import curses

# Get a C character
def CCHAR(ch):
    if type(ch)==str:
        return ord(ch)
    elif type(ch)==int:
        return ch
    else:
        raise Exception("CCHAR: can't parse a non-char/non-int value.")

# Alternate character set
def ALTCHAR(ch):
    if type(ch)==str:
        return ord(ch) | A_ALTCHARSET
    elif type(ch)==int:
        return ch | A_ALTCHARSET
    else:
        raise Exception("ALTCHAR: can't parse a non-char/non-int value.")

def create_newwin(height, width, starty, startx):
    local_win = curses.newwin(height, width, starty, startx)
    local_win.box(0, 0)
    local_win.refresh()
    return local_win

def destroy_win(local_win):
    local_win.border(CCHAR(' '), CCHAR(' '), CCHAR(' '), CCHAR(' '), CCHAR(' '), CCHAR(' '), CCHAR(' '), CCHAR(' '))
    local_win.refresh()
    local_win.erase()
'''
stdscr = curses.initscr()
curses.cbreak()
curses.noecho()
curses.curs_set(0)
stdscr.keypad(True)
'''
def main(stdscr):
    height = 3
    width = 10
    LINES, COLS = stdscr.getmaxyx()
    starty = int((LINES - height) / 2)
    startx = int((COLS - width) / 2)
    stdscr.addstr("Use cursor keys to move the window, press Q to exit")
    stdscr.refresh()

    my_win = create_newwin(height, width, starty, startx)

    ch = 0
    while ( (ch != CCHAR('q')) and (ch != CCHAR('Q')) ):
        ch = stdscr.getch()
        if ch == curses.KEY_LEFT:
            if startx - 1 >= 0:
                destroy_win(my_win)
                startx -= 1
                my_win = create_newwin(height, width, starty, startx)
        elif ch == curses.KEY_RIGHT:
            if startx + width < COLS:
                destroy_win(my_win)
                startx += 1
                my_win = create_newwin(height, width, starty, startx)
        elif ch == curses.KEY_UP:
            if starty - 1 > 0:
                destroy_win(my_win)
                starty -= 1
                my_win = create_newwin(height, width, starty, startx)
        elif ch == curses.KEY_DOWN:
            if starty + height < LINES:
                destroy_win(my_win)
                starty += 1
                my_win = create_newwin(height, width, starty, startx)

    curses.endwin()

if __name__ == '__main__':
    curses.wrapper(main)