Transform the Count enum values into private constants

Summary:
Hides implementation details for the C, Objective-C and Swift APIs.
Closes https://github.com/facebook/yoga/pull/292

Differential Revision: D4351523

Pulled By: emilsjolander

fbshipit-source-id: 18a1149d169f0d52bd078714295000b5d07434dd

enums.py

@@ -111,22 +111,22 @@ def to_java_upper(symbol):
     return out
 
 
-root = os.path.dirname(__file__)
+root = os.path.dirname(os.path.abspath(__file__))
 
-# write out C header
+# write out C headers
 with open(root + '/yoga/YGEnums.h', 'w') as f:
     f.write(LICENSE)
     f.write('#pragma once\n\n')
     f.write('#include "YGMacros.h"\n\n')
     f.write('YG_EXTERN_C_BEGIN\n\n')
     for name, values in ENUMS.items():
+        f.write('#define YG%sCount %s\n' % (name, len(values)))
         f.write('typedef enum YG%s {\n' % name)
         for value in values:
             if isinstance(value, tuple):
                 f.write('  YG%s%s = %d,\n' % (name, value[0], value[1]))
             else:
                 f.write('  YG%s%s,\n' % (name, value))
-        f.write('  YG%sCount,\n' % name)
         f.write('} YG%s;\n' % name)
         f.write('\n')
     f.write('YG_EXTERN_C_END\n')

yoga/YGEnums.h

@@ -13,28 +13,29 @@
 
 YG_EXTERN_C_BEGIN
 
+#define YGFlexDirectionCount 4
 typedef enum YGFlexDirection {
   YGFlexDirectionColumn,
   YGFlexDirectionColumnReverse,
   YGFlexDirectionRow,
   YGFlexDirectionRowReverse,
-  YGFlexDirectionCount,
 } YGFlexDirection;
 
+#define YGMeasureModeCount 3
 typedef enum YGMeasureMode {
   YGMeasureModeUndefined,
   YGMeasureModeExactly,
   YGMeasureModeAtMost,
-  YGMeasureModeCount,
 } YGMeasureMode;
 
+#define YGPrintOptionsCount 3
 typedef enum YGPrintOptions {
   YGPrintOptionsLayout = 1,
   YGPrintOptionsStyle = 2,
   YGPrintOptionsChildren = 4,
-  YGPrintOptionsCount,
 } YGPrintOptions;
 
+#define YGEdgeCount 9
 typedef enum YGEdge {
   YGEdgeLeft,
   YGEdgeTop,
@@ -45,72 +46,71 @@ typedef enum YGEdge {
   YGEdgeHorizontal,
   YGEdgeVertical,
   YGEdgeAll,
-  YGEdgeCount,
 } YGEdge;
 
+#define YGPositionTypeCount 2
 typedef enum YGPositionType {
   YGPositionTypeRelative,
   YGPositionTypeAbsolute,
-  YGPositionTypeCount,
 } YGPositionType;
 
+#define YGDimensionCount 2
 typedef enum YGDimension {
   YGDimensionWidth,
   YGDimensionHeight,
-  YGDimensionCount,
 } YGDimension;
 
+#define YGJustifyCount 5
 typedef enum YGJustify {
   YGJustifyFlexStart,
   YGJustifyCenter,
   YGJustifyFlexEnd,
   YGJustifySpaceBetween,
   YGJustifySpaceAround,
-  YGJustifyCount,
 } YGJustify;
 
+#define YGDirectionCount 3
 typedef enum YGDirection {
   YGDirectionInherit,
   YGDirectionLTR,
   YGDirectionRTL,
-  YGDirectionCount,
 } YGDirection;
 
+#define YGLogLevelCount 5
 typedef enum YGLogLevel {
   YGLogLevelError,
   YGLogLevelWarn,
   YGLogLevelInfo,
   YGLogLevelDebug,
   YGLogLevelVerbose,
-  YGLogLevelCount,
 } YGLogLevel;
 
+#define YGWrapCount 2
 typedef enum YGWrap {
   YGWrapNoWrap,
   YGWrapWrap,
-  YGWrapCount,
 } YGWrap;
 
+#define YGOverflowCount 3
 typedef enum YGOverflow {
   YGOverflowVisible,
   YGOverflowHidden,
   YGOverflowScroll,
-  YGOverflowCount,
 } YGOverflow;
 
+#define YGExperimentalFeatureCount 2
 typedef enum YGExperimentalFeature {
   YGExperimentalFeatureRounding,
   YGExperimentalFeatureWebFlexBasis,
-  YGExperimentalFeatureCount,
 } YGExperimentalFeature;
 
+#define YGAlignCount 5
 typedef enum YGAlign {
   YGAlignAuto,
   YGAlignFlexStart,
   YGAlignCenter,
   YGAlignFlexEnd,
   YGAlignStretch,
-  YGAlignCount,
 } YGAlign;
 
 YG_EXTERN_C_END

yoga/Yoga.c

@@ -133,8 +133,6 @@ static int YGAndroidLog(YGLogLevel level, const char *format, va_list args) {
     case YGLogLevelVerbose:
       androidLevel = ANDROID_LOG_VERBOSE;
       break;
-    case YGLogLevelCount:
-      break;
   }
   const int result = __android_log_vprint(androidLevel, "YG-layout", format, args);
   return result;
@@ -951,8 +949,6 @@ static void YGConstrainMaxSizeForMode(const float maxSize, YGMeasureMode *mode,
         *size = maxSize;
       }
       break;
-    case YGMeasureModeCount:
-      break;
   }
 }
 
@@ -1968,7 +1964,6 @@ static void YGNodelayoutImpl(const YGNodeRef node,
         leadingMainDim = betweenMainDim / 2;
         break;
       case YGJustifyFlexStart:
-      case YGJustifyCount:
         break;
     }
 
@@ -2171,7 +2166,6 @@ static void YGNodelayoutImpl(const YGNodeRef node,
         break;
       case YGAlignAuto:
       case YGAlignFlexStart:
-      case YGAlignCount:
         break;
     }
 
@@ -2231,7 +2225,6 @@ static void YGNodelayoutImpl(const YGNodeRef node,
                 break;
               }
               case YGAlignAuto:
-              case YGAlignCount:
                 break;
             }
           }