Enhance Watcher functionality with cancellation support

Iridium-IO · Iridium-IO · commit f1962269dfaa · 2025-07-16T17:03:39.000+10:00
- Added cancellation tokens to `RunWatcher` and `ParseWatchers` methods in the `Watcher` class for improved operation management.
- Introduced `_isRunning` property to track the running state and manage folder monitoring.
- Updated `Analyse` method to support cancellation during file analysis.
- Implemented `CancelBackgrounding` method in `WatcherViewModel` for cancelling background compaction and updating the UI.
- Improved XAML layout in `FolderWatcherCard` with new buttons for user interaction.
- Updated `Application` class for better service initialization and multi-instance handling.
- Enhanced `WatcherViewModel` with commands for running the watcher and cancelling operations, improving UI responsiveness.
- Moved host initialisation to the OnStartup() of Application.vb to avoid unecessary instantiation when opening CompactGUI while an instance is already running
diff --git a/CompactGUI.Watcher/Watcher.vb b/CompactGUI.Watcher/Watcher.vb
@@ -50,11 +50,11 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
         _logger = logger
         _settingsService = settingsService
         _DataFolder = settingsService.DataFolder
+
         WatcherJSONFile = New IO.FileInfo(IO.Path.Combine(_DataFolder.FullName, "watcher.json"))
 
         IdleSettings = New IdleSettings
         _idleDetector = idleDetector
-
         WatcherLog.WatcherStarted(logger)
         IsActive = True
 
@@ -66,10 +66,6 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
         BGCompactor = New BackgroundCompactor(Array.Empty(Of String), _logger)
 
 
-        AddHandler BGCompactor.IsCompactingEvent, Sub(sender, isCompacting)
-                                                      CancelBackgroundingCommand.NotifyCanExecuteChanged()
-                                                  End Sub
-
         InitializeWatchedFoldersAsync()
 
 
@@ -92,39 +88,50 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
 
     End Sub
 
-    <RelayCommand>
-    Public Async Function RunWatcher() As Task(Of Boolean)
-        Return Await RunWatcher(True)
-    End Function
 
-    Public Async Function RunWatcher(Optional runAll As Boolean = True) As Task(Of Boolean)
+
+    <ObservableProperty> Private _isRunning As Boolean = False
+
+    Public Async Function RunWatcher(Optional runAll As Boolean = True, Optional cToken As CancellationToken = Nothing) As Task(Of Boolean)
         RemoveHandler _idleDetector.IsIdle, _idleHandler
 
-        Trace.WriteLine("Watcher: RunWatcher called")
+        IsRunning = True
+
         For Each watcher In WatchedFolders
             watcher.PauseMonitoring()
         Next
 
         Try
-            Dim now = DateTime.Now
-            If Not IsWatchingEnabled Then Return False
-            Dim recentThresholdDate As DateTime = DateTime.Now.AddSeconds(-IdleSettings.LastSystemModifiedTimeThresholdSeconds)
-            If Not runAll AndAlso WatchedFolders.Any(Function(x) x.LastChangedDate > recentThresholdDate) Then Return False
+            Await Task.Run(Async Function()
+                               _settingsService.AppSettings.ScheduledBackgroundLastRan = DateTime.Now
+                               If Not IsWatchingEnabled Then Return False
+                               Dim recentThresholdDate As DateTime = DateTime.Now.AddSeconds(-IdleSettings.LastSystemModifiedTimeThresholdSeconds)
+                               If Not runAll AndAlso WatchedFolders.Any(Function(x) x.LastChangedDate > recentThresholdDate) Then Return False
+
+                               If _parseWatchersSemaphore.CurrentCount <> 0 Then
+                                   Await ParseWatchers(runAll, cToken)
+                               End If
+                               If cToken <> Nothing AndAlso cToken.IsCancellationRequested Then
+                                   _logger.LogInformation("Watcher run cancelled by user.")
+                                   Return False
+                               End If
+                               If _parseWatchersSemaphore.CurrentCount <> 0 AndAlso (IsBackgroundCompactingEnabled OrElse runAll) Then
+                                   Await BackgroundCompact(runAll) 'Don't need to pass the cancellation token here, as the background compactor handles it internally.
+                               End If
+                               Return True
+                           End Function, cToken)
+
 
-            If _parseWatchersSemaphore.CurrentCount <> 0 Then
-                Await ParseWatchers(runAll)
-            End If
-            If _parseWatchersSemaphore.CurrentCount <> 0 AndAlso (IsBackgroundCompactingEnabled OrElse runAll) Then
-                Await BackgroundCompact(runAll)
-            End If
-            _settingsService.AppSettings.ScheduledBackgroundLastRan = now
             Return True
+        Catch ex As OperationCanceledException
+            Return False
         Finally
 
             AddHandler _idleDetector.IsIdle, _idleHandler
             For Each watcher In WatchedFolders
                 watcher.ResumeMonitoring()
             Next
+            IsRunning = False
         End Try
         Return False
     End Function
@@ -347,7 +354,7 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
 
 
 
-    Public Async Function ParseWatchers(Optional ParseAll As Boolean = False) As Task
+    Public Async Function ParseWatchers(Optional ParseAll As Boolean = False, Optional cToken As CancellationToken = Nothing) As Task
         Dim acquired = Await _parseWatchersSemaphore.WaitAsync(0)
         If Not acquired Then Return
 
@@ -364,9 +371,11 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
 
             For Each fsWatcher In WatchersQuery
                 WatcherLog.FolderChanged(_logger, fsWatcher.DisplayName)
-                Await Analyse(fsWatcher.Folder, ParseAll)
+                If cToken <> Nothing AndAlso cToken.IsCancellationRequested Then Return
+                Await Analyse(fsWatcher.Folder, ParseAll, cToken)
             Next
 
+            If cToken <> Nothing AndAlso cToken.IsCancellationRequested Then Return
             Await WriteToFileAsync()
             LastAnalysed = DateTime.Now
         Finally
@@ -433,37 +442,44 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
     End Function
 
 
-    Public Async Function Analyse(folder As String, checkDiskModified As Boolean) As Task(Of Boolean)
+    Public Async Function Analyse(folder As String, checkDiskModified As Boolean, Optional cToken As CancellationToken = Nothing) As Task(Of Boolean)
 
         Using analyser As New Analyser(folder, NullLogger(Of Analyser).Instance)
             Dim watched = WatchedFolders.First(Function(f) f.Folder = folder)
             watched.IsWorking = True
+            Try
+                Dim analysedFiles = Await analyser.GetAnalysedFilesAsync(cToken)
+                If cToken <> Nothing AndAlso cToken.IsCancellationRequested Then Return False
 
-            Dim analysedFiles = Await analyser.GetAnalysedFilesAsync(CancellationToken.None)
-
-            watched.LastCheckedDate = DateTime.Now
-            watched.LastCheckedSize = analyser.CompressedBytes
-            watched.LastUncompressedSize = analyser.UncompressedBytes
+                watched.LastCheckedDate = DateTime.Now
+                watched.LastCheckedSize = analyser.CompressedBytes
+                watched.LastUncompressedSize = analyser.UncompressedBytes
 
-            watched.LastSystemModifiedDate = watched.LastChangedDate
+                watched.LastSystemModifiedDate = watched.LastChangedDate
 
-            If analysedFiles.Count <> 0 Then
-                Dim mainCompressionLVL = analysedFiles?.Select(Function(f) f.CompressionMode).Max
-                watched.CompressionLevel = If(mainCompressionLVL <> WOFCompressionAlgorithm.NO_COMPRESSION, mainCompressionLVL, watched.CompressionLevel)
+                If analysedFiles.Count <> 0 Then
+                    Dim mainCompressionLVL = analysedFiles?.Select(Function(f) f.CompressionMode).Max
+                    watched.CompressionLevel = If(mainCompressionLVL <> WOFCompressionAlgorithm.NO_COMPRESSION, mainCompressionLVL, watched.CompressionLevel)
 
-                If checkDiskModified Then
-                    Dim lastDiskWriteTime = analysedFiles.Select(Function(fl)
-                                                                     Dim finfo As New IO.FileInfo(fl.FileName)
-                                                                     Return finfo.LastWriteTime
-                                                                 End Function).OrderByDescending(Function(f) f).First
+                    If checkDiskModified Then
+                        Dim lastDiskWriteTime = analysedFiles.Select(Function(fl)
+                                                                         Dim finfo As New IO.FileInfo(fl.FileName)
+                                                                         Return finfo.LastWriteTime
+                                                                     End Function).OrderByDescending(Function(f) f).First
 
-                    watched.LastSystemModifiedDate = If(watched.LastSystemModifiedDate < lastDiskWriteTime, lastDiskWriteTime, watched.LastSystemModifiedDate)
+                        watched.LastSystemModifiedDate = If(watched.LastSystemModifiedDate < lastDiskWriteTime, lastDiskWriteTime, watched.LastSystemModifiedDate)
 
+                    End If
                 End If
-            End If
 
-            watched.HasTargetChanged = False
-            watched.IsWorking = False
+                watched.HasTargetChanged = False
+            Catch ex As OperationCanceledException
+                Return False
+            Finally
+
+                watched.IsWorking = False
+            End Try
+
             Return True
 
         End Using
@@ -480,15 +496,9 @@ Partial Public Class Watcher : Inherits ObservableRecipient : Implements IRecipi
 
     End Sub
 
-    <RelayCommand>
-    Public Sub CancelBackgrounding()
-        BGCompactor.CancelCompacting()
-        CancelBackgroundingCommand.NotifyCanExecuteChanged()
-    End Sub
 
-    Public Function CanCancelBackgrounding() As Boolean
-        Return BGCompactor.IsCompactorActive
-    End Function
+
+
 
 End Class
 
diff --git a/CompactGUI/Application.xaml.vb b/CompactGUI/Application.xaml.vb
@@ -26,7 +26,6 @@ Partial Public Class Application
     Shared Sub New()
         SettingsService = New SettingsService()
         SettingsService.LoadSettings()
-        InitializeHost()
 
         AddHandler AppDomain.CurrentDomain.UnhandledException, AddressOf OnDomainUnhandledException
 
@@ -83,7 +82,7 @@ Partial Public Class Application
                                services.AddSingleton(Of HomeViewModel)()
 
                                services.AddTransient(Of WatcherPage)()
-                               services.AddTransient(Of WatcherViewModel)()
+                               services.AddSingleton(Of WatcherViewModel)()
 
                                services.AddTransient(Of SettingsPage)()
                                services.AddSingleton(Of SettingsViewModel)()
@@ -142,6 +141,8 @@ Partial Public Class Application
             End If
         End If
 
+        InitializeHost()
+
         GetService(Of Watcher.Watcher)()
 
         Await _host.StartAsync()
diff --git a/CompactGUI/ViewModels/WatcherViewModel.vb b/CompactGUI/ViewModels/WatcherViewModel.vb
@@ -1,7 +1,11 @@
-﻿Imports CommunityToolkit.Mvvm.ComponentModel
+﻿Imports System.Threading
+
+Imports CommunityToolkit.Mvvm.ComponentModel
 Imports CommunityToolkit.Mvvm.Input
 Imports CommunityToolkit.Mvvm.Messaging
 
+Imports CompactGUI.Watcher
+
 Imports Wpf.Ui.Controls
 
 Public NotInheritable Class WatcherViewModel : Inherits ObservableObject
@@ -15,6 +19,20 @@ Public NotInheritable Class WatcherViewModel : Inherits ObservableObject
     End Sub
 
 
+
+    <RelayCommand>
+    Public Async Function RunWatcher(token As CancellationToken) As Task
+        Await Watcher.RunWatcher(True, token)
+    End Function
+
+    <RelayCommand>
+    Public Sub CancelBackgrounding()
+        RunWatcherCommand.Cancel()
+        Watcher.BGCompactor.CancelCompacting()
+        Application.Current.Dispatcher.Invoke(Sub() CancelBackgroundingCommand.NotifyCanExecuteChanged())
+    End Sub
+
+
     <RelayCommand>
     Private Async Function RemoveWatcher(watchedFolder As Watcher.WatchedFolder) As Task
         If watchedFolder Is Nothing Then Return
diff --git a/CompactGUI/Views/Components/FolderWatcherCard.xaml b/CompactGUI/Views/Components/FolderWatcherCard.xaml
@@ -29,49 +29,64 @@
             <RowDefinition />
         </Grid.RowDefinitions>
 
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition/>
+            <ColumnDefinition/>
+        </Grid.ColumnDefinitions>
 
 
-        <TextBlock Text="Watched folders"
+        <StackPanel Orientation="Horizontal" Grid.Row="0">
+              <TextBlock Text="Watched Folders"
                    Grid.Row="0"
                    VerticalAlignment="Top"
                    FontSize="26"
                    Foreground="{StaticResource CardForeground}"
                    Visibility="Visible" />
 
-        <Button Content="Add Folder To Watchlist"
-                Grid.Row="0"
-                Height="30"
-                HorizontalAlignment="Right" VerticalAlignment="Top"
+        <Button
+
+                Height="30" Margin="20 0 0 0 "
+                HorizontalAlignment="Left" VerticalAlignment="Center"
                 Command="{Binding ManuallyAddFolderToWatcherCommand}">
+                <StackPanel Orientation="Horizontal">
+                    <ui:SymbolIcon Symbol="FolderAdd24"/>
+                    <TextBlock Text="Add" Margin="8 0 0 0 " FontSize="13" FontWeight="SemiBold"/>
+                </StackPanel>
             <Button.ToolTip>
                 <ToolTip ToolTipService.InitialShowDelay="100">
                     <TextBlock Text="Add a custom folder to the watchlist"
                                FontSize="12" Foreground="#FFBFC7CE" TextWrapping="NoWrap" />
                 </ToolTip>
             </Button.ToolTip>
         </Button>
+        </StackPanel>
+
+      
 
 
 
         <TextBlock Grid.Row="1"
-                   HorizontalAlignment="Left" VerticalAlignment="Center"
-                   FontSize="20"
-                   Foreground="{StaticResource CardForegroundDisabled}">
+                   HorizontalAlignment="Left" VerticalAlignment="Top"
+                   FontSize="18" FontWeight="SemiBold"
+                   Foreground="#40FFFFFF">
             <Run Text="{Binding Watcher.TotalSaved, Mode=OneWay, Converter={StaticResource BytesToReadableConverter}}" d:Text="51.8GB" />
             <Run Text="saved" />
         </TextBlock>
 
-        <StackPanel Grid.Row="1"
-                    Margin="0,0,3,0" HorizontalAlignment="Right" VerticalAlignment="Center"
+        <StackPanel Grid.Row="1" Grid.RowSpan="2"
+                    Margin="0,20,0,0" HorizontalAlignment="Left" VerticalAlignment="Center"
                     Orientation="Horizontal">
+
+            <TextBlock Text="{Binding Watcher.LastAnalysed, StringFormat=Last analysed {0}, Converter={StaticResource RelativeDateConverter}}"
+                       Margin="0,-2,0,0" VerticalAlignment="Center"
+                       d:Text="Last analysed: just now" FontSize="14" FontWeight="SemiBold" Foreground="#40FFFFFF" />
             <Grid Width="45" Height="25"
                   VerticalAlignment="Center">
-                <ui:Button Background="Transparent" BorderThickness="0"
+                <ui:Button Background="Transparent" BorderThickness="0" Margin="2 0"
                            Command="{Binding RefreshWatchedCommand}"
                            Visibility="{Binding RefreshWatchedCommand.IsRunning, Converter={StaticResource BooleanToInverseVisibilityConverter}}">
-
-                    <ui:FontIcon FontFamily="Segoe Fluent Icons, Segoe MDL2 Assets" FontSize="14"
-                                 Glyph="&#xE9F3;" />
+      
+                    <ui:SymbolIcon Symbol="ArrowClockwiseDashes24" FontSize="18"/>
                     <ui:Button.ToolTip>
                         <ToolTip ToolTipService.InitialShowDelay="100">
                             <TextBlock Text="Re-analyse all watched folders"
@@ -80,28 +95,27 @@
                     </ui:Button.ToolTip>
                 </ui:Button>
                 <ui:ProgressRing Width="18" Height="18"
-                                 Margin="-15,0,0,0"
+                                 Margin="0,0,0,0"
                                  Foreground="#FFBFC7CE" IsIndeterminate="True"
                                  Visibility="{Binding RefreshWatchedCommand.IsRunning, Converter={StaticResource BoolToVisConverter}}" />
-
-                <Button Content="Cancel" Margin="-100" Command="{Binding Watcher.CancelBackgroundingCommand}"/>
-                <Button Content="Run Now" Margin="-200" Command="{Binding Watcher.RunWatcherCommand}"/>
             </Grid>
+       
+        </StackPanel>
 
+        <StackPanel Orientation="Horizontal" Grid.Column="1" Grid.Row="1" Grid.RowSpan="2" HorizontalAlignment="Right">
 
-            <TextBlock Text="{Binding Watcher.LastAnalysed, StringFormat=Last analysed {0}, Converter={StaticResource RelativeDateConverter}}"
-                       Margin="0,-2,0,0" VerticalAlignment="Center"
-                       d:Text="Last analysed: just now" FontSize="14" Foreground="#FFBFC7CE" />
+            <Button Content="Cancel Background Compressor"  Command="{Binding CancelBackgroundingCommand}" Visibility="{Binding Watcher.IsRunning, Converter={StaticResource BooleanToVisibilityConverter}}"/>
+            <Button Content="Compress All Now"  Command="{Binding RunWatcherCommand}" Visibility="{Binding Watcher.IsRunning, Converter={StaticResource BooleanToInverseVisibilityConverter}}"/>
         </StackPanel>
+       
 
-
-        <Separator Grid.Row="2"
+        <Separator Grid.Row="2" Grid.ColumnSpan="2"
                    Height="1"
                    VerticalAlignment="Bottom" />
 
 
         <ListView x:Name="UiWatcherListView"
-                  Grid.Row="3"
+                  Grid.Row="3" Grid.ColumnSpan="2"
                   Margin="-10,0,-20,0" Padding="0,0,10,0" HorizontalAlignment="Stretch"
                   d:ItemsSource="{Binding Source={StaticResource Dtd}}"
                   Background="Transparent" BorderThickness="0"
