improved the objective-c and swift api

enums.py

@@ -118,7 +118,7 @@ def to_java_upper(symbol):
 
 root = os.path.dirname(os.path.abspath(__file__))
 
-# write out C headers
+# write out C & Objective-C headers
 with open(root + '/yoga/YGEnums.h', 'w') as f:
     f.write(LICENSE)
     f.write('#pragma once\n\n')
@@ -126,6 +126,7 @@ with open(root + '/yoga/YGEnums.h', 'w') as f:
     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('#ifndef NS_ENUM\n')
         f.write('typedef enum YG%s {\n' % name)
         for value in values:
             if isinstance(value, tuple):
@@ -133,6 +134,15 @@ with open(root + '/yoga/YGEnums.h', 'w') as f:
             else:
                 f.write('  YG%s%s,\n' % (name, value))
         f.write('} YG%s;\n' % name)
+        f.write('#else\n')
+        f.write('typedef NS_ENUM(NSInteger, 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('};\n')
+        f.write('#endif\n')
         f.write('\n')
     f.write('YG_EXTERN_C_END\n')