#!/usr/bin/env python3
from asciimatics.widgets import Frame, TextBox, Layout, Widget
from asciimatics.effects import Background
from asciimatics.scene import Scene
from asciimatics.screen import Screen
from asciimatics.exceptions import ResizeScreenError
from asciimatics.parsers import AnsiTerminalParser
from asciimatics.event import KeyboardEvent
import sys
import subprocess
import threading
import logging
try:
import select
import pty
import os
import fcntl
import curses
except Exception:
print("This demo only runs on Unix systems.")
sys.exit(0)
logging.basicConfig(filename="term.log", level=logging.DEBUG)
class Terminal(TextBox):
def __init__(self, height):
super(Terminal, self).__init__(height, line_wrap=True, parser=AnsiTerminalParser())
#Key definitions
self._map = {}
for k, v in [
(Screen.KEY_LEFT, "kcub1"),
(Screen.KEY_RIGHT, "kcuf1"),
(Screen.KEY_UP, "kcuu1"),
(Screen.KEY_DOWN, "kcud1"),
(Screen.KEY_HOME, "khome"),
(Screen.KEY_END, "kend"),
(Screen.KEY_BACK, "kbs"),
]:
self._map[k] = curses.tigetstr(v)
self._map[Screen.KEY_TAB] = "\t".encode()
# Open a pseudo TTY to control the interactive session. Make it non-blocking.
self._master, slave = pty.openpty()
fl = fcntl.fcntl(self._master, fcntl.F_GETFL)
fcntl.fcntl(self._master, fcntl.F_SETFL, fl | os.O_NONBLOCK)
# Start the shell and thread to pull data from it.
self._shell = subprocess.Popen(["bash", "-i"], preexec_fn=os.setsid, stdin=slave, stdout=slave, stderr=slave)
self._lock = threading.Lock()
self._thread = threading.Thread(target=self._background)
self._thread.daemon = True
self._thread.start()
def update(self, frame_no):
# Don't allow background thread to update values mid screen refresh.
with self._lock:
super(Terminal, self).update(frame_no)
def process_event(self, event):
if isinstance(event, KeyboardEvent):
if event.key_code > 0:
os.write(self._master, chr(event.key_code).encode())
return
elif event.key_code in self._map:
os.write(self._master, self._map[event.key_code])
return
return event
def _background(self):
while True:
ready, _, _ = select.select([self._master], [], [])
for stream in ready:
value = ""
while True:
try:
data = os.read(stream, 102400)
data = data.decode("utf8", "replace")
value += data
# Python 2 and 3 raise different exceptions when they would block
except Exception:
with self._lock:
value = value.split("\n")
if len(self.value) > 0:
value = self.value[:-1] + ["".join([self.value[-1].raw_text, value[0]])] + value[1:]
self.value = value[-self._h:]
cursor = self.value[-1:][0]._cursor
if cursor > 0:
self._column -= cursor
self._frame.screen.force_update()
break
class DemoFrame(Frame):
def __init__(self, screen):
super(DemoFrame, self).__init__(screen, screen.height, screen.width)
# Create the widgets for the demo.
layout = Layout([100], fill_frame=True)
self.add_layout(layout)
layout.add_widget(Terminal(Widget.FILL_FRAME))
self.fix()
self.set_theme("monochrome")
def demo(screen, scene):
screen.play([Scene([
Background(screen),
DemoFrame(screen)
], -1)], stop_on_resize=True, start_scene=scene, allow_int=True)
last_scene = None
while True:
try:
Screen.wrapper(demo, catch_interrupt=False, arguments=[last_scene])
sys.exit(0)
except ResizeScreenError as e:
last_scene = e.scene
