[core/themes] Add "cycling" support

Allow a theme to define a "cycle" of attributes that are cycled through
on a widget-per-widget basis (e.g. for alternating the widget
background). These cycles take precedence over the default values, but
can be overridden by module-specific theme instructions.

see #23

bumblebee/output.py

@@ -57,6 +57,7 @@ class I3BarOutput(object):
     def begin(self):
         """Start one output iteration"""
         self._widgets = []
+        self._theme.reset()
 
     def flush(self):
         """Flushes output"""

bumblebee/theme.py

@@ -16,6 +16,7 @@ class Theme(object):
     """Represents a collection of icons and colors"""
     def __init__(self, name):
         self._init(self.load(name))
+        self._widget = None
 
     def _init(self, data):
         """Initialize theme from data structure"""
@@ -23,14 +24,30 @@ class Theme(object):
             self._merge(data, self._load_icons(iconset))
         self._theme = data
         self._defaults = data.get("defaults", {})
+        self._cycles = self._theme.get("cycle", [])
+        self.reset()
+
+    def data(self):
+        """Return the raw theme data"""
+        return self._theme
+
+    def reset(self):
+        """Reset theme to initial state"""
+        self._cycle = self._cycles[0] if len(self._cycles) > 0 else {}
+        self._cycle_idx = 0
+        self._widget = None
 
     def prefix(self, widget):
         """Return the theme prefix for a widget's full text"""
-        return self._get(widget, "prefix", None)
+        padding = self._get(widget, "padding", "")
+        pre = self._get(widget, "prefix", None)
+        return u"{}{}{}".format(padding, pre, padding) if pre else None
 
     def suffix(self, widget):
         """Return the theme suffix for a widget's full text"""
-        return self._get(widget, "suffix", None)
+        padding = self._get(widget, "padding", "")
+        suf = self._get(widget, "suffix", None)
+        return u"{}{}{}".format(padding, suf, padding) if suf else None
 
     def fg(self, widget):
         """Return the foreground color for this widget"""
@@ -65,18 +82,21 @@ class Theme(object):
 
     def _get(self, widget, name, default=None):
         """Return the config value 'name' for 'widget'"""
+
+        if not self._widget:
+            self._widget = widget
+
+        if self._widget != widget:
+            self._widget = widget
+            self._cycle_idx = (self._cycle_idx + 1) % len(self._cycles)
+            self._cycle = self._cycles[self._cycle_idx]
+
         module_theme = self._theme.get(widget.module, {})
 
-        padding = None
-        if name != "padding":
-            padding = self._get(widget, "padding")
-
         value = self._defaults.get(name, default)
+        value = self._cycle.get(name, value)
         value = module_theme.get(name, value)
 
-        if value and padding:
-            value = u"{}{}{}".format(padding, value, padding)
-
         return value
 
     # algorithm copied from

tests/test_theme.py

@@ -10,18 +10,22 @@ class TestTheme(unittest.TestCase):
         self.nonexistentThemeName = "no-such-theme"
         self.invalidThemeName = "invalid"
         self.validThemeName = "test"
-        self.someWidget = MockWidget("foo")
+        self.themedWidget = MockWidget("foo")
         self.theme = Theme(self.validThemeName)
+        self.cycleTheme = Theme("test_cycle")
+        self.anyWidget = MockWidget("bla")
+        self.anotherWidget = MockWidget("blub")
 
+        data = self.theme.data()
         self.widgetTheme = "test-widget"
-        self.defaultColor = "#000000"
-        self.defaultBgColor = "#111111"
-        self.widgetBgColor = "#222222"
-        self.defaultPrefix = "default-prefix"
-        self.defaultSuffix = "default-suffix"
-        self.widgetPrefix = "widget-prefix"
-        self.widgetSuffix = "widget-suffix"
-        self.widgetColor = "#ababab"
+        self.defaultColor = data["defaults"]["fg"]
+        self.defaultBgColor = data["defaults"]["bg"]
+        self.widgetColor = data[self.widgetTheme]["fg"]
+        self.widgetBgColor = data[self.widgetTheme]["bg"]
+        self.defaultPrefix = data["defaults"]["prefix"]
+        self.defaultSuffix = data["defaults"]["suffix"]
+        self.widgetPrefix = data[self.widgetTheme]["prefix"]
+        self.widgetSuffix = data[self.widgetTheme]["suffix"]
 
     def test_load_valid_theme(self):
         try:
@@ -38,23 +42,32 @@ class TestTheme(unittest.TestCase):
             Theme(self.invalidThemeName)
 
     def test_default_prefix(self):
-        self.assertEquals(self.theme.prefix(self.someWidget), self.defaultPrefix)
+        self.assertEquals(self.theme.prefix(self.themedWidget), self.defaultPrefix)
 
     def test_default_suffix(self):
-        self.assertEquals(self.theme.suffix(self.someWidget), self.defaultSuffix)
+        self.assertEquals(self.theme.suffix(self.themedWidget), self.defaultSuffix)
 
     def test_widget_prefix(self):
-        self.someWidget.module = self.widgetTheme
-        self.assertEquals(self.theme.prefix(self.someWidget), self.widgetPrefix)
+        self.themedWidget.module = self.widgetTheme
+        self.assertEquals(self.theme.prefix(self.themedWidget), self.widgetPrefix)
 
     def test_widget_fg(self):
-        self.assertEquals(self.theme.fg(self.someWidget), self.defaultColor)
-        self.someWidget.module = self.widgetTheme
-        self.assertEquals(self.theme.fg(self.someWidget), self.widgetColor)
+        self.assertEquals(self.theme.fg(self.themedWidget), self.defaultColor)
+        self.themedWidget.module = self.widgetTheme
+        self.assertEquals(self.theme.fg(self.themedWidget), self.widgetColor)
 
     def test_widget_bg(self):
-        self.assertEquals(self.theme.bg(self.someWidget), self.defaultBgColor)
-        self.someWidget.module = self.widgetTheme
-        self.assertEquals(self.theme.bg(self.someWidget), self.widgetBgColor)
+        self.assertEquals(self.theme.bg(self.themedWidget), self.defaultBgColor)
+        self.themedWidget.module = self.widgetTheme
+        self.assertEquals(self.theme.bg(self.themedWidget), self.widgetBgColor)
+
+    def test_reset(self):
+        theme = self.cycleTheme
+        data = theme.data()
+        theme.reset()
+        self.assertEquals(theme.fg(self.anyWidget), data["cycle"][0]["fg"])
+        self.assertEquals(theme.fg(self.anotherWidget), data["cycle"][1]["fg"])
+        theme.reset()
+        self.assertEquals(theme.fg(self.anyWidget), data["cycle"][0]["fg"])
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

tests/util.py

@@ -46,6 +46,9 @@ class MockTheme(object):
         self.attr_fg = None
         self.attr_bg = None
 
+    def reset(self):
+        pass
+
     def prefix(self, widget):
         return self.attr_prefix
 

themes/solarized-powerline.json

@@ -3,10 +3,6 @@
 	"defaults": {
 		"default-separators": false,
 		"separator-block-width": 0,
-		"cycle": [
-			{ "fg": "#93a1a1", "bg": "#002b36" },
-			{ "fg": "#eee8d5", "bg": "#586e75" }
-		],
 		"warning": {
 			"fg": "#002b36",
 			"bg": "#b58900"
@@ -16,6 +12,10 @@
 			"bg": "#dc322f"
 		}
 	},
+	"cycle": [
+		{ "fg": "#93a1a1", "bg": "#002b36" },
+		{ "fg": "#eee8d5", "bg": "#586e75" }
+	],
 	"dnf": {
 		"good": {
 			"fg": "#002b36",

themes/test_cycle.json

@@ -0,0 +1,18 @@
+{
+	"icons": [ "test" ],
+	"defaults": {
+		"prefix": "default-prefix",
+		"suffix": "default-suffix",
+		"fg": "#000000",
+		"bg": "#111111"
+	},
+	"cycle": [
+		{ "fg": "#aa0000" },
+		{ "fg": "#00aa00" },
+		{ "fg": "#0000aa" }
+	],
+	"test-widget": {
+		"fg": "#ababab",
+		"bg": "#222222"
+	}
+}