FZ: warn w/ a toast if an elevated window cannot be dragged and offer learning more

installer/MSIX/appxmanifest.xml

@@ -31,6 +31,12 @@
     <Application Id="PowerToys" Executable="PowerToys.exe" EntryPoint="Windows.FullTrustApplication">
       <uap:VisualElements DisplayName="PowerToys (Experimental)" Description="Windows system utilities to maximize productivity" Square150x150Logo="Images\logo150.png" Square44x44Logo="Images\logo44.png" BackgroundColor="transparent" />
       <Extensions>
+        <uap:Extension Category="windows.protocol">
+          <uap:Protocol Name="powertoys">
+            <uap:Logo>images\logo.png</uap:Logo>
+            <uap:DisplayName>Powertoys custom protocol</uap:DisplayName>
+          </uap:Protocol>
+        </uap:Extension>
         <uap5:Extension Category="windows.startupTask" Executable="PowerToys.exe" EntryPoint="Windows.FullTrustApplication">
           <uap5:StartupTask TaskId="PowerToysStartupTaskID" Enabled="true" DisplayName="PowerToys" />
         </uap5:Extension>

installer/PowerToysSetup/Product.wxs

@@ -236,8 +236,20 @@
           </Shortcut>
         </File>
 
+        <RegistryKey Root="HKCR" Key="powertoys" Action="createAndRemoveOnUninstall">
+          <RegistryValue Type="string" Name="URL Protocol" Value=""/>
+          <RegistryValue Type="string" Value="URL:PowerToys custom internal URI protocol"/>
+          <RegistryKey Key="DefaultIcon">
+            <RegistryValue Type="string" Value="PowerToys.exe" />
+          </RegistryKey>
+          <RegistryKey Key="shell\open\command">
+            <RegistryValue Type="string" Value="&quot;[INSTALLFOLDER]PowerToys.exe&quot; &quot;%1&quot;" />
+          </RegistryKey>
+        </RegistryKey>
+
         <RemoveFolder Id="DeleteShortcutFolder" Directory="ApplicationProgramsFolder" On="uninstall" />
       </Component>
+
       <Component Id="settings_exe" Guid="A5A461A9-7097-4CBA-9D39-3DBBB6B7B80C" Win64="yes">
         <File Id="PowerToysSettings.exe" KeyPath="yes" Checksum="yes" />
       </Component>

src/common/common.vcxproj

@@ -29,6 +29,9 @@
     <ProjectName>common</ProjectName>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <ImportGroup Label="Shared">
+    <Import Project="..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.190716.2\build\native\Microsoft.Windows.ImplementationLibrary.targets" Condition="Exists('..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.190716.2\build\native\Microsoft.Windows.ImplementationLibrary.targets')" />
+  </ImportGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
     <ConfigurationType>StaticLibrary</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
@@ -164,7 +167,16 @@
     <ClCompile Include="window_helpers.cpp" />
     <ClCompile Include="winstore.cpp" />
   </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.190716.2\build\native\Microsoft.Windows.ImplementationLibrary.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\Microsoft.Windows.ImplementationLibrary.1.0.190716.2\build\native\Microsoft.Windows.ImplementationLibrary.targets'))" />
+  </Target>
 </Project>

src/common/notifications.cpp

@@ -145,10 +145,10 @@ void notifications::register_background_toast_handler()
     }
 }
 
-void notifications::show_toast(std::wstring_view message)
+void notifications::show_toast(std::wstring message, toast_params params)
 {
     // The toast won't be actually activated in the background, since it doesn't have any buttons
-    show_toast_with_activations(message, {}, {});
+    show_toast_with_activations(std::move(message), {}, {}, std::move(params));
 }
 
 inline void xml_escape(std::wstring data)
@@ -182,13 +182,13 @@ inline void xml_escape(std::wstring data)
     data.swap(buffer);
 }
 
-void notifications::show_toast_with_activations(std::wstring_view message, std::wstring_view background_handler_id, std::vector<button_t> buttons)
+void notifications::show_toast_with_activations(std::wstring message, std::wstring_view background_handler_id, std::vector<action_t> actions, toast_params params)
 {
     // DO NOT LOCALIZE any string in this function, because they're XML tags and a subject to
     // https://docs.microsoft.com/en-us/windows/uwp/design/shell/tiles-and-notifications/toast-xml-schema
 
     std::wstring toast_xml;
-    toast_xml.reserve(1024);
+    toast_xml.reserve(2048);
     std::wstring title{ L"PowerToys" };
     if (winstore::running_as_packaged())
     {
@@ -200,28 +200,78 @@ void notifications::show_toast_with_activations(std::wstring_view message, std::
     toast_xml += L"</text><text>";
     toast_xml += message;
     toast_xml += L"</text></binding></visual><actions>";
+    for (size_t i = 0; i < size(actions); ++i)
+    {
+        std::visit(overloaded{
+                       [&](const snooze_button& b) {
+                           const bool has_durations = !b.durations.empty() && size(b.durations) <= 5;
+                           std::wstring selection_id = L"snoozeTime";
+                           selection_id += static_cast<wchar_t>(L'0' + i);
+                           if (has_durations)
+                           {
+                               toast_xml += LR"(<input id=")";
+                               toast_xml += selection_id;
+                               toast_xml += LR"(" type="selection" defaultInput=")";
+                               toast_xml += std::to_wstring(b.durations[0].minutes);
+                               toast_xml += LR"(">)";
+                               for (const auto& duration : b.durations)
+                               {
+                                   toast_xml += LR"(<selection id=")";
+                                   toast_xml += std::to_wstring(duration.minutes);
+                                   toast_xml += LR"(" content=")";
+                                   toast_xml += duration.label;
+                                   toast_xml += LR"("/>)";
+                               }
+                               toast_xml += LR"(</input>)";
+                           }
+                       },
+                       [](const auto&) {} },
+                   actions[i]);
+    }
 
-    for (size_t i = 0; i < size(buttons); ++i)
+    for (size_t i = 0; i < size(actions); ++i)
     {
         std::visit(overloaded{
                        [&](const link_button& b) {
-                           toast_xml += LR"(<action activationType="protocol" arguments=")";
+                           toast_xml += LR"(<action activationType="protocol" )";
+                           if (b.context_menu)
+                           {
+                               toast_xml += LR"(placement="contextMenu" )";
+                           }
+                           toast_xml += LR"(arguments=")";
                            toast_xml += b.url;
                            toast_xml += LR"(" content=")";
                            toast_xml += b.label;
-                           toast_xml += LR"("/>)";
+                           toast_xml += LR"(" />)";
                        },
                        [&](const background_activated_button& b) {
-                           toast_xml += LR"(<action activationType="background" arguments=")";
+                           toast_xml += LR"(<action activationType="background" )";
+                           if (b.context_menu)
+                           {
+                               toast_xml += LR"(placement="contextMenu" )";
+                           }
+                           toast_xml += LR"(arguments=")";
                            toast_xml += L"button_id=" + std::to_wstring(i); // pass the button ID
                            toast_xml += L"&amp;handler=";
                            toast_xml += background_handler_id;
                            toast_xml += LR"(" content=")";
                            toast_xml += b.label;
-                           toast_xml += LR"("/>)";
+                           toast_xml += LR"(" />)";
                        },
-                   },
+                       [&](const snooze_button& b) {
-                   buttons[i]);
+                           const bool has_durations = !b.durations.empty() && size(b.durations) <= 5;
+                           std::wstring selection_id = L"snoozeTime";
+                           selection_id += static_cast<wchar_t>(L'0' + i);
+                           toast_xml += LR"(<action activationType="system" arguments="snooze" )";
+                           if (has_durations)
+                           {
+                               toast_xml += LR"(hint-inputId=")";
+                               toast_xml += selection_id;
+                               toast_xml += '"';
+                           }
+                           toast_xml += LR"( content="" />)";
+                       } },
+                   actions[i]);
     }
     toast_xml += L"</actions></toast>";
 
@@ -232,5 +282,22 @@ void notifications::show_toast_with_activations(std::wstring_view message, std::
 
     const auto notifier = winstore::running_as_packaged() ? ToastNotificationManager::ToastNotificationManager::CreateToastNotifier() :
                                                             ToastNotificationManager::ToastNotificationManager::CreateToastNotifier(WIN32_AUMID);
+
+    // Set a tag-related params if it has a valid length
+    if (params.tag.has_value() && params.tag->length() < 64)
+    {
+        notification.Tag(*params.tag);
+        if (!params.resend_if_scheduled)
+        {
+            for (const auto& scheduled_toast : notifier.GetScheduledToastNotifications())
+            {
+                if (scheduled_toast.Tag() == *params.tag)
+                {
+                    return;
+                }
+            }
+        }
+    }
+
     notifier.Show(notification);
 }

src/common/notifications.h

@@ -1,8 +1,10 @@
 #pragma once
 
+#include <string>
 #include <string_view>
 #include <vector>
 #include <variant>
+#include <optional>
 
 namespace notifications
 {
@@ -12,19 +14,38 @@ namespace notifications
 
     void run_desktop_app_activator_loop();
 
+    struct snooze_duration
+    {
+        std::wstring label;
+        int minutes;
+    };
+
+    struct snooze_button
+    {
+        std::vector<snooze_duration> durations;
+    };
+
     struct link_button
     {
-        std::wstring_view label;
+        std::wstring label;
-        std::wstring_view url;
+        std::wstring url;
+        bool context_menu = false;
     };
 
     struct background_activated_button
     {
-        std::wstring_view label;
+        std::wstring label;
+        bool context_menu = false;
     };
 
-    using button_t = std::variant<link_button, background_activated_button>;
+    struct toast_params
+    {
+        std::optional<std::wstring_view> tag;
+        bool resend_if_scheduled = true;
+    };
 
-    void show_toast(std::wstring_view plaintext_message);
+    using action_t = std::variant<link_button, background_activated_button, snooze_button>;
-    void show_toast_with_activations(std::wstring_view plaintext_message, std::wstring_view background_handler_id, std::vector<button_t> buttons);
+
+    void show_toast(std::wstring plaintext_message, toast_params params = {});
+    void show_toast_with_activations(std::wstring plaintext_message, std::wstring_view background_handler_id, std::vector<action_t> actions, toast_params params = {});
 }

src/common/notifications/fancyzones_notifications.h

@@ -0,0 +1,71 @@
+#pragma once
+
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <Windows.h>
+#include <limits>
+
+#include "../timeutil.h"
+namespace
+{
+    const inline wchar_t CANT_DRAG_ELEVATED_DONT_SHOW_AGAIN_REGISTRY_PATH[] = LR"(SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\DontShowMeThisDialogAgain\{e16ea82f-6d94-4f30-bb02-d6d911588afd})";
+    const inline int64_t disable_interval_in_days = 30;
+}
+
+inline bool disable_cant_drag_elevated_warning()
+{
+    HKEY key{};
+    if (RegCreateKeyExW(HKEY_CURRENT_USER,
+                        CANT_DRAG_ELEVATED_DONT_SHOW_AGAIN_REGISTRY_PATH,
+                        0,
+                        nullptr,
+                        REG_OPTION_NON_VOLATILE,
+                        KEY_ALL_ACCESS,
+                        nullptr,
+                        &key,
+                        nullptr) != ERROR_SUCCESS)
+    {
+        return false;
+    }
+    const auto now = timeutil::now();
+    const size_t buf_size = sizeof(now);
+    if (RegSetValueExW(key, nullptr, 0, REG_QWORD, reinterpret_cast<const BYTE*>(&now), sizeof(now)) != ERROR_SUCCESS)
+    {
+        RegCloseKey(key);
+        return false;
+    }
+    RegCloseKey(key);
+    return true;
+}
+
+inline bool is_cant_drag_elevated_warning_disabled()
+{
+    HKEY key{};
+    if (RegOpenKeyExW(HKEY_CURRENT_USER,
+                      CANT_DRAG_ELEVATED_DONT_SHOW_AGAIN_REGISTRY_PATH,
+                      0,
+                      KEY_READ,
+                      &key) != ERROR_SUCCESS)
+    {
+        return false;
+    }
+    std::wstring buffer(std::numeric_limits<time_t>::digits10 + 2, L'\0');
+    time_t last_disabled_time{};
+    DWORD time_size = static_cast<DWORD>(sizeof(last_disabled_time));
+    if (RegGetValueW(
+            key,
+            nullptr,
+            nullptr,
+            RRF_RT_REG_QWORD,
+            nullptr,
+            &last_disabled_time,
+            &time_size) != ERROR_SUCCESS)
+    {
+        RegCloseKey(key);
+        return false;
+    }
+    RegCloseKey(key);
+    return timeutil::diff::in_days(timeutil::now(), last_disabled_time) < disable_interval_in_days;
+    return false;
+}

src/common/packages.config

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Microsoft.Windows.ImplementationLibrary" version="1.0.190716.2" targetFramework="native" />
+</packages>

src/common/window_helpers.cpp

@@ -1,5 +1,7 @@
 #include "window_helpers.h"
 #include "pch.h"
+#include <wil/Resource.h>
+
 
 HWND CreateMsgWindow(_In_ HINSTANCE hInst, _In_ WNDPROC pfnWndProc, _In_ void* p)
 {
@@ -27,4 +29,32 @@ HWND CreateMsgWindow(_In_ HINSTANCE hInst, _In_ WNDPROC pfnWndProc, _In_ void* p
     }
 
     return hwnd;
-}
+}
+
+bool IsProcessOfWindowElevated(HWND window)
+{
+    DWORD pid = 0;
+    GetWindowThreadProcessId(window, &pid);
+    if (!pid)
+    {
+        return false;
+    }
+
+    wil::unique_handle hProcess{ OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION,
+                                             FALSE,
+                                             pid) };
+
+    wil::unique_handle token;
+    bool elevated = false;
+
+    if (OpenProcessToken(hProcess.get(), TOKEN_QUERY, &token))
+    {
+        TOKEN_ELEVATION elevation;
+        DWORD size;
+        if (GetTokenInformation(token.get(), TokenElevation, &elevation, sizeof(elevation), &size))
+        {
+            return elevation.TokenIsElevated != 0;
+        }
+    }
+    return false;
+}

src/common/window_helpers.h

@@ -1,4 +1,7 @@
 #pragma once
 #include "common.h"
 
-HWND CreateMsgWindow(_In_ HINSTANCE hInst, _In_ WNDPROC pfnWndProc, _In_ void* p);
+HWND CreateMsgWindow(_In_ HINSTANCE hInst, _In_ WNDPROC pfnWndProc, _In_ void* p);
+
+// If HWND is already dead, we assume it wasn't elevated
+bool IsProcessOfWindowElevated(HWND window);

src/modules/fancyzones/lib/FancyZones.cpp

@@ -12,9 +12,13 @@
 
 #include <functional>
 #include <common/common.h>
-#include <lib\util.h>
+#include <common/window_helpers.h>
+#include <common/notifications.h>
+#include <lib/util.h>
 #include <unordered_set>
 
+#include <common/notifications/fancyzones_notifications.h>
+
 enum class DisplayChangeType
 {
     WorkArea,
@@ -24,6 +28,8 @@ enum class DisplayChangeType
     Initialization
 };
 
+extern "C" IMAGE_DOS_HEADER __ImageBase;
+
 namespace std
 {
     template<>
@@ -176,7 +182,7 @@ private:
     bool IsInterestingWindow(HWND window) noexcept;
     void UpdateZoneWindows() noexcept;
     void MoveWindowsOnDisplayChange() noexcept;
-    void UpdateDragState(require_write_lock) noexcept;
+    void UpdateDragState(HWND window, require_write_lock) noexcept;
     void CycleActiveZoneSet(DWORD vkCode) noexcept;
     bool OnSnapHotkey(DWORD vkCode) noexcept;
     void MoveSizeStartInternal(HWND window, HMONITOR monitor, POINT const& ptScreen, require_write_lock) noexcept;
@@ -807,7 +813,7 @@ void FancyZones::MoveWindowsOnDisplayChange() noexcept
     EnumWindows(callback, reinterpret_cast<LPARAM>(this));
 }
 
-void FancyZones::UpdateDragState(require_write_lock) noexcept
+void FancyZones::UpdateDragState(HWND window, require_write_lock) noexcept
 {
     const bool shift = GetAsyncKeyState(VK_SHIFT) & 0x8000;
     const bool mouseL = GetAsyncKeyState(VK_LBUTTON) & 0x8000;
@@ -836,6 +842,23 @@ void FancyZones::UpdateDragState(require_write_lock) noexcept
     {
         m_dragEnabled = !(shift | mouse);
     }
+
+    const bool windowElevated = IsProcessOfWindowElevated(window);
+    static const bool meElevated = is_process_elevated();
+    static bool warning_shown = false;
+    if (windowElevated && !meElevated)
+    {
+        m_dragEnabled = false;
+        if (!warning_shown && !is_cant_drag_elevated_warning_disabled())
+        {
+            std::vector<notifications::action_t> actions = {
+                notifications::link_button{ GET_RESOURCE_STRING(IDS_CANT_DRAG_ELEVATED_LEARN_MORE), L"https://aka.ms/powertoysDetectedElevatedHelp" },
+                notifications::link_button{ GET_RESOURCE_STRING(IDS_CANT_DRAG_ELEVATED_DIALOG_DONT_SHOW_AGAIN), L"powertoys://cant_drag_elevated_disable/" }
+            };
+            notifications::show_toast_with_activations(GET_RESOURCE_STRING(IDS_CANT_DRAG_ELEVATED), {}, std::move(actions));
+            warning_shown = true;
+        }
+    }
 }
 
 void FancyZones::CycleActiveZoneSet(DWORD vkCode) noexcept
@@ -936,7 +959,7 @@ void FancyZones::MoveSizeStartInternal(HWND window, HMONITOR monitor, POINT cons
     m_windowMoveSize = window;
 
     // This updates m_dragEnabled depending on if the shift key is being held down.
-    UpdateDragState(writeLock);
+    UpdateDragState(window, writeLock);
 
     if (m_dragEnabled)
     {
@@ -1019,7 +1042,7 @@ void FancyZones::MoveSizeUpdateInternal(HMONITOR monitor, POINT const& ptScreen,
     if (m_inMoveSize)
     {
         // This updates m_dragEnabled depending on if the shift key is being held down.
-        UpdateDragState(writeLock);
+        UpdateDragState(m_windowMoveSize, writeLock);
 
         if (m_zoneWindowMoveSize)
         {
@@ -1226,4 +1249,4 @@ winrt::com_ptr<IFancyZones> MakeFancyZones(HINSTANCE hinstance, const winrt::com
     }
 
     return winrt::make_self<FancyZones>(hinstance, settings);
-}
+}

src/modules/fancyzones/lib/fancyzones.rc

@@ -26,6 +26,10 @@ BEGIN
     IDS_SETTING_EXCLCUDED_APPS_DESCRIPTION                     "To exclude an application from snapping to zones add its name here (one per line). Excluded apps will react to the Windows Snap regardless of all other settings."
     IDS_SETTINGS_HIGHLIGHT_OPACITY                             "Zone opacity (%)" 
     IDS_FANCYZONES                                             L"FancyZones" 
+    IDS_CANT_DRAG_ELEVATED                                     L"We've detected an application running with administrator privileges. This blocks some functionality in PowerToys. Visit our wiki page to learn more."
+    IDS_CANT_DRAG_ELEVATED_LEARN_MORE                          L"Learn more"
+    IDS_CANT_DRAG_ELEVATED_DIALOG_DONT_SHOW_AGAIN              L"Don't show again"
+
 END
 
 1 VERSIONINFO

src/modules/fancyzones/lib/resource.h

@@ -19,3 +19,6 @@
 #define IDS_SETTING_EXCLCUDED_APPS_DESCRIPTION                      119
 #define IDS_SETTINGS_HIGHLIGHT_OPACITY                              120
 #define IDS_FANCYZONES                                              121
+#define IDS_CANT_DRAG_ELEVATED                                      122
+#define IDS_CANT_DRAG_ELEVATED_LEARN_MORE                           123
+#define IDS_CANT_DRAG_ELEVATED_DIALOG_DONT_SHOW_AGAIN               124

src/runner/main.cpp

@@ -25,6 +25,7 @@
 #if _DEBUG && _WIN64
 #include "unhandled_exception_handler.h"
 #endif
+#include <common/notifications/fancyzones_notifications.h>
 
 extern "C" IMAGE_DOS_HEADER __ImageBase;
 
@@ -39,6 +40,8 @@ namespace
 {
     const wchar_t MSI_VERSION_MUTEX_NAME[] = L"Local\\PowerToyRunMutex";
     const wchar_t MSIX_VERSION_MUTEX_NAME[] = L"Local\\PowerToyMSIXRunMutex";
+
+    const wchar_t PT_URI_PROTOCOL_SCHEME[] = L"powertoys://";
 }
 
 void chdir_current_executable()
@@ -116,7 +119,7 @@ std::future<void> check_github_updates()
     std::wstring contents = GITHUB_NEW_VERSION_AVAILABLE_OFFER_VISIT;
     contents += new_version->version_string;
     contents += L'.';
-    notifications::show_toast_with_activations(contents, {}, { notifications::link_button{ GITHUB_NEW_VERSION_AGREE, new_version->release_page_uri.ToString() } });
+    notifications::show_toast_with_activations(std::move(contents), {}, { notifications::link_button{ GITHUB_NEW_VERSION_AGREE, new_version->release_page_uri.ToString().c_str() } });
 }
 
 void github_update_checking_worker()
@@ -228,17 +231,22 @@ int runner(bool isProcessElevated)
 enum class SpecialMode
 {
     None,
-    Win32ToastNotificationCOMServer
+    Win32ToastNotificationCOMServer,
+    ToastNotificationHandler
 };
 
-SpecialMode should_run_in_special_mode()
+SpecialMode should_run_in_special_mode(const int n_cmd_args, LPWSTR* cmd_arg_list)
 {
-    int nArgs;
+    for (size_t i = 1; i < n_cmd_args; ++i)
-    LPWSTR* szArglist = CommandLineToArgvW(GetCommandLineW(), &nArgs);
-    for (size_t i = 1; i < nArgs; ++i)
     {
-        if (!wcscmp(notifications::TOAST_ACTIVATED_LAUNCH_ARG, szArglist[i]))
+        if (!wcscmp(notifications::TOAST_ACTIVATED_LAUNCH_ARG, cmd_arg_list[i]))
+        {
             return SpecialMode::Win32ToastNotificationCOMServer;
+        }
+        else if (n_cmd_args == 2 && !wcsncmp(PT_URI_PROTOCOL_SCHEME, cmd_arg_list[i], wcslen(PT_URI_PROTOCOL_SCHEME)))
+        {
+            return SpecialMode::ToastNotificationHandler;
+        }
     }
 
     return SpecialMode::None;
@@ -250,14 +258,42 @@ int win32_toast_notification_COM_server_mode()
     return 0;
 }
 
+enum class toast_notification_handler_result
+{
+    exit_success,
+    exit_error
+};
+
+toast_notification_handler_result toast_notification_handler(const std::wstring_view param)
+{
+    if (param == L"cant_drag_elevated_disable/")
+    {
+        return disable_cant_drag_elevated_warning() ? toast_notification_handler_result::exit_success : toast_notification_handler_result::exit_error;
+    }
+    else
+    {
+        return toast_notification_handler_result::exit_error;
+    }
+}
+
 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
 {
     winrt::init_apartment();
 
-    switch (should_run_in_special_mode())
+    int n_cmd_args = 0;
+    LPWSTR* cmd_arg_list = CommandLineToArgvW(GetCommandLineW(), &n_cmd_args);
+    switch (should_run_in_special_mode(n_cmd_args, cmd_arg_list))
     {
     case SpecialMode::Win32ToastNotificationCOMServer:
         return win32_toast_notification_COM_server_mode();
+    case SpecialMode::ToastNotificationHandler:
+        switch (toast_notification_handler(cmd_arg_list[1] + wcslen(PT_URI_PROTOCOL_SCHEME)))
+        {
+        case toast_notification_handler_result::exit_error:
+            return 1;
+        case toast_notification_handler_result::exit_success:
+            return 0;
+        }
     case SpecialMode::None:
         // continue as usual
         break;
@@ -339,12 +375,12 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
 
         auto general_settings = load_general_settings();
         int rvalue = 0;
-        bool isProcessElevated = is_process_elevated();
+        const bool elevated = is_process_elevated();
-        if (isProcessElevated ||
+        if ((elevated ||
-            general_settings.GetNamedBoolean(L"run_elevated", false) == false ||
+             general_settings.GetNamedBoolean(L"run_elevated", false) == false ||
-            strcmp(lpCmdLine, "--dont-elevate") == 0)
+             strcmp(lpCmdLine, "--dont-elevate") == 0))
         {
-            result = runner(isProcessElevated);
+            result = runner(elevated);
         }
         else
         {