If you figure out how to make it RTL aware, you could toggle between the go-next-symbolic and go-next-rtl-symbolic icons

Indeed, it's only used in one place (too much copy/paste...).

this is not right-to-left aware; please use the layout direction of the widget to use "go-next" or "go-previous"

(go-next-rtl-symbolic, not go-previous; that would be semantically inaccurate.)

@pino, right; dolphin isn't rtl-aware (or if it is, I couldn't find out how to switch it to rtl). But I agree the code here should account for rtl anyway.

@ngraham: I think we should stick to the icon naming spec[1], so that it works with themes other than breeze/oxygen; so it has to be go-previous.

[1] https://specifications.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html

dolphin --reverse
should run it in right-to-left mode
(or whatever the opposite of your current locale)

(or if it is, I couldn't find out how to switch it to rtl).

$ dolphin --reverse

it is provided directly by QApplication, it works also in Qt-only applications

you can use qApp->isRightToLeft() to check the rtl direction

The interface of Dolphin is RTL-aware, just the panels and the file view are not (for many usability reasons)
Make sure to have Qt translations installed if the layout isn't switching automatically with the language change.