Typography constructor

Typography({TargetPlatform platform, TextTheme black, TextTheme white, TextTheme englishLike, TextTheme dense, TextTheme tall })

Creates a typography instance.

If platform is specified, the default values for black and white are blackCupertino and whiteCupertino respectively. Otherwise they are blackMountainView and whiteMoutainView.

The default values for englishLike, dense, and tall are englishLike2014, dense2014, and tall2014.

Implementation 

factory Typography({
  TargetPlatform platform,
  TextTheme black,
  TextTheme white,
  TextTheme englishLike,
  TextTheme dense,
  TextTheme tall,
}) {
  switch (platform) {
    case TargetPlatform.iOS:
      black ??= blackCupertino;
      white ??= whiteCupertino;
      break;
    case TargetPlatform.android:
    case TargetPlatform.fuchsia:
      black ??= blackMountainView;
      white ??= whiteMountainView;
  }
  englishLike ??= englishLike2014;
  dense ??= dense2014;
  tall ??= tall2014;
  return Typography._(black, white, englishLike, dense, tall);
}