Bug 1289007 - part1: parse and compute initial-letter property. r=heycam

MozReview-Commit-ID: E0eXolZ93oJ

--HG--
extra : rebase_source : 3fc74b84a488bb495f926b420aa6c06a987e09b2

layout/inspector/inDOMUtils.cpp

@@ -844,6 +844,7 @@ PropertySupportsVariant(nsCSSProperty aPropertyID, uint32_t aVariant)
       case eCSSProperty_grid_row_start:
       case eCSSProperty_grid_row_end:
       case eCSSProperty_font_weight:
+      case eCSSProperty_initial_letter:
         supported = VARIANT_NUMBER;
         break;
 

layout/style/nsCSSParser.cpp

@@ -1004,6 +1004,8 @@ protected:
   bool ParseGridArea();
   bool ParseGridGap();
 
+  bool ParseInitialLetter();
+
   // parsing 'align/justify-items/self' from the css-align spec
   bool ParseAlignJustifyPosition(nsCSSValue& aResult,
                                  const KTableEntry aTable[]);
@@ -1245,6 +1247,16 @@ protected:
     return ParseSingleTokenNonNegativeVariant(aValue, VARIANT_NUMBER, nullptr);
   }
 
+  // Helpers for some common ParseSingleTokenOneOrLargerVariant calls.
+  bool ParseOneOrLargerInteger(nsCSSValue& aValue)
+  {
+    return ParseSingleTokenOneOrLargerVariant(aValue, VARIANT_INTEGER, nullptr);
+  }
+  bool ParseOneOrLargerNumber(nsCSSValue& aValue)
+  {
+    return ParseSingleTokenOneOrLargerVariant(aValue, VARIANT_NUMBER, nullptr);
+  }
+
   // http://dev.w3.org/csswg/css-values/#custom-idents
   // Parse an identifier that is none of:
   // * a CSS-wide keyword
@@ -9779,6 +9791,33 @@ CSSParserImpl::ParseGridGap()
   return true;
 }
 
+// normal | [<number> <integer>?]
+bool
+CSSParserImpl::ParseInitialLetter()
+{
+  nsCSSValue value;
+  // 'inherit', 'initial', 'unset', 'none', and 'normal' must be alone
+  if (!ParseSingleTokenVariant(value, VARIANT_INHERIT | VARIANT_NORMAL,
+                               nullptr)) {
+    nsCSSValue first, second;
+    if (!ParseOneOrLargerNumber(first)) {
+      return false;
+    }
+
+    if (!ParseOneOrLargerInteger(second)) {
+      AppendValue(eCSSProperty_initial_letter, first);
+      return true;
+    } else {
+      RefPtr<nsCSSValue::Array> val = nsCSSValue::Array::Create(2);
+      val->Item(0) = first;
+      val->Item(1) = second;
+      value.SetArrayValue(val, eCSSUnit_Array);
+    }
+  }
+  AppendValue(eCSSProperty_initial_letter, value);
+  return true;
+}
+
 // [ $aTable && <overflow-position>? ] ?
 // $aTable is for <content-position> or <self-position>
 bool
@@ -11570,6 +11609,8 @@ CSSParserImpl::ParsePropertyByFunction(nsCSSProperty aPropID)
   case eCSSProperty_align_self:
   case eCSSProperty_justify_self:
     return ParseAlignJustifySelf(aPropID);
+  case eCSSProperty_initial_letter:
+    return ParseInitialLetter();
   case eCSSProperty_justify_items:
     return ParseJustifyItems();
   case eCSSProperty_list_style:

layout/style/nsCSSPropList.h

@@ -2268,6 +2268,17 @@ CSS_PROP_TEXT(
     kHyphensKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_None)
+CSS_PROP_TEXTRESET(
+    initial-letter,
+    initial_letter,
+    InitialLetter,
+    CSS_PROPERTY_PARSE_FUNCTION |
+        CSS_PROPERTY_APPLIES_TO_FIRST_LETTER,
+    "layout.css.initial-letter.enabled",
+    0,
+    nullptr,
+    CSS_PROP_NO_OFFSET,
+    eStyleAnimType_None)
 CSS_PROP_VISIBILITY(
     image-orientation,
     image_orientation,

layout/style/nsComputedDOMStyle.cpp

@@ -3543,6 +3543,25 @@ nsComputedDOMStyle::DoGetImageRegion()
   return val.forget();
 }
 
+already_AddRefed<CSSValue>
+nsComputedDOMStyle::DoGetInitialLetter()
+{
+  const nsStyleTextReset* textReset = StyleTextReset();
+  RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+  if (textReset->mInitialLetterSink == 0) {
+    val->SetIdent(eCSSKeyword_normal);
+    return val.forget();
+  } else {
+    RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(false);
+    val->SetNumber(textReset->mInitialLetterSize);
+    valueList->AppendCSSValue(val.forget());
+    RefPtr<nsROCSSPrimitiveValue> second = new nsROCSSPrimitiveValue;
+    second->SetNumber(textReset->mInitialLetterSink);
+    valueList->AppendCSSValue(second.forget());
+    return valueList.forget();
+  }
+}
+
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetLineHeight()
 {

layout/style/nsComputedDOMStyle.h

@@ -404,6 +404,7 @@ private:
   already_AddRefed<CSSValue> DoGetImageRegion();
 
   /* Text Properties */
+  already_AddRefed<CSSValue> DoGetInitialLetter();
   already_AddRefed<CSSValue> DoGetLineHeight();
   already_AddRefed<CSSValue> DoGetRubyAlign();
   already_AddRefed<CSSValue> DoGetRubyPosition();

layout/style/nsComputedDOMStylePropertyList.h

@@ -153,6 +153,7 @@ COMPUTED_STYLE_PROP(height,                        Height)
 COMPUTED_STYLE_PROP(hyphens,                       Hyphens)
 COMPUTED_STYLE_PROP(image_orientation,             ImageOrientation)
 COMPUTED_STYLE_PROP(ime_mode,                      IMEMode)
+COMPUTED_STYLE_PROP(initial_letter,                InitialLetter)
 COMPUTED_STYLE_PROP(isolation,                     Isolation)
 COMPUTED_STYLE_PROP(justify_content,               JustifyContent)
 COMPUTED_STYLE_PROP(justify_items,                 JustifyItems)

layout/style/nsRuleNode.cpp

@@ -4977,6 +4977,36 @@ nsRuleNode::ComputeTextResetData(void* aStartStruct,
            parentText->mUnicodeBidi,
            NS_STYLE_UNICODE_BIDI_NORMAL);
 
+  // initial-letter: normal, number, array(number, integer?), initial
+  const nsCSSValue* initialLetterValue = aRuleData->ValueForInitialLetter();
+  if (initialLetterValue->GetUnit() == eCSSUnit_Null) {
+    // We don't want to change anything in this case.
+  } else if (initialLetterValue->GetUnit() == eCSSUnit_Inherit) {
+    conditions.SetUncacheable();
+    text->mInitialLetterSink = parentText->mInitialLetterSink;
+    text->mInitialLetterSize = parentText->mInitialLetterSize;
+  } else if (initialLetterValue->GetUnit() == eCSSUnit_Initial ||
+             initialLetterValue->GetUnit() == eCSSUnit_Unset ||
+             initialLetterValue->GetUnit() == eCSSUnit_Normal) {
+    // Use invalid values in initial-letter property to mean normal. So we can
+    // determine whether it is normal by checking mInitialLetterSink == 0.
+    text->mInitialLetterSink = 0;
+    text->mInitialLetterSize = 0.0f;
+  } else if (initialLetterValue->GetUnit() == eCSSUnit_Array) {
+    const nsCSSValue& firstValue = initialLetterValue->GetArrayValue()->Item(0);
+    const nsCSSValue& secondValue = initialLetterValue->GetArrayValue()->Item(1);
+    MOZ_ASSERT(firstValue.GetUnit() == eCSSUnit_Number &&
+               secondValue.GetUnit() == eCSSUnit_Integer,
+               "unexpected value unit");
+    text->mInitialLetterSize = firstValue.GetFloatValue();
+    text->mInitialLetterSink = secondValue.GetIntValue();
+  } else if (initialLetterValue->GetUnit() == eCSSUnit_Number) {
+    text->mInitialLetterSize = initialLetterValue->GetFloatValue();
+    text->mInitialLetterSink = NSToCoordFloorClamped(text->mInitialLetterSize);
+  } else {
+    MOZ_ASSERT_UNREACHABLE("unknown unit for initial-letter");
+  }
+
   COMPUTE_END_RESET(TextReset, text)
 }
 

layout/style/nsStyleStruct.cpp

@@ -3576,6 +3576,8 @@ nsStyleContent::AllocateContents(uint32_t aCount)
 nsStyleTextReset::nsStyleTextReset(StyleStructContext aContext)
   : mTextDecorationLine(NS_STYLE_TEXT_DECORATION_LINE_NONE)
   , mUnicodeBidi(NS_STYLE_UNICODE_BIDI_NORMAL)
+  , mInitialLetterSink(0)
+  , mInitialLetterSize(0.0f)
   , mTextDecorationStyle(NS_STYLE_TEXT_DECORATION_STYLE_SOLID | BORDER_COLOR_FOREGROUND)
   , mTextDecorationColor(NS_RGB(0, 0, 0))
 {
@@ -3596,7 +3598,9 @@ nsStyleTextReset::~nsStyleTextReset()
 nsChangeHint
 nsStyleTextReset::CalcDifference(const nsStyleTextReset& aNewData) const
 {
-  if (mUnicodeBidi != aNewData.mUnicodeBidi) {
+  if (mUnicodeBidi != aNewData.mUnicodeBidi ||
+      mInitialLetterSink != aNewData.mInitialLetterSink ||
+      mInitialLetterSize != aNewData.mInitialLetterSize) {
     return NS_STYLE_HINT_REFLOW;
   }
 

layout/style/nsStyleStruct.h

@@ -1977,6 +1977,8 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleTextReset
 
   uint8_t mTextDecorationLine;          // [reset] see nsStyleConsts.h
   uint8_t mUnicodeBidi;                 // [reset] see nsStyleConsts.h
+  nscoord mInitialLetterSink;           // [reset] 0 means normal
+  float mInitialLetterSize;             // [reset] 0.0f means normal
 protected:
   uint8_t mTextDecorationStyle;         // [reset] see nsStyleConsts.h
 

layout/style/test/property_database.js

@@ -6661,6 +6661,17 @@ if (IsCSSPropertyPrefEnabled("layout.css.image-orientation.enabled")) {
   };
 }
 
+if (IsCSSPropertyPrefEnabled("layout.css.initial-letter.enabled")) {
+  gCSSProperties["initial-letter"] = {
+    domProp: "initialLetter",
+    inherited: false,
+    type: CSS_TYPE_LONGHAND,
+    initial_values: [ "normal" ],
+    other_values: [ "2", "2.5", "3.7 2", "4 3" ],
+    invalid_values: [ "-3", "3.7 -2", "25%", "16px", "1 0", "0", "0 1" ]
+  };
+}
+
 if (IsCSSPropertyPrefEnabled("layout.css.osx-font-smoothing.enabled")) {
   gCSSProperties["-moz-osx-font-smoothing"] = {
     domProp: "MozOsxFontSmoothing",

modules/libpref/init/all.js

@@ -2413,6 +2413,9 @@ pref("layout.css.dpi", -1);
 // of a CSS "px". This is only used for windows on the screen, not for printing.
 pref("layout.css.devPixelsPerPx", "-1.0");
 
+// Is support for CSS initial-letter property enabled?
+pref("layout.css.initial-letter.enabled", false);
+
 // Is support for CSS Masking features enabled?
 pref("layout.css.masking.enabled", true);
 

testing/profiles/prefs_general.js

@@ -163,6 +163,9 @@ user_pref("layout.css.grid-template-subgrid-value.enabled", true);
 // Enable CSS 'contain' for testing
 user_pref("layout.css.contain.enabled", true);
 
+// Enable CSS initial-letter for testing
+user_pref("layout.css.initial-letter.enabled", true);
+
 // Enable CSS object-fit & object-position for testing
 user_pref("layout.css.object-fit-and-position.enabled", true);