termfuncs.cpp

// -- NOTE TO COMP11 STUDENTS ----------------
//
//   DO NOT EDIT OR COPY CODE FROM THIS FILE
//   TO USE THESE FUNCTIONS:
//     at the top of your code put: #include "termfuncs.h"
//     when you compile:  clang++ -Wall myprog.cpp termfuncs.cpp
//
//   DO NOT DO THIS:
//      #include "termfuncs.cpp"
//
//
//   termfuncs.cpp -- some simple functions for using the terminal nicely
//
//   char getachar()     -- returns next char with no echo and no Enter needed
//   char getacharnow(ds)     -- only waits ds/10th seconds
//                               returns '\0' if no input by that time
//   void screen_clear() -- clears the screen
//   void screen_home()  -- moves cursor to top of screen
//   void screen_fg(string color)
//   void screen_bg(string color)
//   void screen_attr(string attr)
//   void screen_bright()
//   void screen_reset()
//   void place_cursor(int, int);   -- move the cursor to row col
//   void place_char(char, int, int)  -- move and place
//   void hide_cursor()
//   void show_cursor()
//   int get_screen_cols();
//   int get_screen_rows();
//

#include <iostream>
#include <termios.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#include <signal.h>
using namespace std;

static const string CSI = "\033[";

static string color_names[] = { "black", "red", "green", "yellow",
                                "navy",  "pink", "blue", "white" };
static const int num_colors = 8;

static string attr_names[] = {  "reset", "bright", "dim", "", 
                                "underscore", "blink", "", 
                                "reverse", "hidden" };
static const int num_attrs = 9;

static termios prev_tty_state;
static int prev_state_stored = 0;

//
// getachar
//  returns a char using noecho and -icanon unless not a tty
//
char getachar()
{
        char c;

        cout << std::flush;
        if (isatty(0)) {
                struct termios  info, orig;
                // system("stty -echo -icanon");
                tcgetattr(0, &info);
                orig = info;
                prev_tty_state = orig;
                prev_state_stored = 1;

                info.c_lflag &= ~ECHO;
                info.c_lflag &= ~ICANON;
                tcsetattr(0, TCSANOW, &info);

                read(0, &c, 1);

                // system("stty echo icanon");
                tcsetattr(0, TCSANOW, &orig);
        } else {
                read(0, &c, 1);
        }

        return c;
}
//
// getacharnow
//  returns a char using noecho and -icanon unless not a tty
//
char getacharnow(int decisecs)
{
        char c;

        cout << std::flush;
        if (isatty(0)) {
                struct termios  info, orig;
                // system("stty -echo -icanon");
                tcgetattr(0, &info);
                orig              = info;
                prev_tty_state    = orig;
                prev_state_stored = 1;

                info.c_lflag    &= ~ECHO;
                info.c_lflag    &= ~ICANON;
                info.c_cc[VMIN]  = 0;
                info.c_cc[VTIME] = decisecs;
                tcsetattr(0, TCSANOW, &info);

                if (read(0, &c, 1) != 1)
                        c = '\0';

                tcsetattr(0, TCSANOW, &orig);
                // system("stty echo icanon");
        } else {
                if (read(0, &c, 1) != 1)
                        c = '\0';
        }

        return c;
}


static void restore_tty_state()
{
        if (prev_state_stored)
                tcsetattr(0, TCSANOW, &prev_tty_state);
}

//
// clear the terminal screen
//
void screen_clear()
{
        cout << (CSI + "H");
        cout << (CSI + "2J");
}

//
// Move the cursor to the home position (upper left corner)
//
void screen_home()
{
        cout << (CSI + "H");
}

static  void (*prev_handler)(int) = NULL;;

//
// Make the cursor invisible
// 
void hide_cursor()
{
        void on_sigint(int);

        prev_handler = signal(SIGINT, on_sigint);
        cout << (CSI + "?25l");
}

//
// make the cursor visible
//
void show_cursor()
{
        cout << (CSI + "?25h");
}

//
// To do if  program gets a SIGINT (e. g., if someone hits Ctrl-c
//
void on_sigint(int s)
{
        cout << std::flush;
        show_cursor();
        if ( prev_handler ){
                prev_handler(s);
        }
        restore_tty_state();
        exit(SIGINT);
}

//
// lookup a string in an array
//   args: string to find, list of strings, len of list
//   rets: index of string or -1 for not found
//
static int lookup(string findme, string list[], int num)
{
        int i;
        for (i = 0; i < num; i++) {
                if (list[i] == findme)
                        return i;
        }
        return -1;
}

//
// set screen foreground color
//
void screen_fg(string color)
{
        int num = lookup(color, color_names, num_colors);

        if (num >= 0) {
                cout << CSI << ( 30 + num ) << "m";
        }
}

//
// set screen background color
//
void screen_bg(string color)
{
        int num = lookup(color, color_names, num_colors);

        if (num >= 0) {
                cout << CSI << ( 40 + num ) << "m";
        }
}

void screen_attr(string attr)
{

        int num = lookup(attr, attr_names, num_attrs);
        if ( num >= 0 ){
                cout << CSI << num  << "m";
        }
}
void screen_bright()
{
        screen_attr("bright");
}

//
// Put screen back in it's normal state
// 
void screen_reset()
{
        screen_attr("reset");
}

//
// Put cursor at given row and column
//
void place_cursor(int row, int col)
{
        cout << "\033[" << (row + 1) << ";" << (col + 1) << "H";
        flush(cout);
}

//
// Place the character c at the given row and column
//
void place_char(char c, int row, int col)
{
        place_cursor(row, col);
        cout << c;
        flush(cout);
}

#include <sys/ioctl.h>

//
// returns number of rows on the screen
//
int get_screen_rows()
{
        struct winsize w;
        ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
        return w.ws_row;
}

//
// returns number of cols on the screen
//
int get_screen_cols()
{
        struct winsize w;
        ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
        return w.ws_col;
}