Refactor LightSwitch and PowerDisplay integration

Simplify theme change notification logic in `LightSwitchService.cpp` by consolidating redundant checks and improving error handling. Remove the `applyMonitorSettings` setting and associated logic from `LightSwitchSettings`.

Introduce `PowerDisplayProfilesHelper` to centralize profile management, ensuring thread safety and simplifying file operations. Update UI in `LightSwitchPage.xaml` to replace `ApplyMonitorSettings` with separate dark and light mode profile settings, adding navigation to PowerDisplay settings.

Enhance `LightSwitchViewModel` with nullable annotations, new profile selection properties, and improved property synchronization. Refactor `PowerDisplayViewModel` to use `PowerDisplayProfilesHelper` for profile management.

Update localization strings for new UI elements. Perform general code cleanup, including null safety annotations, improved logging, and removal of legacy code.

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

@@ -197,44 +197,41 @@ DWORD WINAPI ServiceWorkerThread(LPVOID lpParam)
                 SetAppsTheme(false);
         }
 
-        // Notify PowerDisplay about theme change if monitor settings integration is enabled
-        if (settings.applyMonitorSettings)
+        // Notify PowerDisplay about theme change if any profile is enabled
+        bool shouldNotify = false;
+
+        if (isLightActive && settings.enableLightModeProfile && !settings.lightModeProfile.empty())
         {
-            bool shouldNotify = false;
+            shouldNotify = true;
+        }
+        else if (!isLightActive && settings.enableDarkModeProfile && !settings.darkModeProfile.empty())
+        {
+            shouldNotify = true;
+        }
 
-            if (isLightActive && settings.enableLightModeProfile && settings.lightModeProfile != L"(None)")
+        if (shouldNotify)
+        {
+            try
             {
-                shouldNotify = true;
-            }
-            else if (!isLightActive && settings.enableDarkModeProfile && settings.darkModeProfile != L"(None)")
-            {
-                shouldNotify = true;
-            }
+                // Signal PowerDisplay to check LightSwitch settings and apply appropriate profile
+                // PowerDisplay will read LightSwitch settings to determine which profile to apply
+                Logger::info(L"[LightSwitch] Notifying PowerDisplay about theme change (isLight: {})", isLightActive);
 
-            if (shouldNotify)
+                HANDLE hThemeChangedEvent = CreateEventW(nullptr, FALSE, FALSE, L"Local\\PowerToys_LightSwitch_ThemeChanged");
+                if (hThemeChangedEvent)
+                {
+                    SetEvent(hThemeChangedEvent);
+                    CloseHandle(hThemeChangedEvent);
+                    Logger::info(L"[LightSwitch] Theme change event signaled");
+                }
+                else
+                {
+                    Logger::warn(L"[LightSwitch] Failed to create theme change event");
+                }
+            }
+            catch (...)
             {
-                try
-                {
-                    // Signal PowerDisplay to check LightSwitch settings and apply appropriate profile
-                    // PowerDisplay will read LightSwitch settings to determine which profile to apply
-                    Logger::info(L"[LightSwitch] Notifying PowerDisplay about theme change (isLight: {})", isLightActive);
-                    
-                    HANDLE hThemeChangedEvent = CreateEventW(nullptr, FALSE, FALSE, L"Local\\PowerToys_LightSwitch_ThemeChanged");
-                    if (hThemeChangedEvent)
-                    {
-                        SetEvent(hThemeChangedEvent);
-                        CloseHandle(hThemeChangedEvent);
-                        Logger::info(L"[LightSwitch] Theme change event signaled");
-                    }
-                    else
-                    {
-                        Logger::warn(L"[LightSwitch] Failed to create theme change event");
-                    }
-                }
-                catch (...)
-                {
-                    Logger::error(L"[LightSwitch] Failed to notify PowerDisplay");
-                }
+                Logger::error(L"[LightSwitch] Failed to notify PowerDisplay");
             }
         }
     };

src/modules/LightSwitch/LightSwitchService/LightSwitchSettings.cpp

@@ -160,16 +160,6 @@ void LightSwitchSettings::LoadSettings()
             }
         }
 
-        // ApplyMonitorSettings
-        if (const auto jsonVal = values.get_bool_value(L"applyMonitorSettings"))
-        {
-            auto val = *jsonVal;
-            if (m_settings.applyMonitorSettings != val)
-            {
-                m_settings.applyMonitorSettings = val;
-            }
-        }
-
         // EnableDarkModeProfile
         if (const auto jsonVal = values.get_bool_value(L"enableDarkModeProfile"))
         {

src/modules/LightSwitch/LightSwitchService/LightSwitchSettings.h

@@ -57,11 +57,10 @@ struct LightSwitchConfig
     bool changeSystem = false;
     bool changeApps = false;
 
-    bool applyMonitorSettings = false;
     bool enableDarkModeProfile = false;
     bool enableLightModeProfile = false;
-    std::wstring darkModeProfile = L"(None)";
-    std::wstring lightModeProfile = L"(None)";
+    std::wstring darkModeProfile = L"";
+    std::wstring lightModeProfile = L"";
 };
 
 class LightSwitchSettings

src/settings-ui/Settings.UI.Library/LightSwitchProperties.cs

@@ -17,7 +17,6 @@ namespace Microsoft.PowerToys.Settings.UI.Library
         public const string DefaultLatitude = "0.0";
         public const string DefaultLongitude = "0.0";
         public const string DefaultScheduleMode = "FixedHours";
-        public const bool DefaultApplyMonitorSettings = false;
         public const bool DefaultEnableDarkModeProfile = false;
         public const bool DefaultEnableLightModeProfile = false;
         public const string DefaultDarkModeProfile = "";
@@ -36,7 +35,6 @@ namespace Microsoft.PowerToys.Settings.UI.Library
             SunsetOffset = new IntProperty(DefaultSunsetOffset);
             ScheduleMode = new StringProperty(DefaultScheduleMode);
             ToggleThemeHotkey = new KeyboardKeysProperty(DefaultToggleThemeHotkey);
-            ApplyMonitorSettings = new BoolProperty(DefaultApplyMonitorSettings);
             EnableDarkModeProfile = new BoolProperty(DefaultEnableDarkModeProfile);
             EnableLightModeProfile = new BoolProperty(DefaultEnableLightModeProfile);
             DarkModeProfile = new StringProperty(DefaultDarkModeProfile);
@@ -73,9 +71,6 @@ namespace Microsoft.PowerToys.Settings.UI.Library
         [JsonPropertyName("toggle-theme-hotkey")]
         public KeyboardKeysProperty ToggleThemeHotkey { get; set; }
 
-        [JsonPropertyName("applyMonitorSettings")]
-        public BoolProperty ApplyMonitorSettings { get; set; }
-
         [JsonPropertyName("enableDarkModeProfile")]
         public BoolProperty EnableDarkModeProfile { get; set; }
 

src/settings-ui/Settings.UI.Library/LightSwitchSettings.cs

@@ -60,7 +60,6 @@ namespace Settings.UI.Library
                     Latitude = new StringProperty(Properties.Latitude.Value),
                     Longitude = new StringProperty(Properties.Longitude.Value),
                     ToggleThemeHotkey = new KeyboardKeysProperty(Properties.ToggleThemeHotkey.Value),
-                    ApplyMonitorSettings = new BoolProperty(Properties.ApplyMonitorSettings.Value),
                     EnableDarkModeProfile = new BoolProperty(Properties.EnableDarkModeProfile.Value),
                     EnableLightModeProfile = new BoolProperty(Properties.EnableLightModeProfile.Value),
                     DarkModeProfile = new StringProperty(Properties.DarkModeProfile.Value),

src/settings-ui/Settings.UI.Library/PowerDisplayProfilesHelper.cs

@@ -0,0 +1,151 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#nullable enable
+
+using System;
+using System.IO;
+using System.Text.Json;
+using ManagedCommon;
+
+namespace Microsoft.PowerToys.Settings.UI.Library
+{
+    /// <summary>
+    /// Helper class for managing PowerDisplay profiles storage and retrieval
+    /// Provides centralized access to profile data for both PowerDisplay and LightSwitch modules
+    /// </summary>
+    public static class PowerDisplayProfilesHelper
+    {
+        private static readonly object _lock = new object();
+        private static readonly JsonSerializerOptions _jsonSerializerOptions = new JsonSerializerOptions { WriteIndented = true };
+        private static string? _cachedProfilesFilePath;
+
+        /// <summary>
+        /// Gets the file path where PowerDisplay profiles are stored
+        /// </summary>
+        public static string GetProfilesFilePath()
+        {
+            if (_cachedProfilesFilePath != null)
+            {
+                return _cachedProfilesFilePath;
+            }
+
+            lock (_lock)
+            {
+                if (_cachedProfilesFilePath != null)
+                {
+                    return _cachedProfilesFilePath;
+                }
+
+                var settingsPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+                var powerToysPath = Path.Combine(settingsPath, "Microsoft", "PowerToys", "PowerDisplay");
+
+                if (!Directory.Exists(powerToysPath))
+                {
+                    Directory.CreateDirectory(powerToysPath);
+                }
+
+                _cachedProfilesFilePath = Path.Combine(powerToysPath, "profiles.json");
+                return _cachedProfilesFilePath;
+            }
+        }
+
+        /// <summary>
+        /// Loads PowerDisplay profiles from disk
+        /// </summary>
+        /// <returns>PowerDisplayProfiles object, or a new empty instance if file doesn't exist or load fails</returns>
+        public static PowerDisplayProfiles LoadProfiles()
+        {
+            lock (_lock)
+            {
+                try
+                {
+                    var filePath = GetProfilesFilePath();
+
+                    if (File.Exists(filePath))
+                    {
+                        var json = File.ReadAllText(filePath);
+                        var profiles = JsonSerializer.Deserialize<PowerDisplayProfiles>(json);
+
+                        if (profiles != null)
+                        {
+                            // Clean up any legacy Custom profiles
+                            profiles.Profiles.RemoveAll(p => p.Name.Equals(PowerDisplayProfiles.CustomProfileName, StringComparison.OrdinalIgnoreCase));
+
+                            Logger.LogInfo($"[PowerDisplayProfilesHelper] Loaded {profiles.Profiles.Count} profiles from {filePath}");
+                            return profiles;
+                        }
+                    }
+                    else
+                    {
+                        Logger.LogInfo($"[PowerDisplayProfilesHelper] No profiles file found at {filePath}, returning empty collection");
+                    }
+
+                    return new PowerDisplayProfiles();
+                }
+                catch (Exception ex)
+                {
+                    Logger.LogError($"[PowerDisplayProfilesHelper] Failed to load profiles: {ex.Message}");
+                    return new PowerDisplayProfiles();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Saves PowerDisplay profiles to disk
+        /// </summary>
+        /// <param name="profiles">The profiles collection to save</param>
+        /// <param name="prettyPrint">Whether to format the JSON with indentation</param>
+        public static void SaveProfiles(PowerDisplayProfiles profiles, bool prettyPrint = true)
+        {
+            lock (_lock)
+            {
+                try
+                {
+                    if (profiles == null)
+                    {
+                        Logger.LogWarning("[PowerDisplayProfilesHelper] Cannot save null profiles");
+                        return;
+                    }
+
+                    // Clean up any Custom profiles before saving
+                    profiles.Profiles.RemoveAll(p => p.Name.Equals(PowerDisplayProfiles.CustomProfileName, StringComparison.OrdinalIgnoreCase));
+
+                    profiles.LastUpdated = DateTime.UtcNow;
+
+                    var json = prettyPrint
+                        ? JsonSerializer.Serialize(profiles, _jsonSerializerOptions)
+                        : JsonSerializer.Serialize(profiles);
+
+                    var filePath = GetProfilesFilePath();
+
+                    File.WriteAllText(filePath, json);
+
+                    Logger.LogInfo($"[PowerDisplayProfilesHelper] Saved {profiles.Profiles.Count} profiles to {filePath}");
+                }
+                catch (Exception ex)
+                {
+                    Logger.LogError($"[PowerDisplayProfilesHelper] Failed to save profiles: {ex.Message}");
+                }
+            }
+        }
+
+        /// <summary>
+        /// Checks if the profiles file exists
+        /// </summary>
+        public static bool ProfilesFileExists()
+        {
+            try
+            {
+                var filePath = GetProfilesFilePath();
+                return File.Exists(filePath);
+            }
+            catch (Exception ex)
+            {
+                Logger.LogError($"[PowerDisplayProfilesHelper] Error checking if profiles file exists: {ex.Message}");
+                return false;
+            }
+        }
+    }
+}

src/settings-ui/Settings.UI/SettingsXAML/Views/LightSwitchPage.xaml

@@ -156,40 +156,43 @@
                             x:Uid="LightSwitch_PowerDisplayDisabledWarningBar"
                             IsOpen="True"
                             Severity="Warning"
-                            Visibility="{x:Bind ViewModel.ShowPowerDisplayDisabledWarning, Mode=OneWay}" />
+                            Visibility="{x:Bind ViewModel.ShowPowerDisplayDisabledWarning, Mode=OneWay}">
+                            <InfoBar.ActionButton>
+                                <HyperlinkButton x:Uid="LightSwitch_NavigatePowerDisplaySettings" Click="NavigatePowerDisplaySettings_Click" />
+                            </InfoBar.ActionButton>
+                        </InfoBar>
                         <tkcontrols:SettingsExpander
                             x:Uid="LightSwitch_ApplyMonitorSettingsExpander"
                             HeaderIcon="{ui:FontIcon Glyph=&#xE7F4;}"
-                            IsExpanded="False">
+                            IsExpanded="True">
                             <tkcontrols:SettingsExpander.Items>
-                                <tkcontrols:SettingsCard ContentAlignment="Left">
-                                    <CheckBox
-                                        x:Uid="LightSwitch_EnableMonitorSettings"
-                                        IsChecked="{x:Bind ViewModel.ApplyMonitorSettings, Mode=TwoWay}" />
-                                </tkcontrols:SettingsCard>
-                                <tkcontrols:SettingsCard x:Uid="LightSwitch_DarkModeProfileCard" HorizontalContentAlignment="Left">
-                                    <StackPanel Orientation="Horizontal" Spacing="12">
+                                <tkcontrols:SettingsCard>
+                                    <tkcontrols:SettingsCard.Header>
                                         <CheckBox
+                                            x:Uid="LightSwitch_DarkModeProfileCheckbox"
                                             IsChecked="{x:Bind ViewModel.EnableDarkModeProfile, Mode=TwoWay}"
                                             IsEnabled="{x:Bind ViewModel.IsPowerDisplayEnabled, Mode=OneWay}" />
-                                        <ComboBox
-                                            MinWidth="200"
-                                            IsEnabled="{x:Bind ViewModel.IsPowerDisplayEnabled, Mode=OneWay}"
-                                            ItemsSource="{x:Bind ViewModel.AvailableProfiles, Mode=OneWay}"
-                                            SelectedItem="{x:Bind ViewModel.DarkModeProfile, Mode=TwoWay}" />
-                                    </StackPanel>
+                                    </tkcontrols:SettingsCard.Header>
+                                    <ComboBox
+                                        MinWidth="200"
+                                        DisplayMemberPath="Name"
+                                        IsEnabled="{x:Bind ViewModel.IsPowerDisplayEnabled, Mode=OneWay}"
+                                        ItemsSource="{x:Bind ViewModel.AvailableProfiles, Mode=OneWay}"
+                                        SelectedItem="{x:Bind ViewModel.SelectedDarkModeProfile, Mode=TwoWay}" />
                                 </tkcontrols:SettingsCard>
-                                <tkcontrols:SettingsCard x:Uid="LightSwitch_LightModeProfileCard" HorizontalContentAlignment="Left">
-                                    <StackPanel Orientation="Horizontal" Spacing="12">
+                                <tkcontrols:SettingsCard>
+                                    <tkcontrols:SettingsCard.Header>
                                         <CheckBox
+                                            x:Uid="LightSwitch_LightModeProfileCheckbox"
                                             IsChecked="{x:Bind ViewModel.EnableLightModeProfile, Mode=TwoWay}"
                                             IsEnabled="{x:Bind ViewModel.IsPowerDisplayEnabled, Mode=OneWay}" />
-                                        <ComboBox
-                                            MinWidth="200"
-                                            IsEnabled="{x:Bind ViewModel.IsPowerDisplayEnabled, Mode=OneWay}"
-                                            ItemsSource="{x:Bind ViewModel.AvailableProfiles, Mode=OneWay}"
-                                            SelectedItem="{x:Bind ViewModel.LightModeProfile, Mode=TwoWay}" />
-                                    </StackPanel>
+                                    </tkcontrols:SettingsCard.Header>
+                                    <ComboBox
+                                        MinWidth="200"
+                                        DisplayMemberPath="Name"
+                                        IsEnabled="{x:Bind ViewModel.IsPowerDisplayEnabled, Mode=OneWay}"
+                                        ItemsSource="{x:Bind ViewModel.AvailableProfiles, Mode=OneWay}"
+                                        SelectedItem="{x:Bind ViewModel.SelectedLightModeProfile, Mode=TwoWay}" />
                                 </tkcontrols:SettingsCard>
                             </tkcontrols:SettingsExpander.Items>
                         </tkcontrols:SettingsExpander>

src/settings-ui/Settings.UI/SettingsXAML/Views/LightSwitchPage.xaml.cs

@@ -8,6 +8,7 @@ using System.IO;
 using System.IO.Abstractions;
 using System.Linq;
 using System.Threading.Tasks;
+using Common.UI;
 using ManagedCommon;
 using Microsoft.PowerToys.Settings.UI.Helpers;
 using Microsoft.PowerToys.Settings.UI.Library;
@@ -128,7 +129,7 @@ namespace Microsoft.PowerToys.Settings.UI.Views
                 ViewModel.SelectedCity = null;
 
                 // CityAutoSuggestBox.Text = string.Empty;
-                ViewModel.SyncButtonInformation = $"{ViewModel.Latitude}<7D>, {ViewModel.Longitude}<7D>";
+                ViewModel.SyncButtonInformation = $"{ViewModel.Latitude}<7D>, {ViewModel.Longitude}<7D>";
 
                 // ViewModel.CityTimesText = $"Sunrise: {result.SunriseHour}:{result.SunriseMinute:D2}\n" + $"Sunset: {result.SunsetHour}:{result.SunsetMinute:D2}";
                 SyncButton.IsEnabled = true;
@@ -153,7 +154,7 @@ namespace Microsoft.PowerToys.Settings.UI.Views
             }
             else if (ViewModel.ScheduleMode == "SunriseToSunsetGeo")
             {
-                ViewModel.SyncButtonInformation = $"{ViewModel.Latitude}<7D>, {ViewModel.Longitude}<7D>";
+                ViewModel.SyncButtonInformation = $"{ViewModel.Latitude}<7D>, {ViewModel.Longitude}<7D>";
             }
 
             SunriseModeChartState();
@@ -321,5 +322,10 @@ namespace Microsoft.PowerToys.Settings.UI.Views
         {
             await GetGeoLocation();
         }
+
+        private void NavigatePowerDisplaySettings_Click(object sender, Microsoft.UI.Xaml.RoutedEventArgs e)
+        {
+            ShellPage.Navigate(typeof(PowerDisplayPage));
+        }
     }
 }

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -5336,12 +5336,27 @@ To record a specific window, enter the hotkey with the Alt key in the opposite m
   <data name="LightSwitch_EnableMonitorSettings.Content" xml:space="preserve">
     <value>Enable monitor settings integration</value>
   </data>
+  <data name="LightSwitch_DarkModeProfileCheckbox.Content" xml:space="preserve">
+    <value>Dark mode profile</value>
+  </data>
+  <data name="LightSwitch_LightModeProfileCheckbox.Content" xml:space="preserve">
+    <value>Light mode profile</value>
+  </data>
   <data name="LightSwitch_DarkModeProfileCard.Header" xml:space="preserve">
     <value>Dark mode profile</value>
   </data>
+  <data name="LightSwitch_DarkModeProfileCard.Description" xml:space="preserve">
+    <value>Profile to apply when switching to dark mode</value>
+  </data>
   <data name="LightSwitch_LightModeProfileCard.Header" xml:space="preserve">
     <value>Light mode profile</value>
   </data>
+  <data name="LightSwitch_LightModeProfileCard.Description" xml:space="preserve">
+    <value>Profile to apply when switching to light mode</value>
+  </data>
+  <data name="LightSwitch_NavigatePowerDisplaySettings.Content" xml:space="preserve">
+    <value>Open PowerDisplay settings</value>
+  </data>
   <data name="LightSwitch_LocationDialog.Title" xml:space="preserve">
     <value>Select a location</value>
   </data>

src/settings-ui/Settings.UI/ViewModels/LightSwitchViewModel.cs

@@ -2,6 +2,8 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
@@ -30,10 +32,10 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
 
         public ObservableCollection<SearchLocation> SearchLocations { get; } = new();
 
-        public LightSwitchViewModel(LightSwitchSettings initialSettings = null, Func<string, int> ipcMSGCallBackFunc = null)
+        public LightSwitchViewModel(LightSwitchSettings? initialSettings = null, Func<string, int>? ipcMSGCallBackFunc = null)
         {
             _moduleSettings = initialSettings ?? new LightSwitchSettings();
-            SendConfigMSG = ipcMSGCallBackFunc;
+            SendConfigMSG = ipcMSGCallBackFunc ?? (_ => 0);
 
             ForceLightCommand = new RelayCommand(ForceLightNow);
             ForceDarkCommand = new RelayCommand(ForceDarkNow);
@@ -381,9 +383,9 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
             }
         }
 
-        private SearchLocation _selectedSearchLocation;
+        private SearchLocation? _selectedSearchLocation;
 
-        public SearchLocation SelectedCity
+        public SearchLocation? SelectedCity
         {
             get => _selectedSearchLocation;
             set
@@ -393,7 +395,10 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
                     _selectedSearchLocation = value;
                     NotifyPropertyChanged();
 
-                    UpdateSunTimes(_selectedSearchLocation.Latitude, _selectedSearchLocation.Longitude, _selectedSearchLocation.City);
+                    if (_selectedSearchLocation != null)
+                    {
+                        UpdateSunTimes(_selectedSearchLocation.Latitude, _selectedSearchLocation.Longitude, _selectedSearchLocation.City);
+                    }
                 }
             }
         }
@@ -442,7 +447,7 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
             }
         }
 
-        public void NotifyPropertyChanged([CallerMemberName] string propertyName = null)
+        public void NotifyPropertyChanged([CallerMemberName] string? propertyName = null)
         {
             Logger.LogInfo($"Changed the property {propertyName}");
             OnPropertyChanged(propertyName);
@@ -476,21 +481,7 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
             }
         }
 
-        public bool ShowPowerDisplayDisabledWarning => !IsPowerDisplayEnabled && ModuleSettings.Properties.ApplyMonitorSettings.Value;
-
-        public bool ApplyMonitorSettings
-        {
-            get => ModuleSettings.Properties.ApplyMonitorSettings.Value;
-            set
-            {
-                if (ModuleSettings.Properties.ApplyMonitorSettings.Value != value)
-                {
-                    ModuleSettings.Properties.ApplyMonitorSettings.Value = value;
-                    NotifyPropertyChanged();
-                    NotifyPropertyChanged(nameof(ShowPowerDisplayDisabledWarning));
-                }
-            }
-        }
+        public bool ShowPowerDisplayDisabledWarning => !IsPowerDisplayEnabled && (ModuleSettings.Properties.EnableDarkModeProfile.Value || ModuleSettings.Properties.EnableLightModeProfile.Value);
 
         public bool EnableDarkModeProfile
         {
@@ -501,6 +492,7 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
                 {
                     ModuleSettings.Properties.EnableDarkModeProfile.Value = value;
                     NotifyPropertyChanged();
+                    NotifyPropertyChanged(nameof(ShowPowerDisplayDisabledWarning));
                 }
             }
         }
@@ -514,10 +506,54 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
                 {
                     ModuleSettings.Properties.EnableLightModeProfile.Value = value;
                     NotifyPropertyChanged();
+                    NotifyPropertyChanged(nameof(ShowPowerDisplayDisabledWarning));
                 }
             }
         }
 
+        public PowerDisplayProfile? SelectedDarkModeProfile
+        {
+            get => _selectedDarkModeProfile;
+            set
+            {
+                if (_selectedDarkModeProfile != value)
+                {
+                    _selectedDarkModeProfile = value;
+
+                    // Sync with the string property stored in settings
+                    var newProfileName = value?.Name ?? string.Empty;
+                    if (ModuleSettings.Properties.DarkModeProfile.Value != newProfileName)
+                    {
+                        ModuleSettings.Properties.DarkModeProfile.Value = newProfileName;
+                    }
+
+                    NotifyPropertyChanged();
+                }
+            }
+        }
+
+        public PowerDisplayProfile? SelectedLightModeProfile
+        {
+            get => _selectedLightModeProfile;
+            set
+            {
+                if (_selectedLightModeProfile != value)
+                {
+                    _selectedLightModeProfile = value;
+
+                    // Sync with the string property stored in settings
+                    var newProfileName = value?.Name ?? string.Empty;
+                    if (ModuleSettings.Properties.LightModeProfile.Value != newProfileName)
+                    {
+                        ModuleSettings.Properties.LightModeProfile.Value = newProfileName;
+                    }
+
+                    NotifyPropertyChanged();
+                }
+            }
+        }
+
+        // Legacy string properties for backwards compatibility with settings persistence
         public string DarkModeProfile
         {
             get => ModuleSettings.Properties.DarkModeProfile.Value;
@@ -526,6 +562,10 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
                 if (ModuleSettings.Properties.DarkModeProfile.Value != value)
                 {
                     ModuleSettings.Properties.DarkModeProfile.Value = value;
+
+                    // Sync with the object property
+                    UpdateSelectedProfileFromName(value, isDarkMode: true);
+
                     NotifyPropertyChanged();
                 }
             }
@@ -539,6 +579,10 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
                 if (ModuleSettings.Properties.LightModeProfile.Value != value)
                 {
                     ModuleSettings.Properties.LightModeProfile.Value = value;
+
+                    // Sync with the object property
+                    UpdateSelectedProfileFromName(value, isDarkMode: false);
+
                     NotifyPropertyChanged();
                 }
             }
@@ -548,43 +592,62 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         {
             try
             {
-                var settingsPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
-                var powerToysPath = Path.Combine(settingsPath, "Microsoft", "PowerToys", "PowerDisplay");
-                _profilesFilePath = Path.Combine(powerToysPath, "profiles.json");
+                var profilesData = PowerDisplayProfilesHelper.LoadProfiles();
 
-                if (File.Exists(_profilesFilePath))
+                AvailableProfiles.Clear();
+
+                foreach (var profile in profilesData.Profiles)
                 {
-                    var json = File.ReadAllText(_profilesFilePath);
-                    var profilesData = JsonSerializer.Deserialize<PowerDisplayProfiles>(json);
-
-                    if (profilesData != null)
-                    {
-                        AvailableProfiles.Clear();
-
-                        // Add empty option
-                        AvailableProfiles.Add(new PowerDisplayProfile("(None)", new List<ProfileMonitorSetting>()));
-
-                        foreach (var profile in profilesData.Profiles)
-                        {
-                            AvailableProfiles.Add(profile);
-                        }
-
-                        Logger.LogInfo($"Loaded {profilesData.Profiles.Count} PowerDisplay profiles");
-                    }
-                }
-                else
-                {
-                    // Add empty option
-                    AvailableProfiles.Clear();
-                    AvailableProfiles.Add(new PowerDisplayProfile("(None)", new List<ProfileMonitorSetting>()));
-                    Logger.LogInfo("No PowerDisplay profiles file found");
+                    AvailableProfiles.Add(profile);
                 }
+
+                Logger.LogInfo($"Loaded {profilesData.Profiles.Count} PowerDisplay profiles");
+
+                // Sync selected profiles from settings
+                UpdateSelectedProfileFromName(ModuleSettings.Properties.DarkModeProfile.Value, isDarkMode: true);
+                UpdateSelectedProfileFromName(ModuleSettings.Properties.LightModeProfile.Value, isDarkMode: false);
             }
             catch (Exception ex)
             {
                 Logger.LogError($"Failed to load PowerDisplay profiles: {ex.Message}");
                 AvailableProfiles.Clear();
-                AvailableProfiles.Add(new PowerDisplayProfile("(None)", new List<ProfileMonitorSetting>()));
+            }
+        }
+
+        /// <summary>
+        /// Helper method to sync the selected profile object from the profile name stored in settings
+        /// </summary>
+        private void UpdateSelectedProfileFromName(string profileName, bool isDarkMode)
+        {
+            PowerDisplayProfile? matchingProfile = null;
+
+            if (!string.IsNullOrEmpty(profileName))
+            {
+                matchingProfile = AvailableProfiles.FirstOrDefault(p =>
+                    p.Name.Equals(profileName, StringComparison.OrdinalIgnoreCase));
+            }
+
+            // If not found or empty, default to first available profile
+            if (matchingProfile == null && AvailableProfiles.Count > 0)
+            {
+                matchingProfile = AvailableProfiles[0];
+            }
+
+            if (isDarkMode)
+            {
+                if (_selectedDarkModeProfile != matchingProfile)
+                {
+                    _selectedDarkModeProfile = matchingProfile;
+                    NotifyPropertyChanged(nameof(SelectedDarkModeProfile));
+                }
+            }
+            else
+            {
+                if (_selectedLightModeProfile != matchingProfile)
+                {
+                    _selectedLightModeProfile = matchingProfile;
+                    NotifyPropertyChanged(nameof(SelectedLightModeProfile));
+                }
             }
         }
 
@@ -626,7 +689,6 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
             OnPropertyChanged(nameof(Latitude));
             OnPropertyChanged(nameof(Longitude));
             OnPropertyChanged(nameof(ScheduleMode));
-            OnPropertyChanged(nameof(ApplyMonitorSettings));
             OnPropertyChanged(nameof(EnableDarkModeProfile));
             OnPropertyChanged(nameof(EnableLightModeProfile));
             OnPropertyChanged(nameof(DarkModeProfile));
@@ -692,7 +754,8 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         // PowerDisplay integration
         private ObservableCollection<PowerDisplayProfile> _availableProfiles = new ObservableCollection<PowerDisplayProfile>();
         private bool _isPowerDisplayEnabled;
-        private string _profilesFilePath = string.Empty;
+        private PowerDisplayProfile? _selectedDarkModeProfile;
+        private PowerDisplayProfile? _selectedLightModeProfile;
 
         public ICommand ForceLightCommand { get; }
 

src/settings-ui/Settings.UI/ViewModels/PowerDisplayViewModel.cs

@@ -476,7 +476,6 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
 
         // Profile-related fields
         private ObservableCollection<PowerDisplayProfile> _profiles = new ObservableCollection<PowerDisplayProfile>();
-        private string _profilesFilePath = string.Empty;
 
         /// <summary>
         /// Collection of available profiles (for button display)
@@ -520,11 +519,7 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         {
             try
             {
-                var settingsPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
-                var powerToysPath = Path.Combine(settingsPath, "Microsoft", "PowerToys", "PowerDisplay");
-                _profilesFilePath = Path.Combine(powerToysPath, "profiles.json");
-
-                var profilesData = LoadProfilesFromDisk();
+                var profilesData = PowerDisplayProfilesHelper.LoadProfiles();
 
                 // Load profile objects (no Custom - it's not a profile anymore)
                 Profiles.Clear();
@@ -547,14 +542,7 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         /// </summary>
         private PowerDisplayProfiles LoadProfilesFromDisk()
         {
-            if (File.Exists(_profilesFilePath))
-            {
-                var json = File.ReadAllText(_profilesFilePath);
-                var profiles = JsonSerializer.Deserialize<PowerDisplayProfiles>(json);
-                return profiles ?? new PowerDisplayProfiles();
-            }
-
-            return new PowerDisplayProfiles();
+            return PowerDisplayProfilesHelper.LoadProfiles();
         }
 
         /// <summary>
@@ -562,17 +550,7 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         /// </summary>
         private void SaveProfilesToDisk(PowerDisplayProfiles profiles)
         {
-            try
-            {
-                profiles.LastUpdated = DateTime.UtcNow;
-                var json = JsonSerializer.Serialize(profiles, _jsonSerializerOptions);
-                File.WriteAllText(_profilesFilePath, json);
-                Logger.LogInfo($"Saved profiles to disk: {_profilesFilePath}");
-            }
-            catch (Exception ex)
-            {
-                Logger.LogError($"Failed to save profiles: {ex.Message}");
-            }
+            PowerDisplayProfilesHelper.SaveProfiles(profiles, prettyPrint: true);
         }
 
         /// <summary>