Add type checking for img detection messages

ml/messages/__init__.py

@@ -1 +1,6 @@
-from .img_detections import ImgDetectionsWithKeypoints
+from .img_detections import ImgDetectionWithKeypoints, ImgDetectionsWithKeypoints
+
+__all__ = [
+    "ImgDetectionWithKeypoints",
+    "ImgDetectionsWithKeypoints",
+]

ml/messages/img_detections.py

@@ -1,12 +1,97 @@
 import depthai as dai
-from typing import List
+from typing import List, Tuple, Union
+
+
+class KeypointsDescriptor:
+    """
+    Descriptor for managing the `keypoints` attribute with type checking.
+
+    This descriptor ensures that the `keypoints` attribute is an empty list or
+    list of tuples, where each tuple contains exactly two elements that are either
+    integers or floats.
+
+    Attributes:
+        name (str): The name of the attribute managed by the descriptor.
+
+    Methods:
+        __get__(instance, owner):
+            Retrieves the value of the `keypoints` attribute.
+        __set__(instance, value):
+            Sets the value of the `keypoints` attribute after validating its type.
+    """
+
+    def __init__(self):
+        self.name = "_keypoints"
+
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self
+        return instance.__dict__.get(self.name, [])
+
+    def __set__(
+        self, instance, value: List[Tuple[Union[int, float], Union[int, float]]]
+    ):
+        if not isinstance(value, list):
+            raise TypeError("Keypoints must be a list")
+        for item in value:
+            if (
+                not isinstance(item, tuple)
+                or len(item) != 2
+                or not all(isinstance(i, (int, float)) for i in item)
+            ):
+                raise TypeError(
+                    "Each keypoint must be a tuple of two floats or integers"
+                )
+        instance.__dict__[self.name] = value
+
 
 class ImgDetectionWithKeypoints(dai.ImgDetection):
+    keypoints = KeypointsDescriptor()
+
     def __init__(self):
-        dai.ImgDetection.__init__(self)
-        self.keypoints = [] # TODO: how to enforce type checking for keypoints? e.g. this currently accept strings
+        dai.ImgDetection.__init__(self) # TODO: change to super().__init__()?
+        self.keypoints: List[Tuple[Union[int, float], Union[int, float]]] = []
+
+
+class DetectionsWithKeypointsDescriptor:
+    """
+    Descriptor for managing the `detections` attribute with type checking.
+
+    This descriptor ensures that the `detections` attribute is a list of
+    ImgDetectionWithKeypoints instances.
+
+    Attributes:
+        name (str): The name of the attribute managed by the descriptor.
+
+    Methods:
+        __get__(instance, owner):
+            Retrieves the value of the `detections` attribute.
+        __set__(instance, value):
+            Sets the value of the `detections` attribute after validating its type.
+    """
+
+    def __init__(self):
+        self.name = "_detections"
+
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self
+        return instance.__dict__.get(self.name, [])
+
+    def __set__(self, instance, value: List["ImgDetectionWithKeypoints"]):
+        if not isinstance(value, list):
+            raise TypeError("Detections must be a list")
+        for item in value:
+            if not isinstance(item, ImgDetectionWithKeypoints):
+                raise TypeError(
+                    "Each detection must be an instance of ImgDetectionWithKeypoints"
+                )
+        instance.__dict__[self.name] = value
+
 
 class ImgDetectionsWithKeypoints(dai.Buffer):
+    detections = DetectionsWithKeypointsDescriptor()
+
     def __init__(self):
-        dai.Buffer.__init__(self)
-        self.detections: List[ImgDetectionWithKeypoints] = [] # TODO: how to enforce type checking for ImgDetectionWithKeypoints? e.g. this currently accept ImgDetection
+        dai.Buffer.__init__(self) # TODO: change to super().__init__()?
+        self.detections: List[ImgDetectionWithKeypoints] = []