[core] Add (partial) support for states

Add states to the modules and widgets. Widgets are mostly just a
pass-through (backwards compatibility, and ease of use - making states
directly inside the widgets would require more code inside the modules
to ensure that each widget is correctly updated).

Still missing:
- Separators during partial update (right now, it takes one interval
until separators are drawn correctly)

core/module.py

@@ -20,6 +20,8 @@ class Module(core.input.Object):
         super().__init__()
         self._config = config
         self._widgets = widgets if isinstance(widgets, list) else [ widgets ]
+        for widget in self._widgets:
+            widget.module(self)
         self._name = None
 
     def parameter(self, key, default=None):
@@ -45,6 +47,9 @@ class Module(core.input.Object):
     def widgets(self):
         return self._widgets
 
+    def state(self, widget):
+        return []
+
 class Error(Module):
     def __init__(self, config, module, error):
         super().__init__(config, core.widget.Widget(self.full_text))

core/output.py

@@ -78,6 +78,8 @@ class i3(object):
 
     def update(self, affected_modules=None):
         for module in self._modules:
+            if affected_modules and not module.id() in affected_modules:
+                continue
             module.update()
             self._status[module] = self.widgets(module)
 

core/theme.py

@@ -61,7 +61,9 @@ class Theme(object):
         self.__current.clear()
 
     def __get(self, widget, key, default=None):
-        if widget and isinstance(widget, str):
+        if not widget:
+            widget = core.widget.Widget('')
+        if isinstance(widget, str):
             # special handling
             if widget == 'previous':
                 return self.__previous.get(key, None)
@@ -75,6 +77,11 @@ class Theme(object):
                     tmp = tmp[self.__widget_count % len(tmp)]
                 value = tmp.get(key, value)
 
+        if not key in widget.state():
+            for state in widget.state():
+                theme = self.__get(widget, state, {})
+                value = theme.get(key, value)
+
         self.__current[key] = value
         return value
 

core/widget.py

@@ -5,6 +5,7 @@ class Widget(util.store.Store, core.input.Object):
     def __init__(self, full_text):
         super(Widget, self).__init__()
         self._full_text = full_text
+        self._module = None
 
     def full_text(self, value=None):
         if value:
@@ -14,4 +15,13 @@ class Widget(util.store.Store, core.input.Object):
                 return self._full_text(self)
         return self._full_text
 
+    def module(self, module):
+        self._module = module
+
+    def state(self):
+        rv = []
+        if self._module:
+            rv = self._module.state(self)
+        return rv if isinstance(rv, list) else [rv]
+
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

doc/NOTES.md

@@ -14,10 +14,10 @@
 
 ## Backwards-compatibility
 - aliases
-- charts (hbar, vbar, braille)
+- charts (braille)
 - minimize modules
 - hide modules if not in warning/error state (-a)
-- WAL support
+- WAL support / colorscheme support
 - tkinter / popups
 - scrolling decorator (incl. minwidth, alignment)
 - states