Use trait defaults instead of __init__

src/Camera.py

@@ -18,9 +18,6 @@ class Camera(HasTraits):
     frame_rate = Range(1, 500, 30)
     frame = Array()
 
-    def __init__(self, **traits):
-        super(Camera, self).__init__(**traits)
-
     def __enter__(self):
         self.open()
         return self

src/DummyGaussian.py

@@ -23,12 +23,11 @@ class DummyGaussian(Camera):
         Item('noise_amplitude'),
         title='Dummy Gaussian Plugin')
 
-    def __init__(self, *args, **kwargs):
-        super(DummyGaussian, self).__init__(*args, **kwargs)
-
+    def __init__(self, **traits):
+        super(DummyGaussian, self).__init__(resolution=(320, 240),
+            id_string='Dummy Gaussian Plugin',
+            **traits)
         self._supported_resolutions = [(320, 240), (640, 480)]
-        self.resolution = (320, 240)
-        self.id_string = 'Dummy Gaussian Plugin'
 
     def open(self):
         pass

src/MainWindow.py

@@ -35,15 +35,15 @@ class MainWindow(HasTraits):
     resolution = DelegatesTo('camera')
     frame_rate = DelegatesTo('camera')
     status = Str()
-    screen = Instance(CameraImage)
+    screen = Instance(CameraImage, args=())
     cmap = DelegatesTo('screen')
     display_frame_rate = Range(1, 60, 15)
     transform_plugins = List(Instance(TransformPlugin))
     display_plugins = List(Instance(DisplayPlugin))
-    acquisition_thread = Instance(AcquisitionThread)
-    processing_thread = Instance(ProcessingThread)
-    processing_queue = Instance(queue.Queue)
-    cameras_dialog = Instance(CameraDialog)
+    acquisition_thread = Instance(AcquisitionThread)  # default: None
+    processing_thread = Instance(ProcessingThread)  # default: None
+    processing_queue = Instance(queue.Queue, kw={'maxsize': MAX_QUEUE_SIZE})
+    cameras_dialog = Instance(CameraDialog, args=())
 
     # Actions
     about = Action(
@@ -157,26 +157,26 @@ def _find_resolution_fired(self):
     def _display_frame_rate_changed(self, value):
         self.processing_thread.update_frequency = value
 
+    def _transform_plugins_default(self):
+        plugins = []
+        for name in ['Rotator', 'BackgroundSubtract']:
+            module = __import__(name, globals(), locals(), [name])
+            plugins.append(getattr(module, name)())
+        return plugins
+
+    def _display_plugins_default(self):
+        plugins = []
+        for name in ['BeamProfiler', 'MinMaxDisplay', 'DeltaDetector']:
+            module = __import__(name, globals(), locals(), [name])
+            plugins.append(getattr(module, name)(screen=self.screen))
+        return plugins
+
     def __init__(self, **traits):
         super(MainWindow, self).__init__(**traits)
 
-        self.screen = CameraImage()
-
         # Build the camera selection dialog box
-        self.cameras_dialog = CameraDialog()
         self.cameras_dialog.on_trait_change(self.on_cameras_response, 'closed')
 
-        # Build the plugin components
-        self.camera_plugins = []
-        self.transform_plugins = []
-        self.display_plugins = []
-        for name in ['Rotator', 'BackgroundSubtract']:
-            module = __import__(name, globals(), locals(), [name])
-            self.transform_plugins.append(getattr(module, name)())
-        for name in ['BeamProfiler', 'MinMaxDisplay', 'DeltaDetector']:
-            module = __import__(name, globals(), locals(), [name])
-            self.display_plugins.append(getattr(module, name)(screen=self.screen))
-
         # Open the default plugin
         info = self.cameras_dialog.get_plugin_info()
         try:
@@ -187,8 +187,6 @@ def __init__(self, **traits):
             info = self.cameras_dialog.get_plugin_info()
             self.select_plugin(*info)
 
-        self.processing_queue = queue.Queue(maxsize=MAX_QUEUE_SIZE)
-        self.acquisition_thread = None
         self.processing_thread = ProcessingThread(self, self.processing_queue, self.display_frame_rate)
         self.processing_thread.start()
 

src/Webcam.py

@@ -27,9 +27,10 @@ def ipl2array(im):
 
 
 class Webcam(Camera):
-    def __init__(self, *args, **kwargs):
-        super(Webcam, self).__init__(self, *args, **kwargs)
-        self.id_string = 'OpenCV driver, unknown camera'
+    def __init__(self, **traits):
+        super(Webcam, self).__init__(
+            id_string='OpenCV driver, unknown camera',
+            **traits)
         self._capture = None
 
     def open(self):