code: CharacterHit hitTextLine(CaretOffsetX x, int line) {
          return text.hitLine(x.value, line);
      }
docs: Hits the embedded TextFlow at the given line and x offset.
  
  @param x x coordinate relative to the embedded TextFlow.
  @param line index of the line in the embedded TextFlow.
  @return hit info for the given line and x coordinate