)
{
  const nsFont* defaultVariableFont =
    aPresContext->GetDefaultFont(kPresContext_DefaultVariableFont_ID);

  // -moz-system-font: enum (never inherit!)
  nsFont systemFont;
  if (eCSSUnit_Enumerated == aFontData.mSystemFont.GetUnit()) {
    nsSystemFontID sysID;


  // -moz-script-min-size: length
  if (aFontData.mScriptMinSize.IsLengthUnit()) {
    // scriptminsize in font units (em, ex) has to be interpreted relative
    // to the parent font, or the size definitions are circular and we
    // 
    aFont->mScriptMinSize =
      CalcLengthWith(aFontData.mScriptMinSize, aParentFont->mSize, aParentFont, nsnull,
                     aPresContext, atRoot, aInherited);
  }

  // -moz-script-size-multiplier: factor, inherit, initial
  SetFactor(aFontData.mScriptSizeMultiplier, aFont->mScriptSizeMultiplier,
            aInherited, aParentFont->mScriptSizeMultiplier,
            NS_MATHML_DEFAULT_SCRIPT_SIZE_MULTIPLIER,
            SETFCT_POSITIVE);
  

  scriptLevelAdjustedParentSize =
    ComputeScriptLevelSize(aFont, aParentFont, aPresContext,
                           &scriptLevelAdjustedUnconstrainedParentSize);
  NS_ASSERTION(!aUsedStartStruct || aFont->mScriptUnconstrainedSize == aFont->mSize,
               "If we have a start struct, we should have reset everything coming in here");
#endif
  SetFontSize(aPresContext, aFontData, aFont, aParentFont, &aFont->mSize,
              systemFont, aParentFont->mSize, scriptLevelAdjustedParentSize,
              aUsedStartStruct, atRoot, aInherited);
#ifdef MOZ_MATHML
  if (aParentFont->mSize == aParentFont->mScriptUnconstrainedSize &&
      scriptLevelAdjustedParentSize == scriptLevelAdjustedUnconstrainedParentSize) {
    // Fast path: we have not been affected by scriptminsize so we don't
    // need to call SetFontSize again to compute the
    // scriptminsize-unconstrained size. This is OK even if we have a
    // start struct, because if we have a start struct then 'font-size'
    // was specified and so scriptminsize has no effect.
    aFont->mScriptUnconstrainedSize = aFont->mSize;
  } else {
    SetFontSize(aPresContext, aFontData, aFont, aParentFont,
                &aFont->mScriptUnconstrainedSize, systemFont,
                aParentFont->mScriptUnconstrainedSize,
                scriptLevelAdjustedUnconstrainedParentSize,
                aUsedStartStruct, atRoot, aInherited);
  }
  NS_ASSERTION(aFont->mScriptUnconstrainedSize <= aFont->mSize,
               "scriptminsize should never be making things bigger");
#endif

  // enforce the user' specified minimum font-size on the value that we expose
  // (but don't change font-size:0)
  if (0 < aFont->mSize && aFont->mSize < aMinFontSize)

//    up to the root where default values come from the presentation context)
//  - re-apply cascading rules from there without caching intermediate values
/* static */ void
nsRuleNode::SetGenericFont(nsPresContext* aPresContext,
                           nsStyleContext* aContext,
                           PRUint8 aGenericFontID, nscoord aMinFontSize,
                           nsStyleFont* aFont)
{
  PRBool atRoot;

  // walk up the contexts until a context with the desired generic font
  nsAutoVoidArray contextPath;
  contextPath.AppendElement(aContext);
  nsStyleContext* higherContext = aContext->GetParent();
  while (higherContext) {
    if (higherContext->GetStyleFont()->mGenericID == aGenericFontID) {
      // done walking up the higher contexts
      break;


  // re-apply the cascading rules, starting from the higher context

  // If we stopped earlier because we reached the root of the style tree,
  // we will start with the default generic font from the presentation
  // context. Otherwise we start with the higher context.
  const nsFont* defaultFont = aPresContext->GetDefaultFont(aGenericFontID);
  nsStyleFont parentFont(*defaultFont, aPresContext);
  atRoot = PR_TRUE;
  if (higherContext) {
    const nsStyleFont* tmpFont = higherContext->GetStyleFont();
    parentFont = *tmpFont;
    atRoot = PR_FALSE;
  }
  *aFont = parentFont;

  PRBool dummy;
  PRUint32 fontBit = nsCachedStyleData::GetBitForSID(eStyleStruct_Font);
  
  for (PRInt32 i = contextPath.Count() - 1; i >= 0; --i) {
    nsStyleContext* context = (nsStyleContext*)contextPath[i];


    // Avoid unnecessary operations in SetFont().  But we care if it's
    // the final value that we're computing.
    if (i != 0)
      fontData.mFamily.Reset();

    nsRuleNode::SetFont(aPresContext, context, aMinFontSize,
                        aGenericFontID, fontData, &parentFont, aFont,
                        PR_FALSE, atRoot, dummy);

    // XXX Not sure if we need to do this here
    // If we have a post-resolve callback, handle that now.
    if (ruleData.mPostResolveCallback)
      (ruleData.mPostResolveCallback)(aFont, &ruleData);

    parentFont = *aFont;
  }

nsRuleNode::ComputeFontData(void* aStartStruct,
                            const nsRuleDataStruct& aData, 
                            nsStyleContext* aContext, 
                            nsRuleNode* aHighestNode,
                            const RuleDetail aRuleDetail, PRBool aInherited)
{
  COMPUTE_START_INHERITED(Font, (mPresContext), font, parentFont,
                          Font, fontData)

  PRBool atRoot = (parentFont == font);

  // NOTE:  The |aRuleDetail| passed in is a little bit conservative due
  // to the -moz-system-font property.  We really don't need to consider
  // it here in determining whether to cache in the rule tree.  However,
  // we do need to consider it in WalkRuleTree when deciding whether to
  // walk further up the tree.  So this means that when the font struct
  // is fully specified using *longhand* properties (excluding
  // -moz-system-font), we won't cache in the rule tree even though we

    }
  }

  // Now compute our font struct
  if (generic == kGenericFont_NONE) {
    // continue the normal processing
    nsRuleNode::SetFont(mPresContext, aContext, minimumFontSize, generic,
                        fontData, parentFont, font,
                        aStartStruct != nsnull, atRoot, inherited);
  }
  else {
    // re-calculate the font as a generic font
    inherited = PR_TRUE;
    nsRuleNode::SetGenericFont(mPresContext, aContext, generic,
                               minimumFontSize, font);
  }






                                      const nsRuleDataFont& aFontData,
                                      const nsStyleFont* aFont,
                                      const nsStyleFont* aParentFont,
                                      nscoord* aSize,
                                      const nsFont& aSystemFont,
                                      nscoord aParentSize,
                                      nscoord aScriptLevelAdjustedParentSize,
                                      PRBool aUsedStartStruct,
                                      PRBool atRoot,
                                      PRBool& aInherited);

  static NS_HIDDEN_(void) SetFont(nsPresContext* aPresContext,
                                  nsStyleContext* aContext,
                                  nscoord aMinFontSize,
                                  PRUint8 aGenericFontID,
                                  const nsRuleDataFont& aFontData,
                                  const nsStyleFont* aParentFont,
                                  nsStyleFont* aFont,
                                  PRBool aStartStruct,
                                  PRBool atRoot, PRBool& aInherited);

  static NS_HIDDEN_(void) SetGenericFont(nsPresContext* aPresContext,
                                         nsStyleContext* aContext,
                                         PRUint8 aGenericFontID,
                                         nscoord aMinFontSize,
                                         nsStyleFont* aFont);

  NS_HIDDEN_(void) AdjustLogicalBoxProp(nsStyleContext* aContext,

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