kTextHeightNone top-level constant
          
          double
          const kTextHeightNone
          
        
        
A TextStyle.height value that indicates the text span should take the height defined by the font, which may not be exactly the height of TextStyle.fontSize.
Implementation
// To change the sentinel value, search for "kTextHeightNone" in the source code.
const double kTextHeightNone = 0.0;