Feature: Added option to filter items when typing

src/Files.App/Actions/Show/ToggleFilterHeaderAction.cs

@@ -31,6 +31,11 @@ public Task ExecuteAsync(object? parameter = null)
 
 			if (IsOn)
 				ContentPageContext.ShellPage!.ShellViewModel.InvokeFocusFilterHeader();
+			else
+			{
+				// Clear the filter query when the header is hidden
+				ContentPageContext.ShellPage!.ShellViewModel.FilesAndFoldersFilter = string.Empty;
+			}
 
 			return Task.CompletedTask;
 		}

src/Files.App/Data/Contracts/IFoldersSettingsService.cs

@@ -89,5 +89,10 @@ public interface IFoldersSettingsService : IBaseSettingsService, INotifyProperty
 		/// Gets or sets a value indicating which format to use when displaying item sizes.
 		/// </summary>
 		SizeUnitTypes SizeUnitFormat { get; set; }
+
+		/// <summary>
+		/// Gets or sets a value indicating the keyboard typing behavior.
+		/// </summary>
+		KeyboardTypingBehavior KeyboardTypingBehavior { get; set; }
 	}
 }

src/Files.App/Data/Enums/KeyboardTypingBehavior.cs

@@ -0,0 +1,18 @@
+// Copyright (c) Files Community
+// Licensed under the MIT License.
+
+namespace Files.App.Data.Enums
+{
+	public enum KeyboardTypingBehavior
+	{
+		/// <summary>
+		/// Jump to matching item.
+		/// </summary>
+		JumpToFile,
+
+		/// <summary>
+		/// Filter items.
+		/// </summary>
+		FilterItems
+	}
+}

src/Files.App/Services/Settings/FoldersSettingsService.cs

@@ -114,6 +114,13 @@ public SizeUnitTypes SizeUnitFormat
 			set => Set(value);
 		}
 
+		/// <inheritdoc/>
+		public KeyboardTypingBehavior KeyboardTypingBehavior
+		{
+			get => (KeyboardTypingBehavior)Get((long)KeyboardTypingBehavior.JumpToFile);
+			set => Set((long)value);
+		}
+
 		protected override void RaiseOnSettingChangedEvent(object sender, SettingChangedEventArgs e)
 		{
 			base.RaiseOnSettingChangedEvent(sender, e);

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

@@ -4278,6 +4278,15 @@
   </data>
   <data name="Filename" xml:space="preserve">
     <value>Filename</value>
+  </data>	
+  <data name="KeyboardTypingBehavior" xml:space="preserve">
+    <value>Behavior when typing in the file area</value>
+  </data>
+  <data name="JumpToFile" xml:space="preserve">
+    <value>Jump to file</value>
+  </data>
+  <data name="FilterItems" xml:space="preserve">
+    <value>Filter items</value>
   </data>
   <data name="Signatures" xml:space="preserve">
     <value>Signatures</value>

src/Files.App/Utils/Storage/Operations/FilesystemHelpers.cs

@@ -34,8 +34,8 @@ private static char[] RestrictedCharacters
 			{
 				var userSettingsService = Ioc.Default.GetRequiredService<IUserSettingsService>();
 				return userSettingsService.FoldersSettingsService.AreAlternateStreamsVisible
-					? ['\\', '/', '*', '?', '"', '<', '>', '|'] // Allow ":" char
-					: ['\\', '/', ':', '*', '?', '"', '<', '>', '|'];
+					? Path.GetInvalidFileNameChars().Where(c => c != ':').ToArray() // Allow ":" char when alternate streams are visible
+					: Path.GetInvalidFileNameChars();
 			}
 		}
 

src/Files.App/ViewModels/Settings/AdvancedViewModel.cs

@@ -28,6 +28,7 @@ public sealed partial class AdvancedViewModel : ObservableObject
 		public ICommand ImportSettingsCommand { get; }
 		public AsyncRelayCommand OpenFilesOnWindowsStartupCommand { get; }
 
+		public Dictionary<KeyboardTypingBehavior, string> KeyboardTypingBehaviors { get; private set; } = [];
 
 		public AdvancedViewModel()
 		{
@@ -40,6 +41,11 @@ public AdvancedViewModel()
 			ImportSettingsCommand = new AsyncRelayCommand(ImportSettingsAsync);
 			OpenFilesOnWindowsStartupCommand = new AsyncRelayCommand(OpenFilesOnWindowsStartupAsync);
 
+			// Keyboard typing behavior
+			KeyboardTypingBehaviors.Add(Data.Enums.KeyboardTypingBehavior.JumpToFile, Strings.JumpToFile.GetLocalizedResource());
+			KeyboardTypingBehaviors.Add(Data.Enums.KeyboardTypingBehavior.FilterItems, Strings.FilterItems.GetLocalizedResource());
+			KeyboardTypingBehavior = KeyboardTypingBehaviors[UserSettingsService.FoldersSettingsService.KeyboardTypingBehavior];
+
 			_ = DetectOpenFilesAtStartupAsync();
 		}
 
@@ -354,6 +360,20 @@ public bool ShowFlattenOptions
 				OnPropertyChanged();
 			}
 		}
+
+		private string keyboardTypingBehavior;
+		public string KeyboardTypingBehavior
+		{
+			get => keyboardTypingBehavior;
+			set
+			{
+				if (SetProperty(ref keyboardTypingBehavior, value))
+				{
+					UserSettingsService.FoldersSettingsService.KeyboardTypingBehavior = KeyboardTypingBehaviors.First(e => e.Value == value).Key;
+				}
+			}
+		}
+
 		public async Task OpenFilesOnWindowsStartupAsync()
 		{
 			var stateMode = await ReadState();

src/Files.App/ViewModels/ShellViewModel.cs

@@ -777,9 +777,42 @@ public void UpdateEmptyTextType()
 		public string? FilesAndFoldersFilter
 		{
 			get => _filesAndFoldersFilter;
-			set => SetProperty(ref _filesAndFoldersFilter, value);
+			set
+			{
+				if (SetProperty(ref _filesAndFoldersFilter, value))
+				{
+					// Apply the updated filter to the files and folders list
+					FilesAndFolderFilterUpdated();
+				}
+			}
+		}
+
+		private void FilesAndFolderFilterUpdated()
+		{
+			_ = ApplyFilesAndFoldersChangesAsync();
 		}
 
+		/// <summary>
+		/// Clears the files and folder filter.
+		/// This is used when the directory is changed or refreshed.
+		/// </summary>
+		private void ClearFilesAndFolderFilter()
+		{
+			// Hide the filter header if:
+			// - Keyboard behavior is set to filter items
+			// - A filter is currently applied
+			//
+			// Keep the header visible if:
+			// - The filter is already empty (e.g. opened manually)
+			if (UserSettingsService.FoldersSettingsService.KeyboardTypingBehavior == KeyboardTypingBehavior.FilterItems &&
+				!string.IsNullOrEmpty(FilesAndFoldersFilter))
+			{
+				UserSettingsService.GeneralSettingsService.ShowFilterHeader = false;
+			}
+
+			// Clear the filter
+			FilesAndFoldersFilter = string.Empty;
+		}
 
 		// Apply changes immediately after manipulating on filesAndFolders completed
 		public async Task ApplyFilesAndFoldersChangesAsync()
@@ -1894,7 +1927,6 @@ await Task.Run(async () =>
 						});
 
 						filesAndFolders.AddRange(fileList);
-						FilesAndFoldersFilter = null;
 
 						await OrderFilesAndFoldersAsync();
 						await ApplyFilesAndFoldersChangesAsync();
@@ -1903,6 +1935,7 @@ await dispatcherQueue.EnqueueOrInvokeAsync(() =>
 						{
 							GetDesktopIniFileData();
 							CheckForBackgroundImage();
+							ClearFilesAndFolderFilter();
 						},
 						Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
 					});

src/Files.App/Views/Layouts/BaseGroupableLayoutPage.cs

@@ -95,7 +95,7 @@ protected override void UnhookEvents()
 			ItemManipulationModel.RefreshItemsThumbnailInvoked -= ItemManipulationModel_RefreshItemsThumbnail;
 		}
 
-		protected override void Page_CharacterReceived(UIElement sender, CharacterReceivedRoutedEventArgs args)
+		protected override void Page_PreviewKeyDown(object sender, KeyRoutedEventArgs e)
 		{
 			if (ParentShellPageInstance is null ||
 				ParentShellPageInstance.CurrentPageType != this.GetType() ||
@@ -112,7 +112,7 @@ focusedElement is PasswordBox ||
 				DependencyObjectHelpers.FindParent<ContentDialog>(focusedElement) is not null)
 				return;
 
-			base.Page_CharacterReceived(sender, args);
+			base.Page_PreviewKeyDown(sender, e);
 		}
 
 		// Virtual methods

src/Files.App/Views/Layouts/BaseLayoutPage.cs

@@ -15,6 +15,7 @@
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices.ComTypes;
+using System.Text;
 using Vanara.Extensions;
 using Vanara.PInvoke;
 using Windows.ApplicationModel.DataTransfer;
@@ -23,6 +24,7 @@
 using Windows.Foundation.Collections;
 using Windows.Storage;
 using Windows.System;
+using Windows.Win32;
 using static Files.App.Helpers.PathNormalization;
 using DispatcherQueueTimer = Microsoft.UI.Dispatching.DispatcherQueueTimer;
 using SortDirection = Files.App.Data.Enums.SortDirection;
@@ -40,6 +42,8 @@ public abstract class BaseLayoutPage : Page, IBaseLayoutPage, INotifyPropertyCha
 		protected IFileTagsSettingsService FileTagsSettingsService { get; } = Ioc.Default.GetService<IFileTagsSettingsService>()!;
 		protected IUserSettingsService UserSettingsService { get; } = Ioc.Default.GetService<IUserSettingsService>()!;
 		protected ILayoutSettingsService LayoutSettingsService { get; } = Ioc.Default.GetService<ILayoutSettingsService>()!;
+		protected IGeneralSettingsService GeneralSettingsService { get; } = Ioc.Default.GetService<IGeneralSettingsService>()!;
+		protected IFoldersSettingsService FoldersSettingsService { get; } = Ioc.Default.GetService<IFoldersSettingsService>()!;
 		protected ICommandManager Commands { get; } = Ioc.Default.GetRequiredService<ICommandManager>();
 		public InfoPaneViewModel InfoPaneViewModel { get; } = Ioc.Default.GetRequiredService<InfoPaneViewModel>();
 		protected readonly IWindowContext WindowContext = Ioc.Default.GetRequiredService<IWindowContext>();
@@ -401,7 +405,7 @@ protected override async void OnNavigatedTo(NavigationEventArgs e)
 			base.OnNavigatedTo(e);
 
 			// Add item jumping handler
-			CharacterReceived += Page_CharacterReceived;
+			PreviewKeyDown += Page_PreviewKeyDown;
 
 			navigationArguments = (NavigationArguments)e.Parameter;
 			ParentShellPageInstance = navigationArguments.AssociatedTabInstance;
@@ -565,7 +569,7 @@ protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 			base.OnNavigatingFrom(e);
 
 			// Remove item jumping handler
-			CharacterReceived -= Page_CharacterReceived;
+			PreviewKeyDown -= Page_PreviewKeyDown;
 			FolderSettings!.LayoutModeChangeRequested -= BaseFolderSettings_LayoutModeChangeRequested;
 			FolderSettings.GroupOptionPreferenceUpdated -= FolderSettings_GroupOptionPreferenceUpdated;
 			FolderSettings.GroupDirectionPreferenceUpdated -= FolderSettings_GroupDirectionPreferenceUpdated;
@@ -996,12 +1000,82 @@ private void RemoveOverflow(CommandBarFlyout contextMenuFlyout)
 				overflowSeparator.Visibility = Visibility.Collapsed;
 		}
 
-		protected virtual void Page_CharacterReceived(UIElement sender, CharacterReceivedRoutedEventArgs args)
+		protected virtual void Page_PreviewKeyDown(object sender, KeyRoutedEventArgs e)
 		{
-			if (ParentShellPageInstance!.IsCurrentInstance)
+			var shellPage = ParentShellPageInstance;
+			if (shellPage?.IsCurrentInstance != true)
+				return;
+
+			var pressedKey = e.Key;
+			var currentFilter = shellPage.ShellViewModel.FilesAndFoldersFilter ?? string.Empty;
+			var isFilterModeOn = FoldersSettingsService.KeyboardTypingBehavior == KeyboardTypingBehavior.FilterItems;
+			var buffer = new StringBuilder(4);
+			var state = new byte[256];
+			char? typedCharacter = null;
+
+			if (PInvoke.GetKeyboardState(state))
+			{
+				var virtualKey = (uint)pressedKey;
+				var scanCode = PInvoke.MapVirtualKey(virtualKey, 0);
+				var keyboardLayout = PInvoke.GetKeyboardLayout(0);
+
+				if (Win32PInvoke.ToUnicodeEx(virtualKey, scanCode, state, buffer, buffer.Capacity, 0, keyboardLayout) > 0)
+				{
+					var character = buffer[^1];
+					if (character != ' ')
+						typedCharacter = character;
+				}
+			}
+
+			if (!typedCharacter.HasValue)
+				return;
+
+			// Handle valid character input
+			if (!FilesystemHelpers.ContainsRestrictedCharacters(char.ToString(typedCharacter.Value)))
+			{
+				var lowerCharString = char.ToLowerInvariant(typedCharacter.Value).ToString();
+
+				if (isFilterModeOn)
+				{
+					if (!GeneralSettingsService.ShowFilterHeader)
+						GeneralSettingsService.ShowFilterHeader = true;
+					shellPage.ShellViewModel.FilesAndFoldersFilter += lowerCharString;
+				}
+				else
+				{
+					JumpString += lowerCharString;
+				}
+			}
+			// Handle special keys in filter mode
+			else if (isFilterModeOn && !string.IsNullOrEmpty(currentFilter))
+			{
+				switch (pressedKey)
+				{
+					case VirtualKey.Back when currentFilter.Length > 1:
+						shellPage.ShellViewModel.FilesAndFoldersFilter = currentFilter[..^1];
+						break;
+
+					case VirtualKey.Back when currentFilter.Length == 1:
+						shellPage.ShellViewModel.FilesAndFoldersFilter = string.Empty;
+						GeneralSettingsService.ShowFilterHeader = false;
+						break;
+				}
+			}
+
+			// Update selection in filter mode
+			if (isFilterModeOn)
 			{
-				char letter = args.Character;
-				JumpString += letter.ToString().ToLowerInvariant();
+				var filterText = shellPage.ShellViewModel.FilesAndFoldersFilter;
+				var matchedItem = shellPage.ShellViewModel.FilesAndFolders
+					.FirstOrDefault(item => !string.IsNullOrEmpty(filterText) &&
+										   item.Name?.Contains(filterText, StringComparison.OrdinalIgnoreCase) == true);
+
+				if (matchedItem != null)
+				{
+					ItemManipulationModel.SetSelectedItem(matchedItem);
+					ItemManipulationModel.ScrollIntoView(matchedItem);
+					ItemManipulationModel.FocusSelectedItems();
+				}
 			}
 		}
 

src/Files.App/Views/MainPage.xaml.cs

@@ -216,6 +216,13 @@ private async Task OnPreviewKeyDownAsync(KeyRoutedEventArgs e)
 					if (source?.FindAscendantOrSelf<TextBox>() is not null)
 						break;
 
+					// Prevent the Back and Space keys from executing a command if the keyboard
+					// typing behavior is set to filter items and a filter is currently applied.
+					if ((e.Key is VirtualKey.Back or VirtualKey.Space) &&
+						UserSettingsService.FoldersSettingsService.KeyboardTypingBehavior == KeyboardTypingBehavior.FilterItems &&
+						!string.IsNullOrEmpty(SidebarAdaptiveViewModel.PaneHolder?.ActivePaneOrColumn!.ShellViewModel.FilesAndFoldersFilter))
+						break;
+
 					// Execute command for hotkey
 					var command = Commands[hotKey];
 

src/Files.App/Views/Settings/AdvancedPage.xaml

@@ -8,6 +8,7 @@
 	xmlns:helpers="using:Files.App.Helpers"
 	xmlns:i="using:Microsoft.Xaml.Interactivity"
 	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	xmlns:uc="using:Files.App.UserControls"
 	xmlns:vm="using:Files.App.ViewModels.Settings"
 	xmlns:wctcontrols="using:CommunityToolkit.WinUI.Controls"
 	mc:Ignorable="d">
@@ -161,6 +162,18 @@
 				</ToggleSwitch>
 			</wctcontrols:SettingsCard>
 
+			<!--  Keyboard typing behavior  -->
+			<wctcontrols:SettingsCard Header="{helpers:ResourceString Name=KeyboardTypingBehavior}">
+				<wctcontrols:SettingsCard.HeaderIcon>
+					<FontIcon Glyph="&#xE765;" />
+				</wctcontrols:SettingsCard.HeaderIcon>
+
+				<uc:ComboBoxEx
+					AutomationProperties.Name="{helpers:ResourceString Name=KeyboardTypingBehavior}"
+					ItemsSource="{x:Bind ViewModel.KeyboardTypingBehaviors.Values}"
+					SelectedItem="{x:Bind ViewModel.KeyboardTypingBehavior, Mode=TwoWay}" />
+			</wctcontrols:SettingsCard>
+
 			<!--  Flatten options  -->
 			<wctcontrols:SettingsCard Description="{helpers:ResourceString Name=ShowFlattenOptionsDescription}" Header="{helpers:ResourceString Name=ShowFlattenOptions}">
 				<wctcontrols:SettingsCard.HeaderIcon>

src/Files.App/Views/Shells/ModernShellPage.xaml

@@ -149,7 +149,7 @@
 					VerticalAlignment="Center"
 					PlaceholderText="{helpers:ResourceString Name=Filename}"
 					PreviewKeyDown="FilterTextBox_PreviewKeyDown"
-					TextChanged="FilterTextBox_TextChanged" />
+					Text="{x:Bind ShellViewModel.FilesAndFoldersFilter, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
 			</StackPanel>
 		</Grid>