Opens New Windows Instead of Using Other Window

[noctuid]

With (setq split-width-threshold 0), every time I use peep-dired-next-file or peep-dired-prev-file, peep-dired opens a new window on the right. Would there be a way to fix this without having to set split-width-threshold to something else? Setting it locally for the dired buffer with setq-local doesn't fix the problem.

[asok]

What I'm doing is something pretty simple. Here I'm just calling window-buffer.
I really don't have much knowledge what's the best way to do this in Emacs. Maybe it's worth looking in another packages in how they split a frame, like emacs-swoop for example. Hard for me to do this right now since I do not have a lot of free time.

[asok]

popwin.el looks interesting. The package could depend on it...