fix use of ESC in settings window

[sfo]

When pressing ESC in settings window the application crashed due to missing attribute.

[jooste]

This is an api difference between qt5 and qt6. We're considering dropping support for qt5, which would make this easier, because now your change fixes qt6, but breaks qt5 :)

[sfo]

Thanks for the hint. I had this in mind, as well, and checked the rest of the code:

stanley@gallifrey:~/Development/bluesky|master ⇒  grep "Qt.Key_" -R .  
./bluesky/ui/qtgl/infowindow.py:    #     if event.key() == Qt.Key_Escape:
./bluesky/ui/qtgl/settingswindow.py:        if event.key() == Qt.Key_Escape:
grep: ./utils/Doc generation/bluesky.wiki: No such file or directory
stanley@gallifrey:~/Development/bluesky|master ⇒  grep "Qt\.Key\." -R .
./bluesky/ui/qtgl/console.py:        if event.key() == Qt.Key.Key_Enter or event.key() == Qt.Key.Key_Return:
./bluesky/ui/qtgl/console.py:        if event.key() >= Qt.Key.Key_Space and event.key() <= Qt.Key.Key_AsciiTilde:
./bluesky/ui/qtgl/console.py:        elif event.key() == Qt.Key.Key_Backspace:
./bluesky/ui/qtgl/console.py:        elif event.key() == Qt.Key.Key_Tab:
./bluesky/ui/qtgl/console.py:            if event.key() == Qt.Key.Key_Up:
./bluesky/ui/qtgl/console.py:            elif event.key() == Qt.Key.Key_Down:
./bluesky/ui/qtgl/console.py:            elif event.key() == Qt.Key.Key_Left:
./bluesky/ui/qtgl/console.py:            elif event.key() == Qt.Key.Key_Right:
./bluesky/ui/qtgl/mainwindow.py:                and event.key() in [Qt.Key.Key_Up, Qt.Key.Key_Down, Qt.Key.Key_Left, Qt.Key.Key_Right]:
./bluesky/ui/qtgl/mainwindow.py:            if event.key() == Qt.Key.Key_Up:
./bluesky/ui/qtgl/mainwindow.py:            elif event.key() == Qt.Key.Key_Down:
./bluesky/ui/qtgl/mainwindow.py:            elif event.key() == Qt.Key.Key_Left:
./bluesky/ui/qtgl/mainwindow.py:            elif event.key() == Qt.Key.Key_Right:
./bluesky/ui/qtgl/mainwindow.py:        elif event.key() == Qt.Key.Key_Escape:
./bluesky/ui/qtgl/mainwindow.py:        elif event.key() == Qt.Key.Key_F11:  # F11 = Toggle Full Screen mode
./extra/textclient/textclient.py:        if event.key() == Qt.Key.Key_Enter or event.key() == Qt.Key.Key_Return:
grep: ./utils/Doc generation/bluesky.wiki: No such file or directory

The results show that the settings window was the only one still using the Qt5 API. In all other places, the Qt6 API is used, even in mainwinow:

bluesky/bluesky/ui/qtgl/mainwindow.py

Line 228 in 010a423

elif event.key() == Qt.Key.Key_Escape:

Therefore, I thought it's just fine. Maybe, I am still missing something? Then I could of course adapt the PR to support Qt5 and 6, if required.