Bug 1528940 - convert NS_STYLE_FLEX_DIRECTION to an enum class in nsStyleConsts.h r=emilio

Converted the #define variable NS_STYLE_FLEX_DIRECTION to an enum class in nsStyleConsts.h and made changes in other files that access it

Differential Revision: https://phabricator.services.mozilla.com/D20291

--HG--
extra : moz-landing-system : lando

layout/generic/nsFlexContainerFrame.cpp

@@ -3627,7 +3627,7 @@ void FlexboxAxisTracker::InitAxesFromLegacyProps(
 void FlexboxAxisTracker::InitAxesFromModernProps(
     const nsFlexContainerFrame* aFlexContainer) {
   const nsStylePosition* stylePos = aFlexContainer->StylePosition();
-  uint32_t flexDirection = stylePos->mFlexDirection;
+  StyleFlexDirection flexDirection = stylePos->mFlexDirection;
 
   // Inline dimension ("start-to-end"):
   // (NOTE: I'm intentionally not calling these "inlineAxis"/"blockAxis", since
@@ -3640,22 +3640,22 @@ void FlexboxAxisTracker::InitAxesFromModernProps(
 
   // Determine main axis:
   switch (flexDirection) {
-    case NS_STYLE_FLEX_DIRECTION_ROW:
+    case StyleFlexDirection::Row:
       mMainAxis = inlineDimension;
       mIsRowOriented = true;
       mIsMainAxisReversed = false;
       break;
-    case NS_STYLE_FLEX_DIRECTION_ROW_REVERSE:
+    case StyleFlexDirection::RowReverse:
       mMainAxis = GetReverseAxis(inlineDimension);
       mIsRowOriented = true;
       mIsMainAxisReversed = true;
       break;
-    case NS_STYLE_FLEX_DIRECTION_COLUMN:
+    case StyleFlexDirection::Column:
       mMainAxis = blockDimension;
       mIsRowOriented = false;
       mIsMainAxisReversed = false;
       break;
-    case NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE:
+    case StyleFlexDirection::ColumnReverse:
       mMainAxis = GetReverseAxis(blockDimension);
       mIsRowOriented = false;
       mIsMainAxisReversed = true;
@@ -3667,8 +3667,8 @@ void FlexboxAxisTracker::InitAxesFromModernProps(
   // Determine cross axis:
   // (This is set up so that a bogus |flexDirection| value will
   // give us blockDimension.
-  if (flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN ||
-      flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE) {
+  if (flexDirection == StyleFlexDirection::Column ||
+      flexDirection == StyleFlexDirection::ColumnReverse) {
     mCrossAxis = inlineDimension;
   } else {
     mCrossAxis = blockDimension;
@@ -4447,8 +4447,8 @@ bool nsFlexContainerFrame::IsItemInlineAxisMainAxis(nsIFrame* aFrame) {
   // whether the flex container's main axis is its inline axis.)
   auto flexDirection = flexContainer->StylePosition()->mFlexDirection;
   bool flexContainerIsRowOriented =
-      flexDirection == NS_STYLE_FLEX_DIRECTION_ROW ||
-      flexDirection == NS_STYLE_FLEX_DIRECTION_ROW_REVERSE;
+      flexDirection == StyleFlexDirection::Row ||
+      flexDirection == StyleFlexDirection::RowReverse;
 
   // aFrame's inline axis is its flex container's main axis IFF the above
   // questions have the same answer.

layout/style/ServoBindings.toml

@@ -134,6 +134,7 @@ rusty-enums = [
     "mozilla::StyleWhiteSpace",
     "mozilla::StyleTextRendering",
     "mozilla::StyleColorAdjust",
+    "mozilla::StyleFlexDirection",
     "nsStyleImageType",
     "nsStyleSVGPaintType",
     "nsStyleSVGFallbackType",

layout/style/nsStyleConsts.h

@@ -385,10 +385,12 @@ enum class StyleContent : uint8_t {
 #define NS_STYLE_JUSTIFY_ALL_SHIFT NS_STYLE_ALIGN_ALL_SHIFT
 
 // See nsStylePosition
-#define NS_STYLE_FLEX_DIRECTION_ROW 0
-#define NS_STYLE_FLEX_DIRECTION_ROW_REVERSE 1
-#define NS_STYLE_FLEX_DIRECTION_COLUMN 2
-#define NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE 3
+enum class StyleFlexDirection : uint8_t {
+	Row,
+	RowReverse,
+	Column,
+	ColumnReverse,
+};
 
 // See nsStylePosition
 #define NS_STYLE_FLEX_WRAP_NOWRAP 0

layout/style/nsStyleStruct.cpp

@@ -1311,7 +1311,7 @@ nsStylePosition::nsStylePosition(const Document& aDocument)
       mSpecifiedJustifyItems(NS_STYLE_JUSTIFY_LEGACY),
       mJustifyItems(NS_STYLE_JUSTIFY_NORMAL),
       mJustifySelf(NS_STYLE_JUSTIFY_AUTO),
-      mFlexDirection(NS_STYLE_FLEX_DIRECTION_ROW),
+      mFlexDirection(StyleFlexDirection::Row),
       mFlexWrap(NS_STYLE_FLEX_WRAP_NOWRAP),
       mObjectFit(NS_STYLE_OBJECT_FIT_FILL),
       mOrder(NS_STYLE_ORDER_INITIAL),

layout/style/nsStyleStruct.h

@@ -1291,7 +1291,7 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStylePosition {
   uint8_t mSpecifiedJustifyItems;
   uint8_t mJustifyItems;
   uint8_t mJustifySelf;
-  uint8_t mFlexDirection;  // NS_STYLE_FLEX_DIRECTION_*
+  mozilla::StyleFlexDirection mFlexDirection;  
   uint8_t mFlexWrap;       // NS_STYLE_FLEX_WRAP_*
   uint8_t mObjectFit;      // NS_STYLE_OBJECT_FIT_*
   int32_t mOrder;

servo/components/style/properties/longhands/position.mako.rs

@@ -75,6 +75,7 @@ ${helpers.single_keyword(
     extra_prefixes="webkit",
     animation_value_type="discrete",
     servo_restyle_damage = "reflow",
+    gecko_enum_prefix = "StyleFlexDirection",
 )}
 
 ${helpers.single_keyword(