Adding new UnvalidGazeMovement class.

4 files changed, 55 insertions, 20 deletions

diff --git a/src/argaze/ArFeatures.py b/src/argaze/ArFeatures.py
index 321bd1b..493ca8a 100644
--- a/src/argaze/ArFeatures.py
+++ b/src/argaze/ArFeatures.py
@@ -545,7 +545,7 @@ class ArScreen():
 
 		# Init gaze data
 		self.__gaze_position = GazeFeatures.UnvalidGazePosition()
-		self.__gaze_movement = None
+		self.__gaze_movement = GazeFeatures.UnvalidGazeMovement()
 
 	@classmethod
 	def from_scene(self, aoi_scene, aoi_name, size, gaze_movement_identifier) -> ArScreenType:
@@ -593,6 +593,4 @@ class ArScreen():
 	def draw_gaze_movement(self, color=(255, 255, 255)):
 		"""Draw current gaze movement into screen image."""
 
-		if self.__gaze_movement:
-
-			self.__gaze_movement.draw(self.__image, color)
+		self.__gaze_movement.draw_positions(self.__image, color)
diff --git a/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py b/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py
index 1883d69..147046a 100644
--- a/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py
+++ b/src/argaze/GazeAnalysis/DispersionThresholdIdentification.py
@@ -124,7 +124,7 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
         # Ignore non valid gaze position
         if not gaze_position.valid:
 
-            return None if not terminate else self.current_fixation
+            return GazeFeatures.UnvalidGazeMovement() if not terminate else self.current_fixation
             
         # Check if too much time elapsed since last gaze position
         if len(self.__valid_positions) > 0:
@@ -199,6 +199,9 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
                 first_ts, first_position = self.__valid_positions.pop_first()
                 self.__saccade_positions[first_ts] = first_position
 
+        # Always return unvalid gaze movement at least
+        return GazeFeatures.UnvalidGazeMovement()
+
     @property
     def current_fixation(self) -> FixationType:
 
@@ -206,9 +209,15 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
 
             return Fixation(self.__fixation_positions)
 
+        # Always return unvalid gaze movement at least
+        return GazeFeatures.UnvalidGazeMovement()
+
     @property
     def current_saccade(self) -> SaccadeType:
 
         if len(self.__saccade_positions) > 0:
             
             return Saccade(self.__saccade_positions)
+
+        # Always return unvalid gaze movement at least
+        return GazeFeatures.UnvalidGazeMovement()
diff --git a/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py b/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py
index 7d6c7b2..7131373 100644
--- a/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py
+++ b/src/argaze/GazeAnalysis/VelocityThresholdIdentification.py
@@ -133,7 +133,7 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
         # Ignore non valid gaze position
         if not gaze_position.valid:
 
-            return None if not terminate else self.current_fixation
+            return GazeFeatures.UnvalidGazeMovement() if not terminate else self.current_fixation
 
         # Store first valid position
         if self.__last_ts < 0:
@@ -211,6 +211,9 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
 
                 return self.current_fixation
 
+        # Always return unvalid gaze movement at least
+        return GazeFeatures.UnvalidGazeMovement()
+
     @property
     def current_fixation(self) -> FixationType:
 
@@ -218,9 +221,15 @@ class GazeMovementIdentifier(GazeFeatures.GazeMovementIdentifier):
 
             return Fixation(self.__fixation_positions)
 
+        # Always return unvalid gaze movement at least
+        return GazeFeatures.UnvalidGazeMovement()
+
     @property
     def current_saccade(self) -> SaccadeType:
 
         if len(self.__saccade_positions) > 0:
 
             return Saccade(self.__saccade_positions)
+
+        # Always return unvalid gaze movement at least
+        return GazeFeatures.UnvalidGazeMovement()
diff --git a/src/argaze/GazeFeatures.py b/src/argaze/GazeFeatures.py
index 218858a..65afdf8 100644
--- a/src/argaze/GazeFeatures.py
+++ b/src/argaze/GazeFeatures.py
@@ -223,30 +223,40 @@ class GazeMovement():
 
     def __post_init__(self):
 
-        start_position_ts, start_position = self.positions.first
-        end_position_ts, end_position = self.positions.last
+        if self.valid:
+
+            start_position_ts, start_position = self.positions.first
+            end_position_ts, end_position = self.positions.last
 
-        # Update frozen duration attribute
-        object.__setattr__(self, 'duration', end_position_ts - start_position_ts)
+            # Update frozen duration attribute
+            object.__setattr__(self, 'duration', end_position_ts - start_position_ts)
 
-        _, start_position = self.positions.first
-        _, end_position = self.positions.last
+            _, start_position = self.positions.first
+            _, end_position = self.positions.last
 
-        amplitude = numpy.linalg.norm( numpy.array(start_position.value) - numpy.array(end_position.value))
+            amplitude = numpy.linalg.norm( numpy.array(start_position.value) - numpy.array(end_position.value))
 
-        # Update frozen amplitude attribute
-        object.__setattr__(self, 'amplitude', amplitude)
+            # Update frozen amplitude attribute
+            object.__setattr__(self, 'amplitude', amplitude)
 
     def __str__(self) -> str:
         """String display"""
 
-        output = f'{type(self)}:\n\tduration={self.duration}\n\tsize={len(self.positions)}'
+        if self.valid:
 
-        for ts, position in self.positions.items():
+            output = f'{type(self)}:\n\tduration={self.duration}\n\tsize={len(self.positions)}'
 
-            output += f'\n\t{ts}:\n\t\tvalue={position.value},\n\t\taccurracy={position.precision}'
+            for ts, position in self.positions.items():
 
-        return output
+                output += f'\n\t{ts}:\n\t\tvalue={position.value},\n\t\taccurracy={position.precision}'
+
+            return output
+
+    @property
+    def valid(self) -> bool:
+        """Is there positions?"""
+
+        return len(self.positions) > 0
 
     def draw_positions(self, image: numpy.array, color=(0, 55, 55)):
         """Draw gaze movement positions"""
@@ -262,7 +272,16 @@ class GazeMovement():
             start_gaze_position.draw(image, draw_precision=False)
 
             # Draw movement from start to next
-            cv2.line(image, start_gaze_position, next_gaze_position, color, 1)
+            cv2.line(image, (int(start_gaze_position[0]), int(start_gaze_position[1])), (int(next_gaze_position[0]), int(next_gaze_position[1])), color, 1)
+
+class UnvalidGazeMovement(GazeMovement):
+    """Unvalid gaze movement."""
+
+    def __init__(self, message=None):
+
+        self.message = message
+
+        super().__init__([])
 
 FixationType = TypeVar('Fixation', bound="Fixation")
 # Type definition for type annotation convenience