How about a dirvish-dual(pane) extension?

[lengani]

Dual pane file managers are popular for good reason. While there are other implementations for Emacs such as Sunrise Commander I think it would be great if Dirvish had a good option/polish for this type of workflow.

Dired already allows us to open two windows and customize the variable dired-dwim-target to either true or the most recently used folder that is a dired buffer and other options. While this is possible it is involving and could be polished by offering a good workflow for the dual pane use case.

The VIFM file manager (https://vifm.info/manual.shtml) has an interesting twist on this workflow. It allows one to choose an optional single view of the panes - ":only" , where only one pane is displayed in a window and the other pane is hidden but can be switched to by hitting a configurable key (usually SPACE). This allows one to quickly switch to the source and target directories by hitting one key. The advantage here is the ability to maximize space used for a pane and quick default target folder selection mimicking the dual pane file managers.

An extension to implement this in Dirvish would most likely simply need a function that

• opens a pair of windows if the extension is enabled where the default target is set to the other window and toggles this when the view to a pane is switched. This could be passed to the dired-dwim-target configuration options ...
• dirvish-yank and dirvish-rsync would not need strictly need to change in behaviour but could perhaps be advised if the extension is enabled to allow copying or moving marked files while in the source directory?

This approach could allow a dual pane like workflow without changing much of Dirvish (which is great!!)?