The Fl_Float_Input class is a subclass of Fl_Input that only allows the user to type floating point numbers (sign, digits, decimal point, more digits, 'E' or 'e', sign, digits).
Fl_Float_Input::Fl_Float_Input(int x, int y, int w, int h, const char *label = 0)
Creates a new Fl_Float_Input widget using the given position, size, and label string. The default boxtype is FL_DOWN_BOX.
virtual Fl_Float_Input::~Fl_Float_Input()
Destroys the widget and any value associated with it.