Feature: Display "Play all" button on toolbar when selecting multiple media files.

src/Files.App/Interacts/BaseLayoutCommandImplementationModel.cs

@@ -890,6 +890,11 @@ public Task InstallFont()
 			return Task.CompletedTask;
 		}
 
+		public async Task PlayAll()
+		{
+			await NavigationHelpers.OpenSelectedItems(associatedInstance);
+		}
+
 		#endregion Command Implementation
 	}
 }

src/Files.App/Interacts/BaseLayoutCommandsViewModel.cs

@@ -81,6 +81,7 @@ private void InitializeCommands()
 			RotateImageLeftCommand = new AsyncRelayCommand(CommandsModel.RotateImageLeft);
 			RotateImageRightCommand = new AsyncRelayCommand(CommandsModel.RotateImageRight);
 			InstallFontCommand = new AsyncRelayCommand(CommandsModel.InstallFont);
+			PlayAllCommand = new AsyncRelayCommand(CommandsModel.PlayAll);
 		}
 
 		#endregion Command Initialization
@@ -197,6 +198,8 @@ private void InitializeCommands()
 
 		public ICommand InstallFontCommand { get; private set; }
 
+		public ICommand PlayAllCommand { get; private set; }
+
 		#endregion Commands
 
 		#region IDisposable

src/Files.App/Interacts/IBaseLayoutCommandImplementationModel.cs

@@ -117,5 +117,7 @@ public interface IBaseLayoutCommandImplementationModel : IDisposable
 		Task RotateImageRight();
 
 		Task InstallFont();
+
+		Task PlayAll();
 	}
 }

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

@@ -2955,4 +2955,7 @@
   <data name="ShowHiddenItems" xml:space="preserve">
     <value>Show hidden items</value>
   </data>
+  <data name="PlayAll" xml:space="preserve">
+    <value>Play all</value>
+  </data>
 </root>

src/Files.App/UserControls/InnerNavigationToolbar.xaml

@@ -409,6 +409,17 @@
 						<local:ColoredIcon BaseLayerGlyph="&#xF041;" OverlayLayerGlyph="&#xF042;" />
 					</AppBarButton.Content>
 				</AppBarButton>
+				<AppBarButton
+					x:Name="PlayAllMediaButton"
+					x:Load="{x:Bind ViewModel.IsMultipleMediaFilesSelected, Mode=OneWay, FallbackValue=False}"
+					Command="{x:Bind ViewModel.PlayAllCommand, Mode=OneWay}"
+					Label="{helpers:ResourceString Name=PlayAll}"
+					LabelPosition="Default"
+					ToolTipService.ToolTip="{helpers:ResourceString Name=PlayAll}">
+					<AppBarButton.Icon>
+						<FontIcon Glyph="&#xE768;" />
+					</AppBarButton.Icon>
+				</AppBarButton>
 			</CommandBar.PrimaryCommands>
 		</CommandBar>
 		<CommandBar
@@ -570,7 +581,6 @@
 					<Flyout contract8Present:ShouldConstrainToRootBounds="False" Placement="Bottom">
 						<StackPanel Spacing="12">
 							<TextBlock FontWeight="Medium" Text="{helpers:ResourceString Name=NavToolbarLayout/Text}" />
-
 							<Grid ColumnSpacing="8" RowSpacing="8">
 								<Grid.RowDefinitions>
 									<RowDefinition MinHeight="30" />

src/Files.App/ViewModels/ToolbarViewModel.cs

@@ -1000,6 +1000,8 @@ private void SearchRegion_Escaped(object? sender, ISearchBox searchBox)
 
 		public ICommand? UpdateCommand { get; set; }
 
+		public ICommand? PlayAllCommand { get; set; }
+
 		public async Task SetPathBoxDropDownFlyoutAsync(MenuFlyout flyout, PathBoxItem pathItem, IShellPage shellPage)
 		{
 			var nextPathItemTitle = PathComponents[PathComponents.IndexOf(pathItem) + 1].Title;
@@ -1288,6 +1290,7 @@ public List<ListedItem> SelectedItems
 					OnPropertyChanged(nameof(IsImage));
 					OnPropertyChanged(nameof(IsMultipleImageSelected));
 					OnPropertyChanged(nameof(IsFont));
+					OnPropertyChanged(nameof(IsMultipleMediaFilesSelected));
 					OnPropertyChanged(nameof(HasAdditionalAction));
 					OnPropertyChanged(nameof(CanEmptyRecycleBin));
 					OnPropertyChanged(nameof(CanRestoreRecycleBin));
@@ -1313,6 +1316,7 @@ public List<ListedItem> SelectedItems
 		public bool IsMultipleImageSelected => SelectedItems is not null && SelectedItems.Count > 1 && SelectedItems.All(x => FileExtensionHelpers.IsImageFile(x.FileExtension)) && !InstanceViewModel.IsPageTypeRecycleBin;
 		public bool IsInfFile => SelectedItems is not null && SelectedItems.Count == 1 && FileExtensionHelpers.IsInfFile(SelectedItems.First().FileExtension) && !InstanceViewModel.IsPageTypeRecycleBin;
 		public bool IsFont => SelectedItems is not null && SelectedItems.Any() && SelectedItems.All(x => FileExtensionHelpers.IsFontFile(x.FileExtension)) && !InstanceViewModel.IsPageTypeRecycleBin;
+		public bool IsMultipleMediaFilesSelected => SelectedItems is not null && SelectedItems.Count > 1 && SelectedItems.All(x => FileExtensionHelpers.IsMediaFile(x.FileExtension)) && !InstanceViewModel.IsPageTypeRecycleBin;
 
 		public string ExtractToText
 			=> IsSelectionArchivesOnly ? SelectedItems.Count > 1 ? string.Format("ExtractToChildFolder".GetLocalizedResource(), $"*{Path.DirectorySeparatorChar}") : string.Format("ExtractToChildFolder".GetLocalizedResource() + "\\", Path.GetFileNameWithoutExtension(selectedItems.First().Name)) : "ExtractToChildFolder".GetLocalizedResource();

src/Files.App/Views/BaseShellPage.cs

@@ -646,6 +646,7 @@ protected void InitToolbarCommands()
 			ToolbarViewModel.RotateImageRightCommand = new RelayCommand(() => SlimContentPage?.CommandsViewModel.RotateImageRightCommand.Execute(null), () => SlimContentPage?.CommandsViewModel.RotateImageRightCommand.CanExecute(null) == true);
 			ToolbarViewModel.InstallFontCommand = new RelayCommand(() => SlimContentPage?.CommandsViewModel.InstallFontCommand.Execute(null));
 			ToolbarViewModel.UpdateCommand = new AsyncRelayCommand(async () => await updateSettingsService.DownloadUpdates());
+			ToolbarViewModel.PlayAllCommand = new RelayCommand(() => SlimContentPage?.CommandsViewModel.PlayAllCommand.Execute(null));
 		}
 
 		protected async Task<BaseLayout> GetContentOrNullAsync()

src/Files.Backend/Helpers/FileExtensionHelpers.cs

@@ -131,5 +131,16 @@ public static bool IsMsiFile(string? filePathToCheck)
 		/// <remarks>Vhd disk file types are; vhd, vhdx</remarks>
 		public static bool IsVhdFile(string? fileExtensionToCheck)
 			=> HasExtension(fileExtensionToCheck, ".vhd", ".vhdx");
+
+		/// <summary>
+		/// Check if the file extension is a media (audio/video) file.
+		/// </summary>
+		/// <param name="filePathToCheck">The file extension to check.</param>
+		/// <returns><c>true</c> if the filePathToCheck is a media file;
+		/// otherwise <c>false</c>.</returns>
+		public static bool IsMediaFile(string? filePathToCheck)
+			=> HasExtension(filePathToCheck, ".mp4", ".m4v", ".mp4v", ".3g2", ".3gp2", ".3gp", ".3gpp",
+				".mpg", ".mp2", ".mpeg", ".mpe", ".mpv", ".ogg", ".avi", ".wmv", ".mov", ".qt");
+
 	}
 }