adjust UI

Gallery.Share/Services/GalleryCollection.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using Gallery.Resources.UI;
+using Gallery.Util.Model;
+using Xamarin.Essentials;
+
+namespace Gallery.Services
+{
+    public class GalleryCollection : List<GalleryItem>, ICollectionChanged
+    {
+        private static GalleryCollection empty;
+
+        public static GalleryCollection Empty
+        {
+            get
+            {
+                if (empty == null)
+                {
+                    empty = new GalleryCollection();
+                }
+                return empty;
+            }
+        }
+
+        public event EventHandler<CollectionChangedEventArgs> CollectionChanged;
+
+        public bool Running { get; set; }
+
+        public GalleryCollection() : base()
+        {
+            Running = true;
+        }
+
+        public GalleryCollection(IEnumerable<GalleryItem> gallery) : base(gallery)
+        {
+            Running = true;
+        }
+
+        public void AddRange(List<GalleryItem> items)
+        {
+            var e = new CollectionChangedEventArgs
+            {
+                NewStartingIndex = Count,
+                NewItems = items
+            };
+            base.AddRange(items);
+            if (MainThread.IsMainThread)
+            {
+                CollectionChanged?.Invoke(this, e);
+            }
+            else
+            {
+                MainThread.BeginInvokeOnMainThread(() => CollectionChanged?.Invoke(this, e));
+            }
+        }
+    }
+}

Gallery.Share/Services/IDataStore.cs

@@ -1,15 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-
-namespace Gallery.Services
-{
-    public interface IDataStore<T>
-    {
-        Task<bool> AddItemAsync(T item);
-        Task<bool> UpdateItemAsync(T item);
-        Task<bool> DeleteItemAsync(string id);
-        Task<T> GetItemAsync(string id);
-        Task<IEnumerable<T>> GetItemsAsync(bool forceRefresh = false);
-    }
-}

Gallery.Share/Services/MockDataStore.cs

@@ -1,60 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using Gallery.Models;
-
-namespace Gallery.Services
-{
-    public class MockDataStore : IDataStore<Item>
-    {
-        readonly List<Item> items;
-
-        public MockDataStore()
-        {
-            items = new List<Item>()
-            {
-                new Item { Id = Guid.NewGuid().ToString(), Text = "First item", Description="This is an item description." },
-                new Item { Id = Guid.NewGuid().ToString(), Text = "Second item", Description="This is an item description." },
-                new Item { Id = Guid.NewGuid().ToString(), Text = "Third item", Description="This is an item description." },
-                new Item { Id = Guid.NewGuid().ToString(), Text = "Fourth item", Description="This is an item description." },
-                new Item { Id = Guid.NewGuid().ToString(), Text = "Fifth item", Description="This is an item description." },
-                new Item { Id = Guid.NewGuid().ToString(), Text = "Sixth item", Description="This is an item description." }
-            };
-        }
-
-        public async Task<bool> AddItemAsync(Item item)
-        {
-            items.Add(item);
-
-            return await Task.FromResult(true);
-        }
-
-        public async Task<bool> UpdateItemAsync(Item item)
-        {
-            var oldItem = items.Where((Item arg) => arg.Id == item.Id).FirstOrDefault();
-            items.Remove(oldItem);
-            items.Add(item);
-
-            return await Task.FromResult(true);
-        }
-
-        public async Task<bool> DeleteItemAsync(string id)
-        {
-            var oldItem = items.Where((Item arg) => arg.Id == id).FirstOrDefault();
-            items.Remove(oldItem);
-
-            return await Task.FromResult(true);
-        }
-
-        public async Task<Item> GetItemAsync(string id)
-        {
-            return await Task.FromResult(items.FirstOrDefault(s => s.Id == id));
-        }
-
-        public async Task<IEnumerable<Item>> GetItemsAsync(bool forceRefresh = false)
-        {
-            return await Task.FromResult(items);
-        }
-    }
-}