Cleaning initialization, enter and exit processes.

26 files changed, 239 insertions, 153 deletions

diff --git a/src/argaze/ArFeatures.py b/src/argaze/ArFeatures.py
index bb6a71b..1585780 100644
--- a/src/argaze/ArFeatures.py
+++ b/src/argaze/ArFeatures.py
@@ -106,7 +106,6 @@ class ArLayer(DataFeatures.SharedObject, DataFeatures.PipelineStepObject):
 
 		# Init parent classes
 		DataFeatures.SharedObject.__init__(self)
-		DataFeatures.PipelineStepObject.__init__(self)
 
 		# Init private attributes
 		self.__aoi_scene = None
@@ -461,7 +460,6 @@ class ArFrame(DataFeatures.SharedObject, DataFeatures.PipelineStepObject):
 
 		# Init parent classes
 		DataFeatures.SharedObject.__init__(self)
-		DataFeatures.PipelineStepObject.__init__(self)
 
 		# Init private attributes
 		self.__size = (1, 1)
@@ -728,6 +726,20 @@ class ArFrame(DataFeatures.SharedObject, DataFeatures.PipelineStepObject):
 
 		return d
 
+	@DataFeatures.PipelineStepEnter
+	def __enter__(self):
+
+		for name, layer in self._layers.items():
+
+			layer.__enter__()
+
+	@DataFeatures.PipelineStepExit
+	def __exit__(self, exception_type, exception_value, exception_traceback):
+
+		for name, layer in self._layers.items():
+
+			layer.__exit__(exception_type, exception_value, exception_traceback)
+
 	@DataFeatures.PipelineStepMethod
 	def look(self, timestamped_gaze_position: GazeFeatures.GazePosition = GazeFeatures.GazePosition()) -> Iterator[Union[object, type, dict]]:
 		"""
@@ -920,9 +932,6 @@ class ArScene(DataFeatures.PipelineStepObject):
 	def __init__(self, **kwargs):
 		"""Initialize ArScene"""
 
-		# Init parent classes
-		super().__init__()
-
 		# Init private attributes
 		self._layers = {}
 		self.__frames = {}
@@ -1116,7 +1125,7 @@ class ArCamera(ArFrame):
 	def __init__(self, **kwargs):
 		"""Initialize ArCamera."""
 		
-		# Init parent class
+		# Init ArFrame class
 		super().__init__()
 
 		# Init private attributes
@@ -1366,8 +1375,6 @@ class ArContext(DataFeatures.PipelineStepObject):
 	@DataFeatures.PipelineStepInit
 	def __init__(self, **kwargs):
 
-		DataFeatures.PipelineStepObject.__init__(self)
-
 		# Init private attributes
 		self.__pipeline = None
 		self.__exceptions = DataFeatures.TimestampedExceptions()
@@ -1424,7 +1431,7 @@ class ArContext(DataFeatures.PipelineStepObject):
 
 		return self
 
-	@DataFeatures.PipelineStepEnter
+	@DataFeatures.PipelineStepExit
 	def __exit__(self, exception_type, exception_value, exception_traceback):
 		"""Exit from ArContext."""
 		pass
diff --git a/src/argaze/ArUcoMarkers/ArUcoCamera.py b/src/argaze/ArUcoMarkers/ArUcoCamera.py
index e84d71a..1371a38 100644
--- a/src/argaze/ArUcoMarkers/ArUcoCamera.py
+++ b/src/argaze/ArUcoMarkers/ArUcoCamera.py
@@ -47,7 +47,7 @@ class ArUcoCamera(ArFeatures.ArCamera):
 	def __init__(self, **kwargs):
 		"""Initialize ArUcoCamera"""
 
-		# Init parent class
+		# Init ArCamera class
 		super().__init__()
 
 		# Init private attribute
diff --git a/src/argaze/ArUcoMarkers/ArUcoDetector.py b/src/argaze/ArUcoMarkers/ArUcoDetector.py
index b84030c..f135c1d 100644
--- a/src/argaze/ArUcoMarkers/ArUcoDetector.py
+++ b/src/argaze/ArUcoMarkers/ArUcoDetector.py
@@ -131,9 +131,6 @@ class ArUcoDetector(DataFeatures.PipelineStepObject):
     def __init__(self, **kwargs):
         """Initialize ArUcoDetector."""
 
-        # Init parent class
-        super().__init__()
-
         # Init private attributes
         self.__dictionary = None
         self.__optic_parameters = None
@@ -327,15 +324,12 @@ class ArUcoDetector(DataFeatures.PipelineStepObject):
 
         return self.__board_corners
 
-class Observer(DataFeatures.PipelineStepObserver):
+class Observer():
     """Define ArUcoDetector observer to count how many times detection succeeded and how many times markers are detected."""
 
-    @DataFeatures.PipelineStepInit
-    def __init__(self, **kwargs):
+    def __init__(self):
         """Initialize marker detection metrics."""
 
-        DataFeatures.PipelineStepObserver.__init__(self)
-
         self.__try_count = 0
         self.__success_count = 0
         self.__detected_ids = []
diff --git a/src/argaze/ArUcoMarkers/ArUcoMarkersGroup.py b/src/argaze/ArUcoMarkers/ArUcoMarkersGroup.py
index 36960f3..642b1d0 100644
--- a/src/argaze/ArUcoMarkers/ArUcoMarkersGroup.py
+++ b/src/argaze/ArUcoMarkers/ArUcoMarkersGroup.py
@@ -85,9 +85,6 @@ class ArUcoMarkersGroup(DataFeatures.PipelineStepObject):
     def __init__(self, **kwargs):
         """Initialize ArUcoMarkersGroup"""
 
-        # Init parent classes
-        super().__init__()
-
         # Init private attributes
         self.__dictionary = None
         self.__places = {}
diff --git a/src/argaze/ArUcoMarkers/ArUcoScene.py b/src/argaze/ArUcoMarkers/ArUcoScene.py
index 078c9e2..dbad14d 100644
--- a/src/argaze/ArUcoMarkers/ArUcoScene.py
+++ b/src/argaze/ArUcoMarkers/ArUcoScene.py
@@ -35,7 +35,7 @@ class ArUcoScene(ArFeatures.ArScene):
 	def __init__(self, **kwargs):
 		"""Initialize ArUcoScene"""
 
-		# Init parent classes
+		# Init ArScene classes
 		super().__init__()
 
 		# Init private attribute
diff --git a/src/argaze/AreaOfInterest/AOIFeatures.py b/src/argaze/AreaOfInterest/AOIFeatures.py
index a65400d..680397b 100644
--- a/src/argaze/AreaOfInterest/AOIFeatures.py
+++ b/src/argaze/AreaOfInterest/AOIFeatures.py
@@ -548,8 +548,6 @@ class Heatmap(DataFeatures.PipelineStepObject):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
-        super().__init__()
-
         # Init private attributes
         self.__size = (1, 1)
         self.__buffer = 0
diff --git a/src/argaze/DataFeatures.py b/src/argaze/DataFeatures.py
index 48a5b08..90501a3 100644
--- a/src/argaze/DataFeatures.py
+++ b/src/argaze/DataFeatures.py
@@ -627,9 +627,15 @@ def PipelineStepInit(method):
         Parameters:
             kwargs: any arguments defined by PipelineStepMethodInit.
         """
+
+        # Init class attributes
         method(self, **kwargs)
 
-        PipelineStepObject.update_attributes(self, kwargs)
+        # Init pipeline step object attributes
+        PipelineStepObject.__init__(self)
+
+        # Update all attributes
+        self.update_attributes(kwargs)
 
     return wrapper
 
@@ -639,21 +645,11 @@ def PipelineStepEnter(method):
     def wrapper(self):
         """Wrap pipeline step __enter__ method to call super, observers and children __enter__ method."""
 
-        PipelineStepObject.__enter__(self)
+        logging.debug('%s.__enter__', type(self).__name__)
 
         method(self)
 
-        # Start children pipeline step objects
-        for child in self.children:
-
-            child.__enter__()
-
-        # Start observers
-        for observer in self.observers:
-
-            observer.__enter__()
-
-        return self
+        return PipelineStepObject.__enter__(self)
 
     return wrapper
 
@@ -663,17 +659,9 @@ def PipelineStepExit(method):
     def wrapper(self, *args):
         """Wrap pipeline step __exit__ method to call super, observers and children __exit__ method."""
 
-        PipelineStepObject.__exit__(self, *args)
+        logging.debug('%s.__exit__', type(self).__name__)
 
-        # Stop observers
-        for observer in self.observers:
-
-            observer.__exit__(*args)
-
-        # Stop children pipeline step objects
-        for child in self.children:
-
-            child.__exit__(*args)
+        PipelineStepObject.__exit__(self, *args)
 
         method(self, *args)
 
@@ -764,7 +752,7 @@ class PipelineStepObject():
     Define class to assess pipeline step methods execution time and observe them.
     """
 
-    def __init__(self, **kwargs):
+    def __init__(self):
         """Initialize PipelineStepObject."""
 
         logging.debug('%s.__init__', type(self).__name__)
@@ -777,20 +765,39 @@ class PipelineStepObject():
         # Parent attribute will be setup later by parent it self
         self.__parent = None
 
-        # Update attributes
-        self.update_attributes(kwargs)
-
     def __enter__(self):
         """Define default method to enter into pipeline step object context."""
 
-        logging.debug('%s.__enter__', type(self).__name__)
+        # Start children pipeline step objects
+        for child in self.children:
+
+            # DEBUG
+            print('ENTERING CHILD', type(child))
+
+            child.__enter__()
+
+        # Start observers
+        for observer in self.observers:
+
+            # DEBUG
+            print('ENTERING OBSERVER', type(observer))
+
+            observer.__enter__()
 
         return self
 
     def __exit__(self, exception_type, exception_value, exception_traceback):
         """Define default method to exit from pipeline step object context."""
 
-        logging.debug('PipelineStepObject.__exit__')
+        # Stop observers
+        for observer in self.observers:
+
+            observer.__exit__(exception_type, exception_value, exception_traceback)
+
+        # Stop children pipeline step objects
+        for child in self.children:
+
+            child.__exit__(exception_type, exception_value, exception_traceback)
 
     def update_attributes(self, object_data: dict):
         """Update pipeline step object attributes with dictionary."""
@@ -1060,28 +1067,3 @@ def PipelineStepMethod(method):
         return result
 
     return wrapper
-
-class PipelineStepObserver():
-    """Define abstract class to observe pipeline step object use.
-
-    !!! note
-        To subscribe to a method call, the inherited class simply needs to define 'on_<method_name>' functions with timestamp, object and traceback argument.
-    """
-
-    def __enter__(self):
-        """
-        Define abstract __enter__ method to use observer as a context.
-
-        !!! warning
-            This method is called provided that the observed PipelineStepObject is created as a context using a with statement.
-        """
-        return self
-
-    def __exit__(self, exception_type, exception_value, exception_traceback):
-        """
-        Define abstract __exit__ method to use observer as a context.
-
-        !!! warning
-            This method is called provided that the observed PipelineStepObject is created as a context using a with statement.
-        """
-        pass
diff --git a/src/argaze/GazeAnalysis/Basic.py b/src/argaze/GazeAnalysis/Basic.py
index 74426de..063ee2b 100644
--- a/src/argaze/GazeAnalysis/Basic.py
+++ b/src/argaze/GazeAnalysis/Basic.py
@@ -27,6 +27,7 @@ class ScanPathAnalyzer(GazeFeatures.ScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init ScanPathAnalyzer class
         super().__init__()
 
         self.__path_duration = 0
@@ -72,6 +73,7 @@ class AOIScanPathAnalyzer(GazeFeatures.AOIScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIScanPathAnalyzer class
         super().__init__()
 
         self.__path_duration = 0
diff --git a/src/argaze/GazeAnalysis/DeviationCircleCoverage.py b/src/argaze/GazeAnalysis/DeviationCircleCoverage.py
index 48ecbda..9e2aa77 100644
--- a/src/argaze/GazeAnalysis/DeviationCircleCoverage.py
+++ b/src/argaze/GazeAnalysis/DeviationCircleCoverage.py
@@ -31,6 +31,7 @@ class AOIMatcher(GazeFeatures.AOIMatcher):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIMatcher class
         super().__init__()
 
         self.__coverage_threshold = 0
diff --git a/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py b/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py
index 3fd9613..0864b18 100644
--- a/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py
+++ b/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py
@@ -115,6 +115,7 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init GazeMovementIdentifier class
         super().__init__()
 
         self.__deviation_max_threshold = 0
diff --git a/src/argaze/GazeAnalysis/Entropy.py b/src/argaze/GazeAnalysis/Entropy.py
index c1cddd6..a73901e 100644
--- a/src/argaze/GazeAnalysis/Entropy.py
+++ b/src/argaze/GazeAnalysis/Entropy.py
@@ -35,6 +35,7 @@ class AOIScanPathAnalyzer(GazeFeatures.AOIScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIScanPathAnalyzer class
         super().__init__()
 
         self.__transition_matrix_analyzer = None
diff --git a/src/argaze/GazeAnalysis/ExploreExploitRatio.py b/src/argaze/GazeAnalysis/ExploreExploitRatio.py
index 44addd3..3b2d53b 100644
--- a/src/argaze/GazeAnalysis/ExploreExploitRatio.py
+++ b/src/argaze/GazeAnalysis/ExploreExploitRatio.py
@@ -33,6 +33,7 @@ class ScanPathAnalyzer(GazeFeatures.ScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init ScanPathAnalyzer class
         super().__init__()
 
         self.__short_fixation_duration_threshold = 0.
diff --git a/src/argaze/GazeAnalysis/FocusPointInside.py b/src/argaze/GazeAnalysis/FocusPointInside.py
index 3626e22..dbcb438 100644
--- a/src/argaze/GazeAnalysis/FocusPointInside.py
+++ b/src/argaze/GazeAnalysis/FocusPointInside.py
@@ -31,6 +31,7 @@ class AOIMatcher(GazeFeatures.AOIMatcher):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIMatcher class
         super().__init__()
 
         self.__reset()
diff --git a/src/argaze/GazeAnalysis/KCoefficient.py b/src/argaze/GazeAnalysis/KCoefficient.py
index 9bed17c..7e3caab 100644
--- a/src/argaze/GazeAnalysis/KCoefficient.py
+++ b/src/argaze/GazeAnalysis/KCoefficient.py
@@ -33,6 +33,7 @@ class ScanPathAnalyzer(GazeFeatures.ScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init ScanPathAnalyzer class
         super().__init__()
 
         self.__K = 0
@@ -90,6 +91,7 @@ class AOIScanPathAnalyzer(GazeFeatures.AOIScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIScanPathAnalyzer class
         super().__init__()
 
         self.__K = 0
diff --git a/src/argaze/GazeAnalysis/LempelZivComplexity.py b/src/argaze/GazeAnalysis/LempelZivComplexity.py
index fc50991..810dbba 100644
--- a/src/argaze/GazeAnalysis/LempelZivComplexity.py
+++ b/src/argaze/GazeAnalysis/LempelZivComplexity.py
@@ -34,6 +34,7 @@ class AOIScanPathAnalyzer(GazeFeatures.AOIScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIScanPathAnalyzer class
         super().__init__()
 
         self.__lempel_ziv_complexity = 0
diff --git a/src/argaze/GazeAnalysis/LinearRegression.py b/src/argaze/GazeAnalysis/LinearRegression.py
index c2f532a..00fd649 100644
--- a/src/argaze/GazeAnalysis/LinearRegression.py
+++ b/src/argaze/GazeAnalysis/LinearRegression.py
@@ -34,6 +34,7 @@ class GazePositionCalibrator(GazeFeatures.GazePositionCalibrator):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init GazePositionCalibrator class
         super().__init__()
 
         self.__linear_regression = LinearRegression()
diff --git a/src/argaze/GazeAnalysis/NGram.py b/src/argaze/GazeAnalysis/NGram.py
index ac5a0dd..ca60734 100644
--- a/src/argaze/GazeAnalysis/NGram.py
+++ b/src/argaze/GazeAnalysis/NGram.py
@@ -31,6 +31,7 @@ class AOIScanPathAnalyzer(GazeFeatures.AOIScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIScanPathAnalyzer class
         super().__init__()
 
         self.__n_min = 2
diff --git a/src/argaze/GazeAnalysis/NearestNeighborIndex.py b/src/argaze/GazeAnalysis/NearestNeighborIndex.py
index 615643e..a577eba 100644
--- a/src/argaze/GazeAnalysis/NearestNeighborIndex.py
+++ b/src/argaze/GazeAnalysis/NearestNeighborIndex.py
@@ -34,6 +34,7 @@ class ScanPathAnalyzer(GazeFeatures.ScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init ScanPathAnalyzer class
         super().__init__()
 
         self.__size = (0, 0)
diff --git a/src/argaze/GazeAnalysis/TransitionMatrix.py b/src/argaze/GazeAnalysis/TransitionMatrix.py
index 16cb56e..dd5cf87 100644
--- a/src/argaze/GazeAnalysis/TransitionMatrix.py
+++ b/src/argaze/GazeAnalysis/TransitionMatrix.py
@@ -34,6 +34,7 @@ class AOIScanPathAnalyzer(GazeFeatures.AOIScanPathAnalyzer):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init AOIScanPathAnalyzer class
         super().__init__()
 
         self.__transition_matrix_probabilities = pandas.DataFrame()
diff --git a/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py b/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py
index f881132..a0aab68 100644
--- a/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py
+++ b/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py
@@ -114,6 +114,7 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
+        # Init GazeMovementIdentifier class
         super().__init__()
 
         self.__velocity_max_threshold = 0
diff --git a/src/argaze/GazeFeatures.py b/src/argaze/GazeFeatures.py
index bb2fb5b..bd7970b 100644
--- a/src/argaze/GazeFeatures.py
+++ b/src/argaze/GazeFeatures.py
@@ -290,7 +290,7 @@ class GazePositionCalibrator(DataFeatures.PipelineStepObject):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
-        super().__init__()
+        pass
 
     def store(self, observed_gaze_position: GazePosition, expected_gaze_position: GazePosition):
         """Store observed and expected gaze positions.
@@ -538,7 +538,7 @@ class GazeMovementIdentifier(DataFeatures.PipelineStepObject):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
-        super().__init__()
+        pass
 
     @DataFeatures.PipelineStepMethod
     def identify(self, timestamped_gaze_position: GazePosition, terminate:bool=False) -> GazeMovement:
@@ -813,8 +813,6 @@ class ScanPathAnalyzer(DataFeatures.PipelineStepObject):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
-        super().__init__()
-
         self.__analysis = [name for (name, value) in self.__class__.__dict__.items() if isinstance(value, property) and value.fset is None]
 
     def analysis(self) -> DataFeatures.DataDictionary:
@@ -834,8 +832,6 @@ class AOIMatcher(DataFeatures.PipelineStepObject):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
-        super().__init__()
-
         self.__exclude = []
 
     @property
@@ -1182,8 +1178,6 @@ class AOIScanPathAnalyzer(DataFeatures.PipelineStepObject):
     @DataFeatures.PipelineStepInit
     def __init__(self, **kwargs):
 
-        super().__init__()
-
         self.__analysis = [name for (name, value) in self.__class__.__dict__.items() if isinstance(value, property) and value.fset is None]
 
     def analysis(self) -> DataFeatures.DataDictionary:
diff --git a/src/argaze/utils/UtilsFeatures.py b/src/argaze/utils/UtilsFeatures.py
index 26a63ea..75deca8 100644
--- a/src/argaze/utils/UtilsFeatures.py
+++ b/src/argaze/utils/UtilsFeatures.py
@@ -16,9 +16,14 @@ __credits__ = []
 __copyright__ = "Copyright 2023, Ecole Nationale de l'Aviation Civile (ENAC)"
 __license__ = "GPLv3"
 
+import os
+import pathlib
 import time
 import types
 import traceback
+
+from argaze import DataFeatures
+
 import numpy
 import cv2
 
@@ -162,39 +167,75 @@ def tuple_to_string(t: tuple, separator: str = ", ") -> str:
 
     return separator.join(f'\"{e}\"' for e in t)
 
-class FileWriter():
-    """Write data into a file line by line.
+class FileWriter(DataFeatures.PipelineStepObject):
+    """Write data into a file line by line."""
 
-    Parameters:
-        path: File path where to write data.
-        header: String or tuple to write first.
-        separator: String used to separate elements during tuple to string conversion.
-    """
+    @DataFeatures.PipelineStepInit
+    def __init__(self, **kwargs):
+        
+        # Init private attributes
+        self.__path = None
+        self.__separator = ','
+        self.__header = None
+
+    @property
+    def path(self) -> str:
+        """File path where to write data."""
+        return self.__path
+
+    @path.setter
+    def path(self, path: str):
 
-    def __init__(self, path: str, header: str|tuple, separator: str = ','):
-        """Check that folder structure exist and create file then, write header line."""
+        self.__path = pathlib.Path(path)
 
-        import os
-        import pathlib
+    @property
+    def separator(self) -> str:
+        """String used to separate elements during tuple to string conversion."""
+        return self.__separator
+
+    @separator.setter
+    def separator(self, separator: str):
+
+        self.__separator = separator
+
+    @property
+    def header(self) -> str|tuple:
+        """String or tuple to write first."""
+        return self.__header
+
+    @header.setter
+    def header(self, header: str|tuple):
+
+        self.__header = header
+
+    @DataFeatures.PipelineStepEnter
+    def __enter__(self):
+        """Check that folder structure exist and open file then, write header line."""
+        
+        # DEBUG
+        print('FileWriter.__enter__')
 
-        self.path = pathlib.Path(path)
-        self.separator = separator
+        if not os.path.exists(self.__path.parent.absolute()):
 
-        if not os.path.exists(self.path.parent.absolute()):
-            os.makedirs(self.path.parent.absolute())
+            os.makedirs(self.__path.parent.absolute())
 
         # Open file
-        self._file = open(self.path, 'w', encoding='utf-8', buffering=1)
+        self.__file = open(self.__path, 'w', encoding='utf-8', buffering=1)
 
         # Write header if required
-        if header is not None:
+        if self.__header is not None:
 
             # Format list or tuple element into quoted strings
-            if not isinstance(header, str):
+            if not isinstance(self.__header, str):
 
-                header = tuple_to_string(header, self.separator)
+                self.__header = tuple_to_string(self.__header, self.__separator)
 
-            print(header, file=self._file, flush=True)
+            print(self.__header, file=self.__file, flush=True)
+
+    @DataFeatures.PipelineStepExit
+    def __exit__(self, exception_type, exception_value, exception_traceback):
+        """Close file."""
+        self.__file.close()
 
     def write(self, log: str|tuple):
         """Write log as a new line into file. 
@@ -206,28 +247,13 @@ class FileWriter():
         # Format list or tuple element into quoted strings
         if not isinstance(log, str):
 
-            log = tuple_to_string(log, self.separator)
+            log = tuple_to_string(log, self.__separator)
 
         # Write into file
-        print(log, file=self._file, flush=True)
-
-    def __del__(self):
-        """Close file."""
+        print(log, file=self.__file, flush=True)
 
-        self._file.close()
-
-class VideoWriter():
-    """Write images into a file using ffmpeg.
-
-    Parameters:
-        path: File path where to write images.
-        width: video horizontal resolution.
-        height: video vertical resolution.
-        fps: frame per second.
-    """
-
-    def __init__(self, path: str, width: int, height: int, fps: int):
-        """Open ffmpeg application as sub-process.
+class VideoWriter(DataFeatures.PipelineStepObject):
+    """Open ffmpeg application as sub-process.
         FFmpeg input PIPE: RAW images in BGR color format
         FFmpeg output MP4 file encoded with HEVC codec.
 
@@ -242,25 +268,75 @@ class VideoWriter():
             -pix_fmt yuv420p     Output video color space YUV420 (saving space compared to YUV444)
             -crf 24              Constant quality encoding (lower value for higher quality and larger output file).
             {output_filename}    Output file name: output_filename (output.mp4)
-        """
+    """
 
-        import subprocess as sp
-        import shlex
+    @DataFeatures.PipelineStepInit
+    def __init__(self, **kwargs):
+        
+        # Init private attributes
+        self.__path = None
+        self.__width = 320
+        self.__height = 240
+        self.__fps = 25
+
+    @property
+    def path(self) -> str:
+        """File path where to write images."""
+        return self.__path
+
+    @path.setter
+    def path(self, path: str):
+
+        self.__path = pathlib.Path(path)
+
+    @property
+    def width(self) -> int:
+        """Video horizontal resolution."""
+        return self.__width
+
+    @width.setter
+    def width(self, width: int):
 
         self.__width = width
+
+    @property
+    def height(self) -> int:
+        """Video vertical resolution."""
+        return self.__height
+
+    @height.setter
+    def height(self, height: int):
+
         self.__height = height
 
-        self.__process = sp.Popen(shlex.split(f'ffmpeg -hide_banner -loglevel error -y -s {width}x{height} -pixel_format bgr24 -f rawvideo -r {fps} -i pipe: -vcodec libx265 -x265-params log-level=error -pix_fmt yuv420p -crf 24 {path}'), stdin=sp.PIPE)
+    @property
+    def fps(self) -> int:
+        """frame per second."""
+        return self.__fps
+    
+    @fps.setter
+    def fps(self, fps: int):
 
-    def write(self, image: numpy.array):
-        """Write raw video frame to input stream of ffmpeg sub-process."""
+        self.__fps = fps
 
-        # Resize image to adapt to video resolution
-        output = cv2.resize(image, dsize=(self.__width, self.__height), interpolation=cv2.INTER_LINEAR) 
+    @DataFeatures.PipelineStepEnter
+    def __enter__(self):
+        """Check that folder structure exist then, open ffmpeg subprocess."""
+        
+        import subprocess as sp
+        import shlex
 
-        self.__process.stdin.write(output.tobytes())
+        # DEBUG
+        print('VideoWriter.__enter__')
 
-    def __del__(self):
+        if not os.path.exists(self.__path.parent.absolute()):
+            
+            os.makedirs(self.__path.parent.absolute())
+
+        self.__process = sp.Popen(shlex.split(f'ffmpeg -hide_banner -loglevel error -y -s {self.__width}x{self.__height} -pixel_format bgr24 -f rawvideo -r {self.__fps} -i pipe: -vcodec libx265 -x265-params log-level=error -pix_fmt yuv420p -crf 24 {self.__path}'), stdin=sp.PIPE)
+    
+    @DataFeatures.PipelineStepExit
+    def __exit__(self, exception_type, exception_value, exception_traceback):
 
         # Close and flush stdin
         self.__process.stdin.close()
@@ -272,6 +348,14 @@ class VideoWriter():
         # Note: We don't have to terminate the sub-process (after process.wait(), the sub-process is supposed to be closed).
         self.__process.terminate() 
 
+    def write(self, image: numpy.array):
+        """Write raw video frame to input stream of ffmpeg sub-process."""
+
+        # Resize image to adapt to video resolution
+        output = cv2.resize(image, dsize=(self.__width, self.__height), interpolation=cv2.INTER_LINEAR) 
+
+        self.__process.stdin.write(output.tobytes())
+
 def PrintCallStack(method):
     """Define a decorator to print call stack until the decorated method."""
 
diff --git a/src/argaze/utils/contexts/OpenCV.py b/src/argaze/utils/contexts/OpenCV.py
index 5a35fba..a65d40e 100644
--- a/src/argaze/utils/contexts/OpenCV.py
+++ b/src/argaze/utils/contexts/OpenCV.py
@@ -31,7 +31,7 @@ class Window(ArFeatures.ArContext):
 	@DataFeatures.PipelineStepInit
 	def __init__(self, **kwargs):
 
-		# Init parent classes
+		# Init ArContext classe
 		super().__init__()
 
 	@DataFeatures.PipelineStepEnter
diff --git a/src/argaze/utils/contexts/TobiiProGlasses2.py b/src/argaze/utils/contexts/TobiiProGlasses2.py
index 6b7236b..7830036 100644
--- a/src/argaze/utils/contexts/TobiiProGlasses2.py
+++ b/src/argaze/utils/contexts/TobiiProGlasses2.py
@@ -312,7 +312,7 @@ class LiveStream(ArFeatures.ArContext):
 	@DataFeatures.PipelineStepInit
 	def __init__(self, **kwargs):
 
-		# Init parent classes
+		# Init ArContext classe
 		super().__init__()
 
 		# Init private attributes
@@ -1197,7 +1197,7 @@ class PostProcessing(ArFeatures.ArContext):
 	@DataFeatures.PipelineStepInit
 	def __init__(self, **kwargs):
 
-		# Init parent classes
+		# Init ArContext classe
 		super().__init__()
 
 		# Init private attributes
diff --git a/src/argaze/utils/demo/gaze_analysis_pipeline.json b/src/argaze/utils/demo/gaze_analysis_pipeline.json
index 0c81be3..0d1062b 100644
--- a/src/argaze/utils/demo/gaze_analysis_pipeline.json
+++ b/src/argaze/utils/demo/gaze_analysis_pipeline.json
@@ -1,7 +1,7 @@
 {
     "argaze.ArFeatures.ArFrame": {
         "name": "GrayRectangle",
-        "size": [640, 383],
+        "size": [1920, 1149],
         "background": "frame_background.jpg",
         "gaze_movement_identifier": {
             "argaze.GazeAnalysis.DispersionThresholdIdentification.GazeMovementIdentifier": {
@@ -24,7 +24,7 @@
             }
         },
         "heatmap": {
-            "size": [32, 24]
+            "size": [128, 96]
         },
         "layers": {
             "demo_layer": {
@@ -50,8 +50,7 @@
                 },
                 "observers": {
                     "loggers.AOIScanPathAnalysisLogger": {
-                        "path": "_export/logs/aoi_scan_path_metrics.csv", 
-                        "header": ["Timestamp (ms)", "Duration (ms)", "Step", "K", "LZC"]
+                        "path": "_export/logs/aoi_scan_path_metrics.csv"
                     }
                 }
             }
@@ -117,12 +116,10 @@
         },
         "observers": {
             "loggers.FixationLogger": {
-                "path": "_export/logs/fixations.csv",
-                "header": ["Timestamp (ms)", "Focus (px)", "Duration (ms)", "AOI"]
+                "path": "_export/logs/fixations.csv"
             },
             "loggers.ScanPathAnalysisLogger": {
-                "path": "_export/logs/scan_path_metrics.csv",
-                "header": ["Timestamp (ms)", "Duration (ms)", "Step", "K", "NNI", "XXR"]
+                "path": "_export/logs/scan_path_metrics.csv"
             },
             "loggers.VideoRecorder": {
                 "path": "_export/logs/video.mp4", 
diff --git a/src/argaze/utils/demo/loggers.py b/src/argaze/utils/demo/loggers.py
index 5f1986e..071e20b 100644
--- a/src/argaze/utils/demo/loggers.py
+++ b/src/argaze/utils/demo/loggers.py
@@ -20,7 +20,13 @@ from argaze import DataFeatures, GazeFeatures
 from argaze.GazeAnalysis import *
 from argaze.utils import UtilsFeatures
 
-class FixationLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter):
+class FixationLogger(UtilsFeatures.FileWriter):
+
+	def __init__(self, **kwargs):
+
+		super().__init__(**kwargs)
+
+		self.header = "Timestamp (ms)", "Focus (px)", "Duration (ms)", "AOI"
 
 	def on_look(self, timestamp, frame, exception):
 		"""Log frame fixations."""
@@ -37,7 +43,13 @@ class FixationLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter
 
 			self.write(log)
 
-class ScanPathAnalysisLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter):
+class ScanPathAnalysisLogger(UtilsFeatures.FileWriter):
+	
+	def __init__(self, **kwargs):
+
+		super().__init__(**kwargs)
+
+		self.header = "Timestamp (ms)", "Duration (ms)", "Step", "K", "NNI", "XXR"
 
 	def on_look(self, timestamp, frame, exception):
 		"""Log frame scan path metrics."""
@@ -57,14 +69,20 @@ class ScanPathAnalysisLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.Fi
 
 			self.write(log)
 
-class VideoRecorder(DataFeatures.PipelineStepObserver, UtilsFeatures.VideoWriter):
+class VideoRecorder(UtilsFeatures.VideoWriter):
+	
+	def on_look(self, timestamp, frame, exception):
+		"""Write frame image."""
+
+		self.write(frame.image())
+
+class AOIScanPathAnalysisLogger(UtilsFeatures.FileWriter):
 
-		def on_look(self, timestamp, frame, exception):
-			"""Write frame image."""
+	def __init__(self, **kwargs):
 
-			self.write(frame.image())
+		super().__init__(**kwargs)
 
-class AOIScanPathAnalysisLogger(DataFeatures.PipelineStepObserver, UtilsFeatures.FileWriter):
+		self.header = "Timestamp (ms)", "Duration (ms)", "Step", "K", "LZC"
 
 	def on_look(self, timestamp, layer, exception):
 		"""Log layer aoi scan path metrics"""