#pragma once #include // This type implements number typing and // displaying mechanics. It does not perform // any arithmetic operations or anything on // the values it deals with. class Keypad final { public: Keypad(); ~Keypad(); void type_digit(int digit); void type_decimal_point(); void type_backspace(); double value() const; void set_value(double); String to_string() const; private: // Internal representation ofthe current decimal value. bool m_negative { false }; long m_int_value { 0 }; long m_frac_value { 0 }; int m_frac_length { 0 }; // E.g. for -35.004200, // m_negative = true // m_int_value = 35 // m_frac_value = 4200 // m_frac_length = 6 enum class State { External, TypingInteger, TypingDecimal }; State m_state { State::External }; };