made magic number into constant

src/simudator/processor/mia/gui/mia_grx_graphic.py

@@ -28,6 +28,7 @@ class GrxGraphicsItem(ModuleGraphicsItem):
     REGISTER_MARGIN = 10
     LINE_LENGTH = 30
     MUX_WIDTH = 80
+    REGISTER_LENGTH = 4
 
     def __init__(self, module: GRX):
         self.register_text_labels = []
@@ -45,7 +46,7 @@ class GrxGraphicsItem(ModuleGraphicsItem):
             name = "Gr" + str(index)
 
             # Mia uses 4 hex numbers to represent the registers
-            hex_length = 4
+            hex_length = self.REGISTER_LENGTH
             value_text = f"0x{register_value:0{hex_length}x}"
             full_text = name + ": " + value_text[2:]
 
@@ -149,7 +150,7 @@ class GrxGraphicsItem(ModuleGraphicsItem):
             name = "Gr" + str(index)
 
             # Mia uses 4 hex numbers for each register
-            hex_length = 4
+            hex_length = self.REGISTER_LENGTH
 
             value_text = f"0x{register_value:0{hex_length}x}"
             full_text = name + ": " + value_text[2:]