loginx Code

// This file is part of the loginx project
//
// Copyright (c) 2013 by Mike Sharov <msharov@users.sourceforge.net>
// This file is free software, distributed under the ISC license.

#include "defs.h"
#include <ncurses.h>
#include <ctype.h>

#ifndef COLOR_DEFAULT
    #define COLOR_DEFAULT -1
#endif

#define min(a,b)	((a)<(b)?(a):(b))

enum {
    MAX_PROMPT_WIDTH = sizeof(PASSWORD_PROMPT)-1,
    MAX_INPUT_WIDTH = sizeof(PASSWORD_MASKSTR),
    LOGIN_WINDOW_WIDTH = 1+1+MAX_PROMPT_WIDTH+1+MAX_INPUT_WIDTH+1+1,
    LOGIN_WINDOW_HEIGHT = 1+2+1,
    MSG_WINDOW_HEIGHT = 8
};
enum {
    colorpair_None,
    colorpair_StaticText,
    colorpair_Input,
    colorpair_Error
};

//----------------------------------------------------------------------

static WINDOW* _loginbox = NULL;
static WINDOW* _msgboxframe = NULL;
static WINDOW* _msgbox = NULL;

//----------------------------------------------------------------------

static void CursesInit (void)
{
    static bool s_initialized = false;
    if (s_initialized)
	return;
    if (!initscr())
	ExitWithMessage ("failed to initialize curses");
    atexit (CursesCleanup);
    start_color();
    use_default_colors();
    init_pair (colorpair_StaticText, COLOR_GREEN, COLOR_DEFAULT);
    init_pair (colorpair_Input, COLOR_CYAN, COLOR_DEFAULT);
    init_pair (colorpair_Error, COLOR_RED, COLOR_DEFAULT);
    noecho();
    s_initialized = true;
}

void CursesCleanup (void)
{
    if (isendwin())
	return;
#define CLDWIN(w)\
    if (w) {\
	wclear (w);\
	wnoutrefresh (w);\
	delwin (w);\
	w = NULL;\
    }
    CLDWIN(_loginbox)
    CLDWIN(_msgbox)
    CLDWIN(_msgboxframe)
#undef CLDWIN
    wclear (stdscr);
    wnoutrefresh (stdscr);
    doupdate();
    endwin();
}

void LoginBox (char* password, size_t passwordsz)
{
    CursesInit();
    if (!_loginbox) {
	_loginbox = newwin (LOGIN_WINDOW_HEIGHT, LOGIN_WINDOW_WIDTH, (LINES-LOGIN_WINDOW_HEIGHT)/2, (COLS-LOGIN_WINDOW_WIDTH)/2);
	if (!_loginbox)
	    ExitWithMessage ("failed to create login window");
	keypad (_loginbox, true);
	nodelay (_loginbox, false);
    }

    int key;
    unsigned pwlen = 0;
    acclist_t al = ReadAccounts();
    const unsigned aln = NAccounts();
    unsigned ali = SelectedAccount();
    if (!aln || ali >= aln)
	ExitWithMessage ("no usable accounts found");
    memset (password, 0, passwordsz);

    do {
	wattr_set (_loginbox, A_NORMAL, colorpair_StaticText, NULL);
	werase (_loginbox);
	box (_loginbox, 0, 0);
	mvwaddstr (_loginbox, 1,2, USERNAME_PROMPT);
	mvwaddstr (_loginbox, 2,2, PASSWORD_PROMPT);
	wattr_set (_loginbox, A_NORMAL, colorpair_Input, NULL);
	mvwaddnstr (_loginbox, 1,2+sizeof(USERNAME_PROMPT), al[ali]->name, MAX_INPUT_WIDTH);
	mvwhline (_loginbox, 2,2+sizeof(PASSWORD_PROMPT), ' ', strlen(PASSWORD_MASKSTR)+1);
	mvwaddnstr (_loginbox, 2,2+sizeof(PASSWORD_PROMPT), PASSWORD_MASKSTR, min(strlen(PASSWORD_MASKSTR),pwlen));
	wrefresh (_loginbox);
	key = wgetch (_loginbox);
	if (isprint(key) && pwlen < passwordsz-1)
	    password[pwlen++] = key;
	else if (key == KEY_BACKSPACE && pwlen > 0)
	    password[--pwlen] = 0;
	else if (key == KEY_UP)
	    ali = (ali-1) % aln;
	else if (key == KEY_DOWN || key == '\t')
	    ali = (ali+1) % aln;
    } while (key != '\n');

    SetSelectedAccount (ali);
}

void AddMessage (const char* msg, bool is_error)
{
    CursesInit();
    if (!_msgboxframe) {
	_msgboxframe = newwin (MSG_WINDOW_HEIGHT+2, COLS, LINES-MSG_WINDOW_HEIGHT-2, 0);
	if (!_msgboxframe)
	    return;
	wattr_set (_msgboxframe, A_NORMAL, colorpair_StaticText, NULL);
	box (_msgboxframe, 0, 0);
	wnoutrefresh (_msgboxframe);
    }
    if (!_msgbox) {
	_msgbox = newwin (getmaxy(_msgboxframe)-2, getmaxx(_msgboxframe)-2, getbegy(_msgboxframe)+1, getbegx(_msgboxframe)+1);
	if (!_msgbox)
	    return;
	scrollok (_msgbox, true);
    }
    if (is_error)
	wattr_set (_msgbox, A_BOLD, colorpair_Error, NULL);
    else
	wattr_set (_msgbox, A_NORMAL, colorpair_StaticText, NULL);
    waddstr (_msgbox, msg);
    waddstr (_msgbox, "\n");
    wrefresh (_msgbox);
}

void ClearScreen (void)
{
    if (!isatty (STDOUT_FILENO))
	return;
    // Clear the screen; c resets terminal, [r resets scroll region, [H homes cursor, [J erases
    #define RESET_SCREEN_CMD "\ec\e[r\e[H\e[J"
    write (STDOUT_FILENO, RESET_SCREEN_CMD, sizeof(RESET_SCREEN_CMD));
}