terminal/src/cascadia/ShellExtension/OpenTerminalHere.cpp

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

#include "pch.h"
#include "OpenTerminalHere.h"
#include <ShlObj.h>

// TODO GH#6112: Localize these strings
static constexpr std::wstring_view VerbDisplayName{ L"Open in Windows Terminal" };
static constexpr std::wstring_view VerbDevBuildDisplayName{ L"Open in Windows Terminal (Dev Build)" };
static constexpr std::wstring_view VerbName{ L"WindowsTerminalOpenHere" };

static constexpr std::wstring_view WtExe{ L"wt.exe" };
static constexpr std::wstring_view WtdExe{ L"wtd.exe" };
static constexpr std::wstring_view WindowsTerminalExe{ L"WindowsTerminal.exe" };

static constexpr std::wstring_view LocalAppDataAppsPath{ L"%LOCALAPPDATA%\\Microsoft\\WindowsApps\\" };

// This code is aggressively copied from
//   https://github.com/microsoft/Windows-classic-samples/blob/master/Samples/
//   Win7Samples/winui/shell/appshellintegration/ExplorerCommandVerb/ExplorerCommandVerb.cpp

// Function Description:
// - This is a helper to determine if we're running as a part of the Dev Build
//   Package or the release package. We'll need to return different text, icons,
//   and use different commandlines depending on which one the user requested.
// - Uses a C++11 "magic static" to make sure this is only computed once.
// - If we can't determine if it's the dev build or not, we'll default to true
// Arguments:
// - <none>
// Return Value:
// - true if we believe this extension is being run in the dev build package.
static bool IsDevBuild()
{
    // use C++11 magic statics to make sure we only do this once.
    static bool isDevBuild = []() -> bool {
        try
        {
            const auto package{ winrt::Windows::ApplicationModel::Package::Current() };
            const auto id = package.Id();
            const std::wstring name{ id.FullName() };
            // Does our PFN start with WindowsTerminalDev?
            return name.rfind(L"WindowsTerminalDev", 0) == 0;
        }
        CATCH_LOG();
        return true;
    }();

    return isDevBuild;
}

// Function Description:
// - Helper function for getting the path to the appropriate executable to use
//   for this instance of the shell extension. If we're running the dev build,
//   it should be a `wtd.exe`, but if we're preview or release, we want to make
//   sure to get the correct `wt.exe` that corresponds to _us_.
// - If we're unpackaged, this needs to get us `WindowsTerminal.exe`, because
//   the `wt*exe` alias won't have been installed for this install.
// Arguments:
// - <none>
// Return Value:
// - the full path to the exe, one of `wt.exe`, `wtd.exe`, or `WindowsTerminal.exe`.
static std::wstring _getExePath()
{
    // use C++11 magic statics to make sure we only do this once.
    static const std::wstring exePath = []() -> std::wstring {
        // First, check a packaged location for the exe. If we've got a package
        // family name, that means we're one of the packaged Dev build, packaged
        // Release build, or packaged Preview build.
        //
        // If we're the preview or release build, there's no way of knowing if the
        // `wt.exe` on the %PATH% is us or not. Fortunately, _our_ execution alias
        // is located in "%LOCALAPPDATA%\Microsoft\WindowsApps\<our package family
        // name>", _always_, so we can use that to look up the exe easier.
        try
        {
            const auto package{ winrt::Windows::ApplicationModel::Package::Current() };
            const auto id = package.Id();
            const std::wstring pfn{ id.FamilyName() };
            if (!pfn.empty())
            {
                const std::filesystem::path windowsAppsPath{ wil::ExpandEnvironmentStringsW<std::wstring>(LocalAppDataAppsPath.data()) };
                const std::filesystem::path wtPath = windowsAppsPath / pfn / (IsDevBuild() ? WtdExe : WtExe);
                return wtPath;
            }
        }
        CATCH_LOG();

        // If we're here, then we couldn't resolve our exe from the package. This
        // means we're running unpackaged. We should just use the
        // WindowsTerminal.exe that's sitting in the directory next to us.
        try
        {
            HMODULE hModule = GetModuleHandle(nullptr);
            THROW_LAST_ERROR_IF(hModule == nullptr);
            std::wstring dllPathString;
            THROW_IF_FAILED(wil::GetModuleFileNameW(hModule, dllPathString));
            const std::filesystem::path dllPath{ dllPathString };
            const std::filesystem::path rootDir = dllPath.parent_path();
            std::filesystem::path wtPath = rootDir / WindowsTerminalExe;
            return wtPath;
        }
        CATCH_LOG();

        return L"wt.exe";
    }();
    return exePath;
}

// Method Description:
// - This method is called when the user activates the context menu item. We'll
//   launch the Terminal using the current working directory.
// Arguments:
// - psiItemArray: a IShellItemArray which contains the item that's selected.
// Return Value:
// - S_OK if we successfully attempted to launch the Terminal, otherwise a
//   failure from an earlier HRESULT.
HRESULT OpenTerminalHere::Invoke(IShellItemArray* psiItemArray,
                                 IBindCtx* /*pBindContext*/)
{
    wil::unique_cotaskmem_string pszName;

    if (psiItemArray == nullptr)
    {
        // get the current path from explorer.exe
        const auto path = this->_GetPathFromExplorer();

        // no go, unable to get a reasonable path
        if (path.empty())
        {
            return S_FALSE;
        }
        pszName = wil::make_cotaskmem_string(path.c_str(), path.length());
    }
    else
    {
        DWORD count;
        psiItemArray->GetCount(&count);

        winrt::com_ptr<IShellItem> psi;
        RETURN_IF_FAILED(psiItemArray->GetItemAt(0, psi.put()));
        RETURN_IF_FAILED(psi->GetDisplayName(SIGDN_FILESYSPATH, &pszName));
    }

    {
        wil::unique_process_information _piClient;
        STARTUPINFOEX siEx{ 0 };
        siEx.StartupInfo.cb = sizeof(STARTUPINFOEX);

        // Append a "\." to the given path, so that this will work in "C:\"
        std::wstring cmdline = fmt::format(L"\"{}\" -d \"{}\\.\"", _getExePath(), pszName.get());
        RETURN_IF_WIN32_BOOL_FALSE(CreateProcessW(
            nullptr,
            cmdline.data(),
            nullptr, // lpProcessAttributes
            nullptr, // lpThreadAttributes
            false, // bInheritHandles
            EXTENDED_STARTUPINFO_PRESENT | CREATE_UNICODE_ENVIRONMENT, // dwCreationFlags
            nullptr, // lpEnvironment
            nullptr,
            &siEx.StartupInfo, // lpStartupInfo
            &_piClient // lpProcessInformation
            ));
    }

    return S_OK;
}

HRESULT OpenTerminalHere::GetToolTip(IShellItemArray* /*psiItemArray*/,
                                     LPWSTR* ppszInfoTip)
{
    // tooltip provided here, in this case none is provided
    *ppszInfoTip = nullptr;
    return E_NOTIMPL;
}

HRESULT OpenTerminalHere::GetTitle(IShellItemArray* /*psiItemArray*/,
                                   LPWSTR* ppszName)
{
    // Change the string we return depending on if we're running from the dev
    // build package or not.
    const bool isDevBuild = IsDevBuild();
    return SHStrDup(isDevBuild ? VerbDevBuildDisplayName.data() : VerbDisplayName.data(), ppszName);
}

HRESULT OpenTerminalHere::GetState(IShellItemArray* /*psiItemArray*/,
                                   BOOL /*fOkToBeSlow*/,
                                   EXPCMDSTATE* pCmdState)
{
    // compute the visibility of the verb here, respect "fOkToBeSlow" if this is
    // slow (does IO for example) when called with fOkToBeSlow == FALSE return
    // E_PENDING and this object will be called back on a background thread with
    // fOkToBeSlow == TRUE

    // We however don't need to bother with any of that, so we'll just return
    // ECS_ENABLED.

    *pCmdState = ECS_ENABLED;
    return S_OK;
}

HRESULT OpenTerminalHere::GetIcon(IShellItemArray* /*psiItemArray*/,
                                  LPWSTR* ppszIcon)
try
{
    std::filesystem::path modulePath{ wil::GetModuleFileNameW<std::wstring>(wil::GetModuleInstanceHandle()) };
    modulePath.replace_filename(WindowsTerminalExe);
    // WindowsTerminal.exe,-101 will be the first icon group in WT
    // We're using WindowsTerminal here explicitly, and not wt (from _getExePath), because
    // WindowsTerminal is the only one built with the right icons.
    const auto resource{ modulePath.wstring() + L",-101" };
    return SHStrDupW(resource.c_str(), ppszIcon);
}
CATCH_RETURN();

HRESULT OpenTerminalHere::GetFlags(EXPCMDFLAGS* pFlags)
{
    *pFlags = ECF_DEFAULT;
    return S_OK;
}

HRESULT OpenTerminalHere::GetCanonicalName(GUID* pguidCommandName)
{
    *pguidCommandName = __uuidof(this);
    return S_OK;
}

HRESULT OpenTerminalHere::EnumSubCommands(IEnumExplorerCommand** ppEnum)
{
    *ppEnum = nullptr;
    return E_NOTIMPL;
}

std::wstring OpenTerminalHere::_GetPathFromExplorer() const
{
    using namespace std;
    using namespace winrt;

    wstring path;
    HRESULT hr = NOERROR;

    auto hwnd = ::GetForegroundWindow();
    if (hwnd == nullptr)
    {
        return path;
    }

    TCHAR szName[MAX_PATH] = { 0 };
    ::GetClassName(hwnd, szName, MAX_PATH);
    if (0 == StrCmp(szName, L"WorkerW") ||
        0 == StrCmp(szName, L"Progman"))
    {
        //special folder: desktop
        hr = ::SHGetFolderPath(NULL, CSIDL_DESKTOP, NULL, SHGFP_TYPE_CURRENT, szName);
        if (FAILED(hr))
        {
            return path;
        }

        path = szName;
        return path;
    }

    if (0 != StrCmp(szName, L"CabinetWClass"))
    {
        return path;
    }

    com_ptr<IShellWindows> shell;
    try
    {
        shell = create_instance<IShellWindows>(CLSID_ShellWindows, CLSCTX_ALL);
    }
    catch (...)
    {
        //look like try_create_instance is not available no more
    }

    if (shell == nullptr)
    {
        return path;
    }

    com_ptr<IDispatch> disp;
    wil::unique_variant variant;
    variant.vt = VT_I4;

    com_ptr<IWebBrowserApp> browser;
    // look for correct explorer window
    for (variant.intVal = 0;
         shell->Item(variant, disp.put()) == S_OK;
         variant.intVal++)
    {
        com_ptr<IWebBrowserApp> tmp;
        if (FAILED(disp->QueryInterface(tmp.put())))
        {
            disp = nullptr; // get rid of DEBUG non-nullptr warning
            continue;
        }

        HWND tmpHWND = NULL;
        hr = tmp->get_HWND(reinterpret_cast<SHANDLE_PTR*>(&tmpHWND));
        if (hwnd == tmpHWND)
        {
            browser = tmp;
            disp = nullptr; // get rid of DEBUG non-nullptr warning
            break; //found
        }

        disp = nullptr; // get rid of DEBUG non-nullptr warning
    }

    if (browser != nullptr)
    {
        wil::unique_bstr url;
        hr = browser->get_LocationURL(&url);
        if (FAILED(hr))
        {
            return path;
        }

        wstring sUrl(url.get(), SysStringLen(url.get()));
        DWORD size = MAX_PATH;
        hr = ::PathCreateFromUrl(sUrl.c_str(), szName, &size, NULL);
        if (SUCCEEDED(hr))
        {
            path = szName;
        }
    }

    return path;
}