gem-graph-server/include/terminal.h

//=-------------------------------------------------------------------------=//
//  Terminal management tools                                                //
//                                                                           //
//  Copyright © 2021 The Gem-graph Project                                   //
//                                                                           //
//  This file is part of gem-graph.                                          //
//                                                                           //
//  This program is free software: you can redistribute it and/or modify     //
//  it under the terms of the GNU Affero General Public License as           //
//  published by the Free Software Foundation, either version 3 of the       //
//  License, or (at your option) any later version.                          //
//                                                                           //
//  This program 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 Affero General Public License for more details.                      //
//                                                                           //
//  You should have received a copy of the GNU Affero General Public License //
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.   //
//=-------------------------------------------------------------------------=//

#ifndef BASE_H
    #include "../include/base.h"
#endif

#include <sys/ioctl.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>

#define C_CLEARSCREEN "\e[2J"
#define C_CLEARLINE "\e[2K"
#define C_CURSORLEFT "\e[1D"
#define C_CURSORRIGHT "\e[1C"
#define C_SAVE_CURSORPOS "\e7"
#define C_RESTORE_CURSORPOS "\e8"
#define C_COLOR_RED "\e[01;31m"
#define C_COLOR_YELLOW "\e[00;33m"
#define C_COLOR_GREEN "\e[00;32m"
#define C_COLOR_BLUE "\e[01;34m"
#define C_COLOR_REVERSE "\e[7m"
#define C_COLOR_NORMAL "\e[0m"
#define C_COLOR_BLACK_ON_GREEN "\e[30;42m"
#define C_COLOR_LIGHTWHITE_ON_GREEN "\e[47;42m"
#define C_COLOR_LIGHTWHITE_ON_GREY "\e[47;100m"
#define C_COLOR_BLACK_ON_LIGHTGREY "\e[30;102m"
#define C_COLOR_WHITE_ON_BLUE "\e[107;44m"

#define NON_BLOCKING 1

volatile struct winsize terminalSize;

//
// Get a character code from the keyboard
//
static inline int getch(bool nonBlocking)
{
    int buf = 0;
    // old terminal
    struct termios old = {0};

    // force flush stdout
    fflush(stdout);

    // Set non-blocking mode if asked
    if(nonBlocking)
        fcntl(0, F_SETFL, O_NONBLOCK);

    if(tcgetattr(0, &old) < 0) {
        printLog("%sError getting terminal settings! (%s)\n",
                 C_COLOR_RED,
                 strerror(errno));
        return -1;
    }

    old.c_lflag &= ~ICANON; // disable buffered I/O
    old.c_lflag &= ~ECHO;   // set no echo mode

    if(tcsetattr(0, TCSANOW, &old) < 0) {
        printLog("%sError setting terminal settings! (%s)\n",
                 C_COLOR_RED,
                 strerror(errno));
        return -1;
    }

    buf = getchar();
    if(buf < 0) {
        // Check target busy (try again)
        if(errno == EAGAIN)
            return 0;

        printLog("%sError reading character! (%s)\n",
                 C_COLOR_RED,
                 strerror(errno));
        return -1;
    }

    old.c_lflag |= ICANON; // enable buffered I/O
    old.c_lflag |= ECHO;   // set echo mode

    if(tcsetattr(0, TCSADRAIN, &old) < 0) {
        printLog("%sError resetting terminal settings! (%s)\n",
                 C_COLOR_RED,
                 strerror(errno));
        return -1;
    }

    // Reset blocking mode
    if(nonBlocking)
        fcntl(0, F_SETFL, 0);

    return buf;
}

//
// Get the screen size
//
static inline void getScreenSize(int signum)
{
    // Get current terminal size
    ioctl(STDOUT_FILENO, TIOCGWINSZ, &terminalSize);
}

//
// Set cursor location
//
static inline void setCursorLocation(char x, char y)
{
    printf("\x1b[%d;%dH", y, x);
}

//
// Save cursor location
//
static inline void saveCursorLocation(void)
{
    printf(C_SAVE_CURSORPOS);
}

//
// Restore cursor location
//
static inline void restoreCursorLocation(void)
{
    printf(C_RESTORE_CURSORPOS);
}

//
// Move cursor location to the right
//
static inline void moveCursorForward(void)
{
    printf(C_CURSORRIGHT);
}

//
// Move cursor location to the left
//
static inline void moveCursorBackward(void)
{
    printf(C_CURSORLEFT);
}

//
// Clear screen
//
static inline void clearScreen(void)
{
    printf(C_CLEARSCREEN);
    setCursorLocation(1,1);
    fflush(stdout);
}