assaultcube-/source/src/console.h

struct cline { char *line; int millis; };

template<class LINE> struct consolebuffer
{
    int maxlines;
    vector<LINE> conlines;

    consolebuffer(int maxlines = 100) : maxlines(maxlines) {}

    LINE &addline(const char *sf, int millis)        // add a line to the console buffer
    {
        LINE cl;
        cl.line = conlines.length()>maxlines ? conlines.pop().line : newstringbuf("");   // constrain the buffer size
        cl.millis = millis;                        // for how long to keep line on screen
        copystring(cl.line, sf);
        return conlines.insert(0, cl);
    }

    void setmaxlines(int numlines)
    {
        maxlines = numlines;
        while(conlines.length() > maxlines) delete[] conlines.pop().line;
    }
        
    virtual ~consolebuffer() 
    {
        while(conlines.length()) delete[] conlines.pop().line;
    }

    virtual void render() = 0;
};

struct textinputbuffer
{
	string buf;
    int pos, max;

    textinputbuffer() : pos(-1), max(0)
    {
        buf[0] = '\0';
    }

    bool key(int code, bool isdown, int unicode)
    {
        switch(code)
        {
            case SDLK_RETURN:
            case SDLK_KP_ENTER:
                break;

            case SDLK_HOME: 
                if(strlen(buf)) pos = 0; 
                break; 

            case SDLK_END: 
                pos = -1; 
                break; 

            case SDLK_DELETE:
            {
				if(pos < 0) break;

				std::string s(buf);
				int len = utf8::distance(s.begin(), s.end());
				std::string::iterator first = s.begin();
				std::string::iterator second = s.begin();
				utf8::advance(first, pos, s.end());
				utf8::advance(second, pos + 1, s.end());
				s.erase(first, second);
				strcpy(buf, s.c_str());

                if(pos>=len-1) pos = -1;
                return true;
            }

            case SDLK_BACKSPACE:
            {
				std::string s(buf);
				int len = utf8::distance(s.begin(), s.end());
				int i = pos>=0 ? pos : len;
				if(i<1) break;

				std::string::iterator first = s.begin();
				std::string::iterator second = s.begin();
				utf8::advance(first, i - 1, s.end());
				utf8::advance(second, i, s.end());
				s.erase(first, second);
				strcpy(buf, s.c_str());

                if(pos > 0) pos--;
                else if(!pos && len <=1 ) pos = -1;
                return true;
            }

            case SDLK_LEFT:
			{
				std::string s(buf);
				int len = utf8::distance(s.begin(), s.end());

                if(pos > 0) pos--;
                else if(pos < 0) pos = len-1;
                break;
			}

            case SDLK_RIGHT:
			{
				std::string s(buf);
				int len = utf8::distance(s.begin(), s.end());
                if(pos>=0 && ++pos >= len) pos = -1;
                break;
			}

            case SDLK_v:
                extern void pasteconsole(char *dst);
                #ifdef __APPLE__
                    #define MOD_KEYS (KMOD_LMETA|KMOD_RMETA) 
                #else
                    #define MOD_KEYS (KMOD_LCTRL|KMOD_RCTRL)
                #endif
                if(SDL_GetModState()&MOD_KEYS)
                {
                    pasteconsole(buf);
                    return true;
                }
                // fall through
                
            default:
            {
                if(unicode)
                {
					std::string s(buf);
					char tmp[5] = { 0, 0, 0, 0, 0 };
					utf8::append(unicode, tmp);
					std::string newchar(tmp);
					
					int len = utf8::distance(s.begin(), s.end());
					if(max && (int)len>=max) break;

					if(s.length() + newchar.length() < sizeof(buf))
					{
						if(pos < 0)
						{
							s.append(newchar);
						}
						else
						{
							std::string::iterator first = s.begin();
							utf8::advance(first, pos + 1, s.end());
							s.insert(first, newchar.begin(), newchar.end());
							pos++;
						}
						strcpy(buf, s.c_str());
						return true;
					}
                }
                break;
            }
        }
        return false;
    }
};