Code Quality: Added feature flag to developer environment to enable 'Shelf Pane'

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

@@ -289,5 +289,10 @@ public interface IGeneralSettingsService : IBaseSettingsService, INotifyProperty
 		/// Gets or sets a value indicating the default arrangement for Dual Pane.
 		/// </summary>
 		ShellPaneArrangement ShellPaneArrangementOption { get; set; }
+
+		/// <summary>
+		/// Gets or sets a value indicating whether or not to show the shelf pane.
+		/// </summary>
+		bool ShowShelfPane { get; set; }
 	}
 }

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

@@ -357,6 +357,12 @@ public ShellPaneArrangement ShellPaneArrangementOption
 			set => Set((long)value);
 		}
 
+		public bool ShowShelfPane
+		{
+			get => Get(false);
+			set => Set(value);
+		}
+
 		protected override void RaiseOnSettingChangedEvent(object sender, SettingChangedEventArgs e)
 		{
 			base.RaiseOnSettingChangedEvent(sender, e);

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

@@ -4019,4 +4019,7 @@
   <data name="AlwaysSwitchToNewlyOpenedTab" xml:space="preserve">
     <value>Always switch focus to newly created tab</value>
   </data>
+  <data name="ShowShelfPane" xml:space="preserve">
+    <value>Show Shelf Pane</value>
+  </data>
 </root>

src/Files.App/UserControls/Pane/ShelfPane.xaml

@@ -0,0 +1,22 @@
+<!--  Copyright (c) Files Community. Licensed under the MIT License.  -->
+<UserControl
+	x:Class="Files.App.UserControls.ShelfPane"
+	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:controls="using:Files.App.Controls"
+	xmlns:converters="using:Files.App.Converters"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	xmlns:data="using:Files.App.Data.Items"
+	xmlns:helpers="using:Files.App.Helpers"
+	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	xmlns:usercontrols="using:Files.App.UserControls"
+	mc:Ignorable="d">
+
+	<Grid
+		Width="240"
+		Background="{ThemeResource App.Theme.InfoPane.BackgroundBrush}"
+		BackgroundSizing="InnerBorderEdge"
+		BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
+		BorderThickness="1"
+		CornerRadius="8" />
+</UserControl>

src/Files.App/UserControls/Pane/ShelfPane.xaml.cs

@@ -0,0 +1,15 @@
+// Copyright (c) Files Community
+// Licensed under the MIT License.
+
+using Microsoft.UI.Xaml.Controls;
+
+namespace Files.App.UserControls
+{
+	public sealed partial class ShelfPane : UserControl
+	{
+		public ShelfPane()
+		{
+			InitializeComponent();
+		}
+	}
+}

src/Files.App/ViewModels/MainPageViewModel.cs

@@ -20,6 +20,7 @@ public sealed class MainPageViewModel : ObservableObject
 		// Dependency injections
 
 		private IAppearanceSettingsService AppearanceSettingsService { get; } = Ioc.Default.GetRequiredService<IAppearanceSettingsService>();
+		private IGeneralSettingsService GeneralSettingsService { get; } = Ioc.Default.GetRequiredService<IGeneralSettingsService>();
 		private INetworkService NetworkService { get; } = Ioc.Default.GetRequiredService<INetworkService>();
 		private IUserSettingsService UserSettingsService { get; } = Ioc.Default.GetRequiredService<IUserSettingsService>();
 		private IResourcesService ResourcesService { get; } = Ioc.Default.GetRequiredService<IResourcesService>();
@@ -75,6 +76,9 @@ public bool ShouldPreviewPaneBeDisplayed
 			set => SetProperty(ref shouldPreviewPaneBeDisplayed, value);
 		}
 
+		public bool ShowShelfPane
+			=> GeneralSettingsService.ShowShelfPane && AppLifecycleHelper.AppEnvironment is AppEnvironment.Dev;
+
 		public Stretch AppThemeBackgroundImageFit
 			=> AppearanceSettingsService.AppThemeBackgroundImageFit;
 
@@ -130,6 +134,16 @@ public MainPageViewModel()
 						break;
 				}
 			};
+
+			GeneralSettingsService.PropertyChanged += (s, e) =>
+			{
+				switch (e.PropertyName)
+				{
+					case nameof(GeneralSettingsService.ShowShelfPane):
+						OnPropertyChanged(nameof(ShowShelfPane));
+						break;
+				}
+			};
 		}
 
 		// Methods

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

@@ -292,7 +292,7 @@ public bool IsSetAsOpenFileDialog
 			set => SetProperty(ref isSetAsOpenFileDialog, value);
 		}
 
-		public bool CanShowSetAsOpenFileDialog
+		public bool IsAppEnvironmentDev
 		{
 			get => AppLifecycleHelper.AppEnvironment is AppEnvironment.Dev;
 		}
@@ -366,6 +366,20 @@ public bool ShowFlattenOptions
 				OnPropertyChanged();
 			}
 		}
+
+		// TODO remove when feature is marked as stable
+		public bool ShowShelfPane
+		{
+			get => UserSettingsService.GeneralSettingsService.ShowShelfPane;
+			set
+			{
+				if (value == UserSettingsService.GeneralSettingsService.ShowShelfPane)
+					return;
+
+				UserSettingsService.GeneralSettingsService.ShowShelfPane = value;
+				OnPropertyChanged();
+			}
+		}
 
 		public async Task OpenFilesOnWindowsStartupAsync()
 		{

src/Files.App/Views/MainPage.xaml

@@ -193,6 +193,7 @@
 							MinWidth="208" />
 						<ColumnDefinition Width="Auto" />
 						<ColumnDefinition x:Name="PaneColumn" Width="Auto" />
+						<ColumnDefinition x:Name="ShelfPaneColumn" Width="Auto" />
 					</Grid.ColumnDefinitions>
 
 					<!--  File Navigation Toolbar  -->
@@ -247,6 +248,13 @@
 						ShowInfoText="{x:Bind SidebarAdaptiveViewModel.PaneHolder.ActivePaneOrColumn.InstanceViewModel.IsPageTypeNotHome, Mode=OneWay}"
 						Visibility="{x:Bind SidebarAdaptiveViewModel.PaneHolder.ActivePaneOrColumn.InstanceViewModel.IsPageTypeNotHome, Mode=OneWay}" />
 
+					<uc:ShelfPane
+						x:Name="ShelfPane"
+						Grid.Row="0"
+						Grid.RowSpan="2"
+						Grid.Column="3"
+						Margin="4,0,0,0"
+						x:Load="{x:Bind ViewModel.ShowShelfPane, Mode=OneWay}" />
 				</Grid>
 			</sidebar:SidebarView.InnerContent>
 		</sidebar:SidebarView>

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

@@ -169,7 +169,7 @@
 				x:Name="ReplaceOpenFileDialogSetting"
 				Title="{helpers:ResourceString Name=SettingsSetAsOpenDialog}"
 				HorizontalAlignment="Stretch"
-				x:Load="{x:Bind ViewModel.CanShowSetAsOpenFileDialog}">
+				x:Load="{x:Bind ViewModel.IsAppEnvironmentDev}">
 				<local:SettingsBlockControl.Icon>
 					<FontIcon Glyph="&#xE8E5;" />
 				</local:SettingsBlockControl.Icon>
@@ -185,6 +185,21 @@
 				</ToggleSwitch>
 			</local:SettingsBlockControl>
 
+			<!--  Show Shelf Pane  -->
+			<local:SettingsBlockControl
+				x:Name="ShowShelfPane"
+				Title="{helpers:ResourceString Name=ShowShelfPane}"
+				HorizontalAlignment="Stretch"
+				x:Load="{x:Bind ViewModel.IsAppEnvironmentDev}">
+				<local:SettingsBlockControl.Icon>
+					<FontIcon Glyph="&#xE90D;" />
+				</local:SettingsBlockControl.Icon>
+				<ToggleSwitch
+					AutomationProperties.Name="{helpers:ResourceString Name=ShowShelfPane}"
+					IsOn="{x:Bind ViewModel.ShowShelfPane, Mode=TwoWay}"
+					Style="{StaticResource RightAlignedToggleSwitchStyle}" />
+			</local:SettingsBlockControl>
+
 			<!--  Flatten options  -->
 			<local:SettingsBlockControl
 				Title="{helpers:ResourceString Name=ShowFlattenOptions}"