calling an object command feature type as an attribute returns a callable

6 files changed, 28 insertions, 9 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ad0f512..3a9f1f0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 ## [0.3.1] - 2019/02/21
 ### Added
 - Auto adjust packet size upon opening camera.
+- Command type features can now be called directly as an object attribute.
+### Changed
+- Increased default frame buffer size from 3 to 10.
 
 ## [0.3] - 2019/02/11
 ### Added
diff --git a/examples/camera/write_feature_value.py b/examples/camera/set_feature_value.py
index 77f8ce5..77f8ce5 100644
--- a/examples/camera/write_feature_value.py
+++ b/examples/camera/set_feature_value.py
diff --git a/examples/interface/write_feature_value.py b/examples/interface/set_feature_value.py
index 0c71da2..0c71da2 100644
--- a/examples/interface/write_feature_value.py
+++ b/examples/interface/set_feature_value.py
diff --git a/pymba/camera.py b/pymba/camera.py
index 4cda105..5a8b75b 100644
--- a/pymba/camera.py
+++ b/pymba/camera.py
@@ -133,7 +133,7 @@ class Camera(VimbaObject):
 
         # may experience issues with camera comms if not called
         if adjust_packet_size:
-            self.run_feature_command('GVSPAdjustPacketSize')
+            self.GVSPAdjustPacketSize()
 
     def close(self):
         """
@@ -181,7 +181,7 @@ class Camera(VimbaObject):
         """
         return Frame(self)
 
-    def arm(self, mode: str, callback: Optional[Callable] = None, frame_buffer_size: Optional[int] = 3) -> None:
+    def arm(self, mode: str, callback: Optional[Callable] = None, frame_buffer_size: Optional[int] = 10) -> None:
         """
         Arm the camera by starting the capture engine and creating frames.
         :param mode: Either 'SingleFrame' to acquire a single frame or 'Continuous' for streaming frames.
@@ -229,9 +229,9 @@ class Camera(VimbaObject):
 
         # capture a single frame
         self._single_frame.queue_for_capture()
-        self.run_feature_command('AcquisitionStart')
+        self.AcquisitionStart()
         self._single_frame.wait_for_capture()
-        self.run_feature_command('AcquisitionStop')
+        self.AcquisitionStop()
 
         return self._single_frame
 
@@ -259,7 +259,7 @@ class Camera(VimbaObject):
             raise VimbaException(VimbaException.ERR_INVALID_CAMERA_MODE)
 
         # safe to call multiple times
-        self.run_feature_command('AcquisitionStart')
+        self.AcquisitionStart()
         self._is_acquiring = True
 
     def _streaming_callback(self, frame: Frame) -> None:
@@ -279,7 +279,7 @@ class Camera(VimbaObject):
         # implies both is armed and in continuous mode
         if self._is_acquiring:
             self._is_acquiring = False
-            self.run_feature_command('AcquisitionStop')
+            self.AcquisitionStop()
 
     def disarm(self) -> None:
         """
diff --git a/pymba/vimba.py b/pymba/vimba.py
index 66329ab..1079b12 100644
--- a/pymba/vimba.py
+++ b/pymba/vimba.py
@@ -59,7 +59,7 @@ class Vimba:
         # automatically check for the presence of a GigE transport layer
         if self.system().GeVTLIsPresent:
             self.system().GeVDiscoveryAllDuration = 250
-            self.system().run_feature_command('GeVDiscoveryAllOnce')
+            self.system().GeVDiscoveryAllOnce()
 
     @staticmethod
     def shutdown():
@@ -89,8 +89,11 @@ class Vimba:
 
         if interface_id in self._interfaces:
             return self._interfaces[interface_id]
+
+        # cache interface instances
         interface = Interface(interface_id)
         self._interfaces[interface_id] = interface
+
         return interface
 
     @staticmethod
@@ -109,6 +112,9 @@ class Vimba:
 
         if camera_id in self._cameras:
             return self._cameras[camera_id]
+
+        # cache camera instance
         camera = Camera(camera_id)
         self._cameras[camera_id] = camera
+
         return camera
diff --git a/pymba/vimba_object.py b/pymba/vimba_object.py
index 174fe9a..fbc6b05 100644
--- a/pymba/vimba_object.py
+++ b/pymba/vimba_object.py
@@ -2,7 +2,7 @@ from ctypes import byref, sizeof, c_void_p, c_uint32, c_uint64, c_bool
 from typing import List, Optional
 
 from .vimba_exception import VimbaException
-from .feature import Feature
+from .feature import Feature, _FEATURE_DATA_COMMAND
 from . import vimba_c
 
 
@@ -25,7 +25,14 @@ class VimbaObject:
     def __getattr__(self, item: str):
         # allow direct access to feature values as an attribute
         if item in self.feature_names():
-            return self.feature(item).value
+            feature = self.feature(item)
+
+            # command feature types are a special case, return a callable
+            if feature.info.featureDataType == _FEATURE_DATA_COMMAND:
+                return lambda: self.run_feature_command(item)
+
+            # otherwise attempt to get their value
+            return feature.value
 
         raise AttributeError(f'{self.__class__.__name__} object has no attribute {item}')
 
@@ -94,8 +101,11 @@ class VimbaObject:
         """
         if feature_name in self._features:
             return self._features[feature_name]
+
+        # cache feature
         feature = Feature(feature_name, self._handle)
         self._features[feature_name] = feature
+
         return feature
 
     def run_feature_command(self, feature_name: str) -> None: