city_retrofit/venv/lib/python3.7/site-packages/ipykernel/eventloops.py

398 lines
12 KiB
Python

# encoding: utf-8
"""Event loop integration for the ZeroMQ-based kernels."""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
from functools import partial
import os
import sys
import platform
import zmq
from distutils.version import LooseVersion as V
from traitlets.config.application import Application
def _use_appnope():
"""Should we use appnope for dealing with OS X app nap?
Checks if we are on OS X 10.9 or greater.
"""
return sys.platform == 'darwin' and V(platform.mac_ver()[0]) >= V('10.9')
def _notify_stream_qt(kernel, stream):
from IPython.external.qt_for_kernel import QtCore
def process_stream_events():
"""fall back to main loop when there's a socket event"""
# call flush to ensure that the stream doesn't lose events
# due to our consuming of the edge-triggered FD
# flush returns the number of events consumed.
# if there were any, wake it up
if stream.flush(limit=1):
notifier.setEnabled(False)
kernel.app.quit()
fd = stream.getsockopt(zmq.FD)
notifier = QtCore.QSocketNotifier(fd, QtCore.QSocketNotifier.Read, kernel.app)
notifier.activated.connect(process_stream_events)
# there may already be unprocessed events waiting.
# these events will not wake zmq's edge-triggered FD
# since edge-triggered notification only occurs on new i/o activity.
# process all the waiting events immediately
# so we start in a clean state ensuring that any new i/o events will notify.
# schedule first call on the eventloop as soon as it's running,
# so we don't block here processing events
timer = QtCore.QTimer(kernel.app)
timer.setSingleShot(True)
timer.timeout.connect(process_stream_events)
timer.start(0)
# mapping of keys to loop functions
loop_map = {
'inline': None,
'nbagg': None,
'notebook': None,
'ipympl': None,
'widget': None,
None: None,
}
def register_integration(*toolkitnames):
"""Decorator to register an event loop to integrate with the IPython kernel
The decorator takes names to register the event loop as for the %gui magic.
You can provide alternative names for the same toolkit.
The decorated function should take a single argument, the IPython kernel
instance, arrange for the event loop to call ``kernel.do_one_iteration()``
at least every ``kernel._poll_interval`` seconds, and start the event loop.
:mod:`ipykernel.eventloops` provides and registers such functions
for a few common event loops.
"""
def decorator(func):
for name in toolkitnames:
loop_map[name] = func
func.exit_hook = lambda kernel: None
def exit_decorator(exit_func):
"""@func.exit is now a decorator
to register a function to be called on exit
"""
func.exit_hook = exit_func
return exit_func
func.exit = exit_decorator
return func
return decorator
def _loop_qt(app):
"""Inner-loop for running the Qt eventloop
Pulled from guisupport.start_event_loop in IPython < 5.2,
since IPython 5.2 only checks `get_ipython().active_eventloop` is defined,
rather than if the eventloop is actually running.
"""
app._in_event_loop = True
app.exec_()
app._in_event_loop = False
@register_integration('qt4')
def loop_qt4(kernel):
"""Start a kernel with PyQt4 event loop integration."""
from IPython.lib.guisupport import get_app_qt4
kernel.app = get_app_qt4([" "])
kernel.app.setQuitOnLastWindowClosed(False)
for s in kernel.shell_streams:
_notify_stream_qt(kernel, s)
_loop_qt(kernel.app)
@register_integration('qt', 'qt5')
def loop_qt5(kernel):
"""Start a kernel with PyQt5 event loop integration."""
os.environ['QT_API'] = 'pyqt5'
return loop_qt4(kernel)
# exit and watch are the same for qt 4 and 5
@loop_qt4.exit
@loop_qt5.exit
def loop_qt_exit(kernel):
kernel.app.exit()
def _loop_wx(app):
"""Inner-loop for running the Wx eventloop
Pulled from guisupport.start_event_loop in IPython < 5.2,
since IPython 5.2 only checks `get_ipython().active_eventloop` is defined,
rather than if the eventloop is actually running.
"""
app._in_event_loop = True
app.MainLoop()
app._in_event_loop = False
@register_integration('wx')
def loop_wx(kernel):
"""Start a kernel with wx event loop support."""
import wx
# Wx uses milliseconds
poll_interval = int(1000 * kernel._poll_interval)
def wake():
"""wake from wx"""
for stream in kernel.shell_streams:
if stream.flush(limit=1):
kernel.app.ExitMainLoop()
return
# We have to put the wx.Timer in a wx.Frame for it to fire properly.
# We make the Frame hidden when we create it in the main app below.
class TimerFrame(wx.Frame):
def __init__(self, func):
wx.Frame.__init__(self, None, -1)
self.timer = wx.Timer(self)
# Units for the timer are in milliseconds
self.timer.Start(poll_interval)
self.Bind(wx.EVT_TIMER, self.on_timer)
self.func = func
def on_timer(self, event):
self.func()
# We need a custom wx.App to create our Frame subclass that has the
# wx.Timer to defer back to the tornado event loop.
class IPWxApp(wx.App):
def OnInit(self):
self.frame = TimerFrame(wake)
self.frame.Show(False)
return True
# The redirect=False here makes sure that wx doesn't replace
# sys.stdout/stderr with its own classes.
if not (
getattr(kernel, 'app', None)
and isinstance(kernel.app, wx.App)
):
kernel.app = IPWxApp(redirect=False)
# The import of wx on Linux sets the handler for signal.SIGINT
# to 0. This is a bug in wx or gtk. We fix by just setting it
# back to the Python default.
import signal
if not callable(signal.getsignal(signal.SIGINT)):
signal.signal(signal.SIGINT, signal.default_int_handler)
_loop_wx(kernel.app)
@loop_wx.exit
def loop_wx_exit(kernel):
import wx
wx.Exit()
@register_integration('tk')
def loop_tk(kernel):
"""Start a kernel with the Tk event loop."""
from tkinter import Tk, READABLE
def process_stream_events(stream, *a, **kw):
"""fall back to main loop when there's a socket event"""
if stream.flush(limit=1):
app.tk.deletefilehandler(stream.getsockopt(zmq.FD))
app.quit()
# For Tkinter, we create a Tk object and call its withdraw method.
kernel.app = app = Tk()
kernel.app.withdraw()
for stream in kernel.shell_streams:
notifier = partial(process_stream_events, stream)
# seems to be needed for tk
notifier.__name__ = 'notifier'
app.tk.createfilehandler(stream.getsockopt(zmq.FD), READABLE, notifier)
# schedule initial call after start
app.after(0, notifier)
app.mainloop()
@loop_tk.exit
def loop_tk_exit(kernel):
kernel.app.destroy()
@register_integration('gtk')
def loop_gtk(kernel):
"""Start the kernel, coordinating with the GTK event loop"""
from .gui.gtkembed import GTKEmbed
gtk_kernel = GTKEmbed(kernel)
gtk_kernel.start()
kernel._gtk = gtk_kernel
@loop_gtk.exit
def loop_gtk_exit(kernel):
kernel._gtk.stop()
@register_integration('gtk3')
def loop_gtk3(kernel):
"""Start the kernel, coordinating with the GTK event loop"""
from .gui.gtk3embed import GTKEmbed
gtk_kernel = GTKEmbed(kernel)
gtk_kernel.start()
kernel._gtk = gtk_kernel
@loop_gtk3.exit
def loop_gtk3_exit(kernel):
kernel._gtk.stop()
@register_integration('osx')
def loop_cocoa(kernel):
"""Start the kernel, coordinating with the Cocoa CFRunLoop event loop
via the matplotlib MacOSX backend.
"""
from ._eventloop_macos import mainloop, stop
real_excepthook = sys.excepthook
def handle_int(etype, value, tb):
"""don't let KeyboardInterrupts look like crashes"""
# wake the eventloop when we get a signal
stop()
if etype is KeyboardInterrupt:
print("KeyboardInterrupt caught in CFRunLoop", file=sys.__stdout__)
else:
real_excepthook(etype, value, tb)
while not kernel.shell.exit_now:
try:
# double nested try/except, to properly catch KeyboardInterrupt
# due to pyzmq Issue #130
try:
# don't let interrupts during mainloop invoke crash_handler:
sys.excepthook = handle_int
mainloop(kernel._poll_interval)
for stream in kernel.shell_streams:
if stream.flush(limit=1):
# events to process, return control to kernel
return
except:
raise
except KeyboardInterrupt:
# Ctrl-C shouldn't crash the kernel
print("KeyboardInterrupt caught in kernel", file=sys.__stdout__)
finally:
# ensure excepthook is restored
sys.excepthook = real_excepthook
@loop_cocoa.exit
def loop_cocoa_exit(kernel):
from ._eventloop_macos import stop
stop()
@register_integration('asyncio')
def loop_asyncio(kernel):
'''Start a kernel with asyncio event loop support.'''
import asyncio
loop = asyncio.get_event_loop()
# loop is already running (e.g. tornado 5), nothing left to do
if loop.is_running():
return
if loop.is_closed():
# main loop is closed, create a new one
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
loop._should_close = False
# pause eventloop when there's an event on a zmq socket
def process_stream_events(stream):
"""fall back to main loop when there's a socket event"""
if stream.flush(limit=1):
loop.stop()
for stream in kernel.shell_streams:
fd = stream.getsockopt(zmq.FD)
notifier = partial(process_stream_events, stream)
loop.add_reader(fd, notifier)
loop.call_soon(notifier)
while True:
error = None
try:
loop.run_forever()
except KeyboardInterrupt:
continue
except Exception as e:
error = e
if loop._should_close:
loop.close()
if error is not None:
raise error
break
@loop_asyncio.exit
def loop_asyncio_exit(kernel):
"""Exit hook for asyncio"""
import asyncio
loop = asyncio.get_event_loop()
@asyncio.coroutine
def close_loop():
if hasattr(loop, 'shutdown_asyncgens'):
yield from loop.shutdown_asyncgens()
loop._should_close = True
loop.stop()
if loop.is_running():
close_loop()
elif not loop.is_closed():
loop.run_until_complete(close_loop)
loop.close()
def enable_gui(gui, kernel=None):
"""Enable integration with a given GUI"""
if gui not in loop_map:
e = "Invalid GUI request %r, valid ones are:%s" % (gui, loop_map.keys())
raise ValueError(e)
if kernel is None:
if Application.initialized():
kernel = getattr(Application.instance(), 'kernel', None)
if kernel is None:
raise RuntimeError("You didn't specify a kernel,"
" and no IPython Application with a kernel appears to be running."
)
loop = loop_map[gui]
if loop and kernel.eventloop is not None and kernel.eventloop is not loop:
raise RuntimeError("Cannot activate multiple GUI eventloops")
kernel.eventloop = loop