bug#5270: 23.1.90; `image-dired-dired-insert-marked-thumbs' doesn't toggle thumbs visibility

[Juri Linkov]

> Hi, when hitting C-t t in dired `image-dired-dired-insert-marked-thumbs'
> doesnt toggle visibility of thumbs.
> To do that, once thumbs are visible we have to kill the dired buffer and
> reopen it again.

The command `image-dired-dired-insert-marked-thumbs' was designed only
to insert thumbnails.  I agree it would be nice to improve it to allow
also to remove thumbnails with a change like you propose.  However,
currently I'm not sure what would be the best user interface for this.

You propose that `C-t C-t' will toggle thumbnails for marked files.
Another option would be to synchronize thumbnails with marks, i.e.
typing `C-t C-t' will add thumbnails to marked files, and remove
thumbnails from unmarked files.  That's for my typical workflow of using
this command: I usually mark some files and type `C-t C-t' to display
thumbnails.  Later I mark more files and type `C-t C-t' again to
display more thumbnails, and so on.  Toggling like you proposed
would hide previous thumbnails on marked files that is undesirable.
But OTOH I could unmark all files before adding more thumbnails.

-- 
Juri Linkov
http://www.jurta.org/emacs/