From b618f509ad2770ca16f3739842081c5fe161e0b7 Mon Sep 17 00:00:00 2001
From: neuecc <ils@neue.cc>
Date: Thu, 26 Aug 2021 20:13:42 +0900
Subject: [PATCH] v

---
 .../ObservableRingBuffer.Views.cs             | 61 +++++++++----------
 .../ObservableRingBuffer.cs                   | 19 ++++++
 2 files changed, 49 insertions(+), 31 deletions(-)

diff --git a/src/ObservableCollections/ObservableRingBuffer.Views.cs b/src/ObservableCollections/ObservableRingBuffer.Views.cs
index 9811569..77b7481 100644
--- a/src/ObservableCollections/ObservableRingBuffer.Views.cs
+++ b/src/ObservableCollections/ObservableRingBuffer.Views.cs
@@ -155,43 +155,40 @@ namespace ObservableCollections
                             }
                             break;
                         case NotifyCollectionChangedAction.Remove:
-                            if (e.IsSingleItem)
+                            // starting from 0 is RemoveFirst
+                            if (e.OldStartingIndex == 0)
                             {
-                                var v = ringBuffer[e.OldStartingIndex];
-                                ringBuffer.RemoveAt(e.OldStartingIndex);
-                                filter.InvokeOnRemove(v.Item1, v.Item2);
+                                // RemoveFirst
+                                if (e.IsSingleItem)
+                                {
+                                    var v = ringBuffer.RemoveFirst();
+                                    filter.InvokeOnRemove(v);
+                                }
+                                else
+                                {
+                                    for (int i = 0; i < e.OldItems.Length; i++)
+                                    {
+                                        var v = ringBuffer.RemoveFirst();
+                                        filter.InvokeOnRemove(v);
+                                    }
+                                }
                             }
                             else
                             {
-                                var len = e.OldStartingIndex + e.OldItems.Length;
-                                for (int i = e.OldStartingIndex; i < len; i++)
+                                // RemoveLast
+                                if (e.IsSingleItem)
                                 {
-                                    var v = ringBuffer[i];
-                                    filter.InvokeOnRemove(v.Item1, v.Item2);
+                                    var v = ringBuffer.RemoveLast();
+                                    filter.InvokeOnRemove(v);
+                                }
+                                else
+                                {
+                                    for (int i = 0; i < e.OldItems.Length; i++)
+                                    {
+                                        var v = ringBuffer.RemoveLast();
+                                        filter.InvokeOnRemove(v);
+                                    }
                                 }
-
-                                ringBuffer.RemoveRange(e.OldStartingIndex, e.OldItems.Length);
-                            }
-                            break;
-                        case NotifyCollectionChangedAction.Replace:
-                            // ObservableList does not support replace range
-                            {
-                                var v = (e.NewItem, selector(e.NewItem));
-
-                                var oldItem = ringBuffer[e.NewStartingIndex];
-                                ringBuffer[e.NewStartingIndex] = v;
-
-                                filter.InvokeOnRemove(oldItem);
-                                filter.InvokeOnAdd(v);
-                                break;
-                            }
-                        case NotifyCollectionChangedAction.Move:
-                            {
-                                var removeItem = ringBuffer[e.OldStartingIndex];
-                                ringBuffer.RemoveAt(e.OldStartingIndex);
-                                ringBuffer.Insert(e.NewStartingIndex, removeItem);
-
-                                filter.InvokeOnMove(removeItem);
                             }
                             break;
                         case NotifyCollectionChangedAction.Reset:
@@ -204,6 +201,8 @@ namespace ObservableCollections
                             }
                             ringBuffer.Clear();
                             break;
+                        case NotifyCollectionChangedAction.Replace:
+                        case NotifyCollectionChangedAction.Move:
                         default:
                             break;
                     }
diff --git a/src/ObservableCollections/ObservableRingBuffer.cs b/src/ObservableCollections/ObservableRingBuffer.cs
index 13eea04..78997af 100644
--- a/src/ObservableCollections/ObservableRingBuffer.cs
+++ b/src/ObservableCollections/ObservableRingBuffer.cs
@@ -160,8 +160,27 @@ namespace ObservableCollections
                     CollectionChanged?.Invoke(NotifyCollectionChangedEventArgs<T>.Add(value, buffer.Count - 1));
                 }
             }
+        }
 
+        public void AddLastRange(T[] values)
+        {
+            lock (SyncRoot)
+            {
+                if (buffer.Count + values.Length -1 == fixedSize)
+                {
+                    for (int i = 0; i < values.Length; i++)
+                    {
+                        buffer.RemoveFirst(); // removes...
+                    }
+                    for (int i = 0; i < values.Length; i++)
+                    {
+                        buffer.AddLast(values[i]);
+                    }
 
+                    // Remove...
+                }
+
+            }
         }
     }
 }