[core/theme] Add support for default -> prefix/suffix in themes

Themes can now define default prefix and suffix strings.

see #23

bumblebee/output.py

@@ -33,10 +33,12 @@ class I3BarOutput(object):
     def draw_widget(self, result, widget):
         """Draw a single widget"""
         full_text = widget.full_text()
-        if self._theme.prefix():
-            full_text = "{}{}".format(self._theme.prefix(), full_text)
-        if self._theme.suffix():
-            full_text = "{}{}".format(full_text, self._theme.suffix())
+        prefix = self._theme.prefix(widget)
+        suffix = self._theme.suffix(widget)
+        if prefix:
+            full_text = "{}{}".format(prefix, full_text)
+        if suffix:
+            full_text = "{}{}".format(full_text, suffix)
         result.append({
             u"full_text": "{}".format(full_text)
         })

bumblebee/theme.py

@@ -12,15 +12,24 @@ def theme_path():
 class Theme(object):
     """Represents a collection of icons and colors"""
     def __init__(self, name):
-        self._theme = self.load(name)
+        theme = self.load(name)
+        self._init(self.load(name))
 
-    def prefix(self):
+    def _init(self, data):
+        """Initialize theme from data structure"""
+        self._defaults = data.get("defaults", {})
+
+    def prefix(self, widget):
         """Return the theme prefix for a widget's full text"""
-        return None
+        return self._get(widget, "prefix", None)
 
-    def suffix(self):
+    def suffix(self, widget):
         """Return the theme suffix for a widget's full text"""
-        return None
+        return self._get(widget, "suffix", None)
+
+    def loads(self, data):
+        theme = json.loads(data)
+        self._init(theme)
 
     def load(self, name):
         """Load and parse a theme file"""
@@ -35,4 +44,10 @@ class Theme(object):
         else:
             raise bumblebee.error.ThemeLoadError("no such theme: {}".format(name))
 
+    def _get(self, widget, name,default=None):
+        value = default
+        value = self._defaults.get(name, value)
+
+        return value
+
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4