Adding Multible File Support

Added the neccesary functions to support batch processing.

butterflow-ui/InverseBoolVisibilityConverter.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Data;
+
+namespace butterflow_ui
+{
+    [ValueConversion(typeof(bool), typeof(Visibility))]
+    public class InverseBoolVisibilityConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (targetType == typeof(Visibility))
+            {
+                return (bool)value ? Visibility.Hidden : Visibility.Visible;
+            }
+
+            throw new InvalidCastException(string.Format("Cannot convert type to {0} from bool.", targetType.Name));
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (targetType == typeof(Visibility))
+            {
+                return ((Visibility)value == Visibility.Visible) ? false : true;
+            }
+
+            throw new InvalidCastException(string.Format("Cannot convert type {0} to boolean.", targetType.Name));
+        }
+    }
+}