def inputhook_qt5():
"""PyOS_InputHook python hook for Qt5.
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(.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_qt5, unregistering.")
mgr.clear_inputhook()
finally:
allow_CTRL_C()
return 0
def inputhook_qt5():
"""PyOS_InputHook python hook for Qt5.
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(.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_qt5, unregistering.")
mgr.clear_inputhook()
finally:
allow_CTRL_C()
return 0
