wasp: Manager: Rewrite the startup logic

Reduce the number of applications imported by the manager and alter
the way applications are initially registered to allow main.py
complete control over the initial applications (but only if it wants
it).

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>

wasp/boards/simulator/test_smoke.py

@@ -13,6 +13,7 @@ wasp.system.step = step
 wasp.watch.touch.press = wasp.watch.touch.i2c.sim.press
 wasp.watch.touch.swipe = wasp.watch.touch.i2c.sim.swipe
 
+wasp.system.secondary_init()
 wasp.system.apps = {}
 for app in wasp.system.quick_ring + wasp.system.launcher_ring:
     wasp.system.apps[app.NAME] = app

wasp/wasp.py

@@ -22,15 +22,9 @@ import sys
 import watch
 import widgets
 
-from apps.clock import ClockApp
-from apps.faces import FacesApp
-from apps.heart import HeartApp
 from apps.launcher import LauncherApp
 from apps.pager import PagerApp, CrashApp, NotificationApp
-from apps.settings import SettingsApp
 from apps.steps import StepCounterApp
-from apps.software import SoftwareApp
-from apps.stopwatch import StopwatchApp
 
 class EventType():
     """Enumerated interface actions.
@@ -149,39 +143,62 @@ class Manager():
         self._scheduled = False
         self._scheduling = False
 
-        # TODO: Eventually these should move to main.py
+    def secondary_init(self):
-        for app, qr in ( (ClockApp, True),
+        if not self.app:
-                         (StepCounterApp, True),
+            # Register default apps if main hasn't put anything on the quick ring
-                         (StopwatchApp, True),
+            if not self.quick_ring:
-                         (HeartApp, True),
+                self.register_defaults()
-                         (FacesApp, False),
-                         (SettingsApp, False),
-                         (SoftwareApp, False),
-                       ):
-            try:
-                a = app()
 
-                # Special case for watches with working step counters!
+            # System start up...
-                if isinstance(a, StepCounterApp):
+            watch.display.poweron()
-                    self.steps = steplogger.StepLogger(self)
+            watch.display.mute(True)
+            watch.backlight.set(self._brightness)
+            self.sleep_at = watch.rtc.uptime + 90
+            if watch.free:
+                gc.collect()
+                free = gc.mem_free()
 
-                self.register(a, qr)
+            self.switch(self.quick_ring[0])
-            except:
-                # Let's not bring the whole device down just because there's
-                # an exception starting one of the apps...
-                pass
 
-    def register(self, app, quick_ring=False, watch_face=False):
+    def register_defaults(self):
+        """Register the default applications."""
+        self.register('apps.clock.ClockApp', True, no_except=True)
+        self.register('apps.steps.StepCounterApp', True, no_except=True)
+        self.register('apps.stopwatch.StopwatchApp', True, no_except=True)
+        self.register('apps.heart.HeartApp', True, no_except=True)
+
+        self.register('apps.faces.FacesApp', no_except=True)
+        self.register('apps.settings.SettingsApp', no_except=True)
+        self.register('apps.software.SoftwareApp', no_except=True)
+
+    def register(self, app, quick_ring=False, watch_face=False, no_except=False):
         """Register an application with the system.
 
-        :param object app: The application to regsister
+        :param object app: The application to register
+        :param object quick_ring: Place the application on the quick ring
+        :param object watch_face: Make the new application the default watch face
+        :param object no_except: Ignore exceptions when instantiating applications
         """
         if isinstance(app, str):
             modname = app[:app.rindex('.')]
             exec('import ' + modname)
-            app = eval(app + '()')
+            if no_except:
+                try:
+                    app = eval(app + '()')
+                except:
+                    app = None
+            else:
+                    app = eval(app + '()')
             exec('del ' + modname)
             exec('del sys.modules["' + modname + '"]')
+            if not app:
+                return
+
+        # "Special case" for watches that have working step counters!
+        # More usefully it allows other apps to detect the presence/absence
+        # of a working step counter by looking at wasp.system.steps .
+        if isinstance(app, StepCounterApp):
+            self.steps = steplogger.StepLogger(self)
 
         if watch_face:
             self.quick_ring[0] = app
@@ -234,20 +251,11 @@ class Manager():
                 except:
                     # Clear out the old app to ensure we don't recurse when
                     # we switch to to the CrashApp. It's a bit freaky but
-                    # True has an empty directory this is better than
+                    # True has an empty directory and is is better than
-                    # None because it won't re-runt he system start up
+                    # None because it won't re-run the system start up
-                    # code.
+                    # code (else clause).
                     self.app = True
                     raise
-        else:
-            # System start up...
-            watch.display.poweron()
-            watch.display.mute(True)
-            watch.backlight.set(self._brightness)
-            self.sleep_at = watch.rtc.uptime + 90
-            if watch.free:
-                gc.collect()
-                free = gc.mem_free()
 
         # Clear out any configuration from the old application
         self.event_mask = 0
@@ -492,8 +500,7 @@ class Manager():
             print('Watch already running in the background')
             return
 
-        if not self.app:
+        self.secondary_init()
-            self.switch(self.quick_ring[0])
 
         # Reminder: wasptool uses this string to confirm the device has
         # been set running again.
@@ -545,8 +552,7 @@ class Manager():
 
     def schedule(self, enable=True):
         """Run the system manager synchronously."""
-        if not self.app:
+        self.secondary_init()
-            self.switch(self.quick_ring[0])
 
         if enable:
             watch.schedule = self._schedule