In-class Kivy activity

main.py

 from kivy.app import App
 from kivy.modules import inspector # For inspection.
 from kivy.core.window import Window # For inspection.
+from kivy.uix.slider import Slider
+from kivy.properties import BooleanProperty
+from kivy.properties import NumericProperty
+from kivy.uix.slider import Slider
+
 
 __app_package__ = 'edu.unl.cse.soft161.order'
 __app__ = 'Order Meal'
@@ -9,10 +14,36 @@ __flags__ = ['--bootstrap=sdl2', '--requirements=python2,kivy', '--orientation=l
 
 
 class OrderApp(App):
+    cheese_cost = NumericProperty(0.0)
+    vegan_cost = NumericProperty(0.0)
+    chicken_cost = NumericProperty(0.0)
+    extra_charges = NumericProperty(0.0)
+
     def build(self):
         inspector.create_inspector(Window, self) # For inspection (press control-e to toggle).
 
 
+    def active_cheese(self):
+         if self.root.ids.cheese.active:
+            self.cheese_cost +=  7
+         else:
+             self.cheese_cost = 0
+
+    def active_chicken(self):
+         if self.root.ids.chicken.active:
+            self.chicken_cost +=  11
+         else:
+             self.chicken_cost = 0
+    def active_vegan(self):
+         if self.root.ids.vegan.active:
+            self.vegan_cost +=  9.5
+         else:
+             self.vegan_cost = 0
+
+
+
+
+
 if __name__ == '__main__':
     app = OrderApp()
     app.run()

order.kv

 BoxLayout:
     orientation: 'vertical'
+    color: (0, 0, 0)
     Label:
-        text: '[Your meal-ordering GUI here]'
+        text: 'Pizza Restaurant'
+        font_size: '48sp'
+    BoxLayout:
+        orientation: 'horizontal'
+        Widget:
+        CheckBox:
+            id: cheese
+            active: False
+            size_hint: (None, None)
+            size: (sp(32), cheese_pizza.height)
+            on_active: app.active_cheese()
+        Label:
+            id: cheese_pizza
+            text: 'Cheese Pizza'
+            size_hint: (None, 1)
+            size: self.texture_size
+        Widget:
+    BoxLayout:
+        orientation: 'horizontal'
+        Widget:
+        CheckBox:
+            id: chicken
+            active: False
+            size_hint: (None, None)
+            size: (sp(32), chicken_pizza.height)
+            on_active: app.active_chicken()
+        Label:
+            id: chicken_pizza
+            text: 'Chicken Pizza'
+            size_hint: (None, 1)
+            size: self.texture_size
+        Widget:
+    BoxLayout:
+        orientation: 'horizontal'
+        Widget:
+        CheckBox:
+            id: vegan
+            active: False
+            size_hint: (None, None)
+            size: (sp(32), vegan_pizza.height)
+            on_active: app.active_vegan()
+        Label:
+            id: vegan_pizza
+            text: 'Vegan Pizza'
+            size_hint: (None, 1)
+            size: self.texture_size
+        Widget:
+    BoxLayout:
+        orientation: 'horizontal'
+        Label:
+            text: 'Extra pizza sauces'
+            font: '32sp'
+        Slider:
+            id: slider
+            max: 100
+            min: 0
+            value_track: True
+            value_track_color: (1, 1, 1, 1)
+        Label:
+            text: 'extra sausces percent ' + (str(int(slider.value)))
+    BoxLayout:
+        orientation: 'horizontal'
+        Label:
+            text: 'Pizza Cost $' + str(app.cheese_cost + app.chicken_cost + app.vegan_cost)
+            font: '32sp'
+        Label:
+            text: 'Extra Sauces Cost $' + '2' if slider.value > 20 else 'Extra Sauces Cost $' + '0'
+            font: '32sp'
+    BoxLayout:
+        orientation: 'horizontal'
+        Label:
+            text: 'Total Cost: $' + str(app.cheese_cost + app.chicken_cost + app.vegan_cost + 2) if slider.value > 20 else 'Total Cost: $' + str(app.cheese_cost + app.chicken_cost + app.vegan_cost)
+            font: '32sp'
+
+
+