loader.py

import sys
import time
import _nx
from glob import glob
import os
import runpy

sys.argv = [""] # workaround needed for runpy

KEY_A = 1
KEY_UP = 0x222000
KEY_DOWN = 0x888000

CONTROLLER_P1_AUTO = 10

GfxMode_TiledDouble = 1

class AnsiMenu():
    def __init__(self, entries, console=sys.stdout.buffer):
        self.entries = entries
        self.console = console


    def query(self):
        self.selected_idx = 0
        self.render()

        while True:
            if self.poll_input():
                break
            time.sleep(0.01)

        self.console.write(b"\x1b[%dB" % (len(self.entries)-self.selected_idx))
        self.console.flush()
        return self.selected_idx


    def poll_input(self):
        _nx.hid_scan_input()
        keys_down = _nx.hid_keys_down(CONTROLLER_P1_AUTO)

        if keys_down & KEY_A:
            return True
        elif keys_down & KEY_UP:
            if self.selected_idx > 0:
                self.selected_idx -= 1
                self.console.write(b" \x1b[1A\r>\r")
                self.console.flush()
        elif keys_down & KEY_DOWN:
            if self.selected_idx < len(self.entries)-1:
                self.selected_idx += 1
                self.console.write(b" \n\r>\r")
                self.console.flush()

        return False


    def render(self):
        for i, label in enumerate(self.entries):
            marker = b">" if (i == self.selected_idx) else b" "
            self.console.write(b"%s %s\n" % (marker, label.encode()))

        self.console.write(b"\x1b[%dA" % len(self.entries))
        self.console.flush()

#os.chdir("examples")

while True:
    dirs = ["../"] + glob("*/")
    scripts = glob("*.py")
    listing = dirs+scripts
    file_menu = AnsiMenu(listing)
    print("Listing for {}:".format(os.getcwd()), flush=True)
    selected = listing[file_menu.query()]
    sys.stdout.buffer.write(b"\x1b[2J")
    sys.stdout.buffer.flush()
    if selected in dirs:
        os.chdir(selected)
    else:
        runpy.run_path(selected, run_name="__main__")
        _nx.gfx_set_mode(GfxMode_TiledDouble)
        print("{} Exited.".format(selected), flush=True)