NumericFilter.hpp

#ifndef NUMERICFILTER_HPP
#define NUMERICFILTER_HPP

#include <SFML/System/String.hpp>
#include <string>
#include <sstream>
#include <cmath>

template<class T=double>
class NumericFilter {
private:
    bool clamp;
    bool eofCheck;
    bool allowEmpty;
    T min;
    T max;

public:
    NumericFilter(T min = -INFINITY, T max = INFINITY, bool clamp = true, bool eofCheck = true, bool allowEmpty = true) :
        clamp(clamp),
        eofCheck(eofCheck),
        allowEmpty(allowEmpty) {
        if(min > max) {
            T tmp = min;
            min = max;
            max = tmp;
        }
        setMin(min);
        setMax(max);
    }

    bool operator()(sf::String& str) {
        if((allowEmpty && str.isEmpty()) || (str == "-" && min < 0)) {
            return true;
        }
        str.replace(",", ".");

        T num;
        std::istringstream ss(str);
        ss >> num;
        if(ss.fail() || (eofCheck && !ss.eof())) {
            return false;
        } else {
            if(clamp) {
                if(num < min) {
                    str = sf::String(std::to_string(min));
                } else if(num > max) {
                    str = sf::String(std::to_string(max));
                }
                return true;
            } else if(num < min || num > max) {
                return false;
            } else {
                return true;
            }
        }
    }
    void setClamp(bool value) {
        clamp = value;
    }
    void setMin(const T& value) {
        T test = 0;
        test -= 1;
        if(test > 0 && value < 0) {
            min = 0;
        } else {
            min = value;
        }
    }
    void setMax(const T& value) {
        T test = 0;
        test -= 1;
        if(test > 0 && value < 0) {
            max = 0;
        } else {
            max = value;
        }
    }
};

#endif // NUMERICFILTER_HPP