Add remove from Cart functionality

RMWPFUserInterface/ViewModels/SalesViewModel.cs

@@ -67,6 +67,17 @@ namespace RMWPFUserInterface.ViewModels
             }
         }
 
+        private CartItemDisplayModel _selectedCartItem;
+        public CartItemDisplayModel SelectedCartItem
+        {
+            get { return _selectedCartItem; }
+            set
+            {
+                _selectedCartItem = value;
+                NotifyOfPropertyChange(() => SelectedCartItem);
+                NotifyOfPropertyChange(() => CanRemoveFromCart);
+            }
+        }
 
         private BindingList<CartItemDisplayModel> _cart = new BindingList<CartItemDisplayModel>();
 
@@ -189,12 +200,27 @@ namespace RMWPFUserInterface.ViewModels
                 bool output = false;
 
                 // Make sure something is selected
+                if (SelectedCartItem != null && SelectedCartItem?.Product.QuantityInStock > 0)
+                {
+                    output = true;
+                }
 
                 return output;
             }
         }
         public void RemoveFromCart()
         {
+            SelectedCartItem.Product.QuantityInStock += 1;
+
+            if (SelectedCartItem.QuantityInCart > 1)
+            {
+                SelectedCartItem.QuantityInCart -= 1;
+            }
+            else
+            {
+                Cart.Remove(SelectedCartItem);
+            }
+
             NotifyOfPropertyChange(() => SubTotal);
             NotifyOfPropertyChange(() => Tax);
             NotifyOfPropertyChange(() => Total);

RMWPFUserInterface/Views/SalesView.xaml

@@ -66,7 +66,7 @@
         <!-- Column 2 -->
         <TextBlock Text="Cart" Grid.Row="1" Grid.Column="2"/>
         <ListBox x:Name="Cart" Grid.Row="2" Grid.Column="2" 
-                 MinHeight="200" MinWidth="150">
+                 MinHeight="200" MinWidth="150" SelectedItem="{Binding SelectedCartItem}">
             <ListBox.ItemTemplate>
                 <DataTemplate>
                     <TextBlock Text="{Binding DisplayText}"/>