Issue #1673 - Part 1: Allow tab-size to accept <length>.

Currently -moz-tab-size only accepts <number> values, and both Chrome and Firefox currently support <length> values and have for some time now. So with this you would be able to support sizes in px or em, for instance. This was implemented in Firefox 53 and was trivial to backport.

6 files changed, 79 insertions, 33 deletions

diff --git a/layout/style/nsCSSPropList.h b/layout/style/nsCSSPropList.h
index 4f79db5a55..5c5cfcda1c 100644
--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -3885,7 +3885,7 @@ CSS_PROP_TEXT(
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_NONNEGATIVE,
     "",
-    VARIANT_HI,
+    VARIANT_INHERIT | VARIANT_LNCALC,
     nullptr,
     offsetof(nsStyleText, mTabSize),
     eStyleAnimType_Discrete)
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 080932af23..748f990b77 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -4013,7 +4013,7 @@ already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetTabSize()
 {
   RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
-  val->SetNumber(StyleText()->mTabSize);
+  SetValueToCoord(val, StyleText()->mTabSize, true);
   return val.forget();
 }
 
diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index c32369e9bb..e41857db76 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -4507,20 +4507,20 @@ TruncateStringToSingleGrapheme(nsAString& aStr)
   }
 }
 
-struct LineHeightCalcObj
+struct LengthNumberCalcObj
 {
-  float mLineHeight;
+  float LengthNumberCalcObj;
   bool mIsNumber;
 };
 
-struct SetLineHeightCalcOps : public css::NumbersAlreadyNormalizedOps
+struct LengthNumberCalcOps : public css::FloatCoeffsAlreadyNormalizedOps
 {
-  typedef LineHeightCalcObj result_type;
+  typedef LengthNumberCalcObj result_type;
   nsStyleContext* const mStyleContext;
   nsPresContext* const mPresContext;
   RuleNodeCacheConditions& mConditions;
 
-  SetLineHeightCalcOps(nsStyleContext* aStyleContext,
+  LengthNumberCalcOps(nsStyleContext* aStyleContext,
                        nsPresContext* aPresContext,
                        RuleNodeCacheConditions& aConditions)
     : mStyleContext(aStyleContext),
@@ -4535,15 +4535,15 @@ struct SetLineHeightCalcOps : public css::NumbersAlreadyNormalizedOps
   {
     MOZ_ASSERT(aValue1.mIsNumber == aValue2.mIsNumber);
 
-    LineHeightCalcObj result;
+    LengthNumberCalcObj result;
     result.mIsNumber = aValue1.mIsNumber;
     if (aCalcFunction == eCSSUnit_Calc_Plus) {
-      result.mLineHeight = aValue1.mLineHeight + aValue2.mLineHeight;
+      result.mValue = aValue1.mValue + aValue2.mValue;
       return result;
     }
     MOZ_ASSERT(aCalcFunction == eCSSUnit_Calc_Minus,
                "unexpected unit");
-    result.mLineHeight = aValue1.mLineHeight - aValue2.mLineHeight;
+    result.mValue = aValue1.mValue - aValue2.mValue;
     return result;
   }
 
@@ -4553,9 +4553,9 @@ struct SetLineHeightCalcOps : public css::NumbersAlreadyNormalizedOps
   {
     MOZ_ASSERT(aCalcFunction == eCSSUnit_Calc_Times_L,
                "unexpected unit");
-    LineHeightCalcObj result;
+    LengthNumberCalcObj result;
     result.mIsNumber = aValue2.mIsNumber;
-    result.mLineHeight = aValue1 * aValue2.mLineHeight;
+    result.mValue = aValue1 * aValue2.mValue;
     return result;
   }
 
@@ -4563,39 +4563,69 @@ struct SetLineHeightCalcOps : public css::NumbersAlreadyNormalizedOps
   MergeMultiplicativeR(nsCSSUnit aCalcFunction,
                        result_type aValue1, float aValue2)
   {
-    LineHeightCalcObj result;
+    LengthNumberCalcObj result;
     result.mIsNumber = aValue1.mIsNumber;
     if (aCalcFunction == eCSSUnit_Calc_Times_R) {
-      result.mLineHeight = aValue1.mLineHeight * aValue2;
+      result.mValue = aValue1.mValue * aValue2;
       return result;
     }
     MOZ_ASSERT(aCalcFunction == eCSSUnit_Calc_Divided,
                "unexpected unit");
-    result.mLineHeight = aValue1.mLineHeight / aValue2;
+    result.mValue = aValue1.mValue / aValue2;
     return result;
   }
 
   result_type ComputeLeafValue(const nsCSSValue& aValue)
   {
-    LineHeightCalcObj result;
+    LengthNumberCalcObj result;
     if (aValue.IsLengthUnit()) {
       result.mIsNumber = false;
-      result.mLineHeight = CalcLength(aValue, mStyleContext,
+      result.mValue = CalcLength(aValue, mStyleContext,
+                                      mPresContext, mConditions);
+    }
+    else if (eCSSUnit_Number == aValue.GetUnit()) {
+      result.mIsNumber = true;
+      result.mValue = aValue.GetFloatValue();
+    } else {
+      MOZ_ASSERT(false, "unexpected value");
+      result.mIsNumber = true;
+      result.mValue = 1.0f;
+    }
+
+    return result;
+  }
+};
+
+struct SetLineHeightCalcOps : public LengthNumberCalcOps
+{
+  SetLineHeightCalcOps(nsStyleContext* aStyleContext,
+                       nsPresContext* aPresContext,
+                       RuleNodeCacheConditions& aConditions)
+    : LengthNumberCalcOps(aStyleContext, aPresContext, aConditions)
+  {
+  }
+
+  result_type ComputeLeafValue(const nsCSSValue& aValue)
+  {
+    LengthNumberCalcObj result;
+    if (aValue.IsLengthUnit()) {
+      result.mIsNumber = false;
+      result.mValue = CalcLength(aValue, mStyleContext,
                                       mPresContext, mConditions);
     }
     else if (eCSSUnit_Percent == aValue.GetUnit()) {
       mConditions.SetUncacheable();
       result.mIsNumber = false;
       nscoord fontSize = mStyleContext->StyleFont()->mFont.size;
-      result.mLineHeight = fontSize * aValue.GetPercentValue();
+      result.mValue = fontSize * aValue.GetPercentValue();
     }
     else if (eCSSUnit_Number == aValue.GetUnit()) {
       result.mIsNumber = true;
-      result.mLineHeight = aValue.GetFloatValue();
+      result.mValue = aValue.GetFloatValue();
     } else {
       MOZ_ASSERT(false, "unexpected value");
       result.mIsNumber = true;
-      result.mLineHeight = 1.0f;
+      result.mValue = 1.0f;
     }
 
     return result;
@@ -4619,11 +4649,25 @@ nsRuleNode::ComputeTextData(void* aStartStruct,
                                    mPresContext, text->*aField, conditions);
   };
 
-  // tab-size: integer, inherit
-  SetValue(*aRuleData->ValueForTabSize(),
-           text->mTabSize, conditions,
-           SETVAL_INTEGER | SETVAL_UNSET_INHERIT, parentText->mTabSize,
-           NS_STYLE_TABSIZE_INITIAL);
+  // tab-size: number, length, calc, inherit
+  const nsCSSValue* tabSizeValue = aRuleData->ValueForTabSize();
+  if (tabSizeValue->GetUnit() == eCSSUnit_Initial) {
+    text->mTabSize = nsStyleCoord(float(NS_STYLE_TABSIZE_INITIAL), eStyleUnit_Factor);
+  } else if (eCSSUnit_Calc == tabSizeValue->GetUnit()) {
+    LengthNumberCalcOps ops(aContext, mPresContext, conditions);
+    LengthNumberCalcObj obj = css::ComputeCalc(*tabSizeValue, ops);
+    float value = obj.mValue < 0 ? 0 : obj.mValue;
+    if (obj.mIsNumber) {
+      text->mTabSize.SetFactorValue(value);
+    } else {
+      text->mTabSize.SetCoordValue(
+        NSToCoordRoundWithClamp(value));
+    }
+  } else {
+    SetCoord(*tabSizeValue, text->mTabSize, parentText->mTabSize,
+             SETCOORD_LH | SETCOORD_FACTOR | SETCOORD_UNSET_INHERIT,
+             aContext, mPresContext, conditions);
+  }
 
   // letter-spacing: normal, length, inherit
   SetCoord(*aRuleData->ValueForLetterSpacing(),
@@ -4666,12 +4710,12 @@ nsRuleNode::ComputeTextData(void* aStartStruct,
   }
   else if (eCSSUnit_Calc == lineHeightValue->GetUnit()) {
     SetLineHeightCalcOps ops(aContext, mPresContext, conditions);
-    LineHeightCalcObj obj = css::ComputeCalc(*lineHeightValue, ops);
+    LengthNumberCalcObj obj = css::ComputeCalc(*lineHeightValue, ops);
     if (obj.mIsNumber) {
-      text->mLineHeight.SetFactorValue(obj.mLineHeight);
+      text->mLineHeight.SetFactorValue(obj.mValue);
     } else {
       text->mLineHeight.SetCoordValue(
-        NSToCoordRoundWithClamp(obj.mLineHeight));
+        NSToCoordRoundWithClamp(obj.mValue));
     }
   }
   else {
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index c0ea9c256c..073cfcd5e7 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -3806,10 +3806,10 @@ nsStyleText::nsStyleText(StyleStructContext aContext)
   , mControlCharacterVisibility(nsCSSParser::ControlCharVisibilityDefault())
   , mTextEmphasisStyle(NS_STYLE_TEXT_EMPHASIS_STYLE_NONE)
   , mTextRendering(NS_STYLE_TEXT_RENDERING_AUTO)
-  , mTabSize(NS_STYLE_TABSIZE_INITIAL)
   , mTextEmphasisColor(StyleComplexColor::CurrentColor())
   , mWebkitTextFillColor(StyleComplexColor::CurrentColor())
   , mWebkitTextStrokeColor(StyleComplexColor::CurrentColor())
+  , mTabSize(float(NS_STYLE_TABSIZE_INITIAL), eStyleUnit_Factor)
   , mWordSpacing(0, nsStyleCoord::CoordConstructor)
   , mLetterSpacing(eStyleUnit_Normal)
   , mLineHeight(eStyleUnit_Normal)
@@ -3844,10 +3844,10 @@ nsStyleText::nsStyleText(const nsStyleText& aSource)
   , mTextEmphasisPosition(aSource.mTextEmphasisPosition)
   , mTextEmphasisStyle(aSource.mTextEmphasisStyle)
   , mTextRendering(aSource.mTextRendering)
-  , mTabSize(aSource.mTabSize)
   , mTextEmphasisColor(aSource.mTextEmphasisColor)
   , mWebkitTextFillColor(aSource.mWebkitTextFillColor)
   , mWebkitTextStrokeColor(aSource.mWebkitTextStrokeColor)
+  , mTabSize(aSource.mTabSize)
   , mWordSpacing(aSource.mWordSpacing)
   , mLetterSpacing(aSource.mLetterSpacing)
   , mLineHeight(aSource.mLineHeight)
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index 88000c722a..831808edfd 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -2087,11 +2087,11 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleText
   uint8_t mTextEmphasisPosition;        // [inherited] see nsStyleConsts.h
   uint8_t mTextEmphasisStyle;           // [inherited] see nsStyleConsts.h
   uint8_t mTextRendering;               // [inherited] see nsStyleConsts.h
-  int32_t mTabSize;                     // [inherited] see nsStyleConsts.h
   mozilla::StyleComplexColor mTextEmphasisColor;      // [inherited]
   mozilla::StyleComplexColor mWebkitTextFillColor;    // [inherited]
   mozilla::StyleComplexColor mWebkitTextStrokeColor;  // [inherited]
 
+  nsStyleCoord mTabSize;                // [inherited] coord, factor, calc
   nsStyleCoord mWordSpacing;            // [inherited] coord, percent, calc
   nsStyleCoord mLetterSpacing;          // [inherited] coord, normal
   nsStyleCoord mLineHeight;             // [inherited] coord, factor, normal
diff --git a/layout/style/test/property_database.js b/layout/style/test/property_database.js
index d647b57161..5182dd89c1 100644
--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -2032,8 +2032,10 @@ var gCSSProperties = {
     inherited: true,
     type: CSS_TYPE_LONGHAND,
     initial_values: [ "8" ],
-    other_values: [ "0", "3", "99", "12000" ],
-    invalid_values: [ "-1", "-808", "3.0", "17.5" ]
+    other_values: [ "0", "2.5", "3", "99", "12000", "0px", "1em",
+	    "calc(1px + 1em)", "calc(1px - 2px)", "calc(1 + 1)", "calc(-2.5)" ],
+    invalid_values: [ "9%", "calc(9% + 1px)", "calc(1 + 1em)", "-1", "-808",
+	    "auto" ]
   },
   "-moz-text-size-adjust": {
     domProp: "MozTextSizeAdjust",