[core/module] Add error widgets if a module throws

Module should have to care less about thrown exceptions.

core/module.py

@@ -38,6 +38,14 @@ class Module(core.input.Object):
     def update(self):
         pass
 
+    def update_wrapper(self):
+        try:
+            self.update()
+        except Exception as e:
+            module = Error(self._config, 'error', str(e))
+            self._widgets = [module.widgets()[0]]
+            self.update = module.update
+
     def name(self):
         return self._name if self._name else self.module_name()
 

core/output.py

@@ -6,14 +6,20 @@ import core.theme
 import core.event
 
 class i3(object):
-    def __init__(self, theme=core.theme.Theme()):
+    def __init__(self, theme=core.theme.Theme(), config=None):
         self._modules = []
         self._status = {}
         self._theme = theme
+        self._config = config
         core.event.register('start', self.draw, 'start')
         core.event.register('update', self.draw, 'statusline')
         core.event.register('stop', self.draw, 'stop')
 
+    def theme(self, new_theme=None):
+        if new_theme:
+            self._theme = new_theme
+        return self._theme
+
     def modules(self, modules=None):
         if not modules:
             return self._modules
@@ -96,7 +102,7 @@ class i3(object):
         for module in self._modules:
             if affected_modules and not module.id() in affected_modules:
                 continue
-            module.update()
+            module.update_wrapper()
             for widget in module.widgets():
                 self._status[widget] = widget.full_text()
 

core/widget.py

@@ -1,4 +1,5 @@
 import core.input
+import core.decorators
 import util.store
 
 class Widget(util.store.Store, core.input.Object):