Alpha Release

src/API/Discord.API/Rest/IChannelService.cs

@@ -11,6 +11,9 @@ internal interface IChannelService
         [Get("/v9/channels/{channelId}/messages?limit={limit}")]
         Task<JsonMessage[]> GetChannelMessages([AliasAs("channelId")] ulong channelId, [AliasAs("limit")] int limit = 50);
 
+        [Get("/v9/channels/{channelId}/messages?limit={limit}&before={before}")]
+        Task<JsonMessage[]> GetChannelMessagesBefore([AliasAs("channelId")] ulong channelId, [AliasAs("before")] ulong before, [AliasAs("limit")] int limit = 50);
+
         [Post("/v9/channels/{channelId}/messages")]
         Task<JsonMessage> CreateMessage([AliasAs("channelId")] ulong channelId, [Body] JsonMessageUpsert message);
     }

src/Libs/Quarrel.Markdown/Rendering/Elements/BlockQuoteElement.cs

@@ -1,8 +1,6 @@
 // Quarrel © 2022
 
 using Quarrel.Markdown.Parsing;
-using Windows.UI.Xaml.Controls;
-using Windows.UI.Xaml.Documents;
 
 namespace Quarrel.Markdown
 {

src/Libs/Quarrel.Markdown/Rendering/Elements/InlineCodeElement.cs

@@ -1,7 +1,5 @@
 // Quarrel © 2022
 
-using Quarrel.Markdown.Parsing;
-using Windows.UI;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Media;

src/Libs/Quarrel.Markdown/Rendering/Elements/UserMentionElement.cs

@@ -31,9 +31,9 @@ internal UserMentionElement(UserMention mention, BindableMessage? context) : bas
 
         }
 
-        public BindableUser User
+        public BindableUser? User
         {
-            get => (BindableUser)GetValue(UserProperty);
+            get => (BindableUser?)GetValue(UserProperty);
             set => SetValue(UserProperty, value);
         }
 

src/Libs/Quarrel.Markdown/Rendering/MessageRenderer.Properties.cs

@@ -92,13 +92,6 @@ public Style? UserMentionStyle
         private static void OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
             var messageRenderer = (MessageRenderer)d;
-
-            if (messageRenderer.Context is null)
-            {
-                // TODO: Allow context free rendering
-                return;
-            }
-
             var tree = Parser.ParseAST(messageRenderer.Text, true, false);
             var modTree = AdjustTree(tree);
             messageRenderer.RenderMarkdown(modTree);

src/Libs/Quarrel.Markdown/Rendering/MessageRenderer.cs

@@ -217,7 +217,6 @@ private void UpdateOverlays()
 
         private void RenderMarkdown(IList<ASTRoot> tree)
         {
-
             if (_richBlock != null)
             {
                 _richBlock.SizeChanged -= RichBlock_SizeChanged;

src/Quarrel.Client/QuarrelClient.Methods.cs

@@ -41,11 +41,19 @@ public partial class QuarrelClient
         /// Gets messages in a channel.
         /// </summary>
         /// <param name="channelId">The channel's id.</param>
-        public async Task<Message[]> GetMessagesAsync(ulong channelId, ulong? guildId = null)
+        /// <param name="guildId">The id of the guild the channel belongs to.</param>
+        /// <param name="beforeId">The message to get the messages from before.</param>
+        public async Task<Message[]> GetMessagesAsync(ulong channelId, ulong? guildId = null, ulong? beforeId = null)
         {
             Guard.IsNotNull(_channelService, nameof(_channelService));
 
-            JsonMessage[]? jsonMessages = await MakeRefitRequest(() => _channelService.GetChannelMessages(channelId));
+            Func<Task<JsonMessage[]>> request = () => _channelService.GetChannelMessages(channelId);
+            if (beforeId.HasValue)
+            {
+                request = () => _channelService.GetChannelMessagesBefore(channelId, beforeId.Value);
+            }
+
+            JsonMessage[]? jsonMessages = await MakeRefitRequest(request);
             Guard.IsNotNull(jsonMessages, nameof(jsonMessages));
 
             Message[] messages = new Message[jsonMessages.Length];

src/Quarrel.ViewModels/Bindables/Messages/BindableMessage.cs

@@ -6,7 +6,6 @@
 using Quarrel.Bindables.Messages.Embeds;
 using Quarrel.Bindables.Users;
 using Quarrel.Client.Models.Messages;
-using Quarrel.Client.Models.Messages.Embeds;
 using Quarrel.Messages.Discord.Messages;
 using Quarrel.Services.Discord;
 using Quarrel.Services.Dispatcher;
@@ -66,7 +65,7 @@ internal BindableMessage(
             {
                 if (Id == e.Message.Id)
                 {
-                    Message = e.Message;
+                    _dispatcherService.RunOnUIThread(() => Message = e.Message);
                 }
             });
 
@@ -88,7 +87,7 @@ public Message Message
             set
             {
                 SetProperty(ref _message, value);
-                _dispatcherService.RunOnUIThread(AckUpdate);
+                AckUpdate();
             }
         }
 

src/Quarrel.ViewModels/Extensions/System.Collections.ObjectModel/ObservableRangeCollection.cs

@@ -78,7 +78,10 @@ public void InsertRange(int index, IEnumerable<T> collection, NotifyCollectionCh
             OnPropertyChanged(new PropertyChangedEventArgs("Item[]"));
             if (changedItems.Count > 0)
             {
-                OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, changedItems, index));
+                for (int i = changedItems.Count-1; i >= 0; i--)
+                {
+                    OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, new List<T>{ changedItems[i] }, index));
+                }
             }
         }
 

src/Quarrel.ViewModels/Services/Discord/DiscordService.Methods.cs

@@ -74,9 +74,9 @@ public BindableGuildFolder[] GetMyGuildFolders()
         }
 
         /// <inheritdoc/>
-        public async Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel)
+        public async Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel, ulong? beforeId = null)
         {
-            var rawMessages = await _quarrelClient.GetMessagesAsync(channel.Id, channel.GuildId);
+            var rawMessages = await _quarrelClient.GetMessagesAsync(channel.Id, channel.GuildId, beforeId);
             Guard.IsNotNull(rawMessages, nameof(rawMessages));
             return rawMessages;
         }

src/Quarrel.ViewModels/Services/Discord/IDiscordService.cs

@@ -50,13 +50,14 @@ public interface IDiscordService
         /// </remarks>
         /// <returns>The array of <see cref="BindableGuildFolder"/>s that the current user has.</returns>
         BindableGuildFolder[] GetMyGuildFolders();
-        
+
         /// <summary>
         /// Gets the messages in a channel.
         /// </summary>
         /// <param name="channel">The channel to get the messages for.</param>
+        /// <param name="beforeId">The if of the last message to load messages before, or null.</param>
         /// <returns>An array of <see cref="BindableMessage"/>s from the channel.</returns>
-        Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel);
+        Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel, ulong? beforeId = null);
 
         /// <summary>
         /// Gets the channels in a guild.

src/Quarrel.ViewModels/ViewModels/Panels/MessagesViewModel.cs

@@ -11,6 +11,7 @@
 using Quarrel.Services.Discord;
 using Quarrel.Services.Dispatcher;
 using System.Collections.ObjectModel;
+using System.Threading;
 
 namespace Quarrel.ViewModels.Panels
 {
@@ -24,6 +25,7 @@ public partial class MessagesViewModel : ObservableRecipient
         private readonly IDispatcherService _dispatcherService;
 
         private bool _isLoading;
+        private SemaphoreSlim _semaphore;
         private IBindableSelectableChannel? _selectedChannel;
 
         /// <summary>
@@ -34,17 +36,16 @@ public MessagesViewModel(IMessenger messenger, IDiscordService discordService, I
             _messenger = messenger;
             _discordService = discordService;
             _dispatcherService = dispatcherService;
+            _semaphore = new SemaphoreSlim(1,1);
 
             Source = new ObservableRangeCollection<BindableMessage>();
             IsLoading = false;
 
             _messenger.Register<NavigateToChannelMessage<IBindableSelectableChannel>>(this, (_, m) => SelectedChannel = m.Channel);
             _messenger.Register<MessageCreatedMessage>(this, (_, m) =>
             {
-                if (SelectedChannel?.Id == m.Message.ChannelId)
-                {
-                    AppendMessage(m.Message);
-                }
+                if (SelectedChannel?.Id != m.Message.ChannelId) return;
+                _dispatcherService.RunOnUIThread(() => AppendMessage(m.Message));
             });
         }
 
@@ -60,7 +61,7 @@ public IBindableSelectableChannel? SelectedChannel
             {
                 if (SetProperty(ref _selectedChannel, value))
                 {
-                    LoadChannel(value);
+                    LoadChannel();
                 }
             }
         }
@@ -74,47 +75,93 @@ public bool IsLoading
             private set => SetProperty(ref _isLoading, value);
         }
 
-        private void LoadChannel(IBindableSelectableChannel? channel)
+        /// <remarks>
+        /// Must be called on the UI thread.
+        /// </remarks>
+        public async void LoadOlderMessages()
         {
-            if (channel is IBindableMessageChannel messageChannel)
+            if (Source.Count == 0) return;
+            if (IsLoading) return;
+            await _semaphore.WaitAsync();
+            IsLoading = true;
+            try
+            {
+                ulong beforeId = Source[0].Message.Id;
+                IBindableMessageChannel? channel = SelectedChannel as IBindableMessageChannel;
+                Guard.IsNotNull(channel, nameof(channel));
+
+                // Load messages
+                var messages = await _discordService.GetChannelMessagesAsync(channel, beforeId);
+                if (messages.Length > 0)
+                {
+                    var bindableMessages = ParseMessages(messages);
+
+                    // Add messages to the UI and mark loading as finished
+                    Source.InsertRange(0, bindableMessages);
+                }
+            }
+            finally
             {
-                LoadInitialMessages(messageChannel);
+                IsLoading = false;
+                _semaphore.Release();
             }
         }
 
-        private void LoadInitialMessages(IBindableMessageChannel? channel)
+        /// <remarks>
+        /// Must be called on the UI thread.
+        /// </remarks>
+        private async void LoadInitialMessages()
         {
-            Guard.IsNotNull(channel, nameof(channel));
-            _dispatcherService.RunOnUIThread(async () =>
+            await _semaphore.WaitAsync();
+            try
             {
+                IBindableMessageChannel? channel = SelectedChannel as IBindableMessageChannel;
+                Guard.IsNotNull(channel, nameof(channel));
                 // Clear the messages and begin loading
                 Source.Clear();
-                IsLoading = true;
 
                 // Load messages
+                IsLoading = true;
                 var messages = await _discordService.GetChannelMessagesAsync(channel);
-                BindableMessage[] bindableMessages = new BindableMessage[messages.Length];
-                if (bindableMessages.Length > 0)
-                {
-                    bindableMessages[0] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1]);
-                    for (int i = 1; i < messages.Length; i++)
-                    {
-                        bindableMessages[i] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1 - i], messages[messages.Length - i]);
-                    }
-                }
+                var bindableMessages = ParseMessages(messages);
 
                 // Add messages to the UI and mark loading as finished
                 Source.AddRange(bindableMessages);
                 IsLoading = false;
-            });
+            }
+            finally
+            {
+                _semaphore.Release();
+            }
         }
 
-        private void AppendMessage(Message message)
+        private void LoadChannel()
         {
-            _dispatcherService.RunOnUIThread(() =>
+            if (SelectedChannel is IBindableMessageChannel)
             {
-                Source.Add(new BindableMessage(_messenger, _discordService, _dispatcherService, message, Source.Count > 0 ? Source[Source.Count-1].Message : null));
-            });
+                LoadInitialMessages();
+            }
+        }
+
+        private BindableMessage[] ParseMessages(Message[] messages)
+        {
+            BindableMessage[] bindableMessages = new BindableMessage[messages.Length];
+            if (bindableMessages.Length == 0) return bindableMessages;
+
+            bindableMessages[0] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1]);
+            for (int i = 1; i < messages.Length; i++)
+            {
+                bindableMessages[i] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1 - i], messages[messages.Length - i]);
+            }
+            return bindableMessages;
+        }
+
+        /// <remarks>
+        /// Must be called on the UI thread.
+        /// </remarks>
+        private void AppendMessage(Message message)
+        {
+            Source.Add(new BindableMessage(_messenger, _discordService, _dispatcherService, message, Source.Count > 0 ? Source[Source.Count - 1].Message : null));
         }
     }
 }

src/Quarrel/Controls/Panels/Messages/MessagePanel.xaml

@@ -27,7 +27,8 @@
         <ListView ItemsSource="{x:Bind ViewModel.Source}"
                   ItemTemplateSelector="{StaticResource MessageTemplateSelector}"
                   ItemContainerStyle="{StaticResource MessageListItemStyle}"
-                  ShowsScrollingPlaceholders="False">
+                  ShowsScrollingPlaceholders="False"
+                  Loaded="ListView_Loaded">
             <ListView.Header>
                 <ProgressBar IsIndeterminate="True" Visibility="{x:Bind ViewModel.IsLoading, Mode=OneWay}"/>
             </ListView.Header>

src/Quarrel/Controls/Panels/Messages/MessagePanel.xaml.cs

@@ -1,19 +1,46 @@
 // Quarrel © 2022
 
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Toolkit.Uwp.UI;
 using Quarrel.ViewModels.Panels;
+using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 
 namespace Quarrel.Controls.Panels.Messages
 {
     public sealed partial class MessagePanel : UserControl
     {
+        private const double ScrollPadding = 100;
+
         public MessagePanel()
         {
             this.InitializeComponent();
             DataContext = App.Current.Services.GetRequiredService<MessagesViewModel>();
         }
 
         public MessagesViewModel ViewModel => (MessagesViewModel)DataContext;
+
+        private void ListView_Loaded(object sender, RoutedEventArgs e)
+        {
+            ListView messageList = (ListView)sender;
+            var scrollViewer = messageList.FindDescendant<ScrollViewer>();
+            scrollViewer.ViewChanged += OnViewChanged;
+        }
+
+        private void OnViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
+        {
+            var viewer = (ScrollViewer)sender;
+            if (viewer.VerticalOffset <= ScrollPadding)
+            {
+                if (!ViewModel.IsLoading)
+                {
+                    ViewModel.LoadOlderMessages();
+                }
+            }
+            else if (viewer.VerticalOffset >= viewer.ScrollableHeight - ScrollPadding)
+            {
+                // TODO: Scrolled to bottom
+            }
+        }
     }
 }

src/Quarrel/Controls/Shell/QuarrelCommandBar.xaml

@@ -8,6 +8,7 @@
     xmlns:qc="using:Quarrel.Controls"
     xmlns:bchannel="using:Quarrel.Bindables.Channels"
     xmlns:cselector="using:Quarrel.Selectors.Channels"
+    xmlns:cconvert="using:Quarrel.Converters.Discord.Channels"
     xmlns:vconvert="using:Quarrel.Converters.Common.Visible"
     mc:Ignorable="d"
     Background="Transparent"
@@ -80,7 +81,8 @@
             <Button x:Uid="CommandBar/CallBTN"
                     ToolTipService.ToolTip="Call"
                     ToolTipService.Placement="Bottom"
-                    Style="{StaticResource CommandBarButton}">
+                    Style="{StaticResource CommandBarButton}"
+                    Visibility="{x:Bind cconvert:IsPrivateChannelVisibleConverter.Convert(ViewModel.SelectedChannel), Mode=OneWay}">
                 <FontIcon Glyph="&#xE13A;" FontSize="16"/>
             </Button>