Print.cpp

/*
 Print.cpp - Base class that provides print() and println()
 Copyright (c) 2008 David A. Mellis.  All right reserved.

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 Modified 23 November 2006 by David A. Mellis
 Modified December 2014 by Ivan Grokhotkov
 Modified May 2015 by Michael C. Miller - esp8266 progmem support
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <Arduino.h>

#include "Print.h"

// Public Methods //////////////////////////////////////////////////////////////

/* default implementation: may be overridden */
size_t Print::write(const uint8_t *buffer, size_t size) {
    size_t n = 0;
    while (size--) {
        size_t ret = write(*buffer++);
        if (ret == 0) {
            // Write of last byte didn't complete, abort additional processing
            break;
        }
        n += ret;
    }
    return n;
}

size_t Print::printf(const char *format, ...) {
    va_list arg;
    va_start(arg, format);
    char temp[64];
    char* buffer = temp;
    size_t len = vsnprintf(temp, sizeof(temp), format, arg);
    va_end(arg);
    if (len > sizeof(temp) - 1) {
        buffer = new char[len + 1];
        if (!buffer) {
            return 0;
        }
        va_start(arg, format);
        vsnprintf(buffer, len + 1, format, arg);
        va_end(arg);
    }
    len = write((const uint8_t*) buffer, len);
    if (buffer != temp) {
        delete[] buffer;
    }
    return len;
}

size_t Print::printf_P(PGM_P format, ...) {
    va_list arg;
    va_start(arg, format);
    char temp[64];
    char* buffer = temp;
    size_t len = vsnprintf_P(temp, sizeof(temp), format, arg);
    va_end(arg);
    if (len > sizeof(temp) - 1) {
        buffer = new char[len + 1];
        if (!buffer) {
            return 0;
        }
        va_start(arg, format);
        vsnprintf_P(buffer, len + 1, format, arg);
        va_end(arg);
    }
    len = write((const uint8_t*) buffer, len);
    if (buffer != temp) {
        delete[] buffer;
    }
    return len;
}

size_t Print::print(const __FlashStringHelper *ifsh) {
    PGM_P p = reinterpret_cast<PGM_P>(ifsh);

    size_t n = 0;
    while (1) {
        uint8_t c = pgm_read_byte(p++);
        if (c == 0) break;
        n += write(c);
    }
    return n;
}

size_t Print::print(const String &s) {
    return write(s.c_str(), s.length());
}

size_t Print::print(const char str[]) {
    return write(str);
}

size_t Print::print(char c) {
    return write(c);
}

size_t Print::print(unsigned char b, int base) {
    return print((unsigned long) b, base);
}

size_t Print::print(int n, int base) {
    return print((long) n, base);
}

size_t Print::print(unsigned int n, int base) {
    return print((unsigned long) n, base);
}

size_t Print::print(long n, int base) {
    if(base == 0) {
        return write(n);
    } else if(base == 10) {
        if(n < 0) {
            int t = print('-');
            n = -n;
            return printNumber(n, 10) + t;
        }
        return printNumber(n, 10);
    } else {
        return printNumber(n, base);
    }
}

size_t Print::print(unsigned long n, int base) {
    if(base == 0)
        return write(n);
    else
        return printNumber(n, base);
}

size_t Print::print(double n, int digits) {
    return printFloat(n, digits);
}

size_t Print::println(const __FlashStringHelper *ifsh) {
    size_t n = print(ifsh);
    n += println();
    return n;
}

size_t Print::print(const Printable& x) {
    return x.printTo(*this);
}

size_t Print::println(void) {
    return print("\r\n");
}

size_t Print::println(const String &s) {
    size_t n = print(s);
    n += println();
    return n;
}

size_t Print::println(const char c[]) {
    size_t n = print(c);
    n += println();
    return n;
}

size_t Print::println(char c) {
    size_t n = print(c);
    n += println();
    return n;
}

size_t Print::println(unsigned char b, int base) {
    size_t n = print(b, base);
    n += println();
    return n;
}

size_t Print::println(int num, int base) {
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(unsigned int num, int base) {
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(long num, int base) {
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(unsigned long num, int base) {
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(double num, int digits) {
    size_t n = print(num, digits);
    n += println();
    return n;
}

size_t Print::println(const Printable& x) {
    size_t n = print(x);
    n += println();
    return n;
}

// Private Methods /////////////////////////////////////////////////////////////

size_t Print::printNumber(unsigned long n, uint8_t base) {
    char buf[8 * sizeof(long) + 1]; // Assumes 8-bit chars plus zero byte.
    char *str = &buf[sizeof(buf) - 1];

    *str = '\0';

    // prevent crash if called with base == 1
    if(base < 2)
        base = 10;

    do {
        unsigned long m = n;
        n /= base;
        char c = m - base * n;
        *--str = c < 10 ? c + '0' : c + 'A' - 10;
    } while(n);

    return write(str);
}

size_t Print::printFloat(double number, uint8_t digits) {
    size_t n = 0;

    if(isnan(number))
        return print("nan");
    if(isinf(number))
        return print("inf");
    if(number > 4294967040.0)
        return print("ovf");  // constant determined empirically
    if(number < -4294967040.0)
        return print("ovf");  // constant determined empirically

    // Handle negative numbers
    if(number < 0.0) {
        n += print('-');
        number = -number;
    }

    // Round correctly so that print(1.999, 2) prints as "2.00"
    double rounding = 0.5;
    for(uint8_t i = 0; i < digits; ++i)
        rounding /= 10.0;

    number += rounding;

    // Extract the integer part of the number and print it
    unsigned long int_part = (unsigned long) number;
    double remainder = number - (double) int_part;
    n += print(int_part);

    // Print the decimal point, but only if there are digits beyond
    if(digits > 0) {
        n += print(".");
    }

    // Extract digits from the remainder one at a time
    while(digits-- > 0) {
        remainder *= 10.0;
        int toPrint = int(remainder);
        n += print(toPrint);
        remainder -= toPrint;
    }

    return n;
}