How to use arrow keys while navigating through file tree?

How can I use the arrow keys ← → (right and left) to fold or unfold directories (tree nodes) within e.g. Nautilus or Eclipse instead of using the space bar Space?

Is it possible to bind this? (Note: This is very useful if you want to fold a parent node while traversing in its child nodes.)

Solution 1:

From Why do i have to shift - right / left key to open and close folders in nautilus, eclipse, etc.?, dating from 2003 to 2009 :

I think it boils down to this root issue in GTK: "Please add common keybindings for the TreeView". The reply from a developer:

The arrow keys are already being used in GtkTreeView to move the focus rectangle over the horizontal axis.

This issue was opened in 2003, the last substantial comments are also some years old, so I doubt it will be fixed soon...

Currently you can expand a folder using Shift+Left, Space and +.

A more recent bug report (2009 to 2011) gives the same answer, so I doubt that your question has another answer except to use these keys with Shift.