config: barpyrus: config.py: use TabbedLayout for keyboard switcher

Using the ShortLongLayout works well, but having a colored keyboard icon
with changing background color instead of '<'/'>' is fancier. Thus it
has been exchanged by a TabbedLayout using a custom rendering function
(kbd_renderer) which does exactly that.

config/barpyrus/config.py

@@ -108,6 +108,19 @@ setxkbmap += ' -option compose:ralt -option compose:rctrl'
 def frame(content, bg, fg, padding = (3, 3)):
     return Theme(bg = color[bg], fg = color[fg], padding = padding)(content)
 
+# renderer for the keyboard selection
+def kbd_renderer(self, painter):
+    if self.label == '0':
+        painter.fg(color['lightgrey'])
+        painter.symbol(0xe26f)
+        painter.space(8)
+    else:
+        painter.fg(color['cyan'])
+        painter.bg(color['grey'])
+        painter.space(8)
+        painter.symbol(0xe26f)
+        painter.space(8)
+
 # get space for the panel
 hc(['pad', str(monitor), str(height)])
 
@@ -129,12 +142,11 @@ bar.widget = W.ListLayout([
 
     W.RawLabel('%{r}'),
     conky.ConkyWidget(text = conky_text),
-    W.ShortLongLayout(
+    W.TabbedLayout([
-        W.RawLabel(''),
+        ('0', W.RawLabel('')),
-        W.ListLayout([
+        ('1', W.ListLayout([
             hlwm.HLWMLayoutSwitcher(hc, xkblayouts, command = setxkbmap.split(' ')),
-            W.RawLabel(' '),
+            W.RawLabel(' ')]))
-        ])
+        ], tab_renderer = kbd_renderer),
-    ),
     frame(W.DateTime('%d. %B, %H:%M'), 'grey', 'white'),
 ])