def _notify_stream_qt(kernel, stream):
from IPython.external.qt_for_kernel import QtCore
if _use_appnope() and kernel._darwin_app_nap:
from appnope import nope_scope as context
else:
from contextlib import contextmanager
@contextmanager
def context():
yield
def process_stream_events():
while stream.getsockopt(zmq.EVENTS) & zmq.POLLIN:
with context():
kernel.do_one_iteration()
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)
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)
def inputhook(context):
global _appref
app = QtCore.QCoreApplication.instance()
if not app:
_appref = app = QtGui.QApplication([" "])
event_loop = QtCore.QEventLoop(app)
if sys.platform == 'win32':
# The QSocketNotifier method doesn't appear to work on Windows.
# Use polling instead.
timer = QtCore.QTimer()
timer.timeout.connect(event_loop.quit)
while not context.input_is_ready():
timer.start(50) # 50 ms
event_loop.exec_()
timer.stop()
else:
# On POSIX platforms, we can use a file descriptor to quit the event
# loop when there is input ready to read.
notifier = QtCore.QSocketNotifier(context.fileno(),
QtCore.QSocketNotifier.Read)
# connect the callback we care about before we turn it on
notifier.activated.connect(event_loop.exit)
notifier.setEnabled(True)
# only start the event loop we are not already flipped
if not context.input_is_ready():
event_loop.exec_()
def inputhook(context):
global _appref
app = QtCore.QCoreApplication.instance()
if not app:
if sys.platform == 'linux':
if not os.environ.get('DISPLAY') \
and not os.environ.get('WAYLAND_DISPLAY'):
import warnings
global _already_warned
if not _already_warned:
_already_warned = True
warnings.warn(
'The DISPLAY or WAYLAND_DISPLAY environment variable is '
'not set or empty and Qt5 requires this environment '
'variable. Deactivate Qt5 code.')
return
try:
QtCore.QApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
except AttributeError: # Only for Qt>=5.6, <6.
pass
try:
QtCore.QApplication.setHighDpiScaleFactorRoundingPolicy(
QtCore.Qt.HighDpiScaleFactorRoundingPolicy.PassThrough)
except AttributeError: # Only for Qt>=5.14.
pass
_appref = app = QtGui.QApplication([" "])
# "reclaim" IPython sys.excepthook after event loop starts
# without this, it defaults back to BaseIPythonApplication.excepthook
# and exceptions in the Qt event loop are rendered without traceback
# formatting and look like "bug in IPython".
QtCore.QTimer.singleShot(0, _reclaim_excepthook)
event_loop = QtCore.QEventLoop(app)
if sys.platform == 'win32':
# The QSocketNotifier method doesn't appear to work on Windows.
# Use polling instead.
timer = QtCore.QTimer()
timer.timeout.connect(event_loop.quit)
while not context.input_is_ready():
timer.start(50) # 50 ms
_exec(event_loop)
timer.stop()
else:
# On POSIX platforms, we can use a file descriptor to quit the event
# loop when there is input ready to read.
notifier = QtCore.QSocketNotifier(
context.fileno(),
enum_helper("QtCore.QSocketNotifier.Type").Read)
try:
# connect the callback we care about before we turn it on
notifier.activated.connect(lambda: event_loop.exit())
notifier.setEnabled(True)
# only start the event loop we are not already flipped
if not context.input_is_ready():
_exec(event_loop)
finally:
notifier.setEnabled(False)
def inputhook(context):
global _appref
app = QtCore.QCoreApplication.instance()
if not app:
if sys.platform == 'linux':
if not os.environ.get('DISPLAY') \
and not os.environ.get('WAYLAND_DISPLAY'):
import warnings
global _already_warned
if not _already_warned:
_already_warned = True
warnings.warn(
'The DISPLAY or WAYLAND_DISPLAY environment variable is '
'not set or empty and Qt5 requires this environment '
'variable. Deactivate Qt5 code.')
return
QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
_appref = app = QtGui.QApplication([" "])
# "reclaim" IPython sys.excepthook after event loop starts
# without this, it defaults back to BaseIPythonApplication.excepthook
# and exceptions in the Qt event loop are rendered without traceback
# formatting and look like "bug in IPython".
QtCore.QTimer.singleShot(0, _reclaim_excepthook)
event_loop = QtCore.QEventLoop(app)
if sys.platform == 'win32':
# The QSocketNotifier method doesn't appear to work on Windows.
# Use polling instead.
timer = QtCore.QTimer()
timer.timeout.connect(event_loop.quit)
while not context.input_is_ready():
timer.start(50) # 50 ms
event_loop.exec_()
timer.stop()
else:
# On POSIX platforms, we can use a file descriptor to quit the event
# loop when there is input ready to read.
notifier = QtCore.QSocketNotifier(context.fileno(),
QtCore.QSocketNotifier.Read)
try:
# connect the callback we care about before we turn it on
# lambda is necessary as PyQT inspect the function signature to know
# what arguments to pass to. See https://github.com/ipython/ipython/pull/12355
notifier.activated.connect(lambda: event_loop.exit())
notifier.setEnabled(True)
# only start the event loop we are not already flipped
if not context.input_is_ready():
event_loop.exec_()
finally:
notifier.setEnabled(False)
def loop_qt4(kernel):
"""Start a kernel with PyQt4 event loop integration."""
from IPython.external.qt_for_kernel import QtCore
from IPython.lib.guisupport import get_app_qt4, start_event_loop_qt4
kernel.app = get_app_qt4([" "])
kernel.app.setQuitOnLastWindowClosed(False)
kernel.timer = QtCore.QTimer()
kernel.timer.timeout.connect(kernel.do_one_iteration)
# Units for the timer are in milliseconds
kernel.timer.start(1000 * kernel._poll_interval)
start_event_loop_qt4(kernel.app)
def inputhook(context):
global _appref
app = QtCore.QCoreApplication.instance()
if not app:
if sys.platform == 'linux':
if not os.environ.get('DISPLAY') \
and not os.environ.get('WAYLAND_DISPLAY'):
import warnings
global _already_warned
if not _already_warned:
_already_warned = True
warnings.warn(
'The DISPLAY or WAYLAND_DISPLAY environment variable is '
'not set or empty and Qt5 requires this environment '
'variable. Deactivate Qt5 code.'
)
return
QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
_appref = app = QtGui.QApplication([" "])
event_loop = QtCore.QEventLoop(app)
if sys.platform == 'win32':
# The QSocketNotifier method doesn't appear to work on Windows.
# Use polling instead.
timer = QtCore.QTimer()
timer.timeout.connect(event_loop.quit)
while not context.input_is_ready():
timer.start(50) # 50 ms
event_loop.exec_()
timer.stop()
else:
# On POSIX platforms, we can use a file descriptor to quit the event
# loop when there is input ready to read.
notifier = QtCore.QSocketNotifier(context.fileno(),
QtCore.QSocketNotifier.Read)
try:
# connect the callback we care about before we turn it on
notifier.activated.connect(event_loop.exit)
notifier.setEnabled(True)
# only start the event loop we are not already flipped
if not context.input_is_ready():
event_loop.exec_()
finally:
notifier.setEnabled(False)
def inputhook_qt4():
"""PyOS_InputHook python hook for Qt4.
Process pending Qt events and if there's no pending keyboard
input, spend a short slice of time (50ms) running the Qt event
loop.
As a Python ctypes callback can't raise an exception, we catch
the KeyboardInterrupt and temporarily deactivate the hook,
which will let a *second* CTRL+C be processed normally and go
back to a clean prompt line.
"""
try:
allow_CTRL_C()
app = QtCore.QCoreApplication.instance()
if not app: # shouldn't happen, but safer if it happens anyway...
return 0
app.processEvents(QtCore.QEventLoop.AllEvents, 300)
if not stdin_ready():
timer = QtCore.QTimer()
timer.timeout.connect(app.quit)
while not stdin_ready():
timer.start(50)
app.exec_()
timer.stop()
ignore_CTRL_C()
except KeyboardInterrupt:
ignore_CTRL_C()
got_kbdint[0] = True
print("\nKeyboardInterrupt - qt4 event loop interrupted!"
"\n * hit CTRL+C again to clear the prompt"
"\n * use '%gui none' to disable the event loop"
" permanently"
"\n and '%gui qt4' to re-enable it later")
mgr.clear_inputhook()
except: # NO exceptions are allowed to escape from a ctypes callback
mgr.clear_inputhook()
from traceback import print_exc
print_exc()
print("Got exception from inputhook_qt4, unregistering.")
return 0
def inputhook(context):
app = QtCore.QCoreApplication.instance()
if not app:
return
event_loop = QtCore.QEventLoop(app)
if sys.platform == 'win32':
# The QSocketNotifier method doesn't appear to work on Windows.
# Use polling instead.
timer = QtCore.QTimer()
timer.timeout.connect(event_loop.quit)
while not context.input_is_ready():
timer.start(50) # 50 ms
event_loop.exec_()
timer.stop()
else:
# On POSIX platforms, we can use a file descriptor to quit the event
# loop when there is input ready to read.
notifier = QtCore.QSocketNotifier(context.fileno(), QtCore.QSocketNotifier.Read)
notifier.setEnabled(True)
notifier.activated.connect(event_loop.exit)
event_loop.exec_()
def inputhook_qt4():
"""PyOS_InputHook python hook for Qt4.
Process pending Qt events and if there's no pending keyboard
input, spend a short slice of time (50ms) running the Qt event
loop.
As a Python ctypes callback can't raise an exception, we catch
the KeyboardInterrupt and temporarily deactivate the hook,
which will let a *second* CTRL+C be processed normally and go
back to a clean prompt line.
"""
try:
allow_CTRL_C()
app = QtCore.QCoreApplication.instance()
if not app: # shouldn't happen, but safer if it happens anyway...
return 0
app.processEvents(QtCore.QEventLoop.AllEvents, 300)
if not stdin_ready():
# Generally a program would run QCoreApplication::exec()
# from main() to enter and process the Qt event loop until
# quit() or exit() is called and the program terminates.
#
# For our input hook integration, we need to repeatedly
# enter and process the Qt event loop for only a short
# amount of time (say 50ms) to ensure that Python stays
# responsive to other user inputs.
#
# A naive approach would be to repeatedly call
# QCoreApplication::exec(), using a timer to quit after a
# short amount of time. Unfortunately, QCoreApplication
# emits an aboutToQuit signal before stopping, which has
# the undesirable effect of closing all modal windows.
#
# To work around this problem, we instead create a
# QEventLoop and call QEventLoop::exec(). Other than
# setting some state variables which do not seem to be
# used anywhere, the only thing QCoreApplication adds is
# the aboutToQuit signal which is precisely what we are
# trying to avoid.
timer = QtCore.QTimer()
event_loop = QtCore.QEventLoop()
timer.timeout.connect(event_loop.quit)
while not stdin_ready():
timer.start(50)
event_loop.exec_()
timer.stop()
except KeyboardInterrupt:
global got_kbdint, sigint_timer
ignore_CTRL_C()
got_kbdint = True
mgr.clear_inputhook()
# This generates a second SIGINT so the user doesn't have to
# press CTRL+C twice to get a clean prompt.
#
# Since we can't catch the resulting KeyboardInterrupt here
# (because this is a ctypes callback), we use a timer to
# generate the SIGINT after we leave this callback.
#
# Unfortunately this doesn't work on Windows (SIGINT kills
# Python and CTRL_C_EVENT doesn't work).
if os.name == "posix":
pid = os.getpid()
if not sigint_timer:
sigint_timer = threading.Timer(
0.01, os.kill, args=[pid, signal.SIGINT]
)
sigint_timer.start()
else:
print("\nKeyboardInterrupt - Ctrl-C again for new prompt")
except: # NO exceptions are allowed to escape from a ctypes callback
ignore_CTRL_C()
from traceback import print_exc
print_exc()
print("Got exception from inputhook_qt4, unregistering.")
mgr.clear_inputhook()
finally:
allow_CTRL_C()
return 0
