PowerToys/src/modules/ShortcutGuide/ShortcutGuideModuleInterface/dllmain.cpp

// dllmain.cpp : Defines the entry point for the DLL application.
#include "pch.h"

#include <mutex>
#include <common/SettingsAPI/settings_helpers.h>
#include <common/utils/winapi_error.h>
#include <common/utils/logger_helper.h>
#include <common/interop/shared_constants.h>

#include "../interface/powertoy_module_interface.h"
#include "Generated Files/resource.h"
#include <common/SettingsAPI/settings_objects.h>

BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved)
{
    return TRUE;
}

class ShortcutGuideModule : public PowertoyModuleIface
{
public:
    ShortcutGuideModule()
    {
        app_name = GET_RESOURCE_STRING(IDS_SHORTCUT_GUIDE);
        app_key = L"Shortcut Guide";
        LoggerHelpers::init_logger(app_key, L"ModuleInterface", LogSettings::shortcutGuideLoggerName);

        std::filesystem::path oldLogPath(PTSettingsHelper::get_module_save_folder_location(app_key));
        oldLogPath.append("ShortcutGuideLogs");
        LoggerHelpers::delete_old_log_folder(oldLogPath);

        exitEvent = CreateEvent(nullptr, false, false, CommonSharedConstants::SHORTCUT_GUIDE_EXIT_EVENT);
        if (!exitEvent)
        {
            Logger::warn(L"Failed to create {} event. {}", CommonSharedConstants::SHORTCUT_GUIDE_EXIT_EVENT, get_last_error_or_default(GetLastError()));
        }

        InitSettings();
    }

    virtual const wchar_t* get_name() override
    {
        return app_name.c_str();
    }

    virtual const wchar_t* get_key() override
    {
        return app_key.c_str();
    }

    virtual bool get_config(wchar_t* buffer, int* buffer_size) override
    {
        HINSTANCE hinstance = reinterpret_cast<HINSTANCE>(&__ImageBase);
        PowerToysSettings::Settings settings(hinstance, get_name());
        return settings.serialize_to_buffer(buffer, buffer_size);
    }

    virtual void set_config(const wchar_t* config) override
    {
        Logger::trace("set_config()");
        try
        {
            // Parse the input JSON string.
            PowerToysSettings::PowerToyValues values =
                PowerToysSettings::PowerToyValues::from_json_string(config, get_key());

            ParseSettings(values);
        }
        catch (std::exception ex)
        {
            Logger::error("Failed to parse settings. {}", ex.what());
        }
    }

    virtual void enable() override
    {
        Logger::info("Shortcut Guide is enabling");

        if (!_enabled)
        {
            _enabled = true;
        }
        else
        {
            Logger::warn("Shortcut guide is already enabled");
        }
    }

    virtual void disable() override
    {
        Logger::info("ShortcutGuideModule::disable()");
        if (_enabled)
        {
            _enabled = false;
            TerminateProcess();
        }
        else
        {
            Logger::warn("Shortcut Guide is already disabled");
        }
    }

    virtual bool is_enabled() override
    {
        return _enabled;
    }

    virtual void destroy() override
    {
        this->disable();
        if (exitEvent)
        {
            CloseHandle(exitEvent);
        }

        delete this;
    }

    virtual std::optional<HotkeyEx> GetHotkeyEx() override
    {
        Logger::trace("GetHotkeyEx()");
        if (m_shouldReactToPressedWinKey)
        {
            return std::nullopt;
        }
        return m_hotkey;
    }

    virtual void OnHotkeyEx() override
    {
        Logger::trace("OnHotkeyEx()");
        if (!_enabled)
        {
            return;
        }

        if (IsProcessActive())
        {
            TerminateProcess();
            return;
        }

        if (m_hProcess)
        {
            CloseHandle(m_hProcess);
            m_hProcess = nullptr;
        }

        StartProcess();
    }

    virtual void send_settings_telemetry() override
    {
        Logger::trace("Send settings telemetry");
        if (!StartProcess(L"telemetry"))
        {
            Logger::error("Failed to create a process to send settings telemetry");
        }
    }

    virtual bool keep_track_of_pressed_win_key() override
    {
        return m_shouldReactToPressedWinKey;
    }

    virtual UINT milliseconds_win_key_must_be_pressed() override
    {
        return m_millisecondsWinKeyShouldBePressed;
    }

private:
    std::wstring app_name;
    //contains the non localized key of the powertoy
    std::wstring app_key;
    bool _enabled = false;
    HANDLE m_hProcess = nullptr;
    
    // Hotkey to invoke the module
    HotkeyEx m_hotkey;

    // If the module should be activated through the legacy pressing windows key behavior.
    const UINT DEFAULT_MILLISECONDS_WIN_KEY_SHOULD_BE_PRESSED = 900;
    bool m_shouldReactToPressedWinKey = false;
    UINT m_millisecondsWinKeyShouldBePressed = DEFAULT_MILLISECONDS_WIN_KEY_SHOULD_BE_PRESSED;

    HANDLE exitEvent;

    bool StartProcess(std::wstring args = L"")
    {
        if (exitEvent)
        {
            ResetEvent(exitEvent);
        }

        unsigned long powertoys_pid = GetCurrentProcessId();
        std::wstring executable_args = L"";
        executable_args.append(std::to_wstring(powertoys_pid));
        if (!args.empty())
        {
            executable_args.append(L" ");
            executable_args.append(args);
        }

        SHELLEXECUTEINFOW sei{ sizeof(sei) };
        sei.fMask = { SEE_MASK_NOCLOSEPROCESS | SEE_MASK_FLAG_NO_UI };
        sei.lpFile = L"modules\\ShortcutGuide\\ShortcutGuide\\PowerToys.ShortcutGuide.exe";
        sei.nShow = SW_SHOWNORMAL;
        sei.lpParameters = executable_args.data();
        if (ShellExecuteExW(&sei) == false)
        {
            Logger::error(L"Failed to start SG process. {}", get_last_error_or_default(GetLastError()));
            auto message = get_last_error_message(GetLastError());
            if (message.has_value())
            {
                Logger::error(message.value());
            }

            return false;
        }

        Logger::trace(L"Started SG process with pid={}", GetProcessId(sei.hProcess));
        m_hProcess = sei.hProcess;
        return true;    
    }

    void TerminateProcess()
    {
        if (m_hProcess)
        {
            if (WaitForSingleObject(m_hProcess, 0) != WAIT_OBJECT_0)
            {
                if (exitEvent && SetEvent(exitEvent))
                {
                    Logger::trace(L"Signaled {}", CommonSharedConstants::SHORTCUT_GUIDE_EXIT_EVENT);
                }
                else
                {
                    Logger::warn(L"Failed to signal {}", CommonSharedConstants::SHORTCUT_GUIDE_EXIT_EVENT);
                }
            }
            else
            {
                CloseHandle(m_hProcess);
                m_hProcess = nullptr;
                Logger::trace("SG process was already terminated");
            }
        }
    }

    bool IsProcessActive()
    {
        return m_hProcess && WaitForSingleObject(m_hProcess, 0) != WAIT_OBJECT_0;
    }

    void InitSettings()
    {
        try
        {
            PowerToysSettings::PowerToyValues settings =
                PowerToysSettings::PowerToyValues::load_from_settings_file(app_key);

            ParseSettings(settings);
        }
        catch (std::exception ex)
        {
            Logger::error("Failed to init settings. {}", ex.what());
        }
        catch(...)
        {
            Logger::error("Failed to init settings");
        }
    }

    void ParseSettings(PowerToysSettings::PowerToyValues& settings)
    {
        m_shouldReactToPressedWinKey = false;
        m_millisecondsWinKeyShouldBePressed = DEFAULT_MILLISECONDS_WIN_KEY_SHOULD_BE_PRESSED;

        auto settingsObject = settings.get_raw_json();
        if (settingsObject.GetView().Size())
        {
            try
            {
                // Parse HotKey
                auto jsonHotkeyObject = settingsObject.GetNamedObject(L"properties").GetNamedObject(L"open_shortcutguide");
                auto hotkey = PowerToysSettings::HotkeyObject::from_json(jsonHotkeyObject);
                m_hotkey = HotkeyEx();
                if (hotkey.win_pressed())
                {
                    m_hotkey.modifiersMask |= MOD_WIN;
                }

                if (hotkey.ctrl_pressed())
                {
                    m_hotkey.modifiersMask |= MOD_CONTROL;
                }

                if (hotkey.shift_pressed())
                {
                    m_hotkey.modifiersMask |= MOD_SHIFT;
                }

                if (hotkey.alt_pressed())
                {
                    m_hotkey.modifiersMask |= MOD_ALT;
                }

                m_hotkey.vkCode = hotkey.get_code();
            }
            catch (...)
            {
                Logger::warn("Failed to initialize Shortcut Guide start shortcut");
            }
            try
            {
                // Parse Legacy windows key press behavior settings
                auto jsonUseLegacyWinKeyBehaviorObject = settingsObject.GetNamedObject(L"properties").GetNamedObject(L"use_legacy_press_win_key_behavior");
                m_shouldReactToPressedWinKey = (bool)jsonUseLegacyWinKeyBehaviorObject.GetNamedBoolean(L"value");
                auto jsonPressTimeObject = settingsObject.GetNamedObject(L"properties").GetNamedObject(L"press_time");
                m_millisecondsWinKeyShouldBePressed = (UINT)jsonPressTimeObject.GetNamedNumber(L"value");
            }
            catch (...)
            {
                Logger::warn("Failed to get legacy win key behavior settings");
            }
        }
        else
        {
            Logger::info("Shortcut Guide settings are empty");
        }

        if (!m_hotkey.modifiersMask)
        {
            Logger::info("Shortcut Guide is going to use default shortcut");
            m_hotkey.modifiersMask = MOD_SHIFT | MOD_WIN;
            m_hotkey.vkCode = VK_OEM_2;
        }
    }
};

extern "C" __declspec(dllexport) PowertoyModuleIface* __cdecl powertoy_create()
{
    return new ShortcutGuideModule();
}