##// END OF EJS Templates
ENH: support for `PySide6` in `%gui` (#13864)...
ENH: support for `PySide6` in `%gui` (#13864) Addresses #13859 Changes here parallel the changes in [ipykernel](https://github.com/ipython/ipykernel/pull/1054), i.e. prefer `PyQt` over `PySide` and allow requesting explicit versions (e.g. 'qt5') with one difference (see below). I believe that, eventually, the Qt importing logic should be all here, and `ipykernel` should defer to`ipython`. I chose not to do that at this time since it would mean the latest `ipykernel` would require the latest `IPython`; I'm happy to discuss further. The only difference between `IPython` and `ipykernel`, after these two pull requests, is that, in `IPython`, it's not possible to explicitly request an event loop for Qt4. This is because an alias exists [here](https://github.com/ipython/ipython/blob/5409de68d87ddd073a35111aca0cb8360ff63ca8/IPython/terminal/pt_inputhooks/__init__.py#L5) which effectively makes "qt4" be "the latest Qt available". I did not remove the alias because I don't know the history behind it.

File last commit:

r28000:bf4956cb
r28120:0374cf80 merge
Show More
qt.py
86 lines | 3.2 KiB | text/x-python | PythonLexer
import sys
import os
from IPython.external.qt_for_kernel import QtCore, QtGui, enum_helper
from IPython import get_ipython
# If we create a QApplication, keep a reference to it so that it doesn't get
# garbage collected.
_appref = None
_already_warned = False
def _exec(obj):
# exec on PyQt6, exec_ elsewhere.
obj.exec() if hasattr(obj, "exec") else obj.exec_()
def _reclaim_excepthook():
shell = get_ipython()
if shell is not None:
sys.excepthook = shell.excepthook
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():
# NOTE: run the event loop, and after 50 ms, call `quit` to exit it.
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
# 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():
_exec(event_loop)
finally:
notifier.setEnabled(False)