From 1e4a11b6bc608e4c7db8bbba706ed793fc03638d Mon Sep 17 00:00:00 2001
From: Valentin Radu <valentin.radu@valinet.ro>
Date: Sun, 5 Dec 2021 01:36:00 +0200
Subject: [PATCH] Added posibility to use the original Windows 10 Alt-Tab
 switcher

---
 ExplorerPatcher/dllmain.c    | 85 ++++++++++++++++++++++++++++++++++--
 ExplorerPatcher/settings.reg |  9 ++--
 ExplorerPatcher/symbols.c    | 16 +++++--
 ExplorerPatcher/symbols.h    |  5 ++-
 4 files changed, 102 insertions(+), 13 deletions(-)

diff --git a/ExplorerPatcher/dllmain.c b/ExplorerPatcher/dllmain.c
index 85d3c75..8508a21 100644
--- a/ExplorerPatcher/dllmain.c
+++ b/ExplorerPatcher/dllmain.c
@@ -72,6 +72,7 @@ DWORD bToolbarSeparators = FALSE;
 DWORD bTaskbarAutohideOnDoubleClick = FALSE;
 DWORD dwOrbStyle = 0;
 DWORD bEnableSymbolDownload = TRUE;
+DWORD dwAltTabSettings = 0;
 HMODULE hModule = NULL;
 HANDLE hDelayedInjectionThread = NULL;
 HANDLE hIsWinXShown = NULL;
@@ -3845,6 +3846,36 @@ void WINAPI LoadSettings(BOOL bIsExplorer)
         RegCloseKey(hKey);
     }
 
+    RegCreateKeyExW(
+        HKEY_CURRENT_USER,
+        L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer",
+        0,
+        NULL,
+        REG_OPTION_NON_VOLATILE,
+        KEY_READ | KEY_WOW64_64KEY,
+        NULL,
+        &hKey,
+        NULL
+    );
+    if (hKey == NULL || hKey == INVALID_HANDLE_VALUE)
+    {
+        hKey = NULL;
+    }
+    if (hKey)
+    {
+        dwSize = sizeof(DWORD);
+        RegQueryValueExW(
+            hKey,
+            TEXT("AltTabSettings"),
+            0,
+            NULL,
+            &dwAltTabSettings,
+            &dwSize
+        );
+        RegCloseKey(hKey);
+    }
+
+
     RegCreateKeyExW(
         HKEY_CURRENT_USER,
         L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\StartPage",
@@ -4920,14 +4951,14 @@ LSTATUS twinuipcshell_RegGetValueW(
 {
     LSTATUS lRes = RegGetValueW(hkey, lpSubKey, lpValue, dwFlags, pdwType, pvData, pcbData);
 
-    if (!bOldTaskbar && !lstrcmpW(lpValue, L"AltTabSettings"))
+    if (!lstrcmpW(lpValue, L"AltTabSettings"))
     {
-        if (*(DWORD*)pvData)
+        if (lRes == ERROR_SUCCESS && *(DWORD*)pvData)
         {
             *(DWORD*)pvData = 1;
         }
 
-        if (hWin11AltTabInitialized)
+        if (!bOldTaskbar && hWin11AltTabInitialized)
         {
             SetEvent(hWin11AltTabInitialized);
             CloseHandle(hWin11AltTabInitialized);
@@ -5243,6 +5274,24 @@ DWORD InjectBasicFunctions(BOOL bIsExplorer, BOOL bInstall)
     }
 }
 
+INT64(*twinui_pcshell_IsUndockedAssetAvailableFunc)(INT a1, INT64 a2, INT64 a3, const char* a4);
+INT64 twinui_pcshell_IsUndockedAssetAvailableHook(INT a1, INT64 a2, INT64 a3, const char* a4)
+{
+    if (dwAltTabSettings == 3)
+    {
+        return 0;
+    }
+    else
+    {
+        return twinui_pcshell_IsUndockedAssetAvailableFunc(a1, a2, a3, a4);
+    }
+}
+
+BOOL IsDebuggerPresentHook()
+{
+    return FALSE;
+}
+
 DWORD Inject(BOOL bIsExplorer)
 {
 #if defined(DEBUG) | defined(_DEBUG)
@@ -5274,7 +5323,7 @@ DWORD Inject(BOOL bIsExplorer)
         hSwsOpacityMaybeChanged = CreateEventW(NULL, FALSE, FALSE, NULL);
     }
 
-    unsigned int numSettings = bIsExplorer ? 11 : 2;
+    unsigned int numSettings = bIsExplorer ? 12 : 2;
     Setting* settings = calloc(numSettings, sizeof(Setting));
     if (settings)
     {
@@ -5401,6 +5450,17 @@ DWORD Inject(BOOL bIsExplorer)
             cs++;
         }
 
+        if (cs < numSettings)
+        {
+            settings[cs].callback = LoadSettings;
+            settings[cs].data = bIsExplorer;
+            settings[cs].hEvent = NULL;
+            settings[cs].hKey = NULL;
+            wcscpy_s(settings[cs].name, MAX_PATH, L"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer");
+            settings[cs].origin = HKEY_CURRENT_USER;
+            cs++;
+        }
+
         SettingsChangeParameters* settingsParams = calloc(1, sizeof(SettingsChangeParameters));
         if (settingsParams)
         {
@@ -5641,6 +5701,22 @@ DWORD Inject(BOOL bIsExplorer)
         }
     }
 
+    if (symbols_PTRS.twinui_pcshell_PTRS[7] && symbols_PTRS.twinui_pcshell_PTRS[7] != 0xFFFFFFFF)
+    {
+        twinui_pcshell_IsUndockedAssetAvailableFunc = (INT64(*)(void*, POINT*))
+            ((uintptr_t)hTwinuiPcshell + symbols_PTRS.twinui_pcshell_PTRS[7]);
+        rv = funchook_prepare(
+            funchook,
+            (void**)&twinui_pcshell_IsUndockedAssetAvailableFunc,
+            twinui_pcshell_IsUndockedAssetAvailableHook
+        );
+        if (rv != 0)
+        {
+            FreeLibraryAndExitThread(hModule, rv);
+            return rv;
+        }
+    }
+
     if (symbols_PTRS.twinui_pcshell_PTRS[TWINUI_PCSHELL_SB_CNT - 1] && symbols_PTRS.twinui_pcshell_PTRS[TWINUI_PCSHELL_SB_CNT - 1] != 0xFFFFFFFF)
     {
         winrt_Windows_Internal_Shell_implementation_MeetAndChatManager_OnMessageFunc = (INT64(*)(void*, POINT*))
@@ -5657,6 +5733,7 @@ DWORD Inject(BOOL bIsExplorer)
         }
     }
     VnPatchIAT(hTwinuiPcshell, "API-MS-WIN-CORE-REGISTRY-L1-1-0.DLL", "RegGetValueW", twinuipcshell_RegGetValueW);
+    //VnPatchIAT(hTwinuiPcshell, "api-ms-win-core-debug-l1-1-0.dll", "IsDebuggerPresent", IsDebuggerPresentHook);
     printf("Setup twinui.pcshell functions done\n");
 
 
diff --git a/ExplorerPatcher/settings.reg b/ExplorerPatcher/settings.reg
index 2b23c27..caebb91 100644
--- a/ExplorerPatcher/settings.reg
+++ b/ExplorerPatcher/settings.reg
@@ -197,12 +197,13 @@
 
 ;T Window switcher
 [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
-;z 3 Window switcher (Alt+Tab) style *
-;x 0 Windows 11
-;x 2 Windows 10
+;z 4 Window switcher (Alt+Tab) style *
+;x 0 Windows 11 (default)
+;x 3 Windows 10
 ;x 1 Windows NT
+;x 2 Simple Window Switcher
 "AltTabSettings"=dword:00000000
-;t The following settings only apply to the Windows 10 window switcher:
+;t The following settings only apply to the Simple Window Switcher:
 [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ExplorerPatcher\sws]
 ;b Include desktop
 "IncludeWallpaper"=dword:00000001
diff --git a/ExplorerPatcher/symbols.c b/ExplorerPatcher/symbols.c
index cb53421..e7d85d2 100644
--- a/ExplorerPatcher/symbols.c
+++ b/ExplorerPatcher/symbols.c
@@ -237,7 +237,7 @@ DWORD DownloadSymbols(DownloadSymbolsParams* params)
         DWORD dwZero = 0;
         RegSetValueExW(
             hKey,
-            TEXT(TWINUI_PCSHELL_SB_7),
+            TEXT(TWINUI_PCSHELL_SB_8),
             0,
             REG_DWORD,
             &dwZero,
@@ -325,6 +325,14 @@ DWORD DownloadSymbols(DownloadSymbolsParams* params)
         &(symbols_PTRS.twinui_pcshell_PTRS[7]),
         sizeof(DWORD)
     );
+    RegSetValueExW(
+        hKey,
+        TEXT(TWINUI_PCSHELL_SB_8),
+        0,
+        REG_DWORD,
+        &(symbols_PTRS.twinui_pcshell_PTRS[8]),
+        sizeof(DWORD)
+    );
     if (hKey) RegCloseKey(hKey);
 
 
@@ -598,7 +606,8 @@ BOOL LoadSymbols(symbols_addr* symbols_PTRS, HMODULE hModule)
         symbols_PTRS->twinui_pcshell_PTRS[4] = 0x5DAC08;
         symbols_PTRS->twinui_pcshell_PTRS[5] = 0x5DA8C4;
         symbols_PTRS->twinui_pcshell_PTRS[6] = 0x5CD9C0;
-        symbols_PTRS->twinui_pcshell_PTRS[7] = 0x52980;
+        symbols_PTRS->twinui_pcshell_PTRS[7] = 0x5f744c;
+        symbols_PTRS->twinui_pcshell_PTRS[8] = 0x52980;
         bIsTwinuiPcshellHardcoded = TRUE;
     }
     else if (!_stricmp(hash, "03487ccd5bc5a194fad61b616b0a2b28") || !_stricmp(hash, "3f6ef12a59a2f84a3296771ea7753e01")) // 346, 348
@@ -610,7 +619,8 @@ BOOL LoadSymbols(symbols_addr* symbols_PTRS, HMODULE hModule)
         symbols_PTRS->twinui_pcshell_PTRS[4] = 0x5DBDD8;
         symbols_PTRS->twinui_pcshell_PTRS[5] = 0x5DBA94;
         symbols_PTRS->twinui_pcshell_PTRS[6] = 0x5CEB90;
-        symbols_PTRS->twinui_pcshell_PTRS[7] = 0x4D780;
+        symbols_PTRS->twinui_pcshell_PTRS[7] = 0x5f861c;
+        symbols_PTRS->twinui_pcshell_PTRS[8] = 0x4D780;
         bIsTwinuiPcshellHardcoded = TRUE;
     }
     if (bIsTwinuiPcshellHardcoded)
diff --git a/ExplorerPatcher/symbols.h b/ExplorerPatcher/symbols.h
index 62e8ebd..5f10320 100644
--- a/ExplorerPatcher/symbols.h
+++ b/ExplorerPatcher/symbols.h
@@ -17,8 +17,9 @@
 #define TWINUI_PCSHELL_SB_4 "CLauncherTipContextMenu::_ExecuteShutdownCommand"
 #define TWINUI_PCSHELL_SB_5 "CLauncherTipContextMenu::_ExecuteCommand"
 #define TWINUI_PCSHELL_SB_6 "CLauncherTipContextMenu::ShowLauncherTipContextMenu"
-#define TWINUI_PCSHELL_SB_7 "winrt::Windows::Internal::Shell::implementation::MeetAndChatManager::OnMessage" // should be always last
-#define TWINUI_PCSHELL_SB_CNT 8
+#define TWINUI_PCSHELL_SB_7 "IsUndockedAssetAvailable"
+#define TWINUI_PCSHELL_SB_8 "winrt::Windows::Internal::Shell::implementation::MeetAndChatManager::OnMessage" // should be always last
+#define TWINUI_PCSHELL_SB_CNT 9
 #define STARTDOCKED_SB_NAME "StartDocked"
 #define STARTDOCKED_SB_0 "StartDocked::LauncherFrame::ShowAllApps" // UNUSED
 #define STARTDOCKED_SB_1 "StartDocked::LauncherFrame::ShowAllApps"