Would it be possible to implement a system-wide back button?

On certain windows like systemsettings5, it would be nice to be able to go back sometimes to the previous view. However, to avoid reinventing the wheel, I’d like this for all windows ideally.

This immediately seems impossible to place in the purview of the WM due to how each GUI toolkit manages such things differently. However, Android manages to do so. I don’t know whether anything as standardized as Android’s activity system exists in this case, but is it infeasible or undesirable to duplicate?

We already have a global menu bar, which is gaining support. It would be helpful to implement since its absence would be felt by anyone migrating from Android to Plasma Mobile (not that it is quite ready for prime time yet anyway).

Since I use quite a bit of ssb’s ( with no toolbar) and I’m not much of a carpal keyboard fan, I made me a back button as desktop application. The key combo works for most stuff I really need it for. Since I’m on X, I could use xdotool for it, but there are other ways. It sets on an autohidden panel.

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Can you share the content of the shortcut, @dzon? And does it really go back a page in things like systemsettings? That’s impressive. I’m surprised that it’s already possible, even if perhaps somewhat crudely.

Not really, no. In order for this to work, it would need to be implemented as a platform feature such that every app you used implemented support for the feature and wired up the systemwide back button to something that makes sense for the given context.

This is something you can’t really bolt onto an existing system because existing apps won’t have any incentive to support it, and therefore won’t.

You could kinda sorta make a crippled version of this by putting a bottom somewhere that sends Alt+Left, but obviously this would only work in apps where that shortcut was wired up, and you wouldn’t get the kind of interaction you have on Android where for example the back button turns into a “hide keyboard” button while the keyboard is visible. That level of sophistication requires the sort of platform integration I mentioned.

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That’s correct. Like I said, the shortcut emulator works for the things I need it for. The ones that use alt+left to go back and don’t have a visible designated button ( ssb comes to mind and some). Like ngraham said, a full blown systemwide thingie would require another level of integration.
As for systemsettings, I didn’t even know the thing had shortcuts at all. I just put the ones I use most in the application itself.

FWIW my mouse has back/forward buttons on the side that works with most apps, so it is kinda already a thing. But as Nate said it’s up to the app to support this.

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Thanks, @ngraham. That’s what I expected. If it were to be implemented, I expect it would be better as a Qt feature rather than a KDE Frameworks feature, right?

If it were only implemented in Qt, then it would only work for Qt apps that opted in. Hardly systemwide. To really be systemwide, it needs to be first added at a level higher than that of UI toolkits.

But honestly I don’t see this ever happening. Like I said, things like this don’t succeed when bolted onto an existing system later. They need to be included in the system’s core UX at the very beginning in order to have any hope of 3rd-party apps opting in. Because if they don’t, the feature fails.

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