ladybird/Userland/Applications/Calculator/KeypadValue.h
Lucas CHOLLET 7532ef78ad Calculator: Round small number to prevent crash
Small numbers (smaller than 1e-19) can't be displayed in the calculator.
They provoke a division by zero in Keypad::set_value(), as 10^20
overflows.
2022-01-02 15:42:13 +01:00

49 lines
1.4 KiB
C++

/*
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Math.h>
#include <AK/String.h>
#include <AK/Types.h>
class KeypadValue {
friend class Keypad;
friend class Calculator;
public:
KeypadValue(i64, u8);
KeypadValue(i64);
explicit KeypadValue(StringView);
KeypadValue operator+(KeypadValue const&);
KeypadValue operator-(KeypadValue const&);
KeypadValue operator*(KeypadValue const&);
KeypadValue operator-(void) const;
bool operator<(KeypadValue const&);
bool operator==(KeypadValue const&);
KeypadValue sqrt() const;
KeypadValue invert() const;
KeypadValue operator/(KeypadValue const&);
private:
explicit KeypadValue(double);
explicit operator double() const;
template<typename T, typename F>
T operator_helper(KeypadValue const& lhs, KeypadValue const& rhs, F callback);
// This class represents a pair of a value together with the amount of decimal places that value is offset by.
// For example, if we were to represent the value -123.55 in this format, m_value would be -12355 and
// m_decimal_places would be 2, because when you shift -12355 2 digits to the right, you get -123.55.
// This way, most operations don't have to be performed on doubles, but can be performed without loss of
// precision on this class.
i64 m_value { 0 };
u8 m_decimal_places { 0 };
};