[core] Replace aliases logic with simple dict

Since aliases are so rarely used, just hardcode the list of aliases
inside the engine for now.

This combines the advantage of the speedup of the previous
implementation with the robustness of the first implementation. As
trade-off, extensibility suffers, but given the small number of aliases,
that's OK for now.

fixes #437

bumblebee/engine.py

@@ -142,7 +142,7 @@ class Engine(object):
         self._running = True
         self._modules = []
         self.input = inp
-        self._aliases = self._read_aliases()
+        self._aliases = self._aliases()
         self.load_modules(config.modules())
         self._current_module = None
         self._theme = theme
@@ -230,27 +230,15 @@ class Engine(object):
                 self.input.register_callback(obj=module,
                     button=button["id"], cmd=module.parameter(button["name"]))
 
-    def _read_aliases(self):
-        """Retruns a dictionary that maps every alias to its real module name"""
-        result = {}
-        m_path = os.path.abspath(bumblebee.modules.__file__)
-        m_path = os.path.dirname(m_path)
-        ALIASES_PATH = m_path + "/aliases/"
-        for name in os.listdir(ALIASES_PATH):
-            try:
-                # listdir does not retur full paths
-                f_path = ALIASES_PATH + name
-                # skip any directory
-                if not os.path.isfile(f_path): continue
-                with open(f_path) as f:
-                    for alias in f.readlines():
-                        alias = alias.strip()
-                        # skip empty lines
-                        if len(alias) == 0: continue
-                        result[alias] = name 
-            except Exception as error:
-                log.warning("failed to load aliases of {}: {}".format(name, str(error)))
-        return result
+    def _aliases(self):
+        return {
+            'date': 'datetime',
+            'time': 'datetime',
+            'datetz': 'datetimetz',
+            'timetz': 'datetimetz',
+            'pasink': 'pulseaudio',
+            'pasource': 'pulseaudio',
+        }
 
     def _load_module(self, module_name, config_name=None):
         """Load specified module and return it as object"""

bumblebee/modules/aliases/datetime

@@ -1,2 +0,0 @@
-date
-time

bumblebee/modules/aliases/datetimetz

@@ -1,2 +0,0 @@
-datetz
-timetz

bumblebee/modules/aliases/pulseaudio

@@ -1,2 +0,0 @@
-pasink
-pasource

bumblebee/modules/aliases/test

@@ -1 +0,0 @@
-test-alias