fix: make paper size pydantic compatible

Author: Midnighter

src/structurizr/view/paper_size.py

@@ -27,43 +27,58 @@
 class PaperSize(Enum):
     """Represent paper sizes in pixels at 300dpi."""
 
-    A6_Portrait = ("A6", Orientation.Portrait, 1240, 1748)
-    A6_Landscape = ("A6", Orientation.Landscape, 1748, 1240)
+    def __new__(
+        cls,
+        value: str,
+        size: str,
+        orientation: Orientation,
+        width: int,
+        height: int,
+        **kwargs
+    ) -> "PaperSize":
+        """
+        Construct a specific paper size but with a string value.
 
-    A5_Portrait = ("A5", Orientation.Portrait, 1748, 2480)
-    A5_Landscape = ("A5", Orientation.Landscape, 2480, 1748)
+        References:
+            https://docs.python.org/3/library/enum.html#when-to-use-new-vs-init
 
-    A4_Portrait = ("A4", Orientation.Portrait, 2480, 3508)
-    A4_Landscape = ("A4", Orientation.Landscape, 3508, 2480)
+        """
+        obj = object.__new__(cls)
+        obj._value_ = value
+        obj.size = size
+        obj.orientation = orientation
+        obj.width = width
+        obj.height = height
 
-    A3_Portrait = ("A3", Orientation.Portrait, 3508, 4961)
-    A3_Landscape = ("A3", Orientation.Landscape, 4961, 3508)
+        return obj
 
-    A2_Portrait = ("A2", Orientation.Portrait, 4961, 7016)
-    A2_Landscape = ("A2", Orientation.Landscape, 7016, 4961)
+    A6_Portrait = ("A6_Portrait", "A6", Orientation.Portrait, 1240, 1748)
+    A6_Landscape = ("A6_Landscape", "A6", Orientation.Landscape, 1748, 1240)
 
-    A1_Portrait = ("A1", Orientation.Portrait, 7016, 9933)
-    A1_Landscape = ("A1", Orientation.Landscape, 9933, 7016)
+    A5_Portrait = ("A5_Portrait", "A5", Orientation.Portrait, 1748, 2480)
+    A5_Landscape = ("A5_Landscape", "A5", Orientation.Landscape, 2480, 1748)
 
-    A0_Portrait = ("A0", Orientation.Portrait, 9933, 14043)
-    A0_Landscape = ("A0", Orientation.Landscape, 14043, 9933)
+    A4_Portrait = ("A4_Portrait", "A4", Orientation.Portrait, 2480, 3508)
+    A4_Landscape = ("A4_Landscape", "A4", Orientation.Landscape, 3508, 2480)
 
-    Letter_Portrait = ("Letter", Orientation.Portrait, 2550, 3300)
-    Letter_Landscape = ("Letter", Orientation.Landscape, 3300, 2550)
+    A3_Portrait = ("A3_Portrait", "A3", Orientation.Portrait, 3508, 4961)
+    A3_Landscape = ("A3_Landscape", "A3", Orientation.Landscape, 4961, 3508)
 
-    Legal_Portrait = ("Legal", Orientation.Portrait, 2550, 4200)
-    Legal_Landscape = ("Legal", Orientation.Landscape, 4200, 2550)
+    A2_Portrait = ("A2_Portrait", "A2", Orientation.Portrait, 4961, 7016)
+    A2_Landscape = ("A2_Landscape", "A2", Orientation.Landscape, 7016, 4961)
 
-    Slide_4_3 = ("Slide 4:3", Orientation.Landscape, 3306, 2480)
-    Slide_16_9 = ("Slide 16:9", Orientation.Landscape, 3508, 1973)
-    Slide_16_10 = ("Slide 16:10", Orientation.Landscape, 3508, 2193)
+    A1_Portrait = ("A1_Portrait", "A1", Orientation.Portrait, 7016, 9933)
+    A1_Landscape = ("A1_Landscape", "A1", Orientation.Landscape, 9933, 7016)
 
-    def __init__(
-        self, name: str, orientation: Orientation, width: int, height: int, **kwargs
-    ) -> None:
-        """Initialize a specific paper size."""
-        super().__init__(**kwargs)
-        self.size_name = name
-        self.orientation = orientation
-        self.width = width
-        self.height = height
+    A0_Portrait = ("A0_Portrait", "A0", Orientation.Portrait, 9933, 14043)
+    A0_Landscape = ("A0_Landscape", "A0", Orientation.Landscape, 14043, 9933)
+
+    Letter_Portrait = ("Letter_Portrait", "Letter", Orientation.Portrait, 2550, 3300)
+    Letter_Landscape = ("Letter_Landscape", "Letter", Orientation.Landscape, 3300, 2550)
+
+    Legal_Portrait = ("Legal_Portrait", "Legal", Orientation.Portrait, 2550, 4200)
+    Legal_Landscape = ("Legal_Landscape", "Legal", Orientation.Landscape, 4200, 2550)
+
+    Slide_4_3 = ("Slide_4_3", "Slide 4:3", Orientation.Landscape, 3306, 2480)
+    Slide_16_9 = ("Slide_16_9", "Slide 16:9", Orientation.Landscape, 3508, 1973)
+    Slide_16_10 = ("Slide_16_10", "Slide 16:10", Orientation.Landscape, 3508, 2193)