add number_circle

frontend/views/circle.py

@@ -1,16 +1,12 @@
 import tkinter as tk
 from tkinter import ttk
+from PIL import Image, ImageDraw, ImageChops
 
 from .base import View
 
 class CircleView(View):
 
-    def _init_canvas(self):
-        self.target_r = self.center[0] - 10
-        self.draw_circle(self.center[0], self.center[1],
-                         self.target_r,
-                         outline="#000000")
-        
+    def _init_ui(self):
         self.target_frame = tk.Frame(self.actions)
         self.target_frame.pack()
         self.target_label = ttk.Label(self.target_frame, text="Target (g)")
@@ -19,27 +15,31 @@ class CircleView(View):
         self.target.insert(0, 100.0)
         self.target.pack(side=tk.LEFT)
 
-    def draw_circle(self, x, y, r, **kwargs):
-        self.canvas.create_oval(x-r, y-r, x+r, y+r, **kwargs)
+    def _init_im(self):
+        im = Image.new('1', self.size, 'white')
+        draw = ImageDraw.Draw(im)
+        self.target_r = min(self.center)-10
+        draw.circle(self.center, self.target_r,
+                     outline="#000000")
+        return im
     
     def update_weight(self, weight):
-        self.canvas.delete("all")
-
-        weight_r = 0.0
+        weight_radius = 0.0
+        bkg_im = self.bkg_im.copy()
         try:
             target = float(self.target.get())
-            weight_r = weight / target * self.target_r
+            weight_radius = weight / target * self.target_r
 
-            self.draw_circle(self.center[0], self.center[1],
-                            weight_r,
-                            fill="#000000")
-        except:
+            im = Image.new('1', self.size, 'black')
+            draw = ImageDraw.Draw(im)
+
+            if weight_radius > 0.1:
+                draw.circle(self.center, weight_radius, fill="#FFFFFF")
+            
+                return ImageChops.logical_xor(bkg_im, im)
+
+        except Exception as e:
+            print('Invalid target value:', e)
             pass
-        finally:
-            target_outline = "#000000"
-            if weight_r > self.target_r:
-                target_outline = "#FFFFFF"
-            self.draw_circle(self.center[0], self.center[1],
-                            self.target_r,
-                            outline=target_outline)
+        return bkg_im