Improve performance of check box dialogs by using ItemsRepeater instead of ItemsControl

Closes #181

README.md

@@ -51,3 +51,5 @@ Run the `app/build.sh` script, and read the [Distribution](#distribution) sectio
 #### Distribution
 
 The mentioned build scripts will prepare `Release` builds ready for distribution. Once the script finishes, the `app/bin` folder will contain self-contained executables for each major operating system, and a portable version that works on all other systems but requires .NET 5 to be installed.
+
+Note that when building on Windows, the generated `.zip` files for Linux and Mac will not have correct file permissions, so it will not be possible to run them by double-clicking `DiscordHistoryTracker`. I tried using Python to re-create the archives with correct file permissions, but found that Linux `zip` tools could not see them. The only working solution is building the Windows + portable version on Windows, and Linux + Mac version on Linux.

app/Desktop/Dialogs/CheckBox/CheckBoxDialog.axaml

@@ -34,8 +34,8 @@
 
     <StackPanel Margin="20">
         <ScrollViewer MaxHeight="400">
-            <ItemsControl Items="{Binding Items}">
-                <ItemsControl.ItemTemplate>
+            <ItemsRepeater Items="{Binding Items}">
+                <ItemsRepeater.ItemTemplate>
                     <DataTemplate>
                         <CheckBox IsChecked="{Binding Checked}">
                             <Label>
@@ -43,8 +43,8 @@
                             </Label>
                         </CheckBox>
                     </DataTemplate>
-                </ItemsControl.ItemTemplate>
-            </ItemsControl>
+                </ItemsRepeater.ItemTemplate>
+            </ItemsRepeater>
         </ScrollViewer>
         <Panel Classes="buttons">
             <WrapPanel Classes="left">

app/Resources/Tracker/styles/controller.css

@@ -1,4 +1,4 @@
-#app-mount > div[class*="app-"] {
+#app-mount div[class*="app-"] {
   margin-bottom: 48px !important;
 }
 
@@ -8,6 +8,7 @@
   width: 100%;
   height: 48px;
   background-color: #fff;
+  z-index: 1000000;
 }
 
 #dht-ctrl button {

app/Resources/Tracker/styles/settings.css

@@ -7,7 +7,7 @@
   background-color: #000;
   opacity: 0.5;
   display: block;
-  z-index: 1000;
+  z-index: 1000001;
 }
 
 #dht-cfg {
@@ -20,7 +20,7 @@
   margin-top: -131px;
   padding: 8px;
   background-color: #fff;
-  z-index: 1001;
+  z-index: 1000002;
 }
 
 #dht-cfg-note {

app/Server/Endpoints/TrackMessagesEndpoint.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Net;
 using System.Text.Json;
@@ -8,6 +9,7 @@ using DHT.Server.Data;
 using DHT.Server.Data.Filters;
 using DHT.Server.Database;
 using DHT.Server.Service;
+using DHT.Utils.Collections;
 using DHT.Utils.Http;
 using Microsoft.AspNetCore.Http;
 
@@ -53,12 +55,16 @@ namespace DHT.Server.Endpoints {
 			Reactions = json.HasKey("reactions") ? ReadReactions(json.RequireArray("reactions", path + ".reactions"), path + ".reactions[]").ToImmutableArray() : ImmutableArray<Reaction>.Empty
 		};
 
+		[SuppressMessage("ReSharper", "ConvertToLambdaExpression")]
 		private static IEnumerable<Attachment> ReadAttachments(JsonElement.ArrayEnumerator array, string path) => array.Select(ele => new Attachment {
 			Id = ele.RequireSnowflake("id", path),
 			Name = ele.RequireString("name", path),
 			Type = ele.HasKey("type") ? ele.RequireString("type", path) : null,
 			Url = ele.RequireString("url", path),
 			Size = (ulong) ele.RequireLong("size", path)
+		}).DistinctByKeyStable(static attachment => {
+			// Some Discord messages have duplicate attachments with the same id for unknown reasons.
+			return attachment.Id;
 		});
 
 		private static IEnumerable<Embed> ReadEmbeds(JsonElement.ArrayEnumerator array, string path) => array.Select(ele => new Embed {

app/Utils/Collections/LinqExtensions.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+
+namespace DHT.Utils.Collections {
+	public static class LinqExtensions {
+		public static IEnumerable<TItem> DistinctByKeyStable<TItem, TKey>(this IEnumerable<TItem> collection, Func<TItem, TKey> getKeyFromItem) where TKey : IEquatable<TKey> {
+			HashSet<TKey>? seenKeys = null;
+			
+			foreach (var item in collection) {
+				seenKeys ??= new HashSet<TKey>();
+				
+				if (seenKeys.Add(getKeyFromItem(item))) {
+					yield return item;
+				}
+			}
+		}
+	}
+}

app/Version.cs

@@ -7,6 +7,6 @@ using DHT.Utils;
 
 namespace DHT.Utils {
 	static class Version {
-		public const string Tag = "35.1.0.0";
+		public const string Tag = "35.3.0.0";
 	}
 }