Spyder: GNU Emacs Style Key Sequences do not work in master AND shortcut conflicts

[jnsebgosselin]

Problem Description

Key sequences similar to those used in GNU Emacs , allowing up to four key codes, do not work in the Editor after the changes introduced in PR #7768. I haven't thought about this case when working on this PR, so this needs to be fix.

@ccordoba12 what do you think is the severity of this?

Also, I'm not sure, but I think there is a problem with how we check for conflicts for these kind of shortcuts in our keyboard preference editor. For example, I do not understand how a shortcut with a keyseq defined as Ctrl+C, then Ctrl+X could work if Ctrl+C is already used for copy and Ctrl+X is already used for cut.

Ressources:
https://srinikom.github.io/pyside-docs/PySide/QtGui/QKeySequence.html#gnu-emacs-style-key-sequences
https://en.wikipedia.org/wiki/Table_of_keyboard_shortcuts
https://www.gnu.org/software/emacs/refcards/pdf/refcard.pdf

[ccordoba12]

what do you think is the severity of this?

Not that big, but we definitely need to fix this for beta2.

[jnsebgosselin]

what do you think is the severity of this?

Not that big, but we definitely need to fix this for beta2.

Do we have a release date for beta 2?

[ccordoba12]

End of this month, if we manage to fix all pending LSP stuff.

[jnsebgosselin]

End of this month, if we manage to fix all pending LSP stuff.

Ok good, it is going to be fixed by then. But I'm not sure I understand correctly how these kind of Emacs style shortcuts are supposed to work. See my example in the OP.

To activate the Ctrl+C, Ctrl+X shortcuts, do I have to keep the Ctrl modifier down while I press the C and X?

How can such a shortcut work if Ctrl+C and Ctrl+X keyseq are already assigned to other shortcuts? Sorry, I don't get it. I'll try do to some research about this tonight.

[ccordoba12]

do I have to keep the Ctrl modifier down while I press the C and X?

Yes, that's how Emacs shortcuts work.

[jnsebgosselin]

do I have to keep the Ctrl modifier down while I press the C and X?

Yes, that's how Emacs shortcuts work.

OK I see, thanks.

But then, lets say Ctrl+B, Ctrl+D is assigned to the delete line shortcut and Ctrl+B is assigned to the copy shortcut. I took these keyseq so not to have the builtin shortcuts in the way while trying to understand this.

How can I know, when the Ctrl+B combination is pressed, that the user want to do the delete line shorctut and not the copy shortcut?

I can tell you that this situation is currently not working in Spyder 3, i.e. Ctrl+B, Ctrl+D do not trigger the delete line shortcut, but the copy shortcut instead. It is working only if I unbind Ctrl+B from the copy shortcut.

[jitseniesen]

In Emacs, you do not have to keep the Ctrl key pressed down when typing Ctrl+B, Ctrl+D. However, it is not possible to have both Ctrl+B and Ctrl+B, Ctrl-D shortcuts defined. If you do, the Ctrl-B shortcut takes precedence.

[jnsebgosselin]

In Emacs, you do not have to keep the Ctrl key pressed down when typing Ctrl+B, Ctrl+D. However, it is not possible to have both Ctrl+B and Ctrl+B, Ctrl-D shortcuts defined. If you do, the Ctrl-B shortcut takes precedence.

Ok thank you very much.

[jnsebgosselin]

However, it is not possible to have both Ctrl+B and Ctrl+B, Ctrl-D shortcuts defined. If you do, the Ctrl-B shortcut takes precedence.

@ccordoba12 is it ok if I do not allow this in our keyboard shortcut editor? I would display a The new shortcut conflicts with warning in these cases.

[ccordoba12]

Sure, that's fine.

[jnsebgosselin]

@jitseniesen What about something like Ctrl+x, then k? This is an example I've taken from here: https://en.wikipedia.org/wiki/Table_of_keyboard_shortcuts

Does it mean that you need to do a Ctrl+x combo, then you can release the Ctrl if you want and press k? Alone? Without the Ctrl?

I do not think we currently support that kind of shortcut in Spyder. I mean, it's not possible to define such a shortcut currently in our shortcut editor.

[jitseniesen]

@jitseniesen What about something like Ctrl+x, then k? This is an example I've taken from here: https://en.wikipedia.org/wiki/Table_of_keyboard_shortcuts

Does it mean that you need to do a Ctrl+x combo, then you can release the Ctrl if you want and press k? Alone? Without the Ctrl?

Yes. Ctrl+x, Ctrl+k and Ctrl+x, k are two different shortcuts. In the first case, you type x and k while holding Ctrl; in the second case, you type x while holding Ctrl, then release Ctrl and then type k. You can also have Ctrl+x, Shift+k (and many other possibilities).

[jnsebgosselin]

Yes. Ctrl+x, Ctrl+k and Ctrl+x, k are two different shortcuts. In the first case, you type x and k while holding Ctrl; in the second case, you type x while holding Ctrl, then release Ctrl and then type k. You can also have Ctrl+x, Shift+k (and many other possibilities).

Thank you very much @jitseniesen, this is very useful information.

So @ccordoba12... do I try to cover the full range of Emacs keyseq or do I aim only at covering what we were supporting before?

[ccordoba12]

The idea is (one day) to add Emacs support to the Editor, please try to cover the full range of possibilities.