Adding new DrawingFails error.

1 files changed, 16 insertions, 1 deletions

diff --git a/src/argaze/ArFeatures.py b/src/argaze/ArFeatures.py
index 24ba8e3..87293ee 100644
--- a/src/argaze/ArFeatures.py
+++ b/src/argaze/ArFeatures.py
@@ -61,6 +61,15 @@ class LoadingFailed(Exception):
 
 		super().__init__(message)
 
+class DrawingFailed(Exception):
+	"""
+	Exception raised when drawing fails.
+	"""
+
+	def __init__(self, message):  
+
+		super().__init__(message)
+
 # Define default ArLayer draw parameters
 DEFAULT_ARLAYER_DRAW_PARAMETERS = {
 	"draw_aoi_scene": {
@@ -856,7 +865,13 @@ class ArFrame(DataFeatures.SharedObject, DataFeatures.PipelineStepObject):
 
 				for layer_name, draw_layer in draw_layers.items():
 
-					self.__layers[layer_name].draw(image, **draw_layer)
+					try :
+
+						self.__layers[layer_name].draw(image, **draw_layer)
+
+					except KeyError:
+
+						raise(DrawingFailed(f'\'{layer_name}\' layer doesn\'t exist.'))
 
 			# Draw current gaze position if required
 			if draw_gaze_positions is not None: