Console upgrades, PossibleCommands VM

src/AppCommon/FileTime.App.CommandPalette/ViewModels/CommandPaletteViewModel.cs

@@ -14,7 +14,7 @@ public class CommandPaletteViewModel : FuzzyPanelViewModel<ICommandPaletteEntryV
     private readonly ICommandPaletteService _commandPaletteService;
     private readonly IIdentifiableUserCommandService _identifiableUserCommandService;
     private readonly IUserCommandHandlerService _userCommandHandlerService;
-    private readonly IKeyboardConfigurationService _keyboardConfigurationService;
+    private readonly ICommandKeysHelperService _commandKeysHelperService;
     private readonly ILogger<CommandPaletteViewModel> _logger;
     string IModalViewModel.Name => "CommandPalette";
 
@@ -22,14 +22,14 @@ public class CommandPaletteViewModel : FuzzyPanelViewModel<ICommandPaletteEntryV
         ICommandPaletteService commandPaletteService,
         IIdentifiableUserCommandService identifiableUserCommandService,
         IUserCommandHandlerService userCommandHandlerService,
-        IKeyboardConfigurationService keyboardConfigurationService,
+        ICommandKeysHelperService commandKeysHelperService,
         ILogger<CommandPaletteViewModel> logger)
         : base((a, b) => a.Identifier == b.Identifier)
     {
         _commandPaletteService = commandPaletteService;
         _identifiableUserCommandService = identifiableUserCommandService;
         _userCommandHandlerService = userCommandHandlerService;
-        _keyboardConfigurationService = keyboardConfigurationService;
+        _commandKeysHelperService = commandKeysHelperService;
         _logger = logger;
         ShowWindow = _commandPaletteService.ShowWindow;
         UpdateFilteredMatchesInternal();
@@ -47,47 +47,10 @@ public class CommandPaletteViewModel : FuzzyPanelViewModel<ICommandPaletteEntryV
                 || c.Identifier.Contains(SearchText, StringComparison.OrdinalIgnoreCase)
             )
             .Select(c =>
-                (ICommandPaletteEntryViewModel) new CommandPaletteEntryViewModel(c.Identifier, c.Title, GetKeyConfigsString(c.Identifier))
+                (ICommandPaletteEntryViewModel) new CommandPaletteEntryViewModel(c.Identifier, c.Title, _commandKeysHelperService.GetKeyConfigsString(c.Identifier))
             )
             .ToList();
 
-    private string GetKeyConfigsString(string commandIdentifier)
-    {
-        var keyConfigs = GetKeyConfigsForCommand(commandIdentifier);
-        if (keyConfigs.Count == 0) return string.Empty;
-
-        return string.Join(
-            " ; ",
-            keyConfigs
-                .Select(ks =>
-                    string.Join(
-                        ", ",
-                        ks.Select(FormatKeyConfig)
-                    )
-                )
-        );
-    }
-
-    private string FormatKeyConfig(KeyConfig keyConfig)
-    {
-        var stringBuilder = new StringBuilder();
-
-        if (keyConfig.Ctrl) stringBuilder.Append("Ctrl + ");
-        if (keyConfig.Shift) stringBuilder.Append("Shift + ");
-        if (keyConfig.Alt) stringBuilder.Append("Alt + ");
-
-        stringBuilder.Append(keyConfig.Key.ToString());
-
-        return stringBuilder.ToString();
-    }
-
-    private List<List<KeyConfig>> GetKeyConfigsForCommand(string commandIdentifier)
-        => _keyboardConfigurationService
-            .AllShortcut
-            .Where(s => s.Command == commandIdentifier)
-            .Select(k => k.Keys)
-            .ToList();
-
     public override async Task<bool> HandleKeyDown(GeneralKeyEventArgs keyEventArgs)
     {
         if (keyEventArgs.Handled) return false;

src/AppCommon/FileTime.App.Core.Abstraction/Services/ICommandKeysHelperService.cs

@@ -0,0 +1,10 @@
+using FileTime.App.Core.Configuration;
+
+namespace FileTime.App.Core.Services;
+
+public interface ICommandKeysHelperService
+{
+    List<List<KeyConfig>> GetKeysForCommand(string commandName);
+    string GetKeyConfigsString(string commandIdentifier);
+    string FormatKeyConfig(KeyConfig keyConfig);
+}

src/AppCommon/FileTime.App.Core.Abstraction/Services/IPossibleCommandsService.cs

@@ -0,0 +1,13 @@
+using System.Collections.ObjectModel;
+using FileTime.App.Core.Configuration;
+
+namespace FileTime.App.Core.Services;
+
+public interface IPossibleCommandsService
+{
+    ReadOnlyObservableCollection<CommandBindingConfiguration> PossibleCommands { get; set; }
+    void Clear();
+    void Add(CommandBindingConfiguration commandBindingConfiguration);
+    void Remove(CommandBindingConfiguration commandBindingConfiguration);
+    void AddRange(IEnumerable<CommandBindingConfiguration> commandBindingConfigurations);
+}

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IAppState.cs

@@ -16,7 +16,6 @@ public interface IAppState
     IDeclarativeProperty<string?> RapidTravelTextDebounced { get; }
     IDeclarativeProperty<string?> ContainerStatus { get; }
     List<KeyConfig> PreviousKeys { get; }
-    List<CommandBindingConfiguration> PossibleCommands { get; set; }
     bool NoCommandFound { get; set; }
 
     void AddTab(ITabViewModel tabViewModel);

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IPossibleCommandEntryViewModel.cs

@@ -0,0 +1,8 @@
+namespace FileTime.App.Core.ViewModels;
+
+public interface IPossibleCommandEntryViewModel
+{
+    public string CommandName { get; }
+    public string Title { get; }
+    public string KeysText { get; }
+}

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IPossibleCommandsViewModel.cs

@@ -0,0 +1,8 @@
+using System.Collections.ObjectModel;
+
+namespace FileTime.App.Core.ViewModels;
+
+public interface IPossibleCommandsViewModel
+{
+    ObservableCollection<IPossibleCommandEntryViewModel> PossibleCommands { get; }
+}

src/AppCommon/FileTime.App.Core/FileTime.App.Core.csproj

@@ -30,6 +30,7 @@
     <ProjectReference Include="..\..\Core\FileTime.Core.Abstraction\FileTime.Core.Abstraction.csproj" />
     <ProjectReference Include="..\..\Core\FileTime.Core.Models\FileTime.Core.Models.csproj" />
     <ProjectReference Include="..\..\Library\Defer\Defer.csproj" />
+    <ProjectReference Include="..\..\Library\ObservableComputations.Extensions\ObservableComputations.Extensions.csproj" />
     <ProjectReference Include="..\..\Providers\FileTime.Providers.Local.Abstractions\FileTime.Providers.Local.Abstractions.csproj" />
     <ProjectReference Include="..\..\Providers\FileTime.Providers.LocalAdmin.Abstractions\FileTime.Providers.LocalAdmin.Abstractions.csproj" />
     <ProjectReference Include="..\..\Tools\FileTime.Tools\FileTime.Tools.csproj" />

src/AppCommon/FileTime.App.Core/Services/CommandKeysHelperService.cs

@@ -0,0 +1,52 @@
+using System.Text;
+using FileTime.App.Core.Configuration;
+
+namespace FileTime.App.Core.Services;
+
+public class CommandKeysHelperService : ICommandKeysHelperService
+{
+    private readonly IKeyboardConfigurationService _keyboardConfigurationService;
+
+    public CommandKeysHelperService(IKeyboardConfigurationService keyboardConfigurationService)
+    {
+        _keyboardConfigurationService = keyboardConfigurationService;
+    }
+
+    public List<List<KeyConfig>> GetKeysForCommand(string commandName)
+        => _keyboardConfigurationService
+            .AllShortcut
+            .Where(s => s.Command == commandName)
+            .Select(k => k.Keys)
+            .ToList();
+
+
+    public string GetKeyConfigsString(string commandIdentifier)
+    {
+        var keyConfigs = GetKeysForCommand(commandIdentifier);
+        if (keyConfigs.Count == 0) return string.Empty;
+
+        return string.Join(
+            " ; ",
+            keyConfigs
+                .Select(ks =>
+                    string.Join(
+                        ", ",
+                        ks.Select(FormatKeyConfig)
+                    )
+                )
+        );
+    }
+
+    public string FormatKeyConfig(KeyConfig keyConfig)
+    {
+        var stringBuilder = new StringBuilder();
+
+        if (keyConfig.Ctrl) stringBuilder.Append("Ctrl + ");
+        if (keyConfig.Shift) stringBuilder.Append("Shift + ");
+        if (keyConfig.Alt) stringBuilder.Append("Alt + ");
+
+        stringBuilder.Append(keyConfig.Key.ToString());
+
+        return stringBuilder.ToString();
+    }
+}

src/AppCommon/FileTime.App.Core/Services/DefaultModeKeyInputHandler.cs

@@ -21,6 +21,7 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
     private readonly ILogger<DefaultModeKeyInputHandler> _logger;
     private readonly IUserCommandHandlerService _userCommandHandlerService;
     private readonly IIdentifiableUserCommandService _identifiableUserCommandService;
+    private readonly IPossibleCommandsService _possibleCommandsService;
     private readonly BindedCollection<IModalViewModel> _openModals;
 
     public DefaultModeKeyInputHandler(
@@ -29,10 +30,12 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
         IKeyboardConfigurationService keyboardConfigurationService,
         ILogger<DefaultModeKeyInputHandler> logger,
         IUserCommandHandlerService userCommandHandlerService,
-        IIdentifiableUserCommandService identifiableUserCommandService)
+        IIdentifiableUserCommandService identifiableUserCommandService,
+        IPossibleCommandsService possibleCommandsService)
     {
         _appState = appState;
         _identifiableUserCommandService = identifiableUserCommandService;
+        _possibleCommandsService = possibleCommandsService;
         _keyboardConfigurationService = keyboardConfigurationService;
         _logger = logger;
         _modalService = modalService;
@@ -99,7 +102,7 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
             {
                 args.Handled = true;
                 _appState.PreviousKeys.Clear();
-                _appState.PossibleCommands = new();
+                _possibleCommandsService.Clear();
             }
         }
         /*else if (key == Key.Enter
@@ -113,7 +116,7 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
         {
             args.Handled = true;
             _appState.PreviousKeys.Clear();
-            _appState.PossibleCommands = new();
+            _possibleCommandsService.Clear();
             var command = _identifiableUserCommandService.GetCommand(selectedCommandBinding.Command);
             if (command is not null)
             {
@@ -123,7 +126,7 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
         else if (_keysToSkip.Any(k => k.AreKeysEqual(_appState.PreviousKeys)))
         {
             _appState.PreviousKeys.Clear();
-            _appState.PossibleCommands = new();
+            _possibleCommandsService.Clear();
             return;
         }
         else if (_appState.PreviousKeys.Count == 2)
@@ -131,7 +134,7 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
             args.Handled = true;
             _appState.NoCommandFound = true;
             _appState.PreviousKeys.Clear();
-            _appState.PossibleCommands = new();
+            _possibleCommandsService.Clear();
         }
         else
         {
@@ -145,7 +148,8 @@ public class DefaultModeKeyInputHandler : IDefaultModeKeyInputHandler
             }
             else
             {
-                _appState.PossibleCommands = possibleCommands;
+                _possibleCommandsService.Clear();
+                _possibleCommandsService.AddRange(possibleCommands);
             }
         }
     }

src/AppCommon/FileTime.App.Core/Services/PossibleCommandsService.cs

@@ -0,0 +1,31 @@
+using System.Collections.ObjectModel;
+using FileTime.App.Core.Configuration;
+
+namespace FileTime.App.Core.Services;
+
+public class PossibleCommandsService : IPossibleCommandsService
+{
+    private readonly ObservableCollection<CommandBindingConfiguration> _possibleCommands = new();
+    public ReadOnlyObservableCollection<CommandBindingConfiguration> PossibleCommands { get; set; }
+
+    public PossibleCommandsService()
+    {
+        PossibleCommands = new ReadOnlyObservableCollection<CommandBindingConfiguration>(_possibleCommands);
+    }
+
+    public void Clear() => _possibleCommands.Clear();
+
+    public void Add(CommandBindingConfiguration commandBindingConfiguration)
+        => _possibleCommands.Add(commandBindingConfiguration);
+
+    public void AddRange(IEnumerable<CommandBindingConfiguration> commandBindingConfigurations)
+    {
+        foreach (var commandBindingConfiguration in commandBindingConfigurations)
+        {
+            _possibleCommands.Add(commandBindingConfiguration);
+        }
+    }
+
+    public void Remove(CommandBindingConfiguration commandBindingConfiguration)
+        => _possibleCommands.Remove(commandBindingConfiguration);
+}

src/AppCommon/FileTime.App.Core/Startup.cs

@@ -33,6 +33,9 @@ public static class Startup
         serviceCollection.TryAddSingleton<IDefaultModeKeyInputHandler, DefaultModeKeyInputHandler>();
         serviceCollection.TryAddSingleton<IRapidTravelModeKeyInputHandler, RapidTravelModeKeyInputHandler>();
         serviceCollection.TryAddSingleton<IKeyboardConfigurationService, KeyboardConfigurationService>();
+        serviceCollection.TryAddSingleton<ICommandKeysHelperService, CommandKeysHelperService>();
+        serviceCollection.TryAddSingleton<IPossibleCommandsService, PossibleCommandsService>();
+        serviceCollection.TryAddSingleton<IPossibleCommandsViewModel, PossibleCommandsViewModel>();
 
         return serviceCollection
             .AddCommandHandlers()

src/AppCommon/FileTime.App.Core/ViewModels/AppStateBase.cs

@@ -4,9 +4,7 @@ using System.Reactive.Subjects;
 using DeclarativeProperty;
 using FileTime.App.Core.Configuration;
 using FileTime.App.Core.Models.Enums;
-using FileTime.App.Core.ViewModels.Timeline;
 using FileTime.Core.Models.Extensions;
-using MvvmGen;
 using MoreLinq;
 using PropertyChanged.SourceGenerator;
 
@@ -31,7 +29,6 @@ public abstract partial class AppStateBase : IAppState
 
     public IDeclarativeProperty<string?> ContainerStatus { get; }
     [Notify] public List<KeyConfig> PreviousKeys { get; } = new();
-    [Notify] public List<CommandBindingConfiguration> PossibleCommands { get; set; } = new();
     [Notify] public bool NoCommandFound { get; set; }
 
     protected AppStateBase()

src/AppCommon/FileTime.App.Core/ViewModels/PossibleCommandEntryViewModel.cs

@@ -0,0 +1,6 @@
+namespace FileTime.App.Core.ViewModels;
+
+public record PossibleCommandEntryViewModel(
+    string CommandName, 
+    string Title, 
+    string KeysText) : IPossibleCommandEntryViewModel;

src/AppCommon/FileTime.App.Core/ViewModels/PossibleCommandsViewModel.cs

@@ -0,0 +1,36 @@
+using System.Collections.ObjectModel;
+using FileTime.App.Core.Configuration;
+using FileTime.App.Core.Services;
+using ObservableComputations;
+
+namespace FileTime.App.Core.ViewModels;
+
+public class PossibleCommandsViewModel : IPossibleCommandsViewModel, IDisposable
+{
+    private readonly IIdentifiableUserCommandService _identifiableUserCommandService;
+    private readonly OcConsumer _ocConsumer = new();
+    public ObservableCollection<IPossibleCommandEntryViewModel> PossibleCommands { get; }
+
+    public PossibleCommandsViewModel(
+        IPossibleCommandsService possibleCommandsService,
+        IIdentifiableUserCommandService identifiableUserCommandService)
+    {
+        _identifiableUserCommandService = identifiableUserCommandService;
+        PossibleCommands = possibleCommandsService
+            .PossibleCommands
+            .Selecting(c => CreatePossibleCommandViewModel(c))
+            .For(_ocConsumer);
+    }
+    
+    private IPossibleCommandEntryViewModel CreatePossibleCommandViewModel(CommandBindingConfiguration commandBindingConfiguration)
+    {
+        var commandName = commandBindingConfiguration.Command;
+        var title = _identifiableUserCommandService.GetCommand(commandName)?.Title ?? commandName;
+        return new PossibleCommandEntryViewModel(
+            CommandName: commandName,
+            Title: title,
+            KeysText: commandBindingConfiguration.GetKeysDisplayText());
+    }
+
+    public void Dispose() => _ocConsumer.Dispose();
+}

src/ConsoleApp/FileTime.ConsoleUI.App.Abstractions/IConsoleAppState.cs

@@ -4,5 +4,4 @@ namespace FileTime.ConsoleUI.App;
 
 public interface IConsoleAppState : IAppState
 {
-    
 }

src/ConsoleApp/FileTime.ConsoleUI.App.Abstractions/IRootViewModel.cs

@@ -0,0 +1,11 @@
+using FileTime.App.Core.ViewModels;
+
+namespace FileTime.ConsoleUI.App;
+
+public interface IRootViewModel
+{
+    IConsoleAppState AppState { get; }
+    IPossibleCommandsViewModel PossibleCommands { get; }
+    string UserName { get; }
+    string MachineName { get; }
+}

src/ConsoleApp/FileTime.ConsoleUI.App/MainWindow.cs

@@ -1,5 +1,4 @@
-using DeclarativeProperty;
+using FileTime.App.Core.Models.Enums;
-using FileTime.App.Core.Models.Enums;
 using FileTime.App.Core.ViewModels;
 using FileTime.Core.Enums;
 using TerminalUI;
@@ -8,69 +7,103 @@ using TerminalUI.Controls;
 using TerminalUI.Extensions;
 using TerminalUI.Models;
 using TerminalUI.ViewExtensions;
-using ConsoleColor = TerminalUI.Color.ConsoleColor;
 
 namespace FileTime.ConsoleUI.App;
 
 public class MainWindow
 {
-    private readonly IConsoleAppState _consoleAppState;
+    private readonly IRootViewModel _rootViewModel;
     private readonly IApplicationContext _applicationContext;
     private readonly ITheme _theme;
 
     private IView _root;
 
     public MainWindow(
-        IConsoleAppState consoleAppState,
+        IRootViewModel rootViewModel,
         IApplicationContext applicationContext,
         ITheme theme)
     {
-        _consoleAppState = consoleAppState;
+        _rootViewModel = rootViewModel;
         _applicationContext = applicationContext;
         _theme = theme;
     }
 
     public void Initialize()
     {
-        var root = new Grid<IAppState>
+        var root = new Grid<IRootViewModel>
         {
-            DataContext = _consoleAppState,
+            DataContext = _rootViewModel,
             ApplicationContext = _applicationContext,
-            RowDefinitionsObject = "Auto *",
+            RowDefinitionsObject = "Auto * Auto",
             ChildInitializer =
             {
-                new Grid<IAppState>
+                new Grid<IRootViewModel>
                 {
-                    ColumnDefinitionsObject = "* Auto",
+                    ColumnDefinitionsObject = "Auto * Auto",
                     ChildInitializer =
                     {
-                        new TextBlock<IAppState>()
+                        new StackPanel<IRootViewModel>
+                        {
+                            Name = "username_panel",
+                            Orientation = Orientation.Horizontal,
+                            Margin = "0 0 1 0",
+                            ChildInitializer =
                             {
-                                Foreground = _theme.ContainerColor
+                                new TextBlock<IRootViewModel>()
+                                    .Setup(t => t.Bind(
+                                        t,
+                                        root => root.UserName,
+                                        tb => tb.Text
+                                    )),
+                                new TextBlock<IRootViewModel>()
+                                    .Setup(t => t.Bind(
+                                        t,
+                                        root => root.MachineName,
+                                        tb => tb.Text,
+                                        t => $"@{t}"
+                                    ))
                             }
-                            .Setup(t =>
+                        },
-                                t.Bind(
+                        new TextBlock<IRootViewModel>
-                                    t,
+                            {
-                                    appState => appState.SelectedTab.Value.CurrentLocation.Value.FullName.Path,
+                                Foreground = _theme.ContainerColor,
-                                    tb => tb.Text,
+                                Extensions =
-                                    value => value
+                                {
-                                )
+                                    new GridPositionExtension(1, 0)
-                            ),
+                                }
+                            }
+                            .Setup(t => t.Bind(
+                                t,
+                                root => root.AppState.SelectedTab.Value.CurrentLocation.Value.FullName.Path,
+                                tb => tb.Text
+                            )),
                         TabControl()
+                            .WithExtension(new GridPositionExtension(2, 0))
                     }
                 },
-                new Grid<IAppState>
+                new Grid<IRootViewModel>
                 {
                     ColumnDefinitionsObject = "* 4* 4*",
-                    ChildInitializer =
-                    {
-                        ParentsItemsView(),
-                        SelectedItemsView(),
-                        SelectedsItemsView(),
-                    },
                     Extensions =
                     {
                         new GridPositionExtension(0, 1)
+                    },
+                    ChildInitializer =
+                    {
+                        ParentsItemsView().WithExtension(new GridPositionExtension(0, 0)),
+                        SelectedItemsView().WithExtension(new GridPositionExtension(1, 0)),
+                        SelectedsItemsView().WithExtension(new GridPositionExtension(2, 0)),
+                    }
+                },
+                new Grid<IRootViewModel>
+                {
+                    Extensions =
+                    {
+                        new GridPositionExtension(0, 2)
+                    },
+                    ChildInitializer =
+                    {
+                        PossibleCommands()
                     }
                 }
             }
@@ -78,15 +111,58 @@ public class MainWindow
         _root = root;
     }
 
-    private IView<IAppState> TabControl()
+    private IView<IRootViewModel> PossibleCommands()
     {
-        var tabList = new ListView<IAppState, ITabViewModel>
+        //TODO: Create and use DataGrid
+        var commandBindings = new ListView<IRootViewModel, IPossibleCommandEntryViewModel>
+        {
+            ItemTemplate = _ =>
+            {
+                var grid = new Grid<IPossibleCommandEntryViewModel>
+                {
+                    ColumnDefinitionsObject = "10 *",
+                    ChildInitializer =
+                    {
+                        new TextBlock<IPossibleCommandEntryViewModel>()
+                            .Setup(t =>
+                                t.Bind(
+                                    t,
+                                    dc => dc.KeysText,
+                                    tb => tb.Text)
+                            ),
+                        new TextBlock<IPossibleCommandEntryViewModel>
+                        {
+                            Extensions =
+                            {
+                                new GridPositionExtension(1, 0)
+                            }
+                        }.Setup(t =>
+                            t.Bind(
+                                t,
+                                dc => dc.Title,
+                                tb => tb.Text)
+                        )
+                    }
+                };
+
+                return grid;
+            }
+        };
+
+        commandBindings.Bind(
+            commandBindings,
+            root => root.PossibleCommands.PossibleCommands,
+            v => v.ItemsSource,
+            d => d);
+
+        return commandBindings;
+    }
+
+    private IView<IRootViewModel> TabControl()
+    {
+        var tabList = new ListView<IRootViewModel, ITabViewModel>
         {
             Orientation = Orientation.Horizontal,
-            Extensions =
-            {
-                new GridPositionExtension(1, 0)
-            },
             ItemTemplate = item =>
             {
                 var textBlock = item.CreateChild<TextBlock<ITabViewModel>>();
@@ -96,6 +172,7 @@ public class MainWindow
                     textBlock,
                     dc => dc.TabNumber.ToString(),
                     tb => tb.Text,
+                    value => $" {value}",
                     fallbackValue: "?");
 
                 textBlock.Bind(
@@ -110,23 +187,17 @@ public class MainWindow
 
         tabList.Bind(
             tabList,
-            appState => appState == null ? null : appState.Tabs,
+            root => root.AppState.Tabs,
             v => v.ItemsSource);
 
         return tabList;
     }
 
-    private ListView<IAppState, IItemViewModel> SelectedItemsView()
+    private ListView<IRootViewModel, IItemViewModel> SelectedItemsView()
     {
-        var list = new ListView<IAppState, IItemViewModel>
+        var list = new ListView<IRootViewModel, IItemViewModel>
         {
-            DataContext = _consoleAppState,
+            ListPadding = 8
-            ApplicationContext = _applicationContext,
-            ListPadding = 8,
-            Extensions =
-            {
-                new GridPositionExtension(1, 0)
-            }
         };
 
         list.ItemTemplate = item =>
@@ -153,33 +224,22 @@ public class MainWindow
 
         list.Bind(
             list,
-            appState => appState == null ? null : appState.SelectedTab.Map(t => t == null ? null : t.CurrentItems).Switch(),
+            root => root.AppState.SelectedTab.Value.CurrentItems.Value,
             v => v.ItemsSource);
 
         list.Bind(
             list,
-            appState =>
+            root => root.AppState.SelectedTab.Value.CurrentSelectedItem.Value,
-                appState == null
-                    ? null
-                    : appState.SelectedTab.Value == null
-                        ? null
-                        : appState.SelectedTab.Value.CurrentSelectedItem.Value,
             v => v.SelectedItem);
 
         return list;
     }
 
-    private ListView<IAppState, IItemViewModel> SelectedsItemsView()
+    private ListView<IRootViewModel, IItemViewModel> SelectedsItemsView()
     {
-        var list = new ListView<IAppState, IItemViewModel>
+        var list = new ListView<IRootViewModel, IItemViewModel>
         {
-            DataContext = _consoleAppState,
+            ListPadding = 8
-            ApplicationContext = _applicationContext,
-            ListPadding = 8,
-            Extensions =
-            {
-                new GridPositionExtension(2, 0)
-            }
         };
 
         list.ItemTemplate = item =>
@@ -206,23 +266,17 @@ public class MainWindow
 
         list.Bind(
             list,
-            appState => appState == null ? null : appState.SelectedTab.Map(t => t == null ? null : t.SelectedsChildren).Switch(),
+            root => root.AppState.SelectedTab.Value.SelectedsChildren.Value,
             v => v.ItemsSource);
 
         return list;
     }
 
-    private ListView<IAppState, IItemViewModel> ParentsItemsView()
+    private ListView<IRootViewModel, IItemViewModel> ParentsItemsView()
     {
-        var list = new ListView<IAppState, IItemViewModel>
+        var list = new ListView<IRootViewModel, IItemViewModel>
         {
-            DataContext = _consoleAppState,
+            ListPadding = 8
-            ApplicationContext = _applicationContext,
-            ListPadding = 8,
-            Extensions =
-            {
-                new GridPositionExtension(0, 0)
-            }
         };
 
         list.ItemTemplate = item =>
@@ -249,67 +303,12 @@ public class MainWindow
 
         list.Bind(
             list,
-            appState => appState == null ? null : appState.SelectedTab.Map(t => t == null ? null : t.ParentsChildren).Switch(),
+            root => root.AppState.SelectedTab.Value.ParentsChildren.Value,
             v => v.ItemsSource);
 
         return list;
     }
 
-    private void TestGrid()
-    {
-        var grid = new Grid<object>
-        {
-            ApplicationContext = _applicationContext,
-            ColumnDefinitionsObject = "Auto Auto",
-            RowDefinitionsObject = "Auto Auto",
-            ChildInitializer =
-            {
-                new Rectangle<object>
-                {
-                    Fill = new ConsoleColor(System.ConsoleColor.Blue, ColorType.Foreground),
-                    Extensions =
-                    {
-                        new GridPositionExtension(0, 0)
-                    },
-                    Width = 2,
-                    Height = 2,
-                },
-                new Rectangle<object>
-                {
-                    Fill = new ConsoleColor(System.ConsoleColor.Red, ColorType.Foreground),
-                    Extensions =
-                    {
-                        new GridPositionExtension(0, 1)
-                    },
-                    Width = 3,
-                    Height = 3,
-                },
-                new Rectangle<object>
-                {
-                    Fill = new ConsoleColor(System.ConsoleColor.Green, ColorType.Foreground),
-                    Extensions =
-                    {
-                        new GridPositionExtension(1, 0)
-                    },
-                    Width = 4,
-                    Height = 4,
-                },
-                new Rectangle<object>
-                {
-                    Fill = new ConsoleColor(System.ConsoleColor.Yellow, ColorType.Foreground),
-                    Extensions =
-                    {
-                        new GridPositionExtension(1, 1)
-                    },
-                    Width = 5,
-                    Height = 5,
-                }
-            }
-        };
-
-        //_grid = grid;
-    }
-
     public IEnumerable<IView> RootViews() => new IView[]
     {
         _root

src/ConsoleApp/FileTime.ConsoleUI.App/RootViewModel.cs

@@ -0,0 +1,19 @@
+using FileTime.App.Core.ViewModels;
+
+namespace FileTime.ConsoleUI.App;
+
+public class RootViewModel : IRootViewModel
+{
+    public string UserName => Environment.UserName;
+    public string MachineName => Environment.MachineName;
+    public IPossibleCommandsViewModel PossibleCommands { get; }
+    public IConsoleAppState AppState { get; }
+    
+    public RootViewModel(
+        IConsoleAppState appState,
+        IPossibleCommandsViewModel possibleCommands)
+    {
+        AppState = appState;
+        PossibleCommands = possibleCommands;
+    }
+}

src/ConsoleApp/FileTime.ConsoleUI.App/Startup.cs

@@ -28,6 +28,7 @@ public static class Startup
         services.TryAddSingleton<ISystemClipboardService, ConsoleSystemClipboardService>();
         services.AddSingleton<CustomLoggerSink>();
         services.TryAddSingleton(new ApplicationConfiguration(true));
+        services.TryAddSingleton<IRootViewModel, RootViewModel>();
 
         services.Configure<ConsoleApplicationConfiguration>(configuration);
 

src/FileTime.sln

@@ -123,6 +123,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CircularBuffer", "Library\C
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FileTime.ConsoleUI.Styles", "ConsoleApp\FileTime.ConsoleUI.Styles\FileTime.ConsoleUI.Styles.csproj", "{CCB6F86A-7E80-448E-B543-DF9DB337C42A}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ObservableComputations.Extensions", "Library\ObservableComputations.Extensions\ObservableComputations.Extensions.csproj", "{6C3C3151-9341-4792-9B0B-A11C0658524E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -333,6 +335,10 @@ Global
 		{CCB6F86A-7E80-448E-B543-DF9DB337C42A}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{CCB6F86A-7E80-448E-B543-DF9DB337C42A}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{CCB6F86A-7E80-448E-B543-DF9DB337C42A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6C3C3151-9341-4792-9B0B-A11C0658524E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6C3C3151-9341-4792-9B0B-A11C0658524E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6C3C3151-9341-4792-9B0B-A11C0658524E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6C3C3151-9341-4792-9B0B-A11C0658524E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -390,6 +396,7 @@ Global
 		{2F01FC4C-D942-48B0-B61C-7C5BEAED4787} = {07CA18AA-B85D-4DEE-BB86-F569F6029853}
 		{AF4FE804-12D9-46E2-A584-BFF6D4509766} = {07CA18AA-B85D-4DEE-BB86-F569F6029853}
 		{CCB6F86A-7E80-448E-B543-DF9DB337C42A} = {CAEEAD3C-41EB-405C-ACA9-BA1E4C352549}
+		{6C3C3151-9341-4792-9B0B-A11C0658524E} = {07CA18AA-B85D-4DEE-BB86-F569F6029853}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {859FB3DF-C60A-46B1-82E5-90274905D1EF}

src/GuiApp/Avalonia/FileTime.GuiApp.App/Converters/CommandToCommandNameConverter.cs

@@ -1,21 +0,0 @@
-using System.Globalization;
-using Avalonia.Data.Converters;
-using FileTime.App.Core.UserCommand;
-
-namespace FileTime.GuiApp.App.Converters;
-
-public class CommandToCommandNameConverter : IValueConverter
-{
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-    {
-        if(value is not IUserCommand command) return value;
-
-        //TODO: implement
-        return command.ToString();
-    }
-
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-    {
-        throw new NotImplementedException();
-    }
-}

src/GuiApp/Avalonia/FileTime.GuiApp.App/Resources/Converters.axaml

@@ -34,7 +34,6 @@
             <converters:CompareConverter ComparisonCondition="{x:Static converters:ComparisonCondition.NotEqual}" x:Key="NotEqualsConverter" />
             <converters:CompareConverter ComparisonCondition="{x:Static converters:ComparisonCondition.GreaterThan}" x:Key="GreaterThanConverter" />
             <converters:ExceptionToStringConverter x:Key="ExceptionToStringConverter" />
-            <converters:CommandToCommandNameConverter x:Key="CommandToCommandNameConverter" />
             <converters:ItemToImageConverter x:Key="ItemToImageConverter" />
             <converters:StringReplaceConverter
                 NewValue="/"

src/GuiApp/Avalonia/FileTime.GuiApp.App/ViewModels/IMainWindowViewModel.cs

@@ -19,5 +19,6 @@ public interface IMainWindowViewModel : IMainWindowViewModelBase
     IAdminElevationManager AdminElevationManager { get; }
     IClipboardService ClipboardService { get; }
     ITimelineViewModel TimelineViewModel { get; }
+    IPossibleCommandsViewModel PossibleCommands { get; }
     Task RunOrOpenItem(IItemViewModel itemViewModel);
 }

src/GuiApp/Avalonia/FileTime.GuiApp.App/ViewModels/MainWindowViewModel.cs

@@ -37,6 +37,7 @@ namespace FileTime.GuiApp.App.ViewModels;
 [Inject(typeof(IClipboardService), PropertyAccessModifier = AccessModifier.Public)]
 [Inject(typeof(IModalService), PropertyName = "_modalService")]
 [Inject(typeof(ITimelineViewModel), PropertyAccessModifier = AccessModifier.Public)]
+[Inject(typeof(IPossibleCommandsViewModel), PropertyName = "PossibleCommands",PropertyAccessModifier = AccessModifier.Public)]
 public partial class MainWindowViewModel : IMainWindowViewModel
 {
     public bool Loading => false;

src/GuiApp/Avalonia/FileTime.GuiApp.App/Views/MainWindow.axaml

@@ -750,7 +750,7 @@
                                 </StackPanel>
                             </Grid>
 
-                            <Grid IsVisible="{Binding AppState.PossibleCommands.Count, Converter={StaticResource NotEqualsConverter}, ConverterParameter=0}">
+                            <Grid IsVisible="{Binding PossibleCommands.PossibleCommands.Count, Converter={StaticResource NotEqualsConverter}, ConverterParameter=0}">
                                 <Grid.RowDefinitions>
                                     <RowDefinition Height="1" />
                                     <RowDefinition Height="Auto" />
@@ -763,17 +763,17 @@
                                     Margin="10,0"
                                     VerticalAlignment="Center" />
 
-                                <ItemsRepeater Grid.Row="1" ItemsSource="{Binding AppState.PossibleCommands}">
+                                <ItemsRepeater Grid.Row="1" ItemsSource="{Binding PossibleCommands.PossibleCommands}">
                                     <ItemsRepeater.ItemTemplate>
-                                        <DataTemplate x:DataType="configuration:CommandBindingConfiguration">
+                                        <DataTemplate x:DataType="corevm:IPossibleCommandEntryViewModel">
                                             <Grid>
                                                 <Grid.ColumnDefinitions>
                                                     <ColumnDefinition Width="200" />
                                                     <ColumnDefinition Width="*" />
                                                 </Grid.ColumnDefinitions>
 
-                                                <TextBlock Text="{Binding KeysDisplayText}" />
+                                                <TextBlock Text="{Binding KeysText}" />
-                                                <TextBlock Grid.Column="1" Text="{Binding Command, Converter={StaticResource CommandToCommandNameConverter}}" />
+                                                <TextBlock Grid.Column="1" Text="{Binding Title}" />
                                             </Grid>
                                         </DataTemplate>
                                     </ItemsRepeater.ItemTemplate>

src/Library/ObservableComputations.Extensions/Extensions.cs

@@ -0,0 +1,13 @@
+using System.Collections.ObjectModel;
+using System.Linq.Expressions;
+
+namespace ObservableComputations;
+
+public static class Extensions
+{
+    [ObservableComputationsCall]
+    public static Selecting<TSourceItem, TResultItem> Selecting<TSourceItem, TResultItem>(
+        this ReadOnlyObservableCollection<TSourceItem> source,
+        Expression<Func<TSourceItem, TResultItem>> selectorExpression)
+        => new(source, selectorExpression);
+}

src/Library/ObservableComputations.Extensions/ObservableComputations.Extensions.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <RootNamespace>ObservableComputations</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="ObservableComputations" Version="2.3.0" />
+  </ItemGroup>
+
+</Project>

src/Library/TerminalUI/ApplicationContext.cs

@@ -9,6 +9,7 @@ public class ApplicationContext : IApplicationContext
     public ILoggerFactory? LoggerFactory { get; init; }
     public IEventLoop EventLoop { get; init; }
     public bool IsRunning { get; set; }
+    public char EmptyCharacter { get; init; } = ' ';
 
     public ApplicationContext()
     {

src/Library/TerminalUI/Binding.cs

@@ -20,7 +20,7 @@ public class Binding<TDataContext, TExpressionResult, TResult> : IDisposable
 
     public Binding(
         IView<TDataContext> dataSourceView,
-        Expression<Func<TDataContext?, TExpressionResult>> dataContextExpression,
+        Expression<Func<TDataContext?, TExpressionResult>> dataSourceExpression,
         object? propertySource,
         PropertyInfo targetProperty,
         Func<TExpressionResult, TResult> converter,
@@ -28,18 +28,18 @@ public class Binding<TDataContext, TExpressionResult, TResult> : IDisposable
     )
     {
         ArgumentNullException.ThrowIfNull(dataSourceView);
-        ArgumentNullException.ThrowIfNull(dataContextExpression);
+        ArgumentNullException.ThrowIfNull(dataSourceExpression);
         ArgumentNullException.ThrowIfNull(targetProperty);
         ArgumentNullException.ThrowIfNull(converter);
 
         _dataSourceView = dataSourceView;
-        _dataContextMapper = dataContextExpression.Compile();
+        _dataContextMapper = dataSourceExpression.Compile();
         _propertySource = propertySource;
         _targetProperty = targetProperty;
         _converter = converter;
         _fallbackValue = fallbackValue;
 
-        InitTrackingTree(dataContextExpression);
+        InitTrackingTree(dataSourceExpression);
 
         UpdateTrackers();
 
@@ -55,8 +55,8 @@ public class Binding<TDataContext, TExpressionResult, TResult> : IDisposable
     {
         if (propertySource is IDisposableCollection propertySourceDisposableCollection)
         {
-            propertySourceDisposableCollection.AddDisposable(this);
             _propertySourceDisposableCollection = propertySourceDisposableCollection;
+            propertySourceDisposableCollection.AddDisposable(this);
         }
     }
 

src/Library/TerminalUI/Controls/ChildContainerView.cs

@@ -41,6 +41,14 @@ public abstract class ChildContainerView<T> : View<T>, IChildContainer<T>
         };
     }
 
+    protected override void AttachChildren()
+    {
+        foreach (var child in Children)
+        {
+            child.Attached = true;
+        }
+    }
+
     public override TChild AddChild<TChild>(TChild child)
     {
         child = base.AddChild(child);

src/Library/TerminalUI/Controls/ContentView.cs

@@ -1,16 +1,65 @@
-using TerminalUI.Models;
+using PropertyChanged.SourceGenerator;
+using TerminalUI.Models;
 using TerminalUI.Traits;
 
 namespace TerminalUI.Controls;
 
-public abstract class ContentView<T>: View<T>, IContentRenderer
+public abstract partial class ContentView<T> : View<T>, IContentRenderer<T>
 {
+    private bool _placeholderRenderDone;
+    [Notify] private RenderMethod _contentRendererMethod;
+    private IView<T>? _content;
+
+    public IView<T>? Content
+    {
+        get => _content;
+        set
+        {
+            if (Equals(value, _content)) return;
+
+            if (_content is not null)
+            {
+                RemoveChild(_content);
+            }
+
+            _content = value;
+
+            if (_content is not null)
+            {
+                AddChild(_content);
+            }
+
+            OnPropertyChanged();
+        }
+    }
+
     protected ContentView()
     {
-        ContentRendererMethod = DefaultContentRender;
+        _contentRendererMethod = DefaultContentRender;
+        RerenderProperties.Add(nameof(Content));
+        RerenderProperties.Add(nameof(ContentRendererMethod));
     }
-    public IView? Content { get; set; }
-    public Action<Position, Size> ContentRendererMethod { get; set; }
 
-    private void DefaultContentRender(Position position, Size size) => Content?.Render(position, size);
+    protected override void AttachChildren()
+    {
+        base.AttachChildren();
+        if (Content is not null)
+        {
+            Content.Attached = true;
+        }
+    }
+
+    private bool DefaultContentRender(RenderContext renderContext, Position position, Size size)
+    {
+        if (Content is null)
+        {
+            if (_placeholderRenderDone) return false;
+            _placeholderRenderDone = true;
+            RenderEmpty(renderContext, position, size);
+            return true;
+        }
+
+        _placeholderRenderDone = false;
+        return Content.Render(renderContext, position, size);
+    }
 }

src/Library/TerminalUI/Controls/Grid.cs

@@ -1,4 +1,5 @@
 using System.Collections.ObjectModel;
+using System.Diagnostics;
 using Microsoft.Extensions.Logging;
 using TerminalUI.Extensions;
 using TerminalUI.Models;
@@ -8,15 +9,79 @@ namespace TerminalUI.Controls;
 
 public class Grid<T> : ChildContainerView<T>
 {
+    private List<RowDefinition> _rowDefinitions = new() {RowDefinition.Star(1)};
+    private List<ColumnDefinition> _columnDefinitions = new() {ColumnDefinition.Star(1)};
     private ILogger<Grid<T>>? Logger => ApplicationContext?.LoggerFactory?.CreateLogger<Grid<T>>();
 
-    private delegate void WithSizes(Span<int> widths, Span<int> heights);
+    private delegate void WithSizes(RenderContext renderContext, Span<int> widths, Span<int> heights);
 
-    private delegate TResult WithSizes<TResult>(Span<int> widths, Span<int> heights);
+    private delegate TResult WithSizes<TResult>(RenderContext renderContext, Span<int> widths, Span<int> heights);
 
     private const int ToBeCalculated = -1;
-    public ObservableCollection<RowDefinition> RowDefinitions { get; } = new() {RowDefinition.Star(1)};
+
-    public ObservableCollection<ColumnDefinition> ColumnDefinitions { get; } = new() {ColumnDefinition.Star(1)};
+    public IReadOnlyList<RowDefinition> RowDefinitions
+    {
+        get => _rowDefinitions;
+        set
+        {
+            var nextValue = value;
+            if (value.Count == 0)
+            {
+                nextValue = new List<RowDefinition> {RowDefinition.Star(1)};
+            }
+
+            var needUpdate = nextValue.Count != _rowDefinitions.Count;
+            if (!needUpdate)
+            {
+                for (var i = 0; i < nextValue.Count; i++)
+                {
+                    if (!nextValue[i].Equals(_rowDefinitions[i]))
+                    {
+                        needUpdate = true;
+                        break;
+                    }
+                }
+            }
+
+            if (needUpdate)
+            {
+                _rowDefinitions = nextValue.ToList();
+                OnPropertyChanged();
+            }
+        }
+    }
+
+    public IReadOnlyList<ColumnDefinition> ColumnDefinitions
+    {
+        get => _columnDefinitions;
+        set
+        {
+            var nextValue = value;
+            if (value.Count == 0)
+            {
+                nextValue = new List<ColumnDefinition> {ColumnDefinition.Star(1)};
+            }
+
+            var needUpdate = nextValue.Count != _columnDefinitions.Count;
+            if (!needUpdate)
+            {
+                for (var i = 0; i < nextValue.Count; i++)
+                {
+                    if (!nextValue[i].Equals(_columnDefinitions[i]))
+                    {
+                        needUpdate = true;
+                        break;
+                    }
+                }
+            }
+
+            if (needUpdate)
+            {
+                _columnDefinitions = nextValue.ToList();
+                OnPropertyChanged();
+            }
+        }
+    }
 
     public object? ColumnDefinitionsObject
     {
@@ -25,11 +90,7 @@ public class Grid<T> : ChildContainerView<T>
         {
             if (value is IEnumerable<ColumnDefinition> columnDefinitions)
             {
-                ColumnDefinitions.Clear();
+                ColumnDefinitions = columnDefinitions.ToList();
-                foreach (var columnDefinition in columnDefinitions)
-                {
-                    ColumnDefinitions.Add(columnDefinition);
-                }
             }
             else if (value is string s)
             {
@@ -49,11 +110,7 @@ public class Grid<T> : ChildContainerView<T>
         {
             if (value is IEnumerable<RowDefinition> rowDefinitions)
             {
-                RowDefinitions.Clear();
+                RowDefinitions = rowDefinitions.ToList();
-                foreach (var rowDefinition in rowDefinitions)
-                {
-                    RowDefinitions.Add(rowDefinition);
-                }
             }
             else if (value is string s)
             {
@@ -66,85 +123,135 @@ public class Grid<T> : ChildContainerView<T>
         }
     }
 
-    public override Size GetRequestedSize()
+    protected override Size CalculateSize()
-        => WithCalculatedSize((columnWidths, rowHeights) =>
+        => WithCalculatedSize(
-        {
+            RenderContext.Empty,
-            var width = 0;
+            new Option<Size>(new Size(0, 0), false),
-            var height = 0;
+            (_, columnWidths, rowHeights) =>
-
-            for (var i = 0; i < columnWidths.Length; i++)
             {
-                width += columnWidths[i];
+                var width = 0;
-            }
+                var height = 0;
 
-            for (var i = 0; i < rowHeights.Length; i++)
+                for (var i = 0; i < columnWidths.Length; i++)
+                {
+                    width += columnWidths[i];
+                }
+
+                for (var i = 0; i < rowHeights.Length; i++)
+                {
+                    height += rowHeights[i];
+                }
+
+                return new Size(width, height);
+            });
+
+    protected override bool DefaultRenderer(RenderContext renderContext, Position position, Size size)
+        => WithCalculatedSize(
+            renderContext,
+            new Option<Size>(size, true),
+            (context, columnWidths, rowHeights) =>
             {
-                height += rowHeights[i];
+                foreach (var child in Children)
-            }
-
-            return new Size(width, height);
-        }, new Option<Size>(new Size(0, 0), false));
-
-    protected override void DefaultRenderer(Position position, Size size)
-        => WithCalculatedSize((columnWidths, rowHeights) =>
-        {
-            foreach (var child in Children)
-            {
-                var positionExtension = child.GetExtension<GridPositionExtension>();
-                var x = positionExtension?.Column ?? 0;
-                var y = positionExtension?.Row ?? 0;
-
-                if (x > columnWidths.Length)
                 {
-                    Logger?.LogWarning("Child {Child} is out of bounds, x: {X}, y: {Y}", child, x, y);
+                    var (x, y) = GetViewColumnAndRow(child, columnWidths.Length, rowHeights.Length);
-                    x = 0;
+
+                    var width = columnWidths[x];
+                    var height = rowHeights[y];
+
+                    var left = position.X;
+                    var top = position.Y;
+
+                    for (var i = 0; i < x; i++)
+                    {
+                        left += columnWidths[i];
+                    }
+
+                    for (var i = 0; i < y; i++)
+                    {
+                        top += rowHeights[i];
+                    }
+
+                    child.Render(context, new Position(left, top), new Size(width, height));
                 }
 
-                if (y > rowHeights.Length)
+                return true;
-                {
-                    Logger?.LogWarning("Child {Child} is out of bounds, x: {X}, y: {Y}", child, x, y);
-                    y = 0;
-                }
 
-                var width = columnWidths[x];
+                /*var viewsByPosition = GroupViewsByPosition(columnWidths, rowHeights);
-                var height = rowHeights[y];
+                CleanUnusedArea(viewsByPosition, columnWidths, rowHeights);*/
+            });
 
-                var left = 0;
+    /*private void CleanUnusedArea(Dictionary<(int, int),List<IView>> viewsByPosition, Span<int> columnWidths, Span<int> rowHeights)
-                var top = 0;
-
-                for (var i = 0; i < x; i++)
-                {
-                    left += columnWidths[i];
-                }
-
-                for (var i = 0; i < y; i++)
-                {
-                    top += rowHeights[i];
-                }
-
-                child.Render(new Position(position.X + left, position.Y + top), new Size(width, height));
-            }
-        }, new Option<Size>(size, true));
-
-    private void WithCalculatedSize(WithSizes actionWithSizes, Option<Size> size)
     {
-        WithCalculatedSize(Helper, size);
+        for (var x = 0; x < columnWidths.Length; x++)
-
-        object? Helper(Span<int> widths, Span<int> heights)
         {
-            actionWithSizes(widths, heights);
+            for (var y = 0; y < rowHeights.Length; y++)
+            {
+                if (!viewsByPosition.TryGetValue((x, y), out var list)) continue;
+                
+                
+            }
+        }
+    }*/
+
+    /*private Dictionary<(int, int), List<IView>> GroupViewsByPosition(int columns, int rows)
+    {
+        Dictionary<ValueTuple<int, int>, List<IView>> viewsByPosition = new();
+        foreach (var child in Children)
+        {
+            var (x, y) = GetViewColumnAndRow(child, columns, rows);
+            if (viewsByPosition.TryGetValue((x, y), out var list))
+            {
+                list.Add(child);
+            }
+            else
+            {
+                viewsByPosition[(x, y)] = new List<IView> {child};
+            }
+        }
+
+        return viewsByPosition;
+    }*/
+
+    private ValueTuple<int, int> GetViewColumnAndRow(IView view, int columns, int rows)
+    {
+        var positionExtension = view.GetExtension<GridPositionExtension>();
+        var x = positionExtension?.Column ?? 0;
+        var y = positionExtension?.Row ?? 0;
+
+        if (x > columns)
+        {
+            Logger?.LogWarning("Child {Child} is out of bounds, x: {X}, y: {Y}", view, x, y);
+            x = 0;
+        }
+
+        if (y > rows)
+        {
+            Logger?.LogWarning("Child {Child} is out of bounds, x: {X}, y: {Y}", view, x, y);
+            y = 0;
+        }
+
+        return (x, y);
+    }
+
+    private void WithCalculatedSize(RenderContext renderContext, Option<Size> size, WithSizes actionWithSizes)
+    {
+        WithCalculatedSize(renderContext, size, Helper);
+
+        object? Helper(RenderContext renderContext1, Span<int> widths, Span<int> heights)
+        {
+            actionWithSizes(renderContext1, widths, heights);
             return null;
         }
     }
 
-    private TResult WithCalculatedSize<TResult>(WithSizes<TResult> actionWithSizes, Option<Size> size)
+    private TResult WithCalculatedSize<TResult>(RenderContext renderContext, Option<Size> size, WithSizes<TResult> actionWithSizes)
     {
         //TODO: Optimize it, dont calculate all of these, only if there is Auto value(s)
         var columns = ColumnDefinitions.Count;
         var rows = RowDefinitions.Count;
 
-        if (columns < 1) columns = 1;
+        Debug.Assert(columns > 0, "Columns must contain at least one element");
-        if (rows < 1) rows = 1;
+        Debug.Assert(rows > 0, "Rows must contain at least one element");
 
         Span<int> allWidth = stackalloc int[columns * rows];
         Span<int> allHeight = stackalloc int[columns * rows];
@@ -152,9 +259,7 @@ public class Grid<T> : ChildContainerView<T>
         foreach (var child in Children)
         {
             var childSize = child.GetRequestedSize();
-            var positionExtension = child.GetExtension<GridPositionExtension>();
+            var (x, y) = GetViewColumnAndRow(child, columns, rows);
-            var x = positionExtension?.Column ?? 0;
-            var y = positionExtension?.Row ?? 0;
 
             allWidth.SetToMatrix(childSize.Width, x, y, columns);
             allHeight.SetToMatrix(childSize.Height, x, y, columns);
@@ -246,60 +351,64 @@ public class Grid<T> : ChildContainerView<T>
             }
         }
 
-        return actionWithSizes(columnWidths, rowHeights);
+        return actionWithSizes(renderContext, columnWidths, rowHeights);
     }
 
     public void SetRowDefinitions(string value)
     {
         var values = value.Split(' ');
-        RowDefinitions.Clear();
+        var rowDefinitions = new List<RowDefinition>();
 
         foreach (var v in values)
         {
             if (v == "Auto")
             {
-                RowDefinitions.Add(RowDefinition.Auto);
+                rowDefinitions.Add(RowDefinition.Auto);
             }
             else if (v.EndsWith("*"))
             {
                 var starValue = v.Length == 1 ? 1 : int.Parse(v[..^1]);
-                RowDefinitions.Add(RowDefinition.Star(starValue));
+                rowDefinitions.Add(RowDefinition.Star(starValue));
             }
             else if (int.TryParse(v, out var pixelValue))
             {
-                RowDefinitions.Add(RowDefinition.Pixel(pixelValue));
+                rowDefinitions.Add(RowDefinition.Pixel(pixelValue));
             }
             else
             {
                 throw new ArgumentException("Invalid row definition: " + v);
             }
         }
+
+        RowDefinitions = rowDefinitions;
     }
 
     public void SetColumnDefinitions(string value)
     {
         var values = value.Split(' ');
-        ColumnDefinitions.Clear();
+        var columnDefinitions = new List<ColumnDefinition>();
 
         foreach (var v in values)
         {
             if (v == "Auto")
             {
-                ColumnDefinitions.Add(ColumnDefinition.Auto);
+                columnDefinitions.Add(ColumnDefinition.Auto);
             }
             else if (v.EndsWith("*"))
             {
                 var starValue = v.Length == 1 ? 1 : int.Parse(v[..^1]);
-                ColumnDefinitions.Add(ColumnDefinition.Star(starValue));
+                columnDefinitions.Add(ColumnDefinition.Star(starValue));
             }
             else if (int.TryParse(v, out var pixelValue))
             {
-                ColumnDefinitions.Add(ColumnDefinition.Pixel(pixelValue));
+                columnDefinitions.Add(ColumnDefinition.Pixel(pixelValue));
             }
             else
             {
                 throw new ArgumentException("Invalid column definition: " + v);
             }
         }
+
+        ColumnDefinitions = columnDefinitions;
     }
 }

src/Library/TerminalUI/Controls/IView.cs

@@ -4,23 +4,29 @@ using TerminalUI.Traits;
 
 namespace TerminalUI.Controls;
 
+public delegate bool RenderMethod(RenderContext renderContext, Position position, Size size);
+
 public interface IView : INotifyPropertyChanged, IDisposableCollection
 {
     object? DataContext { get; set; }
     int? MinWidth { get; set; }
     int? MaxWidth { get; set; }
     int? Width { get; set; }
+    int ActualWidth { get; }
     int? MinHeight { get; set; }
     int? MaxHeight { get; set; }
     int? Height { get; set; }
+    int ActualHeight { get; }
+    Margin Margin { get; set; }
     bool Attached { get; set; }
-    Size GetRequestedSize();
+    string? Name { get; set; }
     IApplicationContext? ApplicationContext { get; set; }
     List<object> Extensions { get; }
-    
+    RenderMethod RenderMethod { get; set; }
-    Action<Position, Size> RenderMethod { get; set; }
     event Action<IView> Disposed;
-    void Render(Position position, Size size);
+
+    Size GetRequestedSize();
+    bool Render(RenderContext renderContext, Position position, Size size);
 }
 
 public interface IView<T> : IView
@@ -39,8 +45,10 @@ public interface IView<T> : IView
     TChild CreateChild<TChild, TDataContext>(Func<T?, TDataContext?> dataContextMapper)
         where TChild : IView<TDataContext>, new();
 
-    public TChild AddChild<TChild>(TChild child) where TChild : IView<T>;
+    TChild AddChild<TChild>(TChild child) where TChild : IView<T>;
 
-    public TChild AddChild<TChild, TDataContext>(TChild child, Func<T?, TDataContext?> dataContextMapper)
+    TChild AddChild<TChild, TDataContext>(TChild child, Func<T?, TDataContext?> dataContextMapper)
         where TChild : IView<TDataContext>;
+
+    void RemoveChild<TDataContext>(IView<TDataContext> child);
 }

src/Library/TerminalUI/Controls/ListView.cs

@@ -1,5 +1,6 @@
 using System.Buffers;
 using System.Collections.ObjectModel;
+using System.Collections.Specialized;
 using DeclarativeProperty;
 using PropertyChanged.SourceGenerator;
 using TerminalUI.Models;
@@ -79,18 +80,30 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
 
             if (_itemsSource is IDeclarativeProperty<ObservableCollection<TItem>> observableDeclarativeProperty)
             {
-                observableDeclarativeProperty.PropertyChanged += (_, _) => ApplicationContext?.EventLoop.RequestRerender();
+                throw new NotSupportedException();
-                _getItems = () => observableDeclarativeProperty.Value;
             }
             else if (_itemsSource is IDeclarativeProperty<ReadOnlyObservableCollection<TItem>> readOnlyObservableDeclarativeProperty)
             {
-                readOnlyObservableDeclarativeProperty.PropertyChanged += (_, _) => ApplicationContext?.EventLoop.RequestRerender();
+                throw new NotSupportedException();
-                _getItems = () => readOnlyObservableDeclarativeProperty.Value;
             }
             else if (_itemsSource is IDeclarativeProperty<IEnumerable<TItem>> enumerableDeclarativeProperty)
             {
-                enumerableDeclarativeProperty.PropertyChanged += (_, _) => ApplicationContext?.EventLoop.RequestRerender();
+                throw new NotSupportedException();
-                _getItems = () => enumerableDeclarativeProperty.Value;
+            }
+
+            if (_itemsSource is ObservableCollection<TItem> observableDeclarative)
+            {
+                ((INotifyCollectionChanged) observableDeclarative).CollectionChanged +=
+                    (_, _) => ApplicationContext?.EventLoop.RequestRerender();
+
+                _getItems = () => observableDeclarative;
+            }
+            else if (_itemsSource is ReadOnlyObservableCollection<TItem> readOnlyObservableDeclarative)
+            {
+                ((INotifyCollectionChanged) readOnlyObservableDeclarative).CollectionChanged +=
+                    (_, _) => ApplicationContext?.EventLoop.RequestRerender();
+
+                _getItems = () => readOnlyObservableDeclarative;
             }
             else if (_itemsSource is ICollection<TItem> collection)
                 _getItems = () => collection;
@@ -111,7 +124,7 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
         }
     }
 
-    public Func<ListViewItem<TItem>, IView?> ItemTemplate { get; set; } = DefaultItemTemplate;
+    public Func<ListViewItem<TItem>, IView<TItem>?> ItemTemplate { get; set; } = DefaultItemTemplate;
 
     public ListView()
     {
@@ -120,7 +133,7 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
         RerenderProperties.Add(nameof(Orientation));
     }
 
-    public override Size GetRequestedSize()
+    protected override Size CalculateSize()
     {
         InstantiateItemViews();
         if (_listViewItems is null || _listViewItemLength == 0)
@@ -147,19 +160,16 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
         }
     }
 
-    protected override void DefaultRenderer(Position position, Size size)
+    protected override bool DefaultRenderer(RenderContext renderContext, Position position, Size size)
-    {
+        => Orientation == Orientation.Vertical
-        if (Orientation == Orientation.Vertical)
+            ? RenderVertical(renderContext, position, size)
-            RenderVertical(position, size);
+            : RenderHorizontal(renderContext, position, size);
-        else
-            RenderHorizontal(position, size);
-    }
 
-    private void RenderHorizontal(Position position, Size size)
+    private bool RenderHorizontal(RenderContext renderContext, Position position, Size size)
     {
         //Note: no support for same width elements
         var listViewItems = InstantiateItemViews();
-        if (listViewItems.Length == 0) return;
+        if (listViewItems.Length == 0) return false;
 
         Span<Size> requestedSizes = stackalloc Size[_listViewItemLength];
 
@@ -215,20 +225,22 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
                 width = size.Width - deltaX;
             }
 
-            item.Render(position with {X = position.X + deltaX}, size with {Width = width});
+            item.Render(renderContext, position with {X = position.X + deltaX}, size with {Width = width});
             deltaX = nextDeltaX;
         }
+
+        return true;
     }
 
-    private void RenderVertical(Position position, Size size)
+    private bool RenderVertical(RenderContext renderContext, Position position, Size size)
     {
         //Note: only same height is supported
         var requestedItemSize = _requestedItemSize;
         if (requestedItemSize.Height == 0 || requestedItemSize.Width == 0)
-            return;
+            return false;
 
         var listViewItems = InstantiateItemViews();
-        if (listViewItems.Length == 0) return;
+        if (listViewItems.Length == 0) return false;
 
         var itemsToRender = listViewItems.Length;
         var heightNeeded = requestedItemSize.Height * listViewItems.Length;
@@ -264,7 +276,7 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
         for (var i = renderStartIndex; i < lastItemIndex; i++)
         {
             var item = listViewItems[i];
-            item.Render(position with {Y = position.Y + deltaY}, requestedItemSize with {Width = size.Width});
+            item.Render(renderContext, position with {Y = position.Y + deltaY}, requestedItemSize with {Width = size.Width});
             deltaY += requestedItemSize.Height;
         }
 
@@ -276,6 +288,8 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
             driver.SetCursorPosition(position with {Y = position.Y + i});
             driver.Write(placeholder);
         }
+
+        return true;
     }
 
     private Span<ListViewItem<TItem>> InstantiateItemViews()
@@ -300,11 +314,16 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
             {
                 var dataContext = items[i];
                 var child = CreateChild<ListViewItem<TItem>, TItem>(_ => dataContext);
-                child.Content = ItemTemplate(child);
+                var newContent = ItemTemplate(child);
-                ItemTemplate(child);
+                child.Content = newContent;
                 newListViewItems[i] = child;
             }
 
+            if (_listViewItems is not null)
+            {
+                ListViewItemPool.Return(_listViewItems);
+            }
+
             _listViewItems = newListViewItems;
             _listViewItemLength = items.Count;
             listViewItems = newListViewItems[..items.Count];
@@ -324,5 +343,5 @@ public partial class ListView<TDataContext, TItem> : View<TDataContext>
         return _listViewItems;
     }
 
-    private static IView? DefaultItemTemplate(ListViewItem<TItem> listViewItem) => null;
+    private static IView<TItem>? DefaultItemTemplate(ListViewItem<TItem> listViewItem) => null;
 }

src/Library/TerminalUI/Controls/ListViewItem.cs

@@ -4,13 +4,13 @@ namespace TerminalUI.Controls;
 
 public class ListViewItem<T> : ContentView<T>
 {
-    public override Size GetRequestedSize()
+    protected override Size CalculateSize()
     {
         if (Content is null) return new Size(0, 0);
         return Content.GetRequestedSize();
     }
 
-    protected override void DefaultRenderer(Position position, Size size)
+    protected override bool DefaultRenderer(RenderContext renderContext, Position position, Size size)
     {
         if (ContentRendererMethod is null)
         {
@@ -22,6 +22,6 @@ public class ListViewItem<T> : ContentView<T>
                 + DataContext?.GetType().Name);
         }
 
-        ContentRendererMethod(position, size);
+        return ContentRendererMethod(renderContext, position, size);
     }
 }

src/Library/TerminalUI/Controls/Rectangle.cs

@@ -6,19 +6,38 @@ namespace TerminalUI.Controls;
 
 public partial class Rectangle<T> : View<T>
 {
-    [Notify] private IColor? _fill;
+    private record RenderState(
-    public override Size GetRequestedSize() => new(Width ?? 0, Height ?? 0);
+        Position Position,
+        Size Size,
+        IColor? Fill);
 
-    protected override void DefaultRenderer(Position position, Size size)
+    private RenderState? _lastRenderState;
+
+    [Notify] private IColor? _fill;
+    protected override Size CalculateSize() => new(Width ?? 0, Height ?? 0);
+
+    protected override bool DefaultRenderer(RenderContext renderContext, Position position, Size size)
     {
-        var s = new string('█', Width ?? size.Width);
+        var renderState = new RenderState(position, size, Fill);
-        ApplicationContext?.ConsoleDriver.SetBackgroundColor(Fill ?? new Color.ConsoleColor(System.ConsoleColor.Yellow, ColorType.Background));
+        if (!NeedsRerender(renderState) || Fill is null) return false;
-        ApplicationContext?.ConsoleDriver.SetForegroundColor(Fill ?? new Color.ConsoleColor(System.ConsoleColor.Yellow, ColorType.Foreground));
+        _lastRenderState = renderState;
-        var height = Height ?? size.Height;
+
+        var driver = renderContext.ConsoleDriver;
+
+        var s = new string('█', size.Width);
+        driver.SetBackgroundColor(Fill);
+        driver.SetForegroundColor(Fill);
+
+        var height = size.Height;
         for (var i = 0; i < height; i++)
         {
-            ApplicationContext?.ConsoleDriver.SetCursorPosition(position with {Y = position.Y + i});
+            driver.SetCursorPosition(position with {Y = position.Y + i});
-            ApplicationContext?.ConsoleDriver.Write(s);
+            driver.Write(s);
         }
+        
+        return true;
     }
+
+    private bool NeedsRerender(RenderState renderState)
+        => _lastRenderState is null || _lastRenderState != renderState;
 }

src/Library/TerminalUI/Controls/StackPanel.cs

@@ -9,7 +9,7 @@ public partial class StackPanel<T> : ChildContainerView<T>
     private readonly Dictionary<IView, Size> _requestedSizes = new();
     [Notify] private Orientation _orientation = Orientation.Vertical;
 
-    public override Size GetRequestedSize()
+    protected override Size CalculateSize()
     {
         _requestedSizes.Clear();
         var width = 0;
@@ -35,20 +35,38 @@ public partial class StackPanel<T> : ChildContainerView<T>
         return new Size(width, height);
     }
 
-    protected override void DefaultRenderer(Position position, Size size)
+    protected override bool DefaultRenderer(RenderContext renderContext, Position position, Size size)
     {
         var delta = 0;
+        var neededRerender = false;
         foreach (var child in Children)
         {
             if (!_requestedSizes.TryGetValue(child, out var childSize)) throw new Exception("Child size not found");
+
             var childPosition = Orientation == Orientation.Vertical
                 ? position with {Y = position.Y + delta}
                 : position with {X = position.X + delta};
-            child.Render(childPosition, childSize);
+
+            var endX = position.X + size.Width;
+            var endY = position.Y + size.Height;
+            
+            if (childPosition.X > endX || childPosition.Y > endY) break;
+            if (childPosition.X + childSize.Width > endX)
+            {
+                childSize = childSize with {Width = endX - childPosition.X};
+            }
+            if (childPosition.Y + childSize.Height > endY)
+            {
+                childSize = childSize with {Height = endY - childPosition.Y};
+            }
+
+            neededRerender = child.Render(renderContext, childPosition, childSize) || neededRerender;
 
             delta += Orientation == Orientation.Vertical
                 ? childSize.Height
                 : childSize.Width;
         }
+
+        return neededRerender;
     }
 }

src/Library/TerminalUI/Controls/TextBlock.cs

@@ -1,5 +1,7 @@
-using PropertyChanged.SourceGenerator;
+using System.ComponentModel;
+using PropertyChanged.SourceGenerator;
 using TerminalUI.Color;
+using TerminalUI.ConsoleDrivers;
 using TerminalUI.Extensions;
 using TerminalUI.Models;
 
@@ -7,9 +9,16 @@ namespace TerminalUI.Controls;
 
 public partial class TextBlock<T> : View<T>
 {
-    private record RenderContext(Position Position, string? Text, IColor? Foreground, IColor? Background);
+    private record RenderState(
+        Position Position,
+        Size Size,
+        string? Text,
+        IColor? Foreground,
+        IColor? Background);
 
-    private RenderContext? _renderContext;
+    private RenderState? _lastRenderState;
+    private string[]? _textLines;
+    private bool _placeholderRenderDone;
 
     [Notify] private string? _text = string.Empty;
     [Notify] private IColor? _foreground;
@@ -28,23 +37,41 @@ public partial class TextBlock<T> : View<T>
         RerenderProperties.Add(nameof(Foreground));
         RerenderProperties.Add(nameof(Background));
         RerenderProperties.Add(nameof(TextAlignment));
+
+        ((INotifyPropertyChanged) this).PropertyChanged += (o, e) =>
+        {
+            if (e.PropertyName == nameof(Text))
+            {
+                _textLines = Text?.Split(Environment.NewLine);
+            }
+        };
     }
 
-    public override Size GetRequestedSize() => new(Text?.Length ?? 0, 1);
+    protected override Size CalculateSize() => new(_textLines?.Max(l => l.Length) ?? 0, _textLines?.Length ?? 0);
 
-    protected override void DefaultRenderer(Position position, Size size)
+    protected override bool DefaultRenderer(RenderContext renderContext, Position position, Size size)
     {
-        if (size.Width == 0 || size.Height == 0) return;
+        if (size.Width == 0 || size.Height == 0) return false;
 
-        var driver = ApplicationContext!.ConsoleDriver;
+        var driver = renderContext.ConsoleDriver;
-        var renderContext = new RenderContext(position, Text, _foreground, _background);
+        var renderState = new RenderState(position, size, Text, _foreground, _background);
-        if (!NeedsRerender(renderContext)) return;
+        if (!NeedsRerender(renderState)) return false;
 
-        _renderContext = renderContext;
+        _lastRenderState = renderState;
 
-        if (Text is null) return;
+        if (_textLines is null)
+        {
+            if (_placeholderRenderDone)
+            {
+                _placeholderRenderDone = true;
+                RenderEmpty(renderContext, position, size);
+            }
+
+            return false;
+        }
+
+        _placeholderRenderDone = false;
 
-        driver.SetCursorPosition(position);
         driver.ResetColor();
         if (Foreground is { } foreground)
         {
@@ -56,19 +83,31 @@ public partial class TextBlock<T> : View<T>
             driver.SetBackgroundColor(background);
         }
 
-        var text = TextAlignment switch
+        RenderText(_textLines, driver, position, size);
-        {
-            TextAlignment.Right => string.Format($"{{0,{size.Width}}}", Text),
-            _ => string.Format($"{{0,{-size.Width}}}", Text)
-        };
-        if (text.Length > size.Width)
-        {
-            text = text[..size.Width];
-        }
 
-        driver.Write(text);
+        return true;
     }
 
-    private bool NeedsRerender(RenderContext renderContext)
+    private void RenderText(string[] textLines, IConsoleDriver driver, Position position, Size size)
-        => _renderContext is null || _renderContext != renderContext;
+    {
+        for (var i = 0; i < textLines.Length; i++)
+        {
+            var text = textLines[i];
+            text = TextAlignment switch
+            {
+                TextAlignment.Right => string.Format($"{{0,{size.Width}}}", text),
+                _ => string.Format($"{{0,{-size.Width}}}", text)
+            };
+            if (text.Length > size.Width)
+            {
+                text = text[..size.Width];
+            }
+
+            driver.SetCursorPosition(position with {Y = position.Y + i});
+            driver.Write(text);
+        }
+    }
+
+    private bool NeedsRerender(RenderState renderState)
+        => _lastRenderState is null || _lastRenderState != renderState;
 }

src/Library/TerminalUI/Controls/View.cs

@@ -13,9 +13,13 @@ public abstract partial class View<T> : IView<T>
     [Notify] private int? _minWidth;
     [Notify] private int? _maxWidth;
     [Notify] private int? _width;
+    [Notify] private int _actualWidth;
     [Notify] private int? _minHeight;
     [Notify] private int? _maxHeight;
     [Notify] private int? _height;
+    [Notify] private int _actualHeight;
+    [Notify] private Margin _margin = new Margin(0, 0, 0, 0);
+    [Notify] private string? _name;
     [Notify] private IApplicationContext? _applicationContext;
     private bool _attached;
 
@@ -32,17 +36,50 @@ public abstract partial class View<T> : IView<T>
             }
         }
     }
+
     public List<object> Extensions { get; } = new();
-    public Action<Position, Size> RenderMethod { get; set; }
+    public RenderMethod RenderMethod { get; set; }
     public event Action<IView>? Disposed;
     protected List<string> RerenderProperties { get; } = new();
 
     protected View()
     {
         RenderMethod = DefaultRenderer;
+
+        RerenderProperties.Add(nameof(MinWidth));
+        RerenderProperties.Add(nameof(MaxWidth));
+        RerenderProperties.Add(nameof(MinHeight));
+        RerenderProperties.Add(nameof(MaxHeight));
+        RerenderProperties.Add(nameof(Margin));
+
         ((INotifyPropertyChanged) this).PropertyChanged += Handle_PropertyChanged;
     }
-    public abstract Size GetRequestedSize();
+
+    public virtual Size GetRequestedSize()
+    {
+        var size = CalculateSize();
+
+        if (MinWidth.HasValue && size.Width < MinWidth.Value)
+            size = size with {Width = MinWidth.Value};
+        else if (MaxWidth.HasValue && size.Width > MaxWidth.Value)
+            size = size with {Width = MaxWidth.Value};
+
+        if (MinHeight.HasValue && size.Height < MinHeight.Value)
+            size = size with {Height = MinHeight.Value};
+        else if (MaxHeight.HasValue && size.Height > MaxHeight.Value)
+            size = size with {Height = MaxHeight.Value};
+
+        if (Margin.Left != 0 || Margin.Right != 0)
+            size = size with {Width = size.Width + Margin.Left + Margin.Right};
+
+        if (Margin.Top != 0 || Margin.Bottom != 0)
+            size = size with {Height = size.Height + Margin.Top + Margin.Bottom};
+
+        return size;
+    }
+
+    protected abstract Size CalculateSize();
+
 
     protected virtual void AttachChildren()
     {
@@ -50,7 +87,8 @@ public abstract partial class View<T> : IView<T>
 
     private void Handle_PropertyChanged(object? sender, PropertyChangedEventArgs e)
     {
-        if (e.PropertyName is not null
+        if (Attached
+            && e.PropertyName is not null
             && (e.PropertyName == nameof(IView.DataContext)
                 || RerenderProperties.Contains(e.PropertyName)
             )
@@ -60,10 +98,16 @@ public abstract partial class View<T> : IView<T>
         }
     }
 
-    protected abstract void DefaultRenderer(Position position, Size size);
+    protected abstract bool DefaultRenderer(RenderContext renderContext, Position position, Size size);
 
-    public void Render(Position position, Size size)
+    public bool Render(RenderContext renderContext, Position position, Size size)
     {
+        if (!Attached)
+            throw new InvalidOperationException("Cannot render unattached view");
+
+        ActualWidth = size.Width;
+        ActualHeight = size.Height;
+
         if (RenderMethod is null)
         {
             throw new NullReferenceException(
@@ -74,7 +118,31 @@ public abstract partial class View<T> : IView<T>
                 + DataContext?.GetType().Name);
         }
 
-        RenderMethod(position, size);
+        if (Margin.Left != 0 || Margin.Top != 0 || Margin.Right != 0 || Margin.Bottom != 0)
+        {
+            position = new Position(
+                X: position.X + Margin.Left,
+                Y: position.Y + Margin.Top
+            );
+
+            size = new Size(
+                size.Width - Margin.Left - Margin.Right,
+                size.Height - Margin.Top - Margin.Bottom
+            );
+        }
+
+        return RenderMethod(renderContext, position, size);
+    }
+
+    protected void RenderEmpty(RenderContext renderContext, Position position, Size size)
+    {
+        var driver = renderContext.ConsoleDriver;
+        var placeHolder = new string(ApplicationContext!.EmptyCharacter, size.Width);
+        for (var i = 0; i < size.Height; i++)
+        {
+            driver.SetCursorPosition(position with {Y = position.Y + i});
+            driver.Write(placeHolder);
+        }
     }
 
     public TChild CreateChild<TChild>() where TChild : IView<T>, new()
@@ -93,9 +161,9 @@ public abstract partial class View<T> : IView<T>
     public virtual TChild AddChild<TChild>(TChild child) where TChild : IView<T>
     {
         child.DataContext = DataContext;
-        child.ApplicationContext = ApplicationContext;
+        CopyCommonPropertiesToNewChild(child);
 
-        var mapper = new DataContextMapper<T>(this, d => child.DataContext = d);
+        var mapper = new DataContextMapper<T, T>(this, child, d => d);
         AddDisposable(mapper);
         child.AddDisposable(mapper);
 
@@ -106,15 +174,36 @@ public abstract partial class View<T> : IView<T>
         where TChild : IView<TDataContext>
     {
         child.DataContext = dataContextMapper(DataContext);
-        child.ApplicationContext = ApplicationContext;
+        CopyCommonPropertiesToNewChild(child);
 
-        var mapper = new DataContextMapper<T>(this, d => child.DataContext = dataContextMapper(d));
+        var mapper = new DataContextMapper<T, TDataContext>(this, child, dataContextMapper);
         AddDisposable(mapper);
         child.AddDisposable(mapper);
 
         return child;
     }
 
+    private void CopyCommonPropertiesToNewChild(IView child)
+    {
+        child.ApplicationContext = ApplicationContext;
+        child.Attached = Attached;
+    }
+
+    public virtual void RemoveChild<TDataContext>(IView<TDataContext> child)
+    {
+        var mappers = _disposables
+            .Where(d => d is DataContextMapper<T, TDataContext> mapper && mapper.Target == child)
+            .ToList();
+
+        foreach (var mapper in mappers)
+        {
+            mapper.Dispose();
+            RemoveDisposable(mapper);
+        }
+
+        child.Attached = false;
+    }
+
     public void AddDisposable(IDisposable disposable) => _disposables.Add(disposable);
     public void RemoveDisposable(IDisposable disposable) => _disposables.Remove(disposable);
 

src/Library/TerminalUI/DataContextMapper.cs

@@ -3,25 +3,32 @@ using TerminalUI.Controls;
 
 namespace TerminalUI;
 
-public class DataContextMapper<T> : IDisposable
+public class DataContextMapper<TSource, TTarget> : IDisposable
 {
-    private readonly IView<T> _source;
+    private readonly Func<TSource?, TTarget?> _mapper;
-    private readonly Action<T?> _setter;
+    public IView<TSource> Source { get; }
+    public IView<TTarget> Target { get; }
 
-    public DataContextMapper(IView<T> source, Action<T?> setter)
+    public DataContextMapper(IView<TSource> source, IView<TTarget> target, Func<TSource?, TTarget?> mapper)
     {
+        _mapper = mapper;
         ArgumentNullException.ThrowIfNull(source);
 
-        _source = source;
+        Source = source;
-        _setter = setter;
+        Target = target;
         source.PropertyChanged += SourceOnPropertyChanged;
     }
 
     private void SourceOnPropertyChanged(object? sender, PropertyChangedEventArgs e)
     {
         if (e.PropertyName != nameof(IView<object>.DataContext)) return;
-        _setter(_source.DataContext);
+        Target.DataContext = _mapper(Source.DataContext);
     }
 
-    public void Dispose() => _source.PropertyChanged -= SourceOnPropertyChanged;
+    public void Dispose()
+    {
+        Source.PropertyChanged -= SourceOnPropertyChanged;
+        Source.RemoveDisposable(this);
+        Target.RemoveDisposable(this);
+    }
 }

src/Library/TerminalUI/EventLoop.cs

@@ -45,11 +45,12 @@ public class EventLoop : IEventLoop
         }
 
         var size = _applicationContext.ConsoleDriver.GetWindowSize();
+        var renderContext = new RenderContext(_applicationContext.ConsoleDriver);
         foreach (var view in viewsToRender)
         {
             view.Attached = true;
             view.GetRequestedSize();
-            view.Render(new Position(0, 0), size);
+            view.Render(renderContext, new Position(0, 0), size);
         }
     }
 

src/Library/TerminalUI/Extensions/Binding.cs

@@ -9,7 +9,7 @@ public static class Binding
     public static Binding<TDataContext, TResult, TResult> Bind<TView, TDataContext, TResult>(
         this TView targetView,
         IView<TDataContext> dataSourceView,
-        Expression<Func<TDataContext?, TResult>> dataContextExpression,
+        Expression<Func<TDataContext?, TResult>> dataSourceExpression,
         Expression<Func<TView, TResult>> propertyExpression,
         TResult? fallbackValue = default)
     {
@@ -18,7 +18,7 @@ public static class Binding
 
         return new Binding<TDataContext, TResult, TResult>(
             dataSourceView,
-            dataContextExpression,
+            dataSourceExpression,
             targetView,
             propertyInfo,
             value => value,
@@ -29,7 +29,7 @@ public static class Binding
     public static Binding<TDataContext, TExpressionResult, TResult> Bind<TView, TDataContext, TExpressionResult, TResult>(
         this TView targetView,
         IView<TDataContext> dataSourceView,
-        Expression<Func<TDataContext?, TExpressionResult>> dataContextExpression,
+        Expression<Func<TDataContext?, TExpressionResult>> dataSourceExpression,
         Expression<Func<TView, TResult>> propertyExpression,
         Func<TExpressionResult, TResult> converter,
         TResult? fallbackValue = default)
@@ -39,7 +39,7 @@ public static class Binding
 
         return new Binding<TDataContext, TExpressionResult, TResult>(
             dataSourceView,
-            dataContextExpression,
+            dataSourceExpression,
             targetView,
             propertyInfo,
             converter,

src/Library/TerminalUI/Extensions/ViewExtensions.cs

@@ -6,6 +6,12 @@ public static class ViewExtensions
 {
     public static T? GetExtension<T>(this IView view)
         => (T?) view.Extensions.FirstOrDefault(e => e is T);
+    
+    public static IView<TDataContext> WithExtension<TDataContext>(this IView<TDataContext> view, object extension)
+    {
+        view.Extensions.Add(extension);
+        return view;
+    }
 
     public static ChildWithDataContextMapper<TSourceDataContext, TTargetDataContext> WithDataContextMapper<TSourceDataContext, TTargetDataContext>(
         this IView<TTargetDataContext> view,

src/Library/TerminalUI/IApplicationContext.cs

@@ -9,4 +9,5 @@ public interface IApplicationContext
     bool IsRunning { get; set; }
     IConsoleDriver ConsoleDriver { get; init; }
     ILoggerFactory? LoggerFactory { get; init; }
+    char EmptyCharacter { get; init; }
 }

src/Library/TerminalUI/Models/Margin.cs

@@ -0,0 +1,18 @@
+namespace TerminalUI.Models;
+
+public record Margin(int Left, int Top, int Right, int Bottom)
+{
+    public static implicit operator Margin(int value) => new(value, value, value, value);
+    public static implicit operator Margin((int Left, int Top, int Right, int Bottom) value) => new(value.Left, value.Top, value.Right, value.Bottom);
+    public static implicit operator Margin(string s)
+    {
+        var parts = s.Split(' ');
+        return parts.Length switch
+        {
+            1 => new Margin(int.Parse(parts[0])),
+            2 => new Margin(int.Parse(parts[0]), int.Parse(parts[1]), int.Parse(parts[0]), int.Parse(parts[1])),
+            4 => new Margin(int.Parse(parts[0]), int.Parse(parts[1]), int.Parse(parts[2]), int.Parse(parts[3])),
+            _ => throw new ArgumentException("Invalid margin format", nameof(s))
+        };
+    }
+}

src/Library/TerminalUI/Models/RenderContext.cs

@@ -0,0 +1,18 @@
+using TerminalUI.ConsoleDrivers;
+
+namespace TerminalUI.Models;
+
+public readonly ref struct RenderContext
+{
+    private static int _renderId = 0;
+    public readonly int RenderId;
+    public readonly IConsoleDriver ConsoleDriver;
+
+    public RenderContext(IConsoleDriver consoleDriver)
+    {
+        ConsoleDriver = consoleDriver;
+        RenderId = _renderId++;
+    }
+    
+    public static RenderContext Empty => new(null!);
+}

src/Library/TerminalUI/Models/Size.cs

@@ -1,3 +1,3 @@
 namespace TerminalUI.Models;
 
-public record struct Size(int Width, int Height);
+public readonly record struct Size(int Width, int Height);

src/Library/TerminalUI/Traits/IContentRenderer.cs

@@ -1,10 +1,9 @@
 using TerminalUI.Controls;
-using TerminalUI.Models;
 
 namespace TerminalUI.Traits;
 
-public interface IContentRenderer
+public interface IContentRenderer<T>
 {
-    IView? Content { get; set; }
+    IView<T>? Content { get; set; }
-    Action<Position, Size> ContentRendererMethod { get; set; }
+    RenderMethod ContentRendererMethod { get; set; }
 }