get subiquity to the point where it at least starts

subiquity/controllers/filesystem.py

@@ -81,6 +81,9 @@ class FilesystemController(BaseController):
 
     default = filesystem
 
+    def cancel(self):
+        self.signal.emit_signal('prev-screen')
+    
     def filesystem_error(self, error_fname):
         title = "Filesystem error"
         footer = ("Error while installing Ubuntu")

subiquity/controllers/installpath.py

@@ -53,6 +53,9 @@ class InstallpathController(BaseController):
 
     default = installpath
 
+    def cancel(self):
+        self.signal.emit_signal('prev-screen')
+
     def install_ubuntu(self):
         log.debug("Installing Ubuntu path chosen.")
         self.signal.emit_signal('next-screen')

subiquity/controllers/installprogress.py

@@ -138,6 +138,11 @@ class InstallProgressController(BaseController):
         log.debug('After curtin install OK')
         self.install_complete = True
 
+    default = curtin_install
+
+    def cancel(self):
+        pass
+
     @coroutine
     def curtin_postinstall(self):
         log.debug('Curtin Post Install: calling curtin '

subiquitycore/controllers/login.py

@@ -21,17 +21,16 @@ from subiquitycore.controller import BaseController
 
 class LoginController(BaseController):
 
-    signals = [
-        ('menu:login:main', 'login'),
-    ]
-
     def __init__(self, common):
         super().__init__(common)
         self.model = LoginModel()
 
-    def login(self):
+    def default(self):
         title = "Configuration Complete"
         excerpt = "Your device is now configured.  Login details below."
         self.ui.set_header(title, excerpt)
         view = LoginView(self.model, self.signal, self.model.user)
         self.ui.set_body(view)
+
+    def cancel(self):
+        pass