From 1cb9c862d4d252c718f2cce04bfeb178d44f2205 Mon Sep 17 00:00:00 2001
From: mntone <sd8@live.jp>
Date: Mon, 10 Aug 2020 01:09:02 +0900
Subject: [PATCH] Add updating the displays and taskbar position.

---
 .../UI/Bindings/SettingsWindowViewModel.cs    | 69 +++++++++++++------
 source/SylphyHorn/UI/SettingsWindow.xaml.cs   | 50 +++++++++++++-
 2 files changed, 98 insertions(+), 21 deletions(-)

diff --git a/source/SylphyHorn/UI/Bindings/SettingsWindowViewModel.cs b/source/SylphyHorn/UI/Bindings/SettingsWindowViewModel.cs
index 8047e81..96c82de 100644
--- a/source/SylphyHorn/UI/Bindings/SettingsWindowViewModel.cs
+++ b/source/SylphyHorn/UI/Bindings/SettingsWindowViewModel.cs
@@ -27,9 +27,29 @@ public class SettingsWindowViewModel : WindowViewModel
 
 		public IReadOnlyCollection<DisplayViewModel<WindowPlacement>> Placements { get; }
 
-		public bool IsDisplayEnabled { get; }
+		public bool IsDisplayEnabled => this.Displays.Count > 3;
 
-		public IReadOnlyCollection<DisplayViewModel<uint>> Displays { get; }
+		#region Displays notification property
+
+		public IReadOnlyCollection<DisplayViewModel<uint>> _Displays;
+
+		public IReadOnlyCollection<DisplayViewModel<uint>> Displays
+		{
+			get => this._Displays;
+			set
+			{
+				if (this._Displays != value)
+				{
+					this._Displays = value;
+
+					this.RaisePropertyChanged();
+					this.RaisePropertyChanged(nameof(this.Display));
+					this.RaisePropertyChanged(nameof(this.IsDisplayEnabled));
+				}
+			}
+		}
+
+		#endregion
 
 		public IReadOnlyCollection<LicenseViewModel> Licenses { get; }
 
@@ -257,23 +277,7 @@ public SettingsWindowViewModel(HookService hookService)
 				new DisplayViewModel<WindowPlacement> { Display = Resources.Settings_NotificationWindowPlacement_BottomRight, Value = WindowPlacement.BottomRight, },
 			}.ToList();
 
-			this.Displays = new[] { new DisplayViewModel<uint> { Display = Resources.Settings_MultipleDisplays_CurrentDisplay, Value = 0, } }
-				.Concat(MonitorService.GetMonitors()
-					.Select((m, i) => new DisplayViewModel<uint>
-					{
-						Display = string.Format(Resources.Settings_MultipleDisplays_EachDisplay, i + 1, m.Name),
-						Value = (uint)(i + 1),
-					}))
-				.Concat(new[]
-				{
-					new DisplayViewModel<uint>
-					{
-						Display = Resources.Settings_MultipleDisplays_AllDisplays,
-						Value = uint.MaxValue,
-					}
-				})
-				.ToList();
-			if (this.Displays.Count > 3) this.IsDisplayEnabled = true;
+			this.UpdateDisplays();
 
 			this.Licenses = LicenseInfo.All.Select(x => new LicenseViewModel(x)).ToArray();
 
@@ -287,7 +291,7 @@ public SettingsWindowViewModel(HookService hookService)
 			this.PreviewBackgroundBrush = new SolidColorBrush(colAndWall.BackgroundColor);
 			this.PreviewBackgroundPath = colAndWall.Path;
 			this.PreviewBackgroundPosition = colAndWall.Position;
-			this.PreviewTaskbarPosition = GetTaskbarPosition();
+			this.UpdateTaskbarPosition();
 
 			this.Logs = ViewModelHelper.CreateReadOnlyDispatcherCollection(
 				LoggingService.Instance.Logs,
@@ -314,6 +318,31 @@ public SettingsWindowViewModel(HookService hookService)
 				.AddTo(this);
 		}
 
+		public void UpdateDisplays()
+		{
+			this.Displays = new[] { new DisplayViewModel<uint> { Display = Resources.Settings_MultipleDisplays_CurrentDisplay, Value = 0, } }
+				.Concat(MonitorService.GetMonitors()
+					.Select((m, i) => new DisplayViewModel<uint>
+					{
+						Display = string.Format(Resources.Settings_MultipleDisplays_EachDisplay, i + 1, m.Name),
+						Value = (uint)(i + 1),
+					}))
+				.Concat(new[]
+				{
+					new DisplayViewModel<uint>
+					{
+						Display = Resources.Settings_MultipleDisplays_AllDisplays,
+						Value = uint.MaxValue,
+					}
+				})
+				.ToList();
+		}
+
+		public void UpdateTaskbarPosition()
+		{
+			this.PreviewTaskbarPosition = GetTaskbarPosition();
+		}
+
 		protected override void InitializeCore()
 		{
 			base.InitializeCore();
diff --git a/source/SylphyHorn/UI/SettingsWindow.xaml.cs b/source/SylphyHorn/UI/SettingsWindow.xaml.cs
index f571ecc..1126d5b 100644
--- a/source/SylphyHorn/UI/SettingsWindow.xaml.cs
+++ b/source/SylphyHorn/UI/SettingsWindow.xaml.cs
@@ -1,9 +1,11 @@
-using SylphyHorn.UI.Bindings;
+using MetroRadiance.Interop.Win32;
+using SylphyHorn.UI.Bindings;
 using System;
 using System.ComponentModel;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Input;
+using System.Windows.Interop;
 using WindowsDesktop;
 
 namespace SylphyHorn.UI
@@ -12,6 +14,8 @@ partial class SettingsWindow
 	{
 		public static SettingsWindow Instance { get; set; }
 
+		private HwndSource _source;
+
 		public SettingsWindow()
 		{
 			this.InitializeComponent();
@@ -28,12 +32,56 @@ protected override void OnInitialized(EventArgs e)
 				.AddValueChanged(this.PreviewRoot, this.OnPreviewRootCanvasPositionChanged);
 		}
 
+		protected override void OnSourceInitialized(EventArgs e)
+		{
+			base.OnSourceInitialized(e);
+
+			this._source = PresentationSource.FromVisual(this) as HwndSource;
+			if (this._source == null) return;
+			this._source.AddHook(this.WndProc);
+		}
+
+		protected override void OnClosed(EventArgs e)
+		{
+			base.OnClosed(e);
+
+			this._source?.RemoveHook(this.WndProc);
+		}
+
 		protected override void OnContentRendered(EventArgs e)
 		{
 			base.OnContentRendered(e);
 			this.Pin();
 		}
 
+		private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
+		{
+			// Note: "Duplicated" and "Extended" change notification events will be received.
+			if (msg == (int)WindowsMessages.WM_SETTINGCHANGE)
+			{
+				if (wParam == new IntPtr(47) /* SPI_SETWORKAREA */)
+				{
+					this.UpdateViewModel(ref handled, taskbarPosition: true);
+				}
+			}
+			else if (msg == (int)WindowsMessages.WM_DEVICECHANGE)
+			{
+				this.UpdateViewModel(ref handled);
+			}
+			return IntPtr.Zero;
+		}
+
+		private void UpdateViewModel(ref bool handled, bool taskbarPosition = false)
+		{
+			var viewModel = this.DataContext as SettingsWindowViewModel;
+			if (viewModel != null)
+			{
+				viewModel.UpdateDisplays();
+				if (taskbarPosition) viewModel.UpdateTaskbarPosition();
+				handled = true;
+			}
+		}
+
 		private void OnPreviewRootCanvasPositionChanged(object sender, EventArgs e)
 			=> this.UpdatePreviewBlurImageMargin();