Order of root file items in the Outline Explorer should be synced with that of the current EditorStack

Problem Description

As mentioned by @CAM-Gerlach in https://github.com/spyder-ide/spyder/pull/7968#discussion_r221500554, the outline explorer is still ordered alphabetically, rather than the order of the tabs in the Editor. It would be nice to have the option to either alphabetize it or make it follow the order of the editor, since both could potentially be useful depending on one’s workflow.

This would be another step forward into making the Outline Explorer a viable proxy for a vertical tabbar for the Editor Stack.

@ccordoba12 @CAM-Gerlach

• Should we add an option in the context menu for this? Something like: Show files sorted alphabetically or something like that? Checking or unchecking this option would not impact the order of the files in the tabbar of the current EditorStack, only the order of the root file items in the Outline Explorer.

• Alternatively (or additionally), we could add an action in the context menu (with a corresponding button in the Outline Explorer toolbar) to actually sort the files alphabetically in the Outline Explorer and in the tabbar of the current EditorStack.

Also, do you think that one of the above suggestions could be a valid solution for Issue #5911?

[luciansmith]

I was asked to comment as to whether this proposal would fix my issue with #5911, and for me, it does: the actual tab order in the editor is left alone, but the list of files in the Outline Explorer can be sorted alphabetically. That would be perfect!

[jnsebgosselin]

Thank you both for your feedback @luciansmith and @fgotzens

However, in contrast to @luciansmith this does not entirely fix issue #5911 since I would still be happy if a one-way option to sort the tabs (so no toggling!) would be provided in a future version. Nonetheless: Thank you for your great work so far!

OK thank you, so I will leave #5911 opened until I implement an action to sort the tabs permanently in the cog menu of the Editor.