Defer terminal detection to the adapter itself

adapter/__init__.py

@@ -1,10 +1,14 @@
-import os
-
 from adapter.implementations.ITerm import ITerm
 from adapter.implementations.NullAdapter import NullAdapter
 from adapter.implementations.Terminology import Terminology
 from adapter.implementations.Tilix import Tilix
 
+available_terminals = [
+    Terminology,
+    Tilix,
+    ITerm
+]
+
 
 def identify():
     """
@@ -12,13 +16,8 @@ def identify():
     :return: A terminal adapter interface or a NullAdapter.
     :rtype: TerminalAdapterInterface
     """
-    if os.environ.get("TERMINOLOGY") == '1':
-        return Terminology()
-
-    if "TILIX_ID" in os.environ:
-        return Tilix()
-
-    if os.environ.get("ITERM_PROFILE"):
-        return ITerm()
+    for terminal in available_terminals:
+        if terminal.is_available():
+            return terminal()
 
     return NullAdapter()

adapter/base.py

@@ -1,6 +1,22 @@
 class TerminalAdapterInterface(object):
+    @staticmethod
+    def is_available():
+        """
+        :return: True if the environment implies we are using this terminal.
+        :rtype bool
+        """
+        raise NotImplementedError()
+
     def set_pokemon(self, pokemon):
+        """
+        Set the background image of the terminal.
+        :param pokemon: Information about a Pokémon.
+        :type pokemon: dict
+        """
         raise NotImplementedError()
 
     def clear(self):
+        """
+        Clear the terminal's background image.
+        """
         raise NotImplementedError()

adapter/implementations/ITerm.py

@@ -1,9 +1,14 @@
+import os
 import subprocess
 
 from adapter.base import TerminalAdapterInterface
 
 
 class ITerm(TerminalAdapterInterface):
+    @staticmethod
+    def is_available():
+        return os.environ.get("ITERM_PROFILE")
+
     def __generate_osascript(self, path):
         # Create the content for script that will change the terminal background image.
         content = "tell application \"iTerm\"\n"
@@ -19,10 +24,10 @@ class ITerm(TerminalAdapterInterface):
         p.communicate()
         p.stdin.close()
 
-    def clear(self):
-        stdin = self.__generate_osascript("")
-        self.__run_osascript(str.encode(stdin))
-
     def set_pokemon(self, pokemon):
         stdin = self.__generate_osascript(pokemon.get_path())
         self.__run_osascript(str.encode(stdin))
+
+    def clear(self):
+        stdin = self.__generate_osascript("")
+        self.__run_osascript(str.encode(stdin))

adapter/implementations/NullAdapter.py

@@ -4,8 +4,12 @@ from adapter.base import TerminalAdapterInterface
 class NullAdapter(TerminalAdapterInterface):
     err = "This terminal emulator is not supported."
 
-    def clear(self):
-        print(self.err)
+    @staticmethod
+    def is_available():
+        return True
 
     def set_pokemon(self, pokemon):
         print(self.err)
+
+    def clear(self):
+        print(self.err)

adapter/implementations/Terminology.py

@@ -4,6 +4,10 @@ from adapter.base import TerminalAdapterInterface
 
 
 class Terminology(TerminalAdapterInterface):
+    @staticmethod
+    def is_available():
+        return os.environ.get("TERMINOLOGY") == '1'
+
     def set_pokemon(self, pokemon):
         os.system('tybg "{}"'.format(pokemon.get_path()))
 

adapter/implementations/Tilix.py

@@ -7,6 +7,10 @@ class Tilix(TerminalAdapterInterface):
     setting_key = "com.gexperts.Tilix.Settings"
     setting_field = "background-image"
 
+    @staticmethod
+    def is_available():
+        return "TILIX_ID" in os.environ
+
     def set_pokemon(self, pokemon):
         command = 'gsettings set {} {} "{}"'
         os.system(command.format(self.setting_key,