[core/theme] Fix padding

Missing prefix/suffix broke padding.

see #23

bumblebee/output.py

@@ -42,8 +42,9 @@ class I3BarOutput(object):
     def draw(self, widget, engine=None):
         """Draw a single widget"""
         full_text = widget.full_text()
-        prefix = self._theme.prefix(widget)
-        suffix = self._theme.suffix(widget)
+        padding = self._theme.padding(widget)
+        prefix = self._theme.prefix(widget, padding)
+        suffix = self._theme.suffix(widget, padding)
         if prefix:
             full_text = u"{}{}".format(prefix, full_text)
         if suffix:

bumblebee/theme.py

@@ -38,17 +38,21 @@ class Theme(object):
         self._widget = None
         self._prevbg = None
 
-    def prefix(self, widget):
-        """Return the theme prefix for a widget's full text"""
-        padding = self._get(widget, "padding", "")
-        pre = self._get(widget, "prefix", None)
-        return u"{}{}{}".format(padding, pre, padding) if pre else None
+    def padding(self, widget):
+        """Return padding for widget"""
+        return self._get(widget, "padding", "")
 
-    def suffix(self, widget):
+    def prefix(self, widget, default=None):
+        """Return the theme prefix for a widget's full text"""
+        padding = self.padding(widget)
+        pre = self._get(widget, "prefix", None)
+        return u"{}{}{}".format(padding, pre, padding) if pre else default
+
+    def suffix(self, widget, default=None):
         """Return the theme suffix for a widget's full text"""
         padding = self._get(widget, "padding", "")
         suf = self._get(widget, "suffix", None)
-        return u"{}{}{}".format(padding, suf, padding) if suf else None
+        return u"{}{}{}".format(padding, suf, padding) if suf else default
 
     def fg(self, widget):
         """Return the foreground color for this widget"""

tests/util.py

@@ -48,6 +48,9 @@ class MockTheme(object):
         self.attr_separator = None
         self.attr_separator_block_width = 0
 
+    def padding(self, widget):
+        return ""
+
     def reset(self):
         pass
 
@@ -57,10 +60,10 @@ class MockTheme(object):
     def separator(self, widget):
         return self.attr_separator
 
-    def prefix(self, widget):
+    def prefix(self, widget, default=None):
         return self.attr_prefix
 
-    def suffix(self, widget):
+    def suffix(self, widget, default=None):
         return self.attr_suffix
 
     def fg(self, widget):