From 490deac178035e42a7e1aa5b3feb4dafc4343eb5 Mon Sep 17 00:00:00 2001
From: Andrei Zhvaleuski <andrei.zhvaleuski@yandex.by>
Date: Thu, 26 Sep 2024 17:14:28 +0300
Subject: [PATCH 01/16] Use dropdown for active layout selection

---
 .../ActiveLayout/ActiveLayoutWidget.xaml      | 29 +++++-------
 .../ActiveLayoutWidgetViewModel.cs            | 23 +++++++---
 .../ActiveLayout/NextLayoutEngineCommand.cs   | 38 ----------------
 src/Whim.Bar/Workspace/WorkspaceWidget.xaml   | 45 -------------------
 4 files changed, 30 insertions(+), 105 deletions(-)
 delete mode 100644 src/Whim.Bar/ActiveLayout/NextLayoutEngineCommand.cs
 delete mode 100644 src/Whim.Bar/Workspace/WorkspaceWidget.xaml

diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
index 64afc1563..270ca31b6 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
@@ -1,19 +1,14 @@
 <UserControl
-	x:Class="Whim.Bar.ActiveLayoutWidget"
-	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-	d:DesignHeight="450"
-	d:DesignWidth="800"
-	mc:Ignorable="d">
-	<Button
-		Command="{x:Bind Path=ViewModel.NextLayoutEngineCommand}"
-		Content="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=OneWay}"
-		Style="{StaticResource bar:active_layout:button}">
-		<Button.Resources>
-			<SolidColorBrush x:Key="ButtonBackgroundPointerOver" Color="{StaticResource bar:hover:background}" />
-			<SolidColorBrush x:Key="ButtonForegroundPointerOver" Color="{StaticResource bar:hover:foreground}" />
-		</Button.Resources>
-	</Button>
+    x:Class="Whim.Bar.ActiveLayoutWidget"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    d:DesignHeight="450"
+    d:DesignWidth="800"
+    mc:Ignorable="d">
+    <ComboBox
+        Width="200"
+        ItemsSource="{x:Bind Path=ViewModel.LayoutEngines}"
+        SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}" />
 </UserControl>
diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
index 89e2d45a4..8e4c0fa44 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
@@ -1,5 +1,7 @@
 using System;
+using System.Collections.ObjectModel;
 using System.ComponentModel;
+using System.Linq;
 
 namespace Whim.Bar;
 
@@ -20,13 +22,25 @@ internal class ActiveLayoutWidgetViewModel : INotifyPropertyChanged, IDisposable
 	/// <summary>
 	/// The name of the active layout engine.
 	/// </summary>
-	public string ActiveLayoutEngine =>
-		_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor)?.ActiveLayoutEngine.Name ?? "";
+	public ObservableCollection<string> LayoutEngines =>
+		new(_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor)?.LayoutEngines.Select(layoutEngine => layoutEngine.Name).ToArray() ?? []);
 
 	/// <summary>
-	/// Command to switch to the next layout engine.
+	/// The name of the active layout engine.
 	/// </summary>
-	public System.Windows.Input.ICommand NextLayoutEngineCommand { get; }
+	public string ActiveLayoutEngine
+	{
+		get => _context.Butler.Pantry.GetWorkspaceForMonitor(Monitor)?.ActiveLayoutEngine.Name ?? "";
+		set
+		{
+			if (_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor) is IWorkspace workspace
+				&& workspace.ActiveLayoutEngine.Name != value
+				&& workspace.TrySetLayoutEngineFromName(value))
+			{
+				OnPropertyChanged(nameof(ActiveLayoutEngine));
+			}
+		}
+	}
 
 	/// <summary>
 	///
@@ -37,7 +51,6 @@ public ActiveLayoutWidgetViewModel(IContext context, IMonitor monitor)
 	{
 		_context = context;
 		Monitor = monitor;
-		NextLayoutEngineCommand = new NextLayoutEngineCommand(context, this);
 
 		_context.WorkspaceManager.ActiveLayoutEngineChanged += WorkspaceManager_ActiveLayoutEngineChanged;
 		_context.Butler.MonitorWorkspaceChanged += Butler_MonitorWorkspaceChanged;
diff --git a/src/Whim.Bar/ActiveLayout/NextLayoutEngineCommand.cs b/src/Whim.Bar/ActiveLayout/NextLayoutEngineCommand.cs
deleted file mode 100644
index e9bfde7e4..000000000
--- a/src/Whim.Bar/ActiveLayout/NextLayoutEngineCommand.cs
+++ /dev/null
@@ -1,38 +0,0 @@
-using System;
-
-namespace Whim.Bar;
-
-/// <summary>
-/// Command to switch to the next layout engine.
-/// </summary>
-/// <remarks>
-/// Creates a new instance of <see cref="NextLayoutEngineCommand"/>.
-/// </remarks>
-/// <param name="context"></param>
-/// <param name="viewModel"></param>
-internal class NextLayoutEngineCommand(IContext context, ActiveLayoutWidgetViewModel viewModel)
-	: System.Windows.Input.ICommand
-{
-	private readonly IContext _context = context;
-	private readonly ActiveLayoutWidgetViewModel _viewModel = viewModel;
-
-	/// <inheritdoc/>
-	public event EventHandler? CanExecuteChanged
-	{
-		add { }
-		remove { }
-	}
-
-	/// <inheritdoc/>
-	public bool CanExecute(object? parameter) => true;
-
-	/// <inheritdoc/>
-	public void Execute(object? parameter)
-	{
-		Logger.Debug("Switching to next layout engine");
-		if (_context.Butler.Pantry.GetWorkspaceForMonitor(_viewModel.Monitor) is IWorkspace workspace)
-		{
-			workspace.CycleLayoutEngine(false);
-		}
-	}
-}
diff --git a/src/Whim.Bar/Workspace/WorkspaceWidget.xaml b/src/Whim.Bar/Workspace/WorkspaceWidget.xaml
deleted file mode 100644
index 840e964f9..000000000
--- a/src/Whim.Bar/Workspace/WorkspaceWidget.xaml
+++ /dev/null
@@ -1,45 +0,0 @@
-<UserControl
-	x:Class="Whim.Bar.WorkspaceWidget"
-	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-	xmlns:local="using:Whim.Bar"
-	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-	d:DataContext="{d:DesignInstance Type=local:WorkspaceWidgetViewModel}"
-	d:DesignHeight="450"
-	d:DesignWidth="800"
-	mc:Ignorable="d">
-	<ItemsControl ItemsSource="{x:Bind ViewModel.Workspaces}">
-		<ItemsControl.ItemsPanel>
-			<ItemsPanelTemplate>
-				<StackPanel Orientation="Horizontal" />
-			</ItemsPanelTemplate>
-		</ItemsControl.ItemsPanel>
-
-		<ItemsControl.ItemTemplate>
-			<DataTemplate x:DataType="local:WorkspaceModel">
-				<Button
-					Command="{x:Bind SwitchWorkspaceCommand}"
-					CommandParameter="{x:Bind}"
-					Content="{x:Bind Name}"
-					Style="{StaticResource bar:workspace:button}">
-					<Button.Resources>
-						<!--
-							WinUI doesn't let us set `Trigger` styles explicitly. We can
-							change them by modifying the theme resources in
-							Microsoft.UI.Xaml.Controls. The relevant keys are:
-							- Button[Background|Foreground|Borderbrush]
-							- Button[Background|Foreground|Borderbrush]PointerOver
-							- Button[Background|Foreground|Borderbrush]Pressed
-							- Button[Background|Foreground|Borderbrush]Disabled
-						-->
-						<SolidColorBrush x:Key="ButtonBackgroundDisabled" Color="{StaticResource bar:active_workspace:background}" />
-						<SolidColorBrush x:Key="ButtonForegroundDisabled" Color="{StaticResource bar:active_workspace:foreground}" />
-						<SolidColorBrush x:Key="ButtonBackgroundPointerOver" Color="{StaticResource bar:hover:background}" />
-						<SolidColorBrush x:Key="ButtonForegroundPointerOver" Color="{StaticResource bar:hover:foreground}" />
-					</Button.Resources>
-				</Button>
-			</DataTemplate>
-		</ItemsControl.ItemTemplate>
-	</ItemsControl>
-</UserControl>

From 67989088546f86e42c8daf4a77615f3111eb8e90 Mon Sep 17 00:00:00 2001
From: Andrei Zhvaleuski <andrei.zhvaleuski@yandex.by>
Date: Thu, 26 Sep 2024 17:57:23 +0300
Subject: [PATCH 02/16] Add draft styling

---
 .../ActiveLayout/ActiveLayoutWidget.xaml      | 24 +++++-----
 .../ActiveLayoutWidgetViewModel.cs            | 13 ++++--
 src/Whim.Bar/Workspace/WorkspaceWidget.xaml   | 45 +++++++++++++++++++
 src/Whim/Resources/Defaults.xaml              |  9 +++-
 4 files changed, 75 insertions(+), 16 deletions(-)
 create mode 100644 src/Whim.Bar/Workspace/WorkspaceWidget.xaml

diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
index 270ca31b6..2c21467a1 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
@@ -1,14 +1,14 @@
 <UserControl
-    x:Class="Whim.Bar.ActiveLayoutWidget"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    d:DesignHeight="450"
-    d:DesignWidth="800"
-    mc:Ignorable="d">
-    <ComboBox
-        Width="200"
-        ItemsSource="{x:Bind Path=ViewModel.LayoutEngines}"
-        SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}" />
+	x:Class="Whim.Bar.ActiveLayoutWidget"
+	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	d:DesignHeight="450"
+	d:DesignWidth="800"
+	mc:Ignorable="d">
+	<ComboBox
+		ItemsSource="{x:Bind Path=ViewModel.LayoutEngines}"
+		SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}"
+		Style="{StaticResource bar:active_layout:combo_box}" />
 </UserControl>
diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
index 8e4c0fa44..9f0417931 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
@@ -23,7 +23,12 @@ internal class ActiveLayoutWidgetViewModel : INotifyPropertyChanged, IDisposable
 	/// The name of the active layout engine.
 	/// </summary>
 	public ObservableCollection<string> LayoutEngines =>
-		new(_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor)?.LayoutEngines.Select(layoutEngine => layoutEngine.Name).ToArray() ?? []);
+		new(
+			_context
+				.Butler.Pantry.GetWorkspaceForMonitor(Monitor)
+				?.LayoutEngines.Select(layoutEngine => layoutEngine.Name)
+				.ToArray() ?? []
+		);
 
 	/// <summary>
 	/// The name of the active layout engine.
@@ -33,9 +38,11 @@ public string ActiveLayoutEngine
 		get => _context.Butler.Pantry.GetWorkspaceForMonitor(Monitor)?.ActiveLayoutEngine.Name ?? "";
 		set
 		{
-			if (_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor) is IWorkspace workspace
+			if (
+				_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor) is IWorkspace workspace
 				&& workspace.ActiveLayoutEngine.Name != value
-				&& workspace.TrySetLayoutEngineFromName(value))
+				&& workspace.TrySetLayoutEngineFromName(value)
+			)
 			{
 				OnPropertyChanged(nameof(ActiveLayoutEngine));
 			}
diff --git a/src/Whim.Bar/Workspace/WorkspaceWidget.xaml b/src/Whim.Bar/Workspace/WorkspaceWidget.xaml
new file mode 100644
index 000000000..840e964f9
--- /dev/null
+++ b/src/Whim.Bar/Workspace/WorkspaceWidget.xaml
@@ -0,0 +1,45 @@
+<UserControl
+	x:Class="Whim.Bar.WorkspaceWidget"
+	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	xmlns:local="using:Whim.Bar"
+	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	d:DataContext="{d:DesignInstance Type=local:WorkspaceWidgetViewModel}"
+	d:DesignHeight="450"
+	d:DesignWidth="800"
+	mc:Ignorable="d">
+	<ItemsControl ItemsSource="{x:Bind ViewModel.Workspaces}">
+		<ItemsControl.ItemsPanel>
+			<ItemsPanelTemplate>
+				<StackPanel Orientation="Horizontal" />
+			</ItemsPanelTemplate>
+		</ItemsControl.ItemsPanel>
+
+		<ItemsControl.ItemTemplate>
+			<DataTemplate x:DataType="local:WorkspaceModel">
+				<Button
+					Command="{x:Bind SwitchWorkspaceCommand}"
+					CommandParameter="{x:Bind}"
+					Content="{x:Bind Name}"
+					Style="{StaticResource bar:workspace:button}">
+					<Button.Resources>
+						<!--
+							WinUI doesn't let us set `Trigger` styles explicitly. We can
+							change them by modifying the theme resources in
+							Microsoft.UI.Xaml.Controls. The relevant keys are:
+							- Button[Background|Foreground|Borderbrush]
+							- Button[Background|Foreground|Borderbrush]PointerOver
+							- Button[Background|Foreground|Borderbrush]Pressed
+							- Button[Background|Foreground|Borderbrush]Disabled
+						-->
+						<SolidColorBrush x:Key="ButtonBackgroundDisabled" Color="{StaticResource bar:active_workspace:background}" />
+						<SolidColorBrush x:Key="ButtonForegroundDisabled" Color="{StaticResource bar:active_workspace:foreground}" />
+						<SolidColorBrush x:Key="ButtonBackgroundPointerOver" Color="{StaticResource bar:hover:background}" />
+						<SolidColorBrush x:Key="ButtonForegroundPointerOver" Color="{StaticResource bar:hover:foreground}" />
+					</Button.Resources>
+				</Button>
+			</DataTemplate>
+		</ItemsControl.ItemTemplate>
+	</ItemsControl>
+</UserControl>
diff --git a/src/Whim/Resources/Defaults.xaml b/src/Whim/Resources/Defaults.xaml
index 45b660d03..30b152658 100644
--- a/src/Whim/Resources/Defaults.xaml
+++ b/src/Whim/Resources/Defaults.xaml
@@ -59,7 +59,14 @@
 	</Style>
 
 	<!--  Active layout widget  -->
-	<StaticResource x:Key="bar:active_layout:button" ResourceKey="_base:button" />
+	<Style x:Key="bar:active_layout:combo_box" TargetType="ComboBox">
+		<Setter Property="Margin" Value="0" />
+		<Setter Property="Padding" Value="0" />
+		<Setter Property="BorderThickness" Value="0" />
+		<Setter Property="CornerRadius" Value="4" />
+		<Setter Property="FontSize" Value="14" />
+		<Setter Property="FontFamily" Value="{StaticResource _font:family}" />
+	</Style>
 
 	<!--  Tree layout engine widget  -->
 	<StaticResource x:Key="bar:tree_layout:button" ResourceKey="_base:button" />

From 0179706ad1c0b5844508e44d09f43d81a29d3b0a Mon Sep 17 00:00:00 2001
From: Andrei Zhvaleuski <andrei.zhvaleuski@yandex.by>
Date: Thu, 26 Sep 2024 22:19:18 +0300
Subject: [PATCH 03/16] Improve styling

---
 src/Whim/Resources/Defaults.xaml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Whim/Resources/Defaults.xaml b/src/Whim/Resources/Defaults.xaml
index 30b152658..ae8b8cfaa 100644
--- a/src/Whim/Resources/Defaults.xaml
+++ b/src/Whim/Resources/Defaults.xaml
@@ -60,8 +60,9 @@
 
 	<!--  Active layout widget  -->
 	<Style x:Key="bar:active_layout:combo_box" TargetType="ComboBox">
-		<Setter Property="Margin" Value="0" />
-		<Setter Property="Padding" Value="0" />
+		<Setter Property="Margin" Value="5,0" />
+		<Setter Property="Padding" Value="5,0" />
+		<Setter Property="Width" Value="175" />
 		<Setter Property="BorderThickness" Value="0" />
 		<Setter Property="CornerRadius" Value="4" />
 		<Setter Property="FontSize" Value="14" />

From fe6dde5a289f697308a9f8f1d6d03d390d1be6ff Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Sun, 3 Nov 2024 17:54:08 +1100
Subject: [PATCH 04/16] Hide the dropdown when window focus changes

---
 .../ActiveLayout/ActiveLayoutWidget.xaml         |  4 +++-
 .../ActiveLayout/ActiveLayoutWidgetViewModel.cs  | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
index 2c21467a1..626296c71 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
@@ -10,5 +10,7 @@
 	<ComboBox
 		ItemsSource="{x:Bind Path=ViewModel.LayoutEngines}"
 		SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}"
-		Style="{StaticResource bar:active_layout:combo_box}" />
+		Style="{StaticResource bar:active_layout:combo_box}"
+		IsDropDownOpen="{x:Bind Path=ViewModel.IsDropDownOpen, Mode=TwoWay}"
+		/>
 </UserControl>
diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
index 9f0417931..00789e456 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
@@ -49,6 +49,18 @@ public string ActiveLayoutEngine
 		}
 	}
 
+	private bool _isDropDownOpen;
+
+	public bool IsDropDownOpen
+	{
+		get => _isDropDownOpen;
+		set
+		{
+			_isDropDownOpen = value;
+			OnPropertyChanged(nameof(IsDropDownOpen));
+		}
+	}
+
 	/// <summary>
 	///
 	/// </summary>
@@ -59,8 +71,10 @@ public ActiveLayoutWidgetViewModel(IContext context, IMonitor monitor)
 		_context = context;
 		Monitor = monitor;
 
+		// TODO: Update
 		_context.WorkspaceManager.ActiveLayoutEngineChanged += WorkspaceManager_ActiveLayoutEngineChanged;
 		_context.Butler.MonitorWorkspaceChanged += Butler_MonitorWorkspaceChanged;
+		_context.Store.WindowEvents.WindowFocused += WindowEvents_WindowFocused;
 	}
 
 	private void WorkspaceManager_ActiveLayoutEngineChanged(object? sender, EventArgs e) =>
@@ -74,6 +88,8 @@ private void Butler_MonitorWorkspaceChanged(object? sender, MonitorWorkspaceChan
 		}
 	}
 
+	private void WindowEvents_WindowFocused(object? sender, WindowFocusedEventArgs e) => IsDropDownOpen = false;
+
 	/// <inheritdoc/>
 	public event PropertyChangedEventHandler? PropertyChanged;
 

From 7454d59c5e8494b4fd6e8ac746243dd5ae8b550b Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Sun, 3 Nov 2024 18:23:26 +1100
Subject: [PATCH 05/16] Always recalculate list, and rip out legacy API

---
 .../ActiveLayout/ActiveLayoutWidget.xaml      |  2 +-
 .../ActiveLayoutWidgetViewModel.cs            | 82 +++++++++++++------
 2 files changed, 60 insertions(+), 24 deletions(-)

diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
index 626296c71..706c9544e 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
@@ -8,7 +8,7 @@
 	d:DesignWidth="800"
 	mc:Ignorable="d">
 	<ComboBox
-		ItemsSource="{x:Bind Path=ViewModel.LayoutEngines}"
+		ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}"
 		SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}"
 		Style="{StaticResource bar:active_layout:combo_box}"
 		IsDropDownOpen="{x:Bind Path=ViewModel.IsDropDownOpen, Mode=TwoWay}"
diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
index 00789e456..0e07017e6 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
@@ -1,5 +1,5 @@
 using System;
-using System.Collections.ObjectModel;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
 
@@ -22,28 +22,50 @@ internal class ActiveLayoutWidgetViewModel : INotifyPropertyChanged, IDisposable
 	/// <summary>
 	/// The name of the active layout engine.
 	/// </summary>
-	public ObservableCollection<string> LayoutEngines =>
-		new(
-			_context
-				.Butler.Pantry.GetWorkspaceForMonitor(Monitor)
-				?.LayoutEngines.Select(layoutEngine => layoutEngine.Name)
-				.ToArray() ?? []
-		);
+	public List<string> LayoutEngines = [];
 
 	/// <summary>
 	/// The name of the active layout engine.
 	/// </summary>
 	public string ActiveLayoutEngine
 	{
-		get => _context.Butler.Pantry.GetWorkspaceForMonitor(Monitor)?.ActiveLayoutEngine.Name ?? "";
+		get
+		{
+			if (!_context.Store.Pick(Pickers.PickWorkspaceByMonitor(Monitor.Handle)).TryGet(out IWorkspace workspace))
+			{
+				return "";
+			}
+
+			if (
+				!_context
+					.Store.Pick(Pickers.PickActiveLayoutEngine(workspace.Id))
+					.TryGet(out ILayoutEngine layoutEngine)
+			)
+			{
+				return "";
+			}
+
+			return layoutEngine.Name;
+		}
 		set
 		{
+			if (!_context.Store.Pick(Pickers.PickWorkspaceByMonitor(Monitor.Handle)).TryGet(out IWorkspace workspace))
+			{
+				return;
+			}
+
 			if (
-				_context.Butler.Pantry.GetWorkspaceForMonitor(Monitor) is IWorkspace workspace
-				&& workspace.ActiveLayoutEngine.Name != value
-				&& workspace.TrySetLayoutEngineFromName(value)
+				!_context
+					.Store.Pick(Pickers.PickActiveLayoutEngine(workspace.Id))
+					.TryGet(out ILayoutEngine layoutEngine)
 			)
 			{
+				return;
+			}
+
+			if (layoutEngine.Name != value)
+			{
+				_context.Store.Dispatch(new SetLayoutEngineFromNameTransform(workspace.Id, value));
 				OnPropertyChanged(nameof(ActiveLayoutEngine));
 			}
 		}
@@ -51,6 +73,9 @@ public string ActiveLayoutEngine
 
 	private bool _isDropDownOpen;
 
+	/// <summary>
+	/// Whether the combobox's drop down is open.
+	/// </summary>
 	public bool IsDropDownOpen
 	{
 		get => _isDropDownOpen;
@@ -62,7 +87,7 @@ public bool IsDropDownOpen
 	}
 
 	/// <summary>
-	///
+	/// Creates a new instance of the <see cref="ActiveLayoutWidgetViewModel"/> class.
 	/// </summary>
 	/// <param name="context"></param>
 	/// <param name="monitor"></param>
@@ -71,24 +96,34 @@ public ActiveLayoutWidgetViewModel(IContext context, IMonitor monitor)
 		_context = context;
 		Monitor = monitor;
 
-		// TODO: Update
-		_context.WorkspaceManager.ActiveLayoutEngineChanged += WorkspaceManager_ActiveLayoutEngineChanged;
-		_context.Butler.MonitorWorkspaceChanged += Butler_MonitorWorkspaceChanged;
+		_context.Store.WorkspaceEvents.ActiveLayoutEngineChanged += Store_ActiveLayoutEngineChanged;
+		_context.Store.MapEvents.MonitorWorkspaceChanged += Store_MonitorWorkspaceChanged;
 		_context.Store.WindowEvents.WindowFocused += WindowEvents_WindowFocused;
 	}
 
-	private void WorkspaceManager_ActiveLayoutEngineChanged(object? sender, EventArgs e) =>
+	private void Store_ActiveLayoutEngineChanged(object? sender, EventArgs e)
+	{
 		OnPropertyChanged(nameof(ActiveLayoutEngine));
+	}
 
-	private void Butler_MonitorWorkspaceChanged(object? sender, MonitorWorkspaceChangedEventArgs e)
+	private void Store_MonitorWorkspaceChanged(object? sender, MonitorWorkspaceChangedEventArgs e)
 	{
-		if (e.Monitor.Handle == Monitor.Handle)
+		if (e.Monitor.Handle != Monitor.Handle)
 		{
-			OnPropertyChanged(nameof(ActiveLayoutEngine));
+			return;
 		}
+
+		LayoutEngines.Clear();
+		LayoutEngines.AddRange(e.CurrentWorkspace.LayoutEngines.Select(engine => engine.Name));
+
+		OnPropertyChanged(nameof(LayoutEngines));
+		OnPropertyChanged(nameof(ActiveLayoutEngine));
 	}
 
-	private void WindowEvents_WindowFocused(object? sender, WindowFocusedEventArgs e) => IsDropDownOpen = false;
+	private void WindowEvents_WindowFocused(object? sender, WindowFocusedEventArgs e)
+	{
+		IsDropDownOpen = false;
+	}
 
 	/// <inheritdoc/>
 	public event PropertyChangedEventHandler? PropertyChanged;
@@ -105,8 +140,9 @@ protected virtual void Dispose(bool disposing)
 			if (disposing)
 			{
 				// dispose managed state (managed objects)
-				_context.WorkspaceManager.ActiveLayoutEngineChanged -= WorkspaceManager_ActiveLayoutEngineChanged;
-				_context.Butler.MonitorWorkspaceChanged -= Butler_MonitorWorkspaceChanged;
+				_context.Store.WorkspaceEvents.ActiveLayoutEngineChanged -= Store_ActiveLayoutEngineChanged;
+				_context.Store.MapEvents.MonitorWorkspaceChanged -= Store_MonitorWorkspaceChanged;
+				_context.Store.WindowEvents.WindowFocused -= WindowEvents_WindowFocused;
 			}
 
 			// free unmanaged resources (unmanaged objects) and override finalizer

From 69d0bd49f3fe12d75e582b8602f190b7104c719e Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Sun, 3 Nov 2024 20:57:13 +1100
Subject: [PATCH 06/16] Only regenerate source when files change

---
 scripts/Generate-SourceFromSchema.ps1 | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/scripts/Generate-SourceFromSchema.ps1 b/scripts/Generate-SourceFromSchema.ps1
index c166f7335..c653b4d1f 100644
--- a/scripts/Generate-SourceFromSchema.ps1
+++ b/scripts/Generate-SourceFromSchema.ps1
@@ -1,15 +1,17 @@
+$ErrorActionPreference = "Stop"
+
 Write-Host "Generating source from schema..."
 
 $schemaPath = ".\src\Whim.Yaml\schema.json"
 $outputPath = ".\src\Whim.Yaml\Generated"
 $metadataPath = "$outputPath\metadata.json"
 $now = Get-Date
-if ($env:CI) {
-    $gitSha = $env:GITHUB_SHA
-}
-else {
-    $gitSha = (git rev-parse HEAD)
-}
+
+$paths = @(
+    ".\src\Whim.Yaml\Whim.Yaml.csproj",
+    ".\src\Whim.Yaml\schema.json"
+)
+$yamlCodeHash = $paths | ForEach-Object { Get-FileHash $_ } | Out-String
 
 function Test-Regenerate {
     param (
@@ -31,14 +33,14 @@ function Test-Regenerate {
     }
 
     $metadata = Get-Content $metadataPath | ConvertFrom-Json
-    if ($metadata.gitRef -ne $gitSha) {
-        Write-Host "Git ref has changed since last generation, regenerating..."
+    if ($metadata.yamlCodeHash -ne $yamlCodeHash) {
+        Write-Host "YAML schema has changed since last generation, regenerating..."
         return $true
     }
 
     $schemaLastWriteTime = (Get-Item $schemaPath).LastWriteTime
     if ($metadata.lastWriteTime -lt $schemaLastWriteTime) {
-        Write-Host "Schema has changed since last generation, regenerating..."
+        Write-Host "Schema has changed since last generation time, regenerating..."
         return $true
     }
 
@@ -60,5 +62,5 @@ dotnet tool run generatejsonschematypes `
 # If not in CI, write metadata file
 if ($LASTEXITCODE -eq 0 -and $null -eq $env:CI) {
     Write-Host "Writing metadata file..."
-    @{ gitRef = $gitSha; lastWriteTime = $now } | ConvertTo-Json | Set-Content $metadataPath
+    @{ yamlCodeHash = $yamlCodeHash; lastWriteTime = $now } | ConvertTo-Json | Set-Content $metadataPath
 }

From dad6bb9e70d3e4a533ced1b3f0ddfc70bef78721 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Mon, 4 Nov 2024 12:16:18 +1100
Subject: [PATCH 07/16] Ignore the time when regenerating YAML

---
 scripts/Generate-SourceFromSchema.ps1 | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/scripts/Generate-SourceFromSchema.ps1 b/scripts/Generate-SourceFromSchema.ps1
index c653b4d1f..58d9c5aa4 100644
--- a/scripts/Generate-SourceFromSchema.ps1
+++ b/scripts/Generate-SourceFromSchema.ps1
@@ -5,7 +5,6 @@ Write-Host "Generating source from schema..."
 $schemaPath = ".\src\Whim.Yaml\schema.json"
 $outputPath = ".\src\Whim.Yaml\Generated"
 $metadataPath = "$outputPath\metadata.json"
-$now = Get-Date
 
 $paths = @(
     ".\src\Whim.Yaml\Whim.Yaml.csproj",
@@ -35,12 +34,8 @@ function Test-Regenerate {
     $metadata = Get-Content $metadataPath | ConvertFrom-Json
     if ($metadata.yamlCodeHash -ne $yamlCodeHash) {
         Write-Host "YAML schema has changed since last generation, regenerating..."
-        return $true
-    }
-
-    $schemaLastWriteTime = (Get-Item $schemaPath).LastWriteTime
-    if ($metadata.lastWriteTime -lt $schemaLastWriteTime) {
-        Write-Host "Schema has changed since last generation time, regenerating..."
+        Write-Host "Old hash: $($metadata.yamlCodeHash)"
+        Write-Host "New hash: $yamlCodeHash"
         return $true
     }
 
@@ -62,5 +57,5 @@ dotnet tool run generatejsonschematypes `
 # If not in CI, write metadata file
 if ($LASTEXITCODE -eq 0 -and $null -eq $env:CI) {
     Write-Host "Writing metadata file..."
-    @{ yamlCodeHash = $yamlCodeHash; lastWriteTime = $now } | ConvertTo-Json | Set-Content $metadataPath
+    @{ yamlCodeHash = $yamlCodeHash } | ConvertTo-Json | Set-Content $metadataPath
 }

From 4780495d0641c7863d62c8010b243a7f066e8ad9 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Mon, 4 Nov 2024 12:16:40 +1100
Subject: [PATCH 08/16] Create a DropDown which doesn't have the spacing issues

---
 .../ActiveLayout/ActiveLayoutWidget.xaml      |  18 ++-
 src/Whim.Bar/DropDown.xaml                    |  18 +++
 src/Whim.Bar/DropDown.xaml.cs                 | 107 ++++++++++++++++++
 src/Whim.Bar/Whim.Bar.csproj                  |   6 +
 4 files changed, 143 insertions(+), 6 deletions(-)
 create mode 100644 src/Whim.Bar/DropDown.xaml
 create mode 100644 src/Whim.Bar/DropDown.xaml.cs

diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
index 706c9544e..e91ef34f3 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
@@ -2,15 +2,21 @@
 	x:Class="Whim.Bar.ActiveLayoutWidget"
 	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:bar="using:Whim.Bar"
 	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
 	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 	d:DesignHeight="450"
 	d:DesignWidth="800"
 	mc:Ignorable="d">
-	<ComboBox
-		ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}"
-		SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}"
-		Style="{StaticResource bar:active_layout:combo_box}"
-		IsDropDownOpen="{x:Bind Path=ViewModel.IsDropDownOpen, Mode=TwoWay}"
-		/>
+
+	<StackPanel Orientation="Horizontal">
+		<ComboBox
+			IsDropDownOpen="{x:Bind Path=ViewModel.IsDropDownOpen, Mode=TwoWay}"
+			ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}"
+			SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}"
+			Style="{StaticResource bar:active_layout:combo_box}" />
+
+		<bar:DropDown ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}" SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}" />
+	</StackPanel>
+
 </UserControl>
diff --git a/src/Whim.Bar/DropDown.xaml b/src/Whim.Bar/DropDown.xaml
new file mode 100644
index 000000000..cb57fe372
--- /dev/null
+++ b/src/Whim.Bar/DropDown.xaml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<UserControl
+	x:Class="Whim.Bar.DropDown"
+	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	xmlns:local="using:Whim.Bar"
+	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	mc:Ignorable="d">
+
+	<Grid>
+		<DropDownButton Content="{x:Bind Path=SelectedItem, Mode=TwoWay}">
+			<DropDownButton.Flyout>
+				<MenuFlyout x:Name="MenuFlyout" Placement="Bottom" />
+			</DropDownButton.Flyout>
+		</DropDownButton>
+	</Grid>
+</UserControl>
diff --git a/src/Whim.Bar/DropDown.xaml.cs b/src/Whim.Bar/DropDown.xaml.cs
new file mode 100644
index 000000000..3b13e0f97
--- /dev/null
+++ b/src/Whim.Bar/DropDown.xaml.cs
@@ -0,0 +1,107 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Collections.Specialized;
+using System.ComponentModel;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Controls.Primitives;
+using Microsoft.UI.Xaml.Data;
+using Microsoft.UI.Xaml.Input;
+using Microsoft.UI.Xaml.Media;
+using Microsoft.UI.Xaml.Navigation;
+using Whim;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+
+namespace Whim.Bar;
+
+// TODO: Move this justification
+// The ComboBox doesn't easily support variable-width buttons.
+// The DropDownButton + MenuFlyout + MenuFlyoutItem doesn't have data binding.
+
+
+public sealed partial class DropDown : UserControl
+{
+	public string SelectedItem
+	{
+		get => (string)GetValue(SelectedItemProperty);
+		set
+		{
+			SetValue(SelectedItemProperty, value);
+
+			foreach (RadioMenuFlyoutItem item in MenuFlyout.Items.Cast<RadioMenuFlyoutItem>())
+			{
+				item.IsChecked = item.Text == value;
+			}
+		}
+	}
+
+	public static readonly DependencyProperty SelectedItemProperty = DependencyProperty.Register(
+		nameof(SelectedItem),
+		typeof(string),
+		typeof(DropDown),
+		new PropertyMetadata("")
+	);
+
+	public object ItemsSource
+	{
+		get => GetValue(ItemsSourceProperty);
+		set => SetValue(ItemsSourceProperty, value);
+	}
+
+	public static readonly DependencyProperty ItemsSourceProperty = DependencyProperty.Register(
+		nameof(ItemsSource),
+		typeof(object),
+		typeof(DropDown),
+		new PropertyMetadata(null)
+	);
+
+	// TODO: Indicate selection
+	public DropDown()
+	{
+		UIElementExtensions.InitializeComponent(this, "Whim.Bar", "DropDown");
+		RegisterPropertyChangedCallback(ItemsSourceProperty, OnItemsSourceChanged);
+	}
+
+	private void OnItemsSourceChanged(DependencyObject d, DependencyProperty dp)
+	{
+		if (d is not DropDown || dp != ItemsSourceProperty)
+		{
+			return;
+		}
+
+		if (ItemsSource is not IEnumerable<string> items)
+		{
+			return;
+		}
+
+		// Clear the old items and remove their events.
+		foreach (RadioMenuFlyoutItem oldRadioItem in MenuFlyout.Items.Cast<RadioMenuFlyoutItem>())
+		{
+			oldRadioItem.Click -= RadioItem_Click;
+		}
+		MenuFlyout.Items.Clear();
+
+		// Set up the new items.
+		foreach (string item in items)
+		{
+			RadioMenuFlyoutItem radioItem = new() { Text = item, IsChecked = SelectedItem == item };
+			radioItem.Click += RadioItem_Click;
+			MenuFlyout.Items.Add(radioItem);
+		}
+	}
+
+	private void RadioItem_Click(object sender, RoutedEventArgs e)
+	{
+		if (sender is not RadioMenuFlyoutItem item)
+		{
+			return;
+		}
+
+		SelectedItem = item.Text;
+	}
+}
diff --git a/src/Whim.Bar/Whim.Bar.csproj b/src/Whim.Bar/Whim.Bar.csproj
index 9b7aca24c..eddaf52b5 100644
--- a/src/Whim.Bar/Whim.Bar.csproj
+++ b/src/Whim.Bar/Whim.Bar.csproj
@@ -29,6 +29,7 @@
   </PropertyGroup>
   <ItemGroup>
     <None Remove="BarWindow.xaml" />
+    <None Remove="DropDown.xaml" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.WindowsAppSDK" />
@@ -47,4 +48,9 @@
 	  <InternalsVisibleTo Include="Whim.Yaml.Tests" />
     <InternalsVisibleTo Include="DynamicProxyGenAssembly2" />
   </ItemGroup>
+  <ItemGroup>
+    <Page Update="DropDown.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
 </Project>
\ No newline at end of file

From 31f7f18f7132c6b19346136b0aa7d329e4a94dc4 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Mon, 4 Nov 2024 14:28:48 +1100
Subject: [PATCH 09/16] Fix selection on first load

---
 .../ActiveLayout/ActiveLayoutWidget.xaml      | 10 +----
 src/Whim.Bar/DropDown.xaml                    | 13 +++---
 src/Whim.Bar/DropDown.xaml.cs                 | 42 ++++++-------------
 3 files changed, 22 insertions(+), 43 deletions(-)

diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
index e91ef34f3..93afc3049 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidget.xaml
@@ -9,14 +9,8 @@
 	d:DesignWidth="800"
 	mc:Ignorable="d">
 
-	<StackPanel Orientation="Horizontal">
-		<ComboBox
-			IsDropDownOpen="{x:Bind Path=ViewModel.IsDropDownOpen, Mode=TwoWay}"
-			ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}"
-			SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}"
-			Style="{StaticResource bar:active_layout:combo_box}" />
 
-		<bar:DropDown ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}" SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}" />
-	</StackPanel>
+	<bar:DropDown ItemsSource="{x:Bind Path=ViewModel.LayoutEngines, Mode=OneWay}" SelectedItem="{x:Bind Path=ViewModel.ActiveLayoutEngine, Mode=TwoWay}" />
+
 
 </UserControl>
diff --git a/src/Whim.Bar/DropDown.xaml b/src/Whim.Bar/DropDown.xaml
index cb57fe372..ca78c30c4 100644
--- a/src/Whim.Bar/DropDown.xaml
+++ b/src/Whim.Bar/DropDown.xaml
@@ -8,11 +8,14 @@
 	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 	mc:Ignorable="d">
 
+	<!--  We need the grid surrounding the stackpanel to fix the FlowDirection set in a parent.  -->
 	<Grid>
-		<DropDownButton Content="{x:Bind Path=SelectedItem, Mode=TwoWay}">
-			<DropDownButton.Flyout>
-				<MenuFlyout x:Name="MenuFlyout" Placement="Bottom" />
-			</DropDownButton.Flyout>
-		</DropDownButton>
+		<StackPanel FlowDirection="LeftToRight" Orientation="Horizontal">
+			<DropDownButton HorizontalAlignment="Left" Content="{x:Bind Path=SelectedItem, Mode=TwoWay}">
+				<DropDownButton.Flyout>
+					<MenuFlyout x:Name="MenuFlyout" Placement="Bottom" />
+				</DropDownButton.Flyout>
+			</DropDownButton>
+		</StackPanel>
 	</Grid>
 </UserControl>
diff --git a/src/Whim.Bar/DropDown.xaml.cs b/src/Whim.Bar/DropDown.xaml.cs
index 3b13e0f97..1b54a10fc 100644
--- a/src/Whim.Bar/DropDown.xaml.cs
+++ b/src/Whim.Bar/DropDown.xaml.cs
@@ -1,21 +1,8 @@
-using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Collections.Specialized;
-using System.ComponentModel;
-using System.IO;
 using System.Linq;
-using System.Runtime.InteropServices.WindowsRuntime;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
-using Microsoft.UI.Xaml.Controls.Primitives;
-using Microsoft.UI.Xaml.Data;
 using Microsoft.UI.Xaml.Input;
-using Microsoft.UI.Xaml.Media;
-using Microsoft.UI.Xaml.Navigation;
-using Whim;
-using Windows.Foundation;
-using Windows.Foundation.Collections;
 
 namespace Whim.Bar;
 
@@ -29,15 +16,7 @@ public sealed partial class DropDown : UserControl
 	public string SelectedItem
 	{
 		get => (string)GetValue(SelectedItemProperty);
-		set
-		{
-			SetValue(SelectedItemProperty, value);
-
-			foreach (RadioMenuFlyoutItem item in MenuFlyout.Items.Cast<RadioMenuFlyoutItem>())
-			{
-				item.IsChecked = item.Text == value;
-			}
-		}
+		set => SetValue(SelectedItemProperty, value);
 	}
 
 	public static readonly DependencyProperty SelectedItemProperty = DependencyProperty.Register(
@@ -60,20 +39,23 @@ public object ItemsSource
 		new PropertyMetadata(null)
 	);
 
-	// TODO: Indicate selection
 	public DropDown()
 	{
 		UIElementExtensions.InitializeComponent(this, "Whim.Bar", "DropDown");
-		RegisterPropertyChangedCallback(ItemsSourceProperty, OnItemsSourceChanged);
+
+		RegisterPropertyChangedCallback(ItemsSourceProperty, OnPropertyChanged);
+		RegisterPropertyChangedCallback(SelectedItemProperty, OnPropertyChanged);
+
+		// Lazy way to ensure that the selected item is always checked.
+		// Sometimes, on first load the selected item would not be checked.
+		GettingFocus += DropDown_GettingFocus;
 	}
 
-	private void OnItemsSourceChanged(DependencyObject d, DependencyProperty dp)
-	{
-		if (d is not DropDown || dp != ItemsSourceProperty)
-		{
-			return;
-		}
+	private void DropDown_GettingFocus(UIElement sender, GettingFocusEventArgs args) =>
+		OnPropertyChanged(this, ItemsSourceProperty);
 
+	private void OnPropertyChanged(DependencyObject sender, DependencyProperty dp)
+	{
 		if (ItemsSource is not IEnumerable<string> items)
 		{
 			return;

From 6e7b86f51f6d92b48d5c452eb9dac1ab4c3ccae0 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 00:22:26 +1100
Subject: [PATCH 10/16] Apply button styling

---
 src/Whim.Bar/DropDown.xaml       |  7 +++++--
 src/Whim/Resources/Defaults.xaml | 13 ++++---------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/Whim.Bar/DropDown.xaml b/src/Whim.Bar/DropDown.xaml
index ca78c30c4..db052bb95 100644
--- a/src/Whim.Bar/DropDown.xaml
+++ b/src/Whim.Bar/DropDown.xaml
@@ -8,10 +8,13 @@
 	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 	mc:Ignorable="d">
 
-	<!--  We need the grid surrounding the stackpanel to fix the FlowDirection set in a parent.  -->
+	<!--  We need the Grid surrounding the StackPanel to fix the FlowDirection set in a parent.  -->
 	<Grid>
 		<StackPanel FlowDirection="LeftToRight" Orientation="Horizontal">
-			<DropDownButton HorizontalAlignment="Left" Content="{x:Bind Path=SelectedItem, Mode=TwoWay}">
+			<DropDownButton
+				HorizontalAlignment="Left"
+				Content="{x:Bind Path=SelectedItem, Mode=TwoWay}"
+				Style="{StaticResource bar:active_layout:button}">
 				<DropDownButton.Flyout>
 					<MenuFlyout x:Name="MenuFlyout" Placement="Bottom" />
 				</DropDownButton.Flyout>
diff --git a/src/Whim/Resources/Defaults.xaml b/src/Whim/Resources/Defaults.xaml
index ae8b8cfaa..ac87f0b34 100644
--- a/src/Whim/Resources/Defaults.xaml
+++ b/src/Whim/Resources/Defaults.xaml
@@ -59,15 +59,10 @@
 	</Style>
 
 	<!--  Active layout widget  -->
-	<Style x:Key="bar:active_layout:combo_box" TargetType="ComboBox">
-		<Setter Property="Margin" Value="5,0" />
-		<Setter Property="Padding" Value="5,0" />
-		<Setter Property="Width" Value="175" />
-		<Setter Property="BorderThickness" Value="0" />
-		<Setter Property="CornerRadius" Value="4" />
-		<Setter Property="FontSize" Value="14" />
-		<Setter Property="FontFamily" Value="{StaticResource _font:family}" />
-	</Style>
+	<Style
+		x:Key="bar:active_layout:button"
+		BasedOn="{StaticResource _base:button}"
+		TargetType="DropDownButton" />
 
 	<!--  Tree layout engine widget  -->
 	<StaticResource x:Key="bar:tree_layout:button" ResourceKey="_base:button" />

From aceb525cf2e16d470474998da620b14615ffd980 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 00:25:04 +1100
Subject: [PATCH 11/16] Docs

---
 src/Whim.Bar/DropDown.xaml.cs | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/Whim.Bar/DropDown.xaml.cs b/src/Whim.Bar/DropDown.xaml.cs
index 1b54a10fc..8ed904243 100644
--- a/src/Whim.Bar/DropDown.xaml.cs
+++ b/src/Whim.Bar/DropDown.xaml.cs
@@ -6,19 +6,26 @@
 
 namespace Whim.Bar;
 
-// TODO: Move this justification
-// The ComboBox doesn't easily support variable-width buttons.
-// The DropDownButton + MenuFlyout + MenuFlyoutItem doesn't have data binding.
-
+/// <summary>
+/// A custom drop-down control that uses a <see cref="RadioMenuFlyoutItem"/> for each item.
+/// This is used instead of a <see cref="ComboBox"/> because the <see cref="ComboBox"/>
+/// doesn't easily support variable-width buttons, or have data binding.
+/// </summary>
 
 public sealed partial class DropDown : UserControl
 {
+	/// <summary>
+	/// The selected item in the drop-down.
+	/// </summary>
 	public string SelectedItem
 	{
 		get => (string)GetValue(SelectedItemProperty);
 		set => SetValue(SelectedItemProperty, value);
 	}
 
+	/// <summary>
+	/// The selected item in the drop-down.
+	/// </summary>
 	public static readonly DependencyProperty SelectedItemProperty = DependencyProperty.Register(
 		nameof(SelectedItem),
 		typeof(string),
@@ -26,12 +33,18 @@ public string SelectedItem
 		new PropertyMetadata("")
 	);
 
+	/// <summary>
+	/// The items to display in the drop-down.
+	/// </summary>
 	public object ItemsSource
 	{
 		get => GetValue(ItemsSourceProperty);
 		set => SetValue(ItemsSourceProperty, value);
 	}
 
+	/// <summary>
+	/// The items to display in the drop-down.
+	/// </summary>
 	public static readonly DependencyProperty ItemsSourceProperty = DependencyProperty.Register(
 		nameof(ItemsSource),
 		typeof(object),
@@ -39,6 +52,9 @@ public object ItemsSource
 		new PropertyMetadata(null)
 	);
 
+	/// <summary>
+	/// Initializes a new instance of the <see cref="DropDown"/> class.
+	/// </summary>
 	public DropDown()
 	{
 		UIElementExtensions.InitializeComponent(this, "Whim.Bar", "DropDown");
@@ -54,6 +70,11 @@ public DropDown()
 	private void DropDown_GettingFocus(UIElement sender, GettingFocusEventArgs args) =>
 		OnPropertyChanged(this, ItemsSourceProperty);
 
+	/// <summary>
+	/// Rebuild the drop-down when the items source or selected item changes.
+	/// </summary>
+	/// <param name="sender"></param>
+	/// <param name="dp"></param>
 	private void OnPropertyChanged(DependencyObject sender, DependencyProperty dp)
 	{
 		if (ItemsSource is not IEnumerable<string> items)
@@ -77,6 +98,11 @@ private void OnPropertyChanged(DependencyObject sender, DependencyProperty dp)
 		}
 	}
 
+	/// <summary>
+	/// Update the selected item when a radio item is clicked.
+	/// </summary>
+	/// <param name="sender"></param>
+	/// <param name="e"></param>
 	private void RadioItem_Click(object sender, RoutedEventArgs e)
 	{
 		if (sender is not RadioMenuFlyoutItem item)

From 171f6ce466f881c96767bf522945f52b78d00090 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 14:29:41 +1100
Subject: [PATCH 12/16] Add tests

---
 .../ActiveLayoutWidgetViewModelTests.cs       | 315 +++++++++++++++---
 .../NextLayoutEngineCommandTests.cs           |  55 ---
 .../ActiveLayoutWidgetViewModel.cs            |  34 +-
 src/Whim.TestUtils/Whim.TestUtils.csproj      |   1 +
 .../Store/MapSector/MapPickersTests.cs        |  48 +++
 src/Whim/Store/MapSector/MapPickers.cs        |  21 ++
 6 files changed, 345 insertions(+), 129 deletions(-)
 delete mode 100644 src/Whim.Bar.Tests/ActiveLayout/NextLayoutEngineCommandTests.cs

diff --git a/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs b/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs
index 3aa3acc63..3da118cab 100644
--- a/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs
+++ b/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs
@@ -1,5 +1,6 @@
 using NSubstitute;
 using Whim.TestUtils;
+using Windows.Win32.Graphics.Gdi;
 using Xunit;
 
 namespace Whim.Bar.Tests;
@@ -7,71 +8,281 @@ namespace Whim.Bar.Tests;
 [System.Diagnostics.CodeAnalysis.SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope")]
 public class ActiveLayoutWidgetViewModelTests
 {
-	private static ActiveLayoutWidgetViewModel CreateSut(IContext context, IMonitor monitor) => new(context, monitor);
+	private static ActiveLayoutWidgetViewModel CreateSut(IContext ctx, IMonitor monitor) => new(ctx, monitor);
 
-	[Theory, AutoSubstituteData]
-	public void WorkspaceManager_ActiveLayoutEngineChanged(IContext context, IMonitor monitor, IWorkspace workspace)
+	private static ILayoutEngine CreateLayoutEngine(string name)
 	{
-		// Given
-		ActiveLayoutWidgetViewModel viewModel = CreateSut(context, monitor);
-
-		// When
-		// Then
-		Assert.PropertyChanged(
-			viewModel,
-			nameof(viewModel.ActiveLayoutEngine),
-			() =>
-				context.WorkspaceManager.ActiveLayoutEngineChanged += Raise.Event<
-					EventHandler<ActiveLayoutEngineChangedEventArgs>
-				>(
-					context.WorkspaceManager,
-					new ActiveLayoutEngineChangedEventArgs()
-					{
-						Workspace = workspace,
-						PreviousLayoutEngine = workspace.ActiveLayoutEngine,
-						CurrentLayoutEngine = workspace.ActiveLayoutEngine,
-					}
-				)
-		);
+		ILayoutEngine layoutEngine = Substitute.For<ILayoutEngine>();
+		layoutEngine.Name.Returns(name);
+		return layoutEngine;
 	}
 
 	[Theory, AutoSubstituteData]
-	public void WorkspaceManager_MonitorWorkspaceChanged(IContext context, IMonitor monitor, IWorkspace workspace)
+	internal void Constructor_SetsEventListeners(IContext ctx)
 	{
-		// Given
-		ActiveLayoutWidgetViewModel viewModel = CreateSut(context, monitor);
-
-		// When
-		// Then
-		Assert.PropertyChanged(
-			viewModel,
-			nameof(viewModel.ActiveLayoutEngine),
-			() =>
-				context.Butler.MonitorWorkspaceChanged += Raise.Event<EventHandler<MonitorWorkspaceChangedEventArgs>>(
-					context.Butler,
-					new MonitorWorkspaceChangedEventArgs() { Monitor = monitor, CurrentWorkspace = workspace }
-				)
-		);
+		// GIVEN a monitor and view model
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+
+		// THEN all required event listeners are registered with the context store
+		Assert.NotNull(sut);
+		ctx.Store.WorkspaceEvents.Received().ActiveLayoutEngineChanged += Arg.Any<
+			EventHandler<ActiveLayoutEngineChangedEventArgs>
+		>();
+		ctx.Store.MapEvents.Received().MonitorWorkspaceChanged += Arg.Any<
+			EventHandler<MonitorWorkspaceChangedEventArgs>
+		>();
+		ctx.Store.WindowEvents.Received().WindowFocused += Arg.Any<EventHandler<WindowFocusedEventArgs>>();
 	}
 
 	[Theory, AutoSubstituteData]
-	[System.Diagnostics.CodeAnalysis.SuppressMessage(
-		"Usage",
-		"NS5000:Received check.",
-		Justification = "The analyzer is wrong"
-	)]
-	public void Dispose(IContext context, IMonitor monitor)
+	internal void Dispose_RemovesEventListeners(IContext ctx)
 	{
-		// Given
-		ActiveLayoutWidgetViewModel viewModel = CreateSut(context, monitor);
+		// GIVEN a monitor and initialized view model
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
 
-		// When
-		viewModel.Dispose();
+		// WHEN the view model is disposed
+		sut.Dispose();
 
-		// Then
-		context.WorkspaceManager.Received(1).ActiveLayoutEngineChanged -= Arg.Any<
+		// THEN all event listeners are properly unregistered from the context store
+		ctx.Store.WorkspaceEvents.Received().ActiveLayoutEngineChanged -= Arg.Any<
 			EventHandler<ActiveLayoutEngineChangedEventArgs>
 		>();
-		context.Butler.Received(1).MonitorWorkspaceChanged -= Arg.Any<EventHandler<MonitorWorkspaceChangedEventArgs>>();
+		ctx.Store.MapEvents.Received().MonitorWorkspaceChanged -= Arg.Any<
+			EventHandler<MonitorWorkspaceChangedEventArgs>
+		>();
+		ctx.Store.WindowEvents.Received().WindowFocused -= Arg.Any<EventHandler<WindowFocusedEventArgs>>();
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void Store_ActiveLayoutEngineChanged_UpdatesProperty(
+		IContext ctx,
+		MutableRootSector root,
+		ILayoutEngine previousLayoutEngine,
+		ILayoutEngine currentLayoutEngine
+	)
+	{
+		// GIVEN an initialized view model monitoring a specific workspace
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		Workspace workspace = StoreTestUtils.CreateWorkspace(ctx);
+		StoreTestUtils.AddWorkspacesToManager(ctx, root, workspace);
+
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		bool propertyChanged = false;
+		sut.PropertyChanged += (s, e) =>
+		{
+			if (e.PropertyName == nameof(ActiveLayoutWidgetViewModel.ActiveLayoutEngine))
+			{
+				propertyChanged = true;
+			}
+		};
+
+		// WHEN the active layout engine changes in the workspace
+		root.WorkspaceSector.QueueEvent(
+			new ActiveLayoutEngineChangedEventArgs()
+			{
+				Workspace = workspace,
+				PreviousLayoutEngine = previousLayoutEngine,
+				CurrentLayoutEngine = currentLayoutEngine,
+			}
+		);
+		root.WorkspaceSector.DispatchEvents();
+
+		// THEN the view model property is updated and notifies of the change
+		Assert.True(propertyChanged);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void Store_MonitorWorkspaceChanged_SameMonitor_UpdatesProperties(IContext ctx, MutableRootSector root)
+	{
+		// GIVEN
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ILayoutEngine layoutEngine1 = CreateLayoutEngine("Layout1");
+		ILayoutEngine layoutEngine2 = CreateLayoutEngine("Layout2");
+		Workspace workspace = StoreTestUtils.CreateWorkspace(ctx) with
+		{
+			LayoutEngines = [layoutEngine1, layoutEngine2],
+		};
+		StoreTestUtils.PopulateMonitorWorkspaceMap(ctx, root, monitor, workspace);
+
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		bool propertyChangedNames = new List<string>();
+		sut.PropertyChanged += (s, e) => propertyChangedNames.Add(e.PropertyName ?? string.Empty);
+
+		// WHEN
+		root.MapSector.QueueEvent(
+			new MonitorWorkspaceChangedEventArgs
+			{
+				Monitor = monitor,
+				CurrentWorkspace = workspace,
+				PreviousWorkspace = null,
+			}
+		);
+		root.MapSector.DispatchEvents();
+
+		// THEN
+		Assert.Contains(nameof(ActiveLayoutWidgetViewModel.LayoutEngines), propertyChangedNames);
+		Assert.Contains(nameof(ActiveLayoutWidgetViewModel.ActiveLayoutEngine), propertyChangedNames);
+		Assert.Collection(
+			sut.LayoutEngines,
+			item => Assert.Equal("Layout1", item),
+			item => Assert.Equal("Layout2", item)
+		);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void Store_MonitorWorkspaceChanged_DifferentMonitor_DoesNotUpdateProperties(
+		IContext ctx,
+		MutableRootSector root
+	)
+	{
+		// GIVEN
+		IMonitor widgetMonitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		IMonitor differentMonitor = StoreTestUtils.CreateMonitor((HMONITOR)2);
+		ILayoutEngine layoutEngine1 = CreateLayoutEngine("Layout1");
+		ILayoutEngine layoutEngine2 = CreateLayoutEngine("Layout2");
+		Workspace workspace = StoreTestUtils.CreateWorkspace(ctx) with
+		{
+			LayoutEngines = [layoutEngine1, layoutEngine2],
+		};
+		StoreTestUtils.PopulateMonitorWorkspaceMap(ctx, root, differentMonitor, workspace);
+
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, widgetMonitor);
+		bool propertyChangedNames = new List<string>();
+		sut.PropertyChanged += (s, e) => propertyChangedNames.Add(e.PropertyName ?? string.Empty);
+
+		// WHEN
+		root.MapSector.QueueEvent(
+			new MonitorWorkspaceChangedEventArgs
+			{
+				Monitor = differentMonitor,
+				CurrentWorkspace = workspace,
+				PreviousWorkspace = null,
+			}
+		);
+		root.MapSector.DispatchEvents();
+
+		// THEN
+		Assert.DoesNotContain(nameof(ActiveLayoutWidgetViewModel.LayoutEngines), propertyChangedNames);
+		Assert.DoesNotContain(nameof(ActiveLayoutWidgetViewModel.ActiveLayoutEngine), propertyChangedNames);
+		Assert.Empty(sut.LayoutEngines);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void WindowEvents_WindowFocused_ClosesDropDown(IContext ctx, MutableRootSector root, IWindow window)
+	{
+		// GIVEN a view model with an open dropdown
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		sut.IsDropDownOpen = true;
+
+		// WHEN a window focus event occurs
+		root.WindowSector.QueueEvent(new WindowFocusedEventArgs { Window = window });
+		root.WindowSector.DispatchEvents();
+
+		// THEN the dropdown is automatically closed
+		Assert.False(sut.IsDropDownOpen);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void ActiveLayoutEngine_Get_ReturnsEmptyString_WhenNoLayoutEngine(IContext ctx)
+	{
+		// GIVEN a view model with no associated workspace or layout engine
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		// No layout engine or workspace is populated in the store
+
+		// WHEN requesting the active layout engine name
+		string result = sut.ActiveLayoutEngine;
+
+		// THEN an empty string is returned
+		Assert.Equal("", result);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void ActiveLayoutEngine_Get_ReturnsLayoutEngineName(IContext ctx, MutableRootSector root)
+	{
+		// GIVEN a view model with a workspace containing a specific layout engine
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ILayoutEngine layoutEngine = CreateLayoutEngine("TestLayout");
+		Workspace workspace = StoreTestUtils.CreateWorkspace(ctx) with { LayoutEngines = [layoutEngine] };
+		StoreTestUtils.PopulateMonitorWorkspaceMap(ctx, root, monitor, workspace);
+
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+
+		// WHEN requesting the active layout engine name
+		string result = sut.ActiveLayoutEngine;
+
+		// THEN the correct layout engine name is returned
+		Assert.Equal("TestLayout", result);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void ActiveLayoutEngine_Set_DoesNothing_WhenNoWorkspace(IContext ctx)
+	{
+		// GIVEN a view model with no associated workspace
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		// No workspace is populated in the store
+		bool propertyChanged = false;
+		sut.PropertyChanged += (s, e) => propertyChanged = true;
+
+		// WHEN attempting to set a new layout engine
+		sut.ActiveLayoutEngine = "NewLayout";
+
+		// THEN no property change occurs since there is no workspace to modify
+		Assert.False(propertyChanged);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void ActiveLayoutEngine_Set_DoesNotDispatch_WhenSameLayoutEngine(IContext ctx, List<object> transforms)
+	{
+		// GIVEN a view model with a workspace and active layout engine
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ILayoutEngine layoutEngine = CreateLayoutEngine("TestLayout");
+		Workspace workspace = StoreTestUtils.CreateWorkspace(ctx) with { LayoutEngines = [layoutEngine] };
+
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		bool propertyChanged = false;
+		sut.PropertyChanged += (s, e) => propertyChanged = true;
+
+		// WHEN setting the same layout engine name
+		sut.ActiveLayoutEngine = "TestLayout";
+
+		// THEN no changes are dispatched and no property change is triggered
+		Assert.Empty(transforms);
+		Assert.False(propertyChanged);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void ActiveLayoutEngine_Set_Dispatches_WhenDifferentLayoutEngine(
+		IContext ctx,
+		MutableRootSector root,
+		List<object> transforms
+	)
+	{
+		// GIVEN a view model with a workspace and specific layout engine
+		IMonitor monitor = StoreTestUtils.CreateMonitor((HMONITOR)1);
+		ILayoutEngine layoutEngine = CreateLayoutEngine("TestLayout");
+		Workspace workspace = StoreTestUtils.CreateWorkspace(ctx) with { LayoutEngines = [layoutEngine] };
+		StoreTestUtils.PopulateMonitorWorkspaceMap(ctx, root, monitor, workspace);
+
+		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
+		bool propertyChanged = false;
+		sut.PropertyChanged += (s, e) =>
+		{
+			if (e.PropertyName == nameof(ActiveLayoutWidgetViewModel.ActiveLayoutEngine))
+			{
+				propertyChanged = true;
+			}
+		};
+
+		// WHEN setting a different layout engine name
+		sut.ActiveLayoutEngine = "NewLayout";
+
+		// THEN a transform is dispatched and the property change is notified
+		Assert.Contains(transforms, t => t.Equals(new SetLayoutEngineFromNameTransform(workspace.Id, "NewLayout")));
+		Assert.True(propertyChanged);
 	}
 }
diff --git a/src/Whim.Bar.Tests/ActiveLayout/NextLayoutEngineCommandTests.cs b/src/Whim.Bar.Tests/ActiveLayout/NextLayoutEngineCommandTests.cs
deleted file mode 100644
index cac882315..000000000
--- a/src/Whim.Bar.Tests/ActiveLayout/NextLayoutEngineCommandTests.cs
+++ /dev/null
@@ -1,55 +0,0 @@
-using NSubstitute;
-using Whim.TestUtils;
-using Xunit;
-
-namespace Whim.Bar.Tests;
-
-[System.Diagnostics.CodeAnalysis.SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope")]
-public class NextLayoutEngineCommandTests
-{
-	private static ActiveLayoutWidgetViewModel CreateSut(IContext context, IMonitor monitor) => new(context, monitor);
-
-	[Theory, AutoSubstituteData]
-	public void Execute(IContext context, IMonitor monitor)
-	{
-		// Given
-		ActiveLayoutWidgetViewModel viewModel = CreateSut(context, monitor);
-		NextLayoutEngineCommand command = new(context, viewModel);
-
-		// When
-		command.Execute(null);
-
-		// Then
-		context.Butler.Pantry.Received(1).GetWorkspaceForMonitor(Arg.Any<IMonitor>());
-		context.Butler.Pantry.GetWorkspaceForMonitor(monitor)!.Received(1).CycleLayoutEngine(false);
-	}
-
-	[Theory, AutoSubstituteData]
-	public void Execute_NoWorkspaceForMonitor(IContext context, IMonitor monitor)
-	{
-		// Given
-		ActiveLayoutWidgetViewModel viewModel = CreateSut(context, monitor);
-		NextLayoutEngineCommand command = new(context, viewModel);
-		context.Butler.Pantry.GetWorkspaceForMonitor(monitor).Returns((IWorkspace?)null);
-
-		// When
-		command.Execute(null);
-
-		// Then
-		context.Butler.Pantry.Received(1).GetWorkspaceForMonitor(Arg.Any<IMonitor>());
-	}
-
-	[Theory, AutoSubstituteData]
-	public void CanExecute(IContext context, IMonitor monitor)
-	{
-		// Given
-		ActiveLayoutWidgetViewModel viewModel = CreateSut(context, monitor);
-		NextLayoutEngineCommand command = new(context, viewModel);
-
-		// When
-		bool canExecute = command.CanExecute(null);
-
-		// Then
-		Assert.True(canExecute);
-	}
-}
diff --git a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
index 0e07017e6..e5e0ec1bf 100644
--- a/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
+++ b/src/Whim.Bar/ActiveLayout/ActiveLayoutWidgetViewModel.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Linq;
 
@@ -19,10 +20,12 @@ internal class ActiveLayoutWidgetViewModel : INotifyPropertyChanged, IDisposable
 
 	private bool _disposedValue;
 
+	private ImmutableList<string> _layoutEngines = ImmutableList<string>.Empty;
+
 	/// <summary>
-	/// The name of the active layout engine.
+	/// The available layout engines.
 	/// </summary>
-	public List<string> LayoutEngines = [];
+	public IReadOnlyList<string> LayoutEngines => _layoutEngines;
 
 	/// <summary>
 	/// The name of the active layout engine.
@@ -31,21 +34,16 @@ public string ActiveLayoutEngine
 	{
 		get
 		{
-			if (!_context.Store.Pick(Pickers.PickWorkspaceByMonitor(Monitor.Handle)).TryGet(out IWorkspace workspace))
-			{
-				return "";
-			}
-
 			if (
-				!_context
-					.Store.Pick(Pickers.PickActiveLayoutEngine(workspace.Id))
+				_context
+					.Store.Pick(Pickers.PickActiveLayoutEngineByMonitor(Monitor.Handle))
 					.TryGet(out ILayoutEngine layoutEngine)
 			)
 			{
-				return "";
+				return layoutEngine.Name;
 			}
 
-			return layoutEngine.Name;
+			return "";
 		}
 		set
 		{
@@ -54,14 +52,7 @@ public string ActiveLayoutEngine
 				return;
 			}
 
-			if (
-				!_context
-					.Store.Pick(Pickers.PickActiveLayoutEngine(workspace.Id))
-					.TryGet(out ILayoutEngine layoutEngine)
-			)
-			{
-				return;
-			}
+			ILayoutEngine layoutEngine = WorkspaceUtils.GetActiveLayoutEngine(workspace);
 
 			if (layoutEngine.Name != value)
 			{
@@ -101,7 +92,7 @@ public ActiveLayoutWidgetViewModel(IContext context, IMonitor monitor)
 		_context.Store.WindowEvents.WindowFocused += WindowEvents_WindowFocused;
 	}
 
-	private void Store_ActiveLayoutEngineChanged(object? sender, EventArgs e)
+	private void Store_ActiveLayoutEngineChanged(object? sender, ActiveLayoutEngineChangedEventArgs e)
 	{
 		OnPropertyChanged(nameof(ActiveLayoutEngine));
 	}
@@ -113,8 +104,7 @@ private void Store_MonitorWorkspaceChanged(object? sender, MonitorWorkspaceChang
 			return;
 		}
 
-		LayoutEngines.Clear();
-		LayoutEngines.AddRange(e.CurrentWorkspace.LayoutEngines.Select(engine => engine.Name));
+		_layoutEngines = e.CurrentWorkspace.LayoutEngines.Select(engine => engine.Name).ToImmutableList();
 
 		OnPropertyChanged(nameof(LayoutEngines));
 		OnPropertyChanged(nameof(ActiveLayoutEngine));
diff --git a/src/Whim.TestUtils/Whim.TestUtils.csproj b/src/Whim.TestUtils/Whim.TestUtils.csproj
index 5f6f6a0a9..9a0fe9d4f 100644
--- a/src/Whim.TestUtils/Whim.TestUtils.csproj
+++ b/src/Whim.TestUtils/Whim.TestUtils.csproj
@@ -40,6 +40,7 @@
   </ItemGroup>
   <ItemGroup>
     <InternalsVisibleTo Include="Whim.Tests" />
+	  <InternalsVisibleTo Include="Whim.Bar.Tests" />
 	  <InternalsVisibleTo Include="Whim.Gaps.Tests" />
 	  <InternalsVisibleTo Include="Whim.FloatingWindow.Tests" />
     <InternalsVisibleTo Include="Whim.LayoutPreview.Tests" />
diff --git a/src/Whim.Tests/Store/MapSector/MapPickersTests.cs b/src/Whim.Tests/Store/MapSector/MapPickersTests.cs
index 2209706a7..e7b05ab51 100644
--- a/src/Whim.Tests/Store/MapSector/MapPickersTests.cs
+++ b/src/Whim.Tests/Store/MapSector/MapPickersTests.cs
@@ -247,4 +247,52 @@ MutableRootSector root
 		Assert.True(result.IsSuccessful);
 		Assert.Equal(workspaceOrder[expected], result.Value.Id);
 	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void PickActiveLayoutEngineByMonitor_Failure(IContext ctx)
+	{
+		// Given we have an untracked monitor
+		IMonitor monitor = CreateMonitor((HMONITOR)1);
+
+		// When we get the layout engine
+		var result = ctx.Store.Pick(Pickers.PickActiveLayoutEngineByMonitor(monitor.Handle));
+
+		// Then we get an exception
+		Assert.False(result.IsSuccessful);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void PickActiveLayoutEngineByMonitor_NoWorkspaceForMonitor(IContext ctx, MutableRootSector root)
+	{
+		// Given we have a monitor with no workspace
+		IMonitor monitor = CreateMonitor((HMONITOR)1);
+		AddMonitorsToManager(ctx, root, monitor);
+
+		// When we get the layout engine
+		var result = ctx.Store.Pick(Pickers.PickActiveLayoutEngineByMonitor(monitor.Handle));
+
+		// Then we get an exception
+		Assert.False(result.IsSuccessful);
+	}
+
+	[Theory, AutoSubstituteData<StoreCustomization>]
+	internal void PickActiveLayoutEngineByMonitor_Success(
+		IContext ctx,
+		MutableRootSector root,
+		ILayoutEngine layoutEngine
+	)
+	{
+		// Given we have a monitor with an active layout engine
+		IMonitor monitor = CreateMonitor((HMONITOR)1);
+		Workspace workspace = CreateWorkspace(ctx) with { LayoutEngines = [ layoutEngine ] };
+
+		PopulateMonitorWorkspaceMap(ctx, root, monitor, workspace);
+
+		// When we get the layout engine
+		var result = ctx.Store.Pick(Pickers.PickActiveLayoutEngineByMonitor(monitor.Handle));
+
+		// Then we get the layout engine
+		Assert.True(result.IsSuccessful);
+		Assert.Same(layoutEngine, result.Value);
+	}
 }
diff --git a/src/Whim/Store/MapSector/MapPickers.cs b/src/Whim/Store/MapSector/MapPickers.cs
index 9500850a0..1427fb14a 100644
--- a/src/Whim/Store/MapSector/MapPickers.cs
+++ b/src/Whim/Store/MapSector/MapPickers.cs
@@ -150,4 +150,25 @@ public static PurePicker<Result<IWorkspace>> PickAdjacentWorkspace(
 
 			return Result.FromException<IWorkspace>(new WhimException($"No adjacent workspace found to {workspaceId}"));
 		};
+
+	/// <summary>
+	/// Retrieves the active layout engine for the workspace on the given monitor.
+	/// </summary>
+	/// <param name="monitorHandle">
+	/// The handle of the monitor to get the active layout engine for.
+	/// </param>
+	/// <returns>
+	/// The active layout engine for the workspace on the monitor, otherwise <see cref="Result{T, TError}.Error"/>.
+	/// </returns>
+	public static PurePicker<Result<ILayoutEngine>> PickActiveLayoutEngineByMonitor(HMONITOR monitorHandle) =>
+		rootSector =>
+		{
+			Result<IWorkspace> workspaceResult = PickWorkspaceByMonitor(monitorHandle)(rootSector);
+			if (workspaceResult.TryGet(out IWorkspace workspace))
+			{
+				return Result.FromValue(WorkspaceUtils.GetActiveLayoutEngine(workspace));
+			}
+
+			return Result.FromException<ILayoutEngine>(workspaceResult.Error!);
+		};
 }

From 5ef874e3dd25227cb0629d7723c7109dc98470bc Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 14:36:04 +1100
Subject: [PATCH 13/16] Formatting

---
 src/Whim.Tests/Store/MapSector/MapPickersTests.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Whim.Tests/Store/MapSector/MapPickersTests.cs b/src/Whim.Tests/Store/MapSector/MapPickersTests.cs
index e7b05ab51..7a93ba8f8 100644
--- a/src/Whim.Tests/Store/MapSector/MapPickersTests.cs
+++ b/src/Whim.Tests/Store/MapSector/MapPickersTests.cs
@@ -284,7 +284,7 @@ ILayoutEngine layoutEngine
 	{
 		// Given we have a monitor with an active layout engine
 		IMonitor monitor = CreateMonitor((HMONITOR)1);
-		Workspace workspace = CreateWorkspace(ctx) with { LayoutEngines = [ layoutEngine ] };
+		Workspace workspace = CreateWorkspace(ctx) with { LayoutEngines = [layoutEngine] };
 
 		PopulateMonitorWorkspaceMap(ctx, root, monitor, workspace);
 

From a5a8cf2b5025f26f7c9033e58fd55b9960dc0392 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 20:46:59 +1100
Subject: [PATCH 14/16] Hopefully fix CI

---
 .github/workflows/docs_commit.yml                |  4 ++++
 scripts/Generate-SourceFromSchema.ps1            | 16 +++++++++++-----
 .../ActiveLayoutWidgetViewModelTests.cs          |  4 ++--
 src/Whim.Yaml/Whim.Yaml.csproj                   |  2 +-
 4 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/docs_commit.yml b/.github/workflows/docs_commit.yml
index af2983e63..652a5aebf 100644
--- a/.github/workflows/docs_commit.yml
+++ b/.github/workflows/docs_commit.yml
@@ -63,3 +63,7 @@ jobs:
 
       - name: Run docfx
         run: dotnet docfx .\docs\docfx.json
+        continue-on-error: true
+
+      - name: Run docfx (backup)
+        run: dotnet docfx .\docs\docfx.json
diff --git a/scripts/Generate-SourceFromSchema.ps1 b/scripts/Generate-SourceFromSchema.ps1
index 58d9c5aa4..b4cd7ddd8 100644
--- a/scripts/Generate-SourceFromSchema.ps1
+++ b/scripts/Generate-SourceFromSchema.ps1
@@ -6,11 +6,16 @@ $schemaPath = ".\src\Whim.Yaml\schema.json"
 $outputPath = ".\src\Whim.Yaml\Generated"
 $metadataPath = "$outputPath\metadata.json"
 
-$paths = @(
-    ".\src\Whim.Yaml\Whim.Yaml.csproj",
-    ".\src\Whim.Yaml\schema.json"
-)
-$yamlCodeHash = $paths | ForEach-Object { Get-FileHash $_ } | Out-String
+function Get-YamlCodeHash {
+    $paths = @(
+        ".\src\Whim.Yaml\Whim.Yaml.csproj",
+        ".\src\Whim.Yaml\schema.json"
+    )
+
+    return $paths | ForEach-Object { (Get-FileHash $_).Hash } | Join-String $_
+}
+
+$yamlCodeHash = Get-YamlCodeHash
 
 function Test-Regenerate {
     param (
@@ -57,5 +62,6 @@ dotnet tool run generatejsonschematypes `
 # If not in CI, write metadata file
 if ($LASTEXITCODE -eq 0 -and $null -eq $env:CI) {
     Write-Host "Writing metadata file..."
+    $yamlCodeHash = Get-YamlCodeHash
     @{ yamlCodeHash = $yamlCodeHash } | ConvertTo-Json | Set-Content $metadataPath
 }
diff --git a/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs b/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs
index 3da118cab..201b43f3c 100644
--- a/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs
+++ b/src/Whim.Bar.Tests/ActiveLayout/ActiveLayoutWidgetViewModelTests.cs
@@ -107,7 +107,7 @@ internal void Store_MonitorWorkspaceChanged_SameMonitor_UpdatesProperties(IConte
 		StoreTestUtils.PopulateMonitorWorkspaceMap(ctx, root, monitor, workspace);
 
 		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, monitor);
-		bool propertyChangedNames = new List<string>();
+		List<string> propertyChangedNames = [];
 		sut.PropertyChanged += (s, e) => propertyChangedNames.Add(e.PropertyName ?? string.Empty);
 
 		// WHEN
@@ -149,7 +149,7 @@ MutableRootSector root
 		StoreTestUtils.PopulateMonitorWorkspaceMap(ctx, root, differentMonitor, workspace);
 
 		ActiveLayoutWidgetViewModel sut = CreateSut(ctx, widgetMonitor);
-		bool propertyChangedNames = new List<string>();
+		List<string> propertyChangedNames = [];
 		sut.PropertyChanged += (s, e) => propertyChangedNames.Add(e.PropertyName ?? string.Empty);
 
 		// WHEN
diff --git a/src/Whim.Yaml/Whim.Yaml.csproj b/src/Whim.Yaml/Whim.Yaml.csproj
index 368a29391..7721d25e5 100644
--- a/src/Whim.Yaml/Whim.Yaml.csproj
+++ b/src/Whim.Yaml/Whim.Yaml.csproj
@@ -65,7 +65,7 @@
 	</ItemGroup>
 
 	<Target Name="GenerateSchema" BeforeTargets="BeforeCompile">
-		<Exec Command="powershell.exe -NonInteractive -ExecutionPolicy Unrestricted .\scripts\Generate-SourceFromSchema.ps1" WorkingDirectory="..\..\" ConsoleToMsBuild="true">
+		<Exec Command="pwsh.exe -NonInteractive -ExecutionPolicy Unrestricted .\scripts\Generate-SourceFromSchema.ps1" WorkingDirectory="..\..\" ConsoleToMsBuild="true">
 			<Output TaskParameter="ConsoleOutput" PropertyName="OutputOfExec" />
 		</Exec>
 	</Target>

From 0200c5a44e967ae4cc5e6fc206946c77592b6077 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 21:02:07 +1100
Subject: [PATCH 15/16] Try revert to old generate script

---
 scripts/Generate-SourceFromSchema.ps1 | 33 ++++++++++++---------------
 src/output.txt                        |  1 +
 2 files changed, 16 insertions(+), 18 deletions(-)
 create mode 100644 src/output.txt

diff --git a/scripts/Generate-SourceFromSchema.ps1 b/scripts/Generate-SourceFromSchema.ps1
index b4cd7ddd8..c166f7335 100644
--- a/scripts/Generate-SourceFromSchema.ps1
+++ b/scripts/Generate-SourceFromSchema.ps1
@@ -1,21 +1,15 @@
-$ErrorActionPreference = "Stop"
-
 Write-Host "Generating source from schema..."
 
 $schemaPath = ".\src\Whim.Yaml\schema.json"
 $outputPath = ".\src\Whim.Yaml\Generated"
 $metadataPath = "$outputPath\metadata.json"
-
-function Get-YamlCodeHash {
-    $paths = @(
-        ".\src\Whim.Yaml\Whim.Yaml.csproj",
-        ".\src\Whim.Yaml\schema.json"
-    )
-
-    return $paths | ForEach-Object { (Get-FileHash $_).Hash } | Join-String $_
+$now = Get-Date
+if ($env:CI) {
+    $gitSha = $env:GITHUB_SHA
+}
+else {
+    $gitSha = (git rev-parse HEAD)
 }
-
-$yamlCodeHash = Get-YamlCodeHash
 
 function Test-Regenerate {
     param (
@@ -37,10 +31,14 @@ function Test-Regenerate {
     }
 
     $metadata = Get-Content $metadataPath | ConvertFrom-Json
-    if ($metadata.yamlCodeHash -ne $yamlCodeHash) {
-        Write-Host "YAML schema has changed since last generation, regenerating..."
-        Write-Host "Old hash: $($metadata.yamlCodeHash)"
-        Write-Host "New hash: $yamlCodeHash"
+    if ($metadata.gitRef -ne $gitSha) {
+        Write-Host "Git ref has changed since last generation, regenerating..."
+        return $true
+    }
+
+    $schemaLastWriteTime = (Get-Item $schemaPath).LastWriteTime
+    if ($metadata.lastWriteTime -lt $schemaLastWriteTime) {
+        Write-Host "Schema has changed since last generation, regenerating..."
         return $true
     }
 
@@ -62,6 +60,5 @@ dotnet tool run generatejsonschematypes `
 # If not in CI, write metadata file
 if ($LASTEXITCODE -eq 0 -and $null -eq $env:CI) {
     Write-Host "Writing metadata file..."
-    $yamlCodeHash = Get-YamlCodeHash
-    @{ yamlCodeHash = $yamlCodeHash } | ConvertTo-Json | Set-Content $metadataPath
+    @{ gitRef = $gitSha; lastWriteTime = $now } | ConvertTo-Json | Set-Content $metadataPath
 }
diff --git a/src/output.txt b/src/output.txt
new file mode 100644
index 000000000..644d53afa
--- /dev/null
+++ b/src/output.txt
@@ -0,0 +1 @@
+MSBUILD : error MSB1003: Specify a project or solution file. The current working directory does not contain a project or solution file.

From a69468ebf856c4aeb735fe00c0a7ee8ffbf17707 Mon Sep 17 00:00:00 2001
From: Isaac Daly <isaac.daly@outlook.com>
Date: Tue, 5 Nov 2024 21:12:20 +1100
Subject: [PATCH 16/16] Revert more changes

---
 .github/workflows/docs_commit.yml | 4 ----
 src/Whim.Yaml/Whim.Yaml.csproj    | 2 +-
 src/output.txt                    | 1 -
 3 files changed, 1 insertion(+), 6 deletions(-)
 delete mode 100644 src/output.txt

diff --git a/.github/workflows/docs_commit.yml b/.github/workflows/docs_commit.yml
index 652a5aebf..af2983e63 100644
--- a/.github/workflows/docs_commit.yml
+++ b/.github/workflows/docs_commit.yml
@@ -63,7 +63,3 @@ jobs:
 
       - name: Run docfx
         run: dotnet docfx .\docs\docfx.json
-        continue-on-error: true
-
-      - name: Run docfx (backup)
-        run: dotnet docfx .\docs\docfx.json
diff --git a/src/Whim.Yaml/Whim.Yaml.csproj b/src/Whim.Yaml/Whim.Yaml.csproj
index 7721d25e5..368a29391 100644
--- a/src/Whim.Yaml/Whim.Yaml.csproj
+++ b/src/Whim.Yaml/Whim.Yaml.csproj
@@ -65,7 +65,7 @@
 	</ItemGroup>
 
 	<Target Name="GenerateSchema" BeforeTargets="BeforeCompile">
-		<Exec Command="pwsh.exe -NonInteractive -ExecutionPolicy Unrestricted .\scripts\Generate-SourceFromSchema.ps1" WorkingDirectory="..\..\" ConsoleToMsBuild="true">
+		<Exec Command="powershell.exe -NonInteractive -ExecutionPolicy Unrestricted .\scripts\Generate-SourceFromSchema.ps1" WorkingDirectory="..\..\" ConsoleToMsBuild="true">
 			<Output TaskParameter="ConsoleOutput" PropertyName="OutputOfExec" />
 		</Exec>
 	</Target>
diff --git a/src/output.txt b/src/output.txt
deleted file mode 100644
index 644d53afa..000000000
--- a/src/output.txt
+++ /dev/null
@@ -1 +0,0 @@
-MSBUILD : error MSB1003: Specify a project or solution file. The current working directory does not contain a project or solution file.