Various Issues with PyQt6

[RoadrunnerWMC]

Thanks for fixing the StandardButtons bug. I wasn't sure if the other two
would be PyQt or Qt issues; I'll look into it at the Qt level, then.

On Fri, Feb 26, 2021 at 10:10 AM Phil Thompson <phil at riverbankcomputing.com>
wrote:

> On 26/02/2021 04:13, RoadrunnerWMC wrote:
> > Hi again Phil,
> >
> > I just installed PyQt 6.0.2. The problems from my previous email are
> > fixed
> > now (thanks!) and my application is able to launch. I am having a few
> > new
> > issues now, though.
> >
> > Here's the main one:
> >
> >     from PyQt6 import QtCore, QtGui, QtWidgets
> >     app = QtWidgets.QApplication([])
> >
> >     mbox = QtWidgets.QMessageBox()
> >     mbox.setStandardButtons(QtWidgets.QMessageBox.StandardButtons.Yes |
> > QtWidgets.QMessageBox.StandardButtons.No)
> >     ret = mbox.exec()
> >
> >     # The return value is an integer, but
> > QtWidgets.QMessageBox.StandardButtons
> >     # can't be converted or compared to integers.
> >
> >     # This prints False no matter which button you clicked:
> >     print(ret == QtWidgets.QMessageBox.StandardButtons.Yes)
> >
> >     # TypeError: int() argument must be a string, a bytes-like object
> > or a
> > number, not 'StandardButtons'
> >     int(QtWidgets.QMessageBox.StandardButtons.Yes)
> >
> >     # TypeError: unsupported operand type(s) for &: 'int' and
> > 'StandardButtons'
> >     print(ret & QtWidgets.QMessageBox.StandardButtons.Yes)
> >
> > As far as I can tell, there's no way to check the return value of
> > `QtWidgets.QMessageBox.exec()` without hardcoding integer values
> > (yuck).
> > One way to fix it would be to change `.exec()`'s return type to
> > `QtWidgets.QMessageBox.StandardButtons`, but since the integer values
> > of
> > the enum are officially publicly documented (
> > https://doc.qt.io/qt-6/qmessagebox.html#StandardButton-enum), my guess
> > is
> > that adding support for int comparisons to the `StandardButtons` class
> > would be a better solution. Or maybe there already is a way to do this
> > comparison and I just don't see it?
>
> That will be fixed in the next snapshot.
>
> > A second issue:
> >
> >     from PyQt6 import QtCore, QtGui, QtWidgets
> >     app = QtWidgets.QApplication([])
> >     folder = QtWidgets.QFileDialog.getExistingDirectory(None, 'Select a
> > folder')
> >     print(folder)
> >
> > For whatever reason, this actually creates a *file*-selection dialog,
> > which
> > doesn't let me choose a folder. (Platform is KDE Neon (Ubuntu 20.04),
> > if it
> > helps.)
>
> I've only tested on macOS but that puts up the correct dialog so it is
> unlikely to be a PyQt issue.
>
> > One more issue I found on 6.0.1 after my previous email -- though
> > unfortunately without a way to trigger it consistently -- is that
> > sometimes
> > `QMainWindow.restoreState()` or `QMainWindow.restoreGeometry()` (not
> > sure
> > which) crashes if the pre-existing state (or geometry) was saved by
> > PyQt5.
> >
> > The best workaround I can think of is to append the PyQt version name
> > ("PyQt5"/"PyQt6") to the application name passed to the QSettings
> > constructor, thus preventing PyQt6 from ever trying to read PyQt5's
> > settings and vice versa. Luckily, my application has very few settings
> > and
> > I don't expect anyone to switch back and forth between PyQt versions,
> > so
> > this won't be a big problem. It's still not really ideal, though.
> >
> > Is this crash considered a bug? If not, is there a better way for me to
> > handle this situation?
>
> Again I can't see how that is a PyQt issue rather than a Qt issue.
>
> Phil
>
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