lemonbar: Automatically register and remove units

.i3/lemonbar/i3_lemonbar_parser.py

@@ -9,7 +9,12 @@ slr = config.sep_l_right
 sl = config.sep_left
 sll = config.sep_l_left
 
-class IconTextUnit:
+class LemonUnit:
+    def __lt__(self, other):
+        return self.order < other.order
+
+
+class IconTextUnit(LemonUnit):
     def __init__(self, name, order, action = None, alt_scheme=None, external=None):
         self.name = name
         self.action = action
@@ -52,10 +57,7 @@ class IconTextUnit:
             blocks.append(close)
         return ''.join(blocks)
 
-    def __lt__(self, other):
-        return self.order < other.order
-
-class ButtonsUnit:
+class ButtonsUnit(LemonUnit):
     def __init__(self, name, order, alt_scheme=None, external=None):
         self.name = name
         self.order = order
@@ -86,10 +88,7 @@ class ButtonsUnit:
 
         return ''.join(blocks)
 
-    def __lt__(self, other):
-        return self.order < other.order
-
-class CustomUnit:
+class CustomUnit(LemonUnit):
     def __init__(self, name, format_function, order, action = None, alt_scheme=None, external=None):
         self.name = name
         self.action = action
@@ -100,9 +99,6 @@ class CustomUnit:
         self.items = [] # List of tuples (icon, text)
         self.modes = [common.bar_mode.normal]
 
-    def __lt__(self, other):
-        return self.order < other.order
-
 class LemonParser:
     # Handle parsing of units
     # Apply alternating colors