Use Signal-Android's method of determining user color

Author: golf1052

Signal-Windows/Storage/DB.cs

@@ -1130,7 +1130,7 @@ public static SignalContact GetOrCreateContactLocked(string username, long times
                             ThreadDisplayName = username,
                             CanReceive = true,
                             LastActiveTimestamp = timestamp,
-                            Color = Utils.Colors[Utils.CalculateDefaultColorIndex(username)]
+                            Color = Utils.CalculateDefaultColor(username)
                         };
                         ctx.Contacts.Add(contact);
                         ctx.SaveChanges();

Signal-Windows/Utils.cs

@@ -94,19 +94,27 @@ public static void AddRange<T>(this ObservableCollection<T> observableCollection
             }
         }
 
-        public static int CalculateDefaultColorIndex(string title)
+        public static string CalculateDefaultColor(string title)
         {
-            if (title.Length == 0)
-            {
-                return 0;
-            }
-            var hash = 0;
-            for (int i = 0; i < title.Length; i++)
+            return Colors[Math.Abs(JavaStringHashCode(title)) % Colors.Length];
+        }
+
+        public static SolidColorBrush GetDefaultColor(string title)
+        {
+            return GetBrushFromColor(CalculateDefaultColor(title));
+        }
+
+        public static int JavaStringHashCode(string str)
+        {
+            int h = 0;
+            if (str.Length > 0)
             {
-                hash = ((hash << 5) - hash) + title[i];
-                hash = hash & hash;
+                for (int i = 0; i < str.Length; i++)
+                {
+                    h = 31 * h + str[i];
+                }
             }
-            return Math.Abs(hash) % 15;
+            return h;
         }
 
         public static void EnableBackButton()
@@ -949,4 +957,4 @@ public static class CountryArrays
             "ZW"
         };
     };
-}
+}

Signal-Windows/ViewModels/AddContactPageViewModel.cs

@@ -316,7 +316,7 @@ private async Task AddContact(string name, string number)
                 AvatarFile = null,
                 LastActiveTimestamp = 0,
                 Draft = null,
-                Color = "red",
+                Color = Utils.CalculateDefaultColor(name),
                 UnreadCount = 0
             };
             await Task.Run(() =>
@@ -337,4 +337,4 @@ private string ParsePhoneNumber(string number)
             return phoneNumberUtil.Format(phoneNumber, PhoneNumberFormat.E164);
         }
     }
-}
+}