Add hotkey to manually toggle titlebar

Co-authored-by: Arkhist <peyrille.benjamin@gmail.com>

simple/init.lua

@@ -532,7 +532,16 @@ clientkeys = gears.table.join(-- tiling
             c.maximized_horizontal = not c.maximized_horizontal
             c:raise()
         end,
-        { description = "(un)maximize horizontally", group = "client" }))
+        { description = "(un)maximize horizontally", group = "client" }),
+    awful.key({ config.keys.modkey, "Shift"}, "p",
+        function(c)
+            awful.titlebar.toggle(c)
+            if c.maximized then
+               c.maximized = false
+               c.maximized = true
+            end
+        end,
+        { description = "toggle titlebar", group = "client"}))
 
 -- Bind all key numbers to tags.
 -- Be careful: we use keycodes to make it work on any keyboard layout.