@GeorgeSheridan yes I think it is.

If any interested newcomer has questions, just ping me : )

Howdy @bfredl

I'm a newcomer, love Neo(Vim) and would love to give it a shot. Mind if I do?

@claudemuller please go ahead. Also join https://gitter.im/neovim/neovim for general questions about development :)

@claudemuller any updates?
Can I take this up?

@claudemuller @devbhansingh Here's a small reproducer if you want:

import time
from pynvim import attach
from threading import Thread

def isInteresting (evt):
    return True

class UIThread(Thread):
    def __init__(self, nvim):
        Thread.__init__(self)
        self.nvim = nvim
        self.do_print = False
    def run(self):
        self.nvim.run_loop(self.callback, self.callback)
    def callback(self, event_name, events):
        if self.do_print:
            [print(event) for event in events if isInteresting(event[0])]

nvim = attach('child', argv=["nvim", "--embed", "-u", "NORC", "-i", "NONE"])
ui = UIThread(nvim)
ui.start()

# Create a ui with 5 lines of 80 characters.
nvim.async_call(nvim.ui_attach, 80, 5, ext_linegrid = True, ext_messages = True, rgb = True)

# Fillup history
nvim.async_call(nvim.input, ":echom 1<CR>")
nvim.async_call(nvim.input, ":echom 2<CR>")
nvim.async_call(nvim.input, ":echom 3<CR>")

time.sleep(1)
ui.do_print = True

# Print history
nvim.async_call(nvim.input, ":messages<CR>")

# Simulate user pressing keys
time.sleep(1)
nvim.async_call(nvim.input, ":<Esc>")

time.sleep(1)
ui.do_print = False
nvim.async_call(nvim.input, ":qa!<Enter>")
time.sleep(1)

This will print the following:

['msg_clear', []]
['cmdline_show', [[[0, 'messages']], 8, ':', '', 0, 1]]
['mode_change', ['cmdline_normal', 4]]
['flush', []]
['cmdline_hide', [1]]
['msg_history_show', [[['echomsg', [[0, '1']]], ['echomsg', [[0, '2']]], ['echomsg', [[0, '3']]]]]]
['mode_change', ['normal', 0]]
['flush', []]
['cmdline_hide', [1]]
['msg_showmode', [[]]]
['mode_change', ['normal', 0]]
['flush', []]

Notice how there aren't any msg_history_clear messages.

But replace nvim.async_call(nvim.input, ":messages<CR>") with nvim.async_call(nvim.input, ':echo "A"<CR>') and you'll get the following output:

['msg_clear', []]
['cmdline_show', [[[0, "echo 'A'"]], 8, ':', '', 0, 1]]
['mode_change', ['cmdline_normal', 4]]
['flush', []]
['cmdline_hide', [1]]
['msg_show', ['echo', [[0, 'A']], False]]
['mode_change', ['normal', 0]]
['flush', []]
['msg_clear', []]
['cmdline_hide', [1]]
['msg_showmode', [[]]]
['mode_change', ['normal', 0]]
['flush', []]

echo "a" is sent with a msg_show which is then cleared by a msg_clear message.

import time
from pynvim import attach
from threading import Thread

def isInteresting (evt):
return True

class UIThread(Thread):
def init(self, nvim):
Thread.init(self)
self.nvim = nvim
self.do_print = False
def run(self):
self.nvim.run_loop(self.callback, self.callback)
def callback(self, event_name, events):
if self.do_print:
[print(event) for event in events if isInteresting(event[0])]

nvim = attach('child', argv=["nvim", "--embed", "-u", "NORC", "-i", "NONE"])
ui = UIThread(nvim)
ui.start()

Create a ui with 5 lines of 80 characters.

nvim.async_call(nvim.ui_attach, 80, 5, ext_linegrid = True, ext_messages = True, rgb = True)

Fillup history

nvim.async_call(nvim.input, ":echom 1")
nvim.async_call(nvim.input, ":echom 2")
nvim.async_call(nvim.input, ":echom 3")

time.sleep(1)
ui.do_print = True

Print history

nvim.async_call(nvim.input, ":messages")

Simulate user pressing keys

time.sleep(1)
nvim.async_call(nvim.input, ":")

time.sleep(1)
ui.do_print = False
nvim.async_call(nvim.input, ":qa!")
time.sleep(1)