[Light Switch] Hotfixes by Jaylyn-Barbee · Pull Request #42434 · microsoft/PowerToys

Jaylyn-Barbee · 2025-10-16T17:57:04Z

Summary of the Pull Request

Adds new "Off" mode for the schedule mode options which disable the schedule.
Adds explicit function to disable light switch by default.

PR Checklist

Closes:

Light Switch: "Off" mode for Schedule #42402
New behavior: "Off" mode added. when off, the regular service loop stops and all actions are event driven to either resume the loop or listen for hotkey.
Light switch: switching modes shouldn't be enabled by default #42386
New behavior: Disabled explicitly by default
Light Switch: switching to light mode keeps accent color on start menu enabled #42389
New behavior: When switching from dark to light mode the system theme will remove the accent color.
Light Switch settings are resetting #42513
New behavior: Manual mode no longer gets reset. It was being overridden by the sun calculations that were invertedly running when in manual mode.

Todo:

Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx @alvinashcraft we will need to add this new mode to the documentation.

Validation Steps Performed

Removed all default settings and tested new logic. Light Switch is set to off by default.
Updated UI and tested new "Off" mode, logs indicate mode switched and ticker stopped. Polling resumes on mode change. (need to check that the shortcut still works)

…ht mode

Jaylyn-Barbee · 2025-10-16T19:43:20Z

/azp run

azure-pipelines · 2025-10-16T19:43:30Z

Azure Pipelines successfully started running 1 pipeline(s).

niels9001 · 2025-10-17T06:13:05Z

/azp run

azure-pipelines · 2025-10-17T06:13:15Z

Azure Pipelines successfully started running 1 pipeline(s).

Copilot

Pull Request Overview

This PR adds a new "Off" mode to the Light Switch module's schedule options, allowing users to disable automatic theme switching while still preserving manual toggle functionality. Additionally, Light Switch is now disabled by default for new installations.

Key Changes

Added "Off" as a new schedule mode option, which suspends automatic theme switching
Changed the default schedule mode from "FixedHours" to "Off"
Implemented is_enabled_by_default() to return false, disabling Light Switch by default

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/settings-ui/Settings.UI/ViewModels/LightSwitchViewModel.cs	Added "Off" to the AvailableScheduleModes collection
src/settings-ui/Settings.UI/Strings/en-us/Resources.resw	Added localized strings for the "Off" mode option and informational message
src/settings-ui/Settings.UI/SettingsXAML/Views/LightSwitchPage.xaml	Added UI elements for "Off" mode ComboBox item and InfoBar message with visibility converters
src/settings-ui/Settings.UI/Converters/HideIfEnumValueConverter.cs	New converter that hides UI elements when enum matches specified parameter
src/settings-ui/Settings.UI.Library/LightSwitchProperties.cs	Changed DefaultScheduleMode constant from "FixedHours" to "Off"
src/runner/general_settings.cpp	Added logging for powertoys disabled by default
src/modules/LightSwitch/LightSwitchService/ThemeHelper.cpp	Added ResetColorPrevalence() function to reset color prevalence when switching to light mode
src/modules/LightSwitch/LightSwitchService/LightSwitchSettings.h	Added "Off" enum value and updated ToString/FromString functions to handle it
src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp	Modified service worker to skip theme scheduling when mode is "Off" while maintaining settings monitoring
src/modules/LightSwitch/LightSwitchModuleInterface/dllmain.cpp	Added "Off" enum value, updated default schedule mode, and implemented is_enabled_by_default() returning false

src/runner/general_settings.cpp

src/settings-ui/Settings.UI/Converters/HideIfEnumValueConverter.cs

src/modules/LightSwitch/LightSwitchService/ThemeHelper.cpp

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

src/modules/LightSwitch/LightSwitchModuleInterface/dllmain.cpp

src/runner/general_settings.cpp

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

…is indeed fixed.

…into jay/ls-hotfixes

Xiphoseer · 2025-10-20T08:52:49Z

Why does this need to be running in an "Off" mode? I'd expect it to disable/unregister the dedicated Service/DLL completely when it's turned off.

src/modules/LightSwitch/LightSwitchModuleInterface/dllmain.cpp

This reverts commit 77febb4.

…into jay/ls-hotfixes

khmyznikov

LGTM

@alvinashcraft

## Summary of the Pull Request Adds new "Off" mode for the schedule mode options which disable the schedule. Adds explicit function to disable light switch by default.  ## PR Checklist Closes: - #42402 New behavior: "Off" mode added. when off, the regular service loop stops and all actions are event driven to either resume the loop or listen for hotkey. - #42386 New behavior: Disabled explicitly by default - #42389 New behavior: When switching from dark to light mode the system theme will remove the accent color. - #42513 New behavior: Manual mode no longer gets reset. It was being overridden by the sun calculations that were invertedly running when in manual mode. Todo: - [ ] **Documentation updated:** If checked, please file a pull request on [our docs repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys) and link it here: #xxx @alvinashcraft we will need to add this new mode to the documentation. ## Validation Steps Performed - Removed all default settings and tested new logic. Light Switch is set to off by default. - Updated UI and tested new "Off" mode, logs indicate mode switched and ticker stopped. Polling resumes on mode change. (need to check that the shortcut still works) --------- Co-authored-by: Niels Laute <niels.laute@live.nl> Co-authored-by: Gordon Lam <73506701+yeelam-gordon@users.noreply.github.com>

Hotfixes #42467 #42434 #42405 #42399 --------- Co-authored-by: Jiří Polášek <me@jiripolasek.com> Co-authored-by: Niels Laute <niels.laute@live.nl> Co-authored-by: Jaylyn Barbee <51131738+Jaylyn-Barbee@users.noreply.github.com> Co-authored-by: Gordon Lam <73506701+yeelam-gordon@users.noreply.github.com> Co-authored-by: Dustin L. Howett <duhowett@microsoft.com>

Copilot

Pull Request Overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 5 comments.

Comments suppressed due to low confidence (1)

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp:1

Grammatical error in comment. Should be 'if we are changing to light mode'.

#include <windows.h>

Copilot · 2025-11-07T01:56:51Z

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

                SetSystemTheme(true);
+                Logger::info(L"[LightSwitchService] Changing system theme to light mode.");
            if (settings.changeApps && !isAppsCurrentlyLight)
                SetAppsTheme(true);
+                Logger::info(L"[LightSwitchService] Changing apps theme to light mode.");
        }
        else
        {
            if (settings.changeSystem && isSystemCurrentlyLight)
                SetSystemTheme(false);
+                Logger::info(L"[LightSwitchService] Changing system theme to dark mode.");
            if (settings.changeApps && isAppsCurrentlyLight)
                SetAppsTheme(false);
+                Logger::info(L"[LightSwitchService] Changing apps theme to light mode.");


Line 201 incorrectly logs 'light mode' when setting dark mode. Should be 'Changing apps theme to dark mode.'. Additionally, missing braces around if-statement bodies cause Logger::info calls to execute unconditionally.

Suggested change

SetSystemTheme(true);

Logger::info(L"[LightSwitchService] Changing system theme to light mode.");

if (settings.changeApps && !isAppsCurrentlyLight)

SetAppsTheme(true);

Logger::info(L"[LightSwitchService] Changing apps theme to light mode.");

}

else

{

if (settings.changeSystem && isSystemCurrentlyLight)

SetSystemTheme(false);

Logger::info(L"[LightSwitchService] Changing system theme to dark mode.");

if (settings.changeApps && isAppsCurrentlyLight)

SetAppsTheme(false);

Logger::info(L"[LightSwitchService] Changing apps theme to light mode.");

{

SetSystemTheme(true);

Logger::info(L"[LightSwitchService] Changing system theme to light mode.");

}

if (settings.changeApps && !isAppsCurrentlyLight)

{

SetAppsTheme(true);

Logger::info(L"[LightSwitchService] Changing apps theme to light mode.");

}

}

else

{

if (settings.changeSystem && isSystemCurrentlyLight)

{

SetSystemTheme(false);

Logger::info(L"[LightSwitchService] Changing system theme to dark mode.");

}

if (settings.changeApps && isAppsCurrentlyLight)

{

SetAppsTheme(false);

Logger::info(L"[LightSwitchService] Changing apps theme to dark mode.");

}

Copilot · 2025-11-07T01:56:52Z

src/modules/LightSwitch/LightSwitchModuleInterface/ThemeHelper.cpp

        RegSetValueEx(hKey, L"SystemUsesLightTheme", 0, REG_DWORD, reinterpret_cast<const BYTE*>(&value), sizeof(value));
        RegCloseKey(hKey);

+        if (mode) // if are changing to light mode


Grammatical error in comment. Should be 'if we are changing to light mode'.

Suggested change

if (mode) // if are changing to light mode

if (mode) // if we are changing to light mode

Copilot · 2025-11-07T01:56:52Z

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

+                }
+
+                // --- Manual override triggered ---
+                if (wait == WAIT_OBJECT_0 + (hParent ? 2 : 1))


Magic number calculation for wait index is error-prone. When hParent is null, manual override is at index 1, but when hParent exists, it's at index 2. Consider using named constants or calculating the index based on the order waits were added.

Copilot · 2025-11-07T01:56:52Z

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

+                }
+
+                // --- Settings file changed ---
+                if (wait == WAIT_OBJECT_0 + (hParent ? 3 : 2))


Magic number calculation for wait index is error-prone. The settings event should always be the last one added. Consider calculating the index based on 'count - 1' to make the relationship explicit.

Suggested change

if (wait == WAIT_OBJECT_0 + (hParent ? 3 : 2))

if (wait == WAIT_OBJECT_0 + count - 1)

Copilot · 2025-11-07T01:56:52Z

src/modules/LightSwitch/LightSwitchModuleInterface/dllmain.cpp

+                                 ToString(newMode));
+                    g_settings.m_scheduleMode = newMode;
+
+                    start_service_if_needed();


[nitpick] The service is started regardless of whether the mode is 'Off' or not. When changing to 'Off' mode, the service should remain running (to handle manual overrides) but the logic should consider that starting when already running is redundant. However, this may be intentional since start_service_if_needed checks if the service is already running.

Suggested change

start_service_if_needed();

if (newMode != ScheduleMode::Off)

{

start_service_if_needed();

}

@alvinashcraft

## Summary of the Pull Request Adds new "Off" mode for the schedule mode options which disable the schedule. Adds explicit function to disable light switch by default.  ## PR Checklist Closes: - microsoft#42402 New behavior: "Off" mode added. when off, the regular service loop stops and all actions are event driven to either resume the loop or listen for hotkey. - microsoft#42386 New behavior: Disabled explicitly by default - microsoft#42389 New behavior: When switching from dark to light mode the system theme will remove the accent color. - microsoft#42513 New behavior: Manual mode no longer gets reset. It was being overridden by the sun calculations that were invertedly running when in manual mode. Todo: - [ ] **Documentation updated:** If checked, please file a pull request on [our docs repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys) and link it here: #xxx @alvinashcraft we will need to add this new mode to the documentation. ## Validation Steps Performed - Removed all default settings and tested new logic. Light Switch is set to off by default. - Updated UI and tested new "Off" mode, logs indicate mode switched and ticker stopped. Polling resumes on mode change. (need to check that the shortcut still works) --------- Co-authored-by: Niels Laute <niels.laute@live.nl> Co-authored-by: Gordon Lam <73506701+yeelam-gordon@users.noreply.github.com>

Jaylyn-Barbee added 5 commits October 16, 2025 09:55

Light fix first round of hotfixes

37020ef

more changes

6dc7918

minor updates

aed5983

added fix to change color prevalence when changing system back to lig…

c0a228e

…ht mode

xaml styling

fb3178f

Jaylyn-Barbee added the Hot Fix Items we will product an out-of-band release for label Oct 16, 2025

Merge branch 'main' into jay/ls-hotfixes

061e69c

niels9001 mentioned this pull request Oct 17, 2025

Light switch: switching modes shouldn't be enabled by default #42386

Closed

Merge branch 'main' into jay/ls-hotfixes

aaa02b0

yeelam-gordon requested a review from Copilot October 17, 2025 09:55

Copilot AI reviewed Oct 17, 2025

View reviewed changes

yeelam-gordon reviewed Oct 17, 2025

View reviewed changes

src/runner/general_settings.cpp Outdated Show resolved Hide resolved

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp Outdated Show resolved Hide resolved

Jaylyn-Barbee mentioned this pull request Oct 17, 2025

Light Switch settings are resetting #42513

Closed

Jaylyn-Barbee added 4 commits October 17, 2025 11:10

Fixed and verfied everything from yesterday (currently listed in pr) …

09f0ec6

…is indeed fixed.

Merge branch 'jay/ls-hotfixes' of github.com:Jaylyn-Barbee/PowerToys …

2776024

…into jay/ls-hotfixes

xaml styling

e5fca62

fixed times resetting

f76a506

Jaylyn-Barbee mentioned this pull request Oct 17, 2025

DO NOT ACTIVATE NEW FEATURES BY DEFAULT!!!!!! #42522

Closed

Jaylyn-Barbee added 2 commits October 17, 2025 13:07

fix shortcut not working when mode = off

a6b1917

inserted removed call

0a801aa

niels9001 requested a review from yeelam-gordon October 19, 2025 09:03

shuaiyuanxx reviewed Oct 20, 2025

View reviewed changes

src/modules/LightSwitch/LightSwitchModuleInterface/dllmain.cpp Show resolved Hide resolved

new off mode logic

f1422a4

This was referenced Oct 20, 2025

Light Switch 'Manual' Mode Schedule Buggy #42652

Closed

Dark mode scheduling doesn't work. #42638

Closed

Jaylyn-Barbee mentioned this pull request Oct 20, 2025

PowerToys Update prevents Dark Mode #42645

Closed

niels9001 and others added 6 commits October 20, 2025 19:50

Update MainPage.xaml

77febb4

Revert "Update MainPage.xaml"

4df0200

This reverts commit 77febb4.

Fix visual states

4881797

Styling tweaks

da50161

Adding more logging to the service

e4659da

Merge branch 'jay/ls-hotfixes' of github.com:Jaylyn-Barbee/PowerToys …

a6505ba

…into jay/ls-hotfixes

khmyznikov approved these changes Oct 20, 2025

View reviewed changes

khmyznikov merged commit f45d54a into microsoft:main Oct 20, 2025
10 checks passed

khmyznikov mentioned this pull request Oct 20, 2025

0.95.1 hotfix #42686

Merged

chiiexe mentioned this pull request Oct 23, 2025

Light switch enabled by default #42800

Closed

SanePainTrain mentioned this pull request Oct 24, 2025

dark mode gone #42860

Open

Lyhtande mentioned this pull request Oct 29, 2025

Allow accent color on taskbar and Start menu in Light Mode #43065

Open

bcalvery mentioned this pull request Oct 31, 2025

After update #42434 that "fixes" Light Switch on by default, Light Switch is still on. #43163

Closed

yeelam-gordon requested a review from Copilot November 7, 2025 01:46

Copilot AI reviewed Nov 7, 2025

View reviewed changes

yeelam-gordon added the Product-LightSwitch label Nov 11, 2025

yeelam-gordon added this to the PowerToys 0.96 milestone Nov 11, 2025

Miuzarte mentioned this pull request Jan 2, 2026

Please do not auto enabled tools!!! #44469

Closed

	if (mode) // if are changing to light mode
	if (mode) // if we are changing to light mode

	if (wait == WAIT_OBJECT_0 + (hParent ? 3 : 2))
	if (wait == WAIT_OBJECT_0 + count - 1)

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Jaylyn-Barbee commented Oct 16, 2025 •

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