fix path

QuickLook.Common/ExtensionMethods/FileExtensions.cs

@@ -0,0 +1,48 @@
+// Copyright © 2017 Paddy Xu
+// 
+// This file is part of QuickLook program.
+// 
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+using System;
+
+namespace QuickLook.Common.ExtensionMethods
+{
+    public static class FileExtensions
+    {
+        public static string ToPrettySize(this long value, int decimalPlaces = 0)
+        {
+            const long OneKb = 1024;
+            const long OneMb = OneKb * 1024;
+            const long OneGb = OneMb * 1024;
+            const long OneTb = OneGb * 1024;
+
+            var asTb = Math.Round((double) value / OneTb, decimalPlaces);
+            var asGb = Math.Round((double) value / OneGb, decimalPlaces);
+            var asMb = Math.Round((double) value / OneMb, decimalPlaces);
+            var asKb = Math.Round((double) value / OneKb, decimalPlaces);
+            var chosenValue = asTb > 1
+                ? $"{asTb} TB"
+                : asGb > 1
+                    ? $"{asGb} GB"
+                    : asMb > 1
+                        ? $"{asMb} MB"
+                        : asKb > 1
+                            ? $"{asKb} KB"
+                            : $"{Math.Round((double) value, decimalPlaces)} bytes";
+
+            return chosenValue;
+        }
+    }
+}