add number_circle

frontend/views/base.py

@@ -1,4 +1,7 @@
 from tkinter import ttk, Frame, Canvas
+from PIL import Image, ImageDraw
+from tkinter import PhotoImage
+import io
 
 class View(Frame):
 
@@ -12,15 +15,37 @@ class View(Frame):
         self.tare_button = ttk.Button(self.actions, text="Tare", command=tare_command)
         self.tare_button.pack()
         
-        self.canvas = Canvas(self, width=144, height=168, background='white')
+        self.size = (168, 144)
+        self.center = (168 // 2, 144 // 2)
+        self.bkg_im = self._init_im()
+        self._init_ui()
+
+        self.canvas = Canvas(self, width=168, height=144, background='white',
+                             highlightthickness=1, highlightbackground="black")
         self.canvas.pack()
 
-        self.center = (144 // 2, 168 // 2)
+        self.refresh(0.0)
+    
+    def _init_ui(self):
+        pass
 
-        self._init_canvas()
-
-    def _init_canvas(self):
+    def _init_im(self):
+        return Image.new('1', self.size, 'white')
+    
+    def update_weight(self,
+                      weight: float) -> None:
         raise NotImplementedError()
     
-    def update_weight(self, weight: float):
-        raise NotImplementedError()
+    def refresh(self, weight: float):
+        # draw weight on bkg_im
+        im = self.update_weight(weight)
+
+        # Convert PIL image to bytes
+        buffer = io.BytesIO()
+        im.save(buffer, format='PNG')
+        buffer.seek(0)
+        
+        # Load into PhotoImage and display on canvas
+        self.photo = PhotoImage(data=buffer.getvalue())
+        self.canvas.delete("all")
+        self.canvas.create_image(0, 0, anchor="nw", image=self.photo)