Implement progress reporting when downloading messages (#57)

DiscordChatExporter.Gui/ViewModels/IMainViewModel.cs

@@ -9,6 +9,9 @@ namespace DiscordChatExporter.Gui.ViewModels
         bool IsBusy { get; }
         bool IsDataAvailable { get; }
 
+        bool IsProgressIndeterminate { get; }
+        double Progress { get; }
+
         string Token { get; set; }
 
         IReadOnlyList<Guild> AvailableGuilds { get; }

DiscordChatExporter.Gui/ViewModels/MainViewModel.cs

@@ -25,6 +25,7 @@ namespace DiscordChatExporter.Gui.ViewModels
         private readonly Dictionary<Guild, IReadOnlyList<Channel>> _guildChannelsMap;
 
         private bool _isBusy;
+        private double _progress;
         private string _token;
         private IReadOnlyList<Guild> _availableGuilds;
         private Guild _selectedGuild;
@@ -43,6 +44,18 @@ namespace DiscordChatExporter.Gui.ViewModels
 
         public bool IsDataAvailable => AvailableGuilds.NotNullAndAny();
 
+        public bool IsProgressIndeterminate => Progress <= 0;
+
+        public double Progress
+        {
+            get => _progress;
+            private set
+            {
+                Set(ref _progress, value);
+                RaisePropertyChanged(() => IsProgressIndeterminate);
+            }
+        }
+
         public string Token
         {
             get => _token;
@@ -225,10 +238,13 @@ namespace DiscordChatExporter.Gui.ViewModels
             // Get guild
             var guild = SelectedGuild;
 
+            // Create progress handler
+            var progressHandler = new Progress<double>(p => Progress = p);
+
             try
             {
                 // Get messages
-                var messages = await _dataService.GetChannelMessagesAsync(token, channel.Id, from, to);
+                var messages = await _dataService.GetChannelMessagesAsync(token, channel.Id, from, to, progressHandler);
 
                 // Group messages
                 var messageGroups = _messageGroupService.GroupMessages(messages);
@@ -253,6 +269,7 @@ namespace DiscordChatExporter.Gui.ViewModels
                 MessengerInstance.Send(new ShowNotificationMessage("You don't have access to this channel"));
             }
 
+            Progress = 0;
             IsBusy = false;
         }
     }

DiscordChatExporter.Gui/Views/MainWindow.xaml

@@ -98,7 +98,8 @@
                     <!--  Progress bar  -->
                     <ProgressBar
                         Background="Transparent"
-                        IsIndeterminate="True"
+                        IsIndeterminate="{Binding IsProgressIndeterminate}"
+                        Value="{Binding Progress, Mode=OneWay}"
                         Visibility="{Binding IsBusy, Converter={StaticResource BoolToVisibilityConverter}}" />
                 </StackPanel>
             </Border>