callback_stream.h

#pragma once
 
#include <iostream>
#include <string>
 
#include <cgv/signal/signal.h>
 
namespace cgv {
        namespace signal {
 
struct callback_streambuf : public std::streambuf
{
        cgv::signal::signal<const std::string&>& write;
 
        callback_streambuf(cgv::signal::signal<const std::string&>& _write) : write(_write)
        {
        }
        std::streambuf *setbuf(char_type *buf, std::streamsize n)
        {
                setp(buf,buf+n-1);
                return this;
        }
        int_type overflow(int_type c)
        {
                if (c != std::char_traits<char>::eof()) {
                        *pptr() = c;
                        pbump(1);
                }
                int num = static_cast<int>(pptr()-pbase());
                std::string text(pbase(),num);
                write(text);
        pbump(-num);
                return c;
        }
        int sync()
        {
                int num = static_cast<int>(pptr()-pbase());
                std::string text(pbase(),num);
                write(text);
        pbump(-num);
        return num;
        }
};
 
class callback_stream : public std::ostream
{
protected:
        callback_streambuf buf;
        char buffer[256];
public:
        cgv::signal::signal<const std::string&> write;
        callback_stream() : std::ostream(0), buf(write)
        {
                buf.setbuf(buffer,256);
                init(&buf);
        }
};
 
        }
}