Rated 4 out of 5 stars

code pour l'extension custom Buttons (fleche droite)
/* CODE ok TB52-J2m06@laposte.net */
/* http://j2m-06.pagesperso-orange.fr/ */

var currentMode = gFolderTreeView.baseMode();
if (currentMode === "all")
gFolderTreeView.toggleMode("smart");
else
gFolderTreeView.toggleMode("all");

if (currentMode === "smart")
gFolderTreeView.toggleMode("unread");

if (currentMode === "unread")
gFolderTreeView.toggleMode("favorite");

/**************************************]
Cde pour flèche gauche
/* CODE ok TB52-J2m06@laposte.net */
/*http://j2m-06.pagesperso-orange.fr/ */

var currentMode = gFolderTreeView.baseMode();
if (currentMode === "smart")
gFolderTreeView.toggleMode("all");
else
gFolderTreeView.toggleMode("smart");

This review is for a previous version of the add-on (1.11). 

That's easier than I thought it would be. ;-) I'll try to find some time in the next few weeks to add the buttons back to Folder Pane View Switcher.

Rated 4 out of 5 stars

Hello
A workaround is to use the Custom Buttons extension
See here http://j2m-06.pagesperso-orange.fr/faq_tb_A.html#reta_flec_chgt_vues2
(google translate)
/-------------------------------------------\

Bonjour
Une solution de contournement, qui fonctionnent, c'est d'utiliser l'extension Custom Buttons
Voir ici http://j2m-06.pagesperso-orange.fr/faq_tb_A.html#reta_flec_chgt_vues2

This review is for a previous version of the add-on (1.11). 

I don't see anything at that link or anywhere else which explains in detail _how_ to use that extension to put back these buttons. I would love to document this workaround, but I can't do that unless there are specific instructions I can give or point people at. Do you know where they are?