Feature: Added a comparison text box for hashes

src/Files.App/Strings/en-US/Resources.resw

@@ -4113,6 +4113,18 @@
     <value>Add to shelf</value>
     <comment>Tooltip that displays when dragging items to the Shelf Pane</comment>
   </data>
+  <data name="EnterHashToCompare" xml:space="preserve">
+    <value>Enter a hash to compare</value>
+    <comment>Placeholder that appears in the compare hash text box</comment>
+  </data>
+  <data name="HashesMatch" xml:space="preserve">
+    <value>Matches {0}</value>
+    <comment>Appears when two compared hashes match, e.g. "Matches SHA256"</comment>
+  </data>
+  <data name="HashesDoNotMatch" xml:space="preserve">
+    <value>No matches found</value>
+    <comment>Appears when two compared hashes don't match</comment>
+  </data>
   <data name="PathOrAlias" xml:space="preserve">
     <value>Path or alias</value>
   </data>
@@ -4156,4 +4168,8 @@
     <value>Cannot clone repo</value>
     <comment>Cannot clone repo dialog title</comment>
   </data>
+  <data name="CompareFile" xml:space="preserve">
+    <value>Compare a file</value>
+    <comment>Button that appears in file hash properties that allows the user to compare two files</comment>
+  </data>
 </root>

src/Files.App/ViewModels/Properties/HashesViewModel.cs

@@ -1,16 +1,22 @@
-// Copyright (c) Files Community
+// Copyright (c) Files Community
 // Licensed under the MIT License.
 
 using Files.Shared.Helpers;
+using Microsoft.UI.Windowing;
+using Microsoft.UI.Xaml.Controls;
 using System.IO;
+using System.Security.Cryptography;
 using System.Windows.Input;
 
 namespace Files.App.ViewModels.Properties
 {
 	public sealed partial class HashesViewModel : ObservableObject, IDisposable
 	{
+		private ICommonDialogService CommonDialogService { get; } = Ioc.Default.GetRequiredService<ICommonDialogService>();
 		private IUserSettingsService UserSettingsService { get; } = Ioc.Default.GetService<IUserSettingsService>()!;
 
+		private readonly AppWindow _appWindow;
+
 		private HashInfoItem _selectedItem;
 		public HashInfoItem SelectedItem
 		{
@@ -23,16 +29,48 @@ public HashInfoItem SelectedItem
 		public Dictionary<string, bool> ShowHashes { get; private set; }
 
 		public ICommand ToggleIsEnabledCommand { get; private set; }
+		public ICommand CompareFileCommand { get; private set; }
 
 		private ListedItem _item;
 
 		private CancellationTokenSource _cancellationTokenSource;
 
-		public HashesViewModel(ListedItem item)
+		private string _hashInput;
+		public string HashInput
+		{
+			get => _hashInput;
+			set
+			{
+				SetProperty(ref _hashInput, value);
+
+				OnHashInputTextChanged();
+				OnPropertyChanged(nameof(IsInfoBarOpen));
+			}
+		}
+
+		private InfoBarSeverity _infoBarSeverity;
+		public InfoBarSeverity InfoBarSeverity
+		{
+			get => _infoBarSeverity;
+			set => SetProperty(ref _infoBarSeverity, value);
+		}
+
+		private string _infoBarTitle;
+		public string InfoBarTitle
+		{
+			get => _infoBarTitle;
+			set => SetProperty(ref _infoBarTitle, value);
+		}
+
+		public bool IsInfoBarOpen
+			=> !string.IsNullOrEmpty(HashInput);
+
+		public HashesViewModel(ListedItem item, AppWindow appWindow)
 		{
 			ToggleIsEnabledCommand = new RelayCommand<string>(ToggleIsEnabled);
 
 			_item = item;
+			_appWindow = appWindow;
 			_cancellationTokenSource = new();
 
 			Hashes =
@@ -55,6 +93,8 @@ public HashesViewModel(ListedItem item)
 			ShowHashes.TryAdd("SHA512", false);
 
 			Hashes.Where(x => ShowHashes[x.Algorithm]).ForEach(x => ToggleIsEnabledCommand.Execute(x.Algorithm));
+
+			CompareFileCommand = new RelayCommand(async () => await OnCompareFileAsync());
 		}
 
 		private void ToggleIsEnabled(string? algorithm)
@@ -71,7 +111,7 @@ private void ToggleIsEnabled(string? algorithm)
 			// Don't calculate hashes for online files
 			if (_item.SyncStatusUI.SyncStatus is CloudDriveSyncStatus.FileOnline or CloudDriveSyncStatus.FolderOnline)
 			{
-				hashInfoItem.HashValue = "CalculationOnlineFileHashError".GetLocalizedResource();
+				hashInfoItem.HashValue = Strings.CalculationOnlineFileHashError.GetLocalizedResource();
 				return;
 			}
 
@@ -106,11 +146,11 @@ private void ToggleIsEnabled(string? algorithm)
 					catch (IOException)
 					{
 						// File is currently open
-						hashInfoItem.HashValue = "CalculationErrorFileIsOpen".GetLocalizedResource();
+						hashInfoItem.HashValue = Strings.CalculationErrorFileIsOpen.GetLocalizedResource();
 					}
 					catch (Exception)
 					{
-						hashInfoItem.HashValue = "CalculationError".GetLocalizedResource();
+						hashInfoItem.HashValue = Strings.CalculationError.GetLocalizedResource();
 					}
 					finally
 					{
@@ -120,6 +160,54 @@ private void ToggleIsEnabled(string? algorithm)
 			}
 		}
 
+		public string FindMatchingAlgorithm(string hash)
+		{
+			if (string.IsNullOrEmpty(hash))
+				return string.Empty;
+
+			return Hashes
+				.FirstOrDefault(h => h.HashValue?.Equals(hash, StringComparison.OrdinalIgnoreCase) == true)
+				?.Algorithm ?? string.Empty;
+		}
+
+		public async Task<string> CalculateFileHashAsync(string filePath)
+		{
+			using var stream = File.OpenRead(filePath);
+			using var md5 = MD5.Create();
+			var hash = await Task.Run(() => md5.ComputeHash(stream));
+			return BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
+		}
+
+		private void OnHashInputTextChanged()
+		{
+			string matchingAlgorithm = FindMatchingAlgorithm(HashInput);
+
+			InfoBarSeverity = string.IsNullOrEmpty(matchingAlgorithm)
+				? InfoBarSeverity.Error
+				: InfoBarSeverity.Success;
+
+			InfoBarTitle = string.IsNullOrEmpty(matchingAlgorithm)
+				? Strings.HashesDoNotMatch.GetLocalizedResource()
+				: string.Format(Strings.HashesMatch.GetLocalizedResource(), matchingAlgorithm);
+		}
+
+		private async Task OnCompareFileAsync()
+		{
+			var hWnd = Microsoft.UI.Win32Interop.GetWindowFromWindowId(_appWindow.Id);
+
+			var result = CommonDialogService.Open_FileOpenDialog(
+				hWnd,
+				false,
+				[],
+				Environment.SpecialFolder.Desktop,
+				out var filePath
+			);
+
+			HashInput = result && filePath != null
+				? await CalculateFileHashAsync(filePath)
+				: string.Empty;
+		}
+
 		public void Dispose()
 		{
 			_cancellationTokenSource.Cancel();

src/Files.App/Views/Properties/HashesPage.xaml

@@ -1,4 +1,4 @@
-<!--  Copyright (c) Files Community. Licensed under the MIT License.  -->
+<!--  Copyright (c) Files Community. Licensed under the MIT License.  -->
 <vm:BasePropertiesPage
 	x:Class="Files.App.Views.Properties.HashesPage"
 	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
@@ -25,20 +25,66 @@
 	</vm:BasePropertiesPage.Resources>
 
 	<Grid x:Name="RootGrid">
+		<Grid.RowDefinitions>
+			<RowDefinition Height="Auto" />
+			<RowDefinition Height="Auto" />
+			<RowDefinition Height="*" />
+		</Grid.RowDefinitions>
 
+		<!--  Hash Comparison Section  -->
 		<Grid
-			x:Name="HashesListGrid"
-			Margin="12"
+			x:Name="HashComparisonGrid"
+			Margin="12,12,12,4"
+			Padding="12"
 			VerticalAlignment="Top"
 			Background="{ThemeResource CardBackgroundFillColorDefaultBrush}"
 			BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
 			BorderThickness="1"
+			ColumnSpacing="8"
+			CornerRadius="4">
+			<Grid.ColumnDefinitions>
+				<ColumnDefinition Width="*" />
+				<ColumnDefinition Width="Auto" />
+			</Grid.ColumnDefinitions>
+
+			<!--  Hash Input  -->
+			<TextBox
+				x:Name="HashInputTextBox"
+				Grid.Column="0"
+				PlaceholderText="{helpers:ResourceString Name=EnterHashToCompare}"
+				Text="{x:Bind HashesViewModel.HashInput, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
+
+			<!--  Compare File Button  -->
+			<Button
+				x:Name="CompareFileButton"
+				Grid.Column="1"
+				Command="{x:Bind HashesViewModel.CompareFileCommand}"
+				Content="{helpers:ResourceString Name=CompareFile}" />
+		</Grid>
+
+		<InfoBar
+			x:Name="HashMatchInfoBar"
+			Grid.Row="1"
+			Margin="12,4,12,4"
+			x:Load="{x:Bind HashesViewModel.IsInfoBarOpen, Mode=OneWay}"
+			IsClosable="False"
+			IsOpen="True"
+			Message="{x:Bind HashesViewModel.InfoBarTitle, Mode=OneWay}"
+			Severity="{x:Bind HashesViewModel.InfoBarSeverity, Mode=OneWay}" />
+
+		<Grid
+			x:Name="HashesListGrid"
+			Grid.Row="2"
+			Margin="12,4,12,12"
+			Background="{ThemeResource CardBackgroundFillColorDefaultBrush}"
+			BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
+			BorderThickness="1"
 			CornerRadius="4">
 
 			<!--  Hashes ListView  -->
 			<ListView
 				x:Name="HashesListView"
-				ItemsSource="{x:Bind HashesViewModel.Hashes, Mode=TwoWay}"
+				ItemsSource="{x:Bind HashesViewModel.Hashes, Mode=OneWay}"
 				SelectedItem="{x:Bind HashesViewModel.SelectedItem, Mode=TwoWay}">
 
 				<!--  Header  -->

src/Files.App/Views/Properties/HashesPage.xaml.cs

@@ -1,14 +1,11 @@
-// Copyright (c) Files Community
+// Copyright (c) Files Community
 // Licensed under the MIT License.
 
-using Files.App.Data.Parameters;
-using Files.App.Utils;
 using Files.App.ViewModels.Properties;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Controls.Primitives;
 using Microsoft.UI.Xaml.Navigation;
-using System.Threading.Tasks;
 
 namespace Files.App.Views.Properties
 {
@@ -25,9 +22,10 @@ public HashesPage()
 
 		protected override void OnNavigatedTo(NavigationEventArgs e)
 		{
-			var np = (PropertiesPageNavigationParameter)e.Parameter;
-			if (np.Parameter is ListedItem listedItem)
-				HashesViewModel = new(listedItem);
+			var parameter = (PropertiesPageNavigationParameter)e.Parameter;
+
+			if (parameter.Parameter is ListedItem listedItem)
+				HashesViewModel = new(listedItem, parameter.Window.AppWindow);
 
 			base.OnNavigatedTo(e);
 		}