LineBuffer.h

/****
 * Sming Framework Project - Open Source framework for high efficiency native ESP8266 development.
 * Created 2015 by Skurydin Alexey
 * http://github.com/SmingHub/Sming
 * All files of the Sming Core are provided under the LGPL v3 license.
 *
 * LineBuffer.h - support for buffering/editing a line of text
 *
 * author mikee47 <mike@sillyhouse.net> Feb 2019
 *
 ****/

#ifndef _SMING_CORE_DATA_BUFFER_LINE_BUFFER_H_
#define _SMING_CORE_DATA_BUFFER_LINE_BUFFER_H_

#include <user_config.h>

template <uint16_t BUFSIZE> class LineBuffer
{
public:
    char addChar(char c);

    void clear()
    {
        length = 0;
    }

    char* getBuffer()
    {
        return buffer;
    }

    unsigned getLength() const
    {
        return length;
    }

    bool startsWith(const char* text) const;

    bool contains(const char* text) const;

    bool backspace();

private:
    char buffer[BUFSIZE] = {'\0'}; 
    uint16_t length = 0;           
};

template <uint16_t BUFSIZE> char LineBuffer<BUFSIZE>::addChar(char c)
{
    if(c == '\n' || c == '\r') {
        return '\n';
    }

    if(c >= 0x20 && c < 0x7f && length < (BUFSIZE - 1)) {
        buffer[length++] = c;
        buffer[length] = '\0';
        return c;
    }

    return '\0';
}

template <uint16_t BUFSIZE> bool LineBuffer<BUFSIZE>::backspace()
{
    if(length == 0) {
        return false;
    } else {
        --length;
        buffer[length] = '\0';
        return true;
    }
}

template <uint16_t BUFSIZE> bool LineBuffer<BUFSIZE>::startsWith(const char* text) const
{
    auto len = strlen(text);
    return memcmp(buffer, text, len) == 0;
}

template <uint16_t BUFSIZE> bool LineBuffer<BUFSIZE>::contains(const char* text) const
{
    return strstr(buffer, text) != nullptr;
}

#endif /* _SMING_CORE_DATA_BUFFER_LINE_BUFFER_H_ */