awful.tag: add viewtoggle function

Helper function to toggle tag selection whilst updating history.

Signed-off-by: koniu <gkusnierz@gmail.com>
Signed-off-by: Julien Danjou <julien@danjou.info>

lib/awful/tag.lua.in

@@ -268,6 +268,13 @@ function viewmore(tags, screen)
     capi.screen[screen]:emit_signal("tag::history::update")
 end
 
+--- Toggle selection of a tag
+-- @param tag Tag to be toggled
+function viewtoggle(t)
+    t.selected = not t.selected
+    capi.screen[t.screen]:emit_signal("tag::history::update")
+end
+
 --- Get tag data table.
 -- @param tag The Tag.
 -- @return The data table.