CMenuFocusManager.cpp

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/*
 * Shell Menu Band
 *
 * Copyright 2014 David Quintana
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

/*
This file implements the CMenuFocusManager class.

This class manages the shell menus, by overriding the hot-tracking behaviour.

For the shell menus, it uses a GetMessage hook,
where it intercepts messages directed to the menu windows.

In order to show submenus using system popups, it also has a MessageFilter hook.

The menu is tracked using a stack structure. When a CMenuBand wants to open a submenu,
it pushes the submenu band, or HMENU to track in case of system popups,
and when the menu has closed, it pops the same pointer or handle.

While a shell menu is open, it overrides the menu toolbar's hottracking behaviour,
using its own logic to track both the active menu item, and the opened submenu's parent item.

While a system popup is open, it tracks the mouse movements so that it can cancel the popup,
and switch to another submenu when the mouse goes over another item from the parent.

*/
#include "shellmenu.h"
#include <windowsx.h>
#include <commoncontrols.h>
#include <shlwapi_undoc.h>

#include "CMenuFocusManager.h"
#include "CMenuToolbars.h"
#include "CMenuBand.h"

#if DBG
#   undef _ASSERT
#   define _ASSERT(x) DbgAssert(!!(x), __FILE__, __LINE__, #x)

bool DbgAssert(bool x, const char * filename, int line, const char * expr)
{
    if (!x)
    {
        char szMsg[512];
        const char *fname;

        fname = strrchr(filename, '\\');
        if (fname == NULL)
        {
            fname = strrchr(filename, '/');
        }

        if (fname == NULL)
            fname = filename;
        else
            fname++;

        sprintf(szMsg, "%s:%d: Assertion failed: %s\n", fname, line, expr);

        OutputDebugStringA(szMsg);

        __debugbreak();
    }
    return x;
}
#else
#   undef _ASSERT
#   define _ASSERT(x) (!!(x))
#endif

WINE_DEFAULT_DEBUG_CHANNEL(CMenuFocus);

DWORD CMenuFocusManager::TlsIndex = 0;

// Gets the thread's assigned manager without refcounting
CMenuFocusManager * CMenuFocusManager::GetManager()
{
    return reinterpret_cast<CMenuFocusManager *>(TlsGetValue(TlsIndex));
}

// Obtains a manager for the thread, with refcounting
CMenuFocusManager * CMenuFocusManager::AcquireManager()
{
    CMenuFocusManager * obj = NULL;

    if (!TlsIndex)
    {
        if ((TlsIndex = TlsAlloc()) == TLS_OUT_OF_INDEXES)
            return NULL;
    }

    obj = GetManager();

    if (!obj)
    {
        obj = new CComObject<CMenuFocusManager>();
        TlsSetValue(TlsIndex, obj);
    }

    obj->AddRef();

    return obj;
}

// Releases a previously acquired manager, and deletes it if the refcount reaches 0
void CMenuFocusManager::ReleaseManager(CMenuFocusManager * obj)
{
    if (!obj->Release())
    {
        TlsSetValue(TlsIndex, NULL);
    }
}

LRESULT CALLBACK CMenuFocusManager::s_MsgFilterHook(INT nCode, WPARAM wParam, LPARAM lParam)
{
    return GetManager()->MsgFilterHook(nCode, wParam, lParam);
}

LRESULT CALLBACK CMenuFocusManager::s_GetMsgHook(INT nCode, WPARAM wParam, LPARAM lParam)
{
    return GetManager()->GetMsgHook(nCode, wParam, lParam);
}

HRESULT CMenuFocusManager::PushToArray(StackEntryType type, CMenuBand * mb, HMENU hmenu)
{
    if (m_bandCount >= MAX_RECURSE)
        return E_OUTOFMEMORY;

    m_bandStack[m_bandCount].type = type;
    m_bandStack[m_bandCount].mb = mb;
    m_bandStack[m_bandCount].hmenu = hmenu;
    m_bandCount++;

    return S_OK;
}

HRESULT CMenuFocusManager::PopFromArray(StackEntryType * pType, CMenuBand ** pMb, HMENU * pHmenu)
{
    if (pType)  *pType = NoEntry;
    if (pMb)    *pMb = NULL;
    if (pHmenu) *pHmenu = NULL;

    if (m_bandCount <= 0)
        return S_FALSE;

    m_bandCount--;

    if (pType)  *pType = m_bandStack[m_bandCount].type;
    if (*pType == TrackedMenuEntry)
    {
        if (pHmenu) *pHmenu = m_bandStack[m_bandCount].hmenu;
    }
    else
    {
        if (pMb) *pMb = m_bandStack[m_bandCount].mb;
    }

    return S_OK;
}

CMenuFocusManager::CMenuFocusManager() :
    m_current(NULL),
    m_parent(NULL),
    m_hMsgFilterHook(NULL),
    m_hGetMsgHook(NULL),
    m_mouseTrackDisabled(FALSE),
    m_captureHwnd(0),
    m_hwndUnderMouse(NULL),
    m_entryUnderMouse(NULL),
    m_selectedMenu(NULL),
    m_selectedItem(0),
    m_selectedItemFlags(0),
    m_movedSinceDown(FALSE),
    m_windowAtDown(NULL),
    m_PreviousForeground(NULL),
    m_bandCount(0),
    m_menuDepth(0)
{
    m_ptPrev.x = 0;
    m_ptPrev.y = 0;
    m_threadId = GetCurrentThreadId();
}

CMenuFocusManager::~CMenuFocusManager()
{
}

// Used so that the toolbar can properly ignore mouse events, when the menu is being used with the keyboard
void CMenuFocusManager::DisableMouseTrack(HWND parent, BOOL disableThis)
{
    BOOL bDisable = FALSE;
    BOOL lastDisable = FALSE;

    int i = m_bandCount;
    while (--i >= 0)
    {
        StackEntry& entry = m_bandStack[i];

        if (entry.type != TrackedMenuEntry)
        {
            HWND hwnd;
            HRESULT hr = entry.mb->_GetTopLevelWindow(&hwnd);
            if (FAILED_UNEXPECTEDLY(hr))
                break;

            if (hwnd == parent)
            {
                lastDisable = disableThis;
                entry.mb->_DisableMouseTrack(disableThis);
                bDisable = TRUE;
            }
            else
            {
                lastDisable = bDisable;
                entry.mb->_DisableMouseTrack(bDisable);
            }
        }
    }
    m_mouseTrackDisabled = lastDisable;
}

void CMenuFocusManager::SetMenuCapture(HWND child)
{
    if (m_captureHwnd != child)
    {
        if (child)
        {
            ::SetCapture(child);
            m_captureHwnd = child;
            TRACE("Capturing %p\n", child);
        }
        else
        {
            ::ReleaseCapture();
            m_captureHwnd = NULL;
            TRACE("Capture is now off\n");
        }

    }
}

HRESULT CMenuFocusManager::IsTrackedWindow(HWND hWnd, StackEntry ** pentry)
{
    if (pentry)
        *pentry = NULL;

    for (int i = m_bandCount; --i >= 0;)
    {
        StackEntry& entry = m_bandStack[i];

        if (entry.type != TrackedMenuEntry)
        {
            HRESULT hr = entry.mb->IsWindowOwner(hWnd);
            if (FAILED_UNEXPECTEDLY(hr))
                return hr;
            if (hr == S_OK)
            {
                if (pentry)
                    *pentry = &entry;
                return S_OK;
            }
        }
    }

    return S_FALSE;
}

HRESULT CMenuFocusManager::IsTrackedWindowOrParent(HWND hWnd)
{
    for (int i = m_bandCount; --i >= 0;)
    {
        StackEntry& entry = m_bandStack[i];

        if (entry.type != TrackedMenuEntry)
        {
            HRESULT hr = entry.mb->IsWindowOwner(hWnd);
            if (FAILED_UNEXPECTEDLY(hr))
                return hr;
            if (hr == S_OK)
                return S_OK;
            if (entry.mb->_IsPopup() == S_OK)
            {
                CComPtr<IUnknown> site;
                CComPtr<IOleWindow> pw;
                hr = entry.mb->GetSite(IID_PPV_ARG(IUnknown, &site));
                if (FAILED_UNEXPECTEDLY(hr))
                    continue;
                hr = IUnknown_QueryService(site, SID_SMenuBandParent, IID_PPV_ARG(IOleWindow, &pw));
                if (FAILED_UNEXPECTEDLY(hr))
                    continue;

                HWND hParent;
                if (pw->GetWindow(&hParent) == S_OK && hParent == hWnd)
                    return S_OK;
            }
        }
    }

    return S_FALSE;
}

LRESULT CMenuFocusManager::ProcessMouseMove(MSG* msg)
{
    HWND child;
    int iHitTestResult = -1;

    POINT pt2 = { GET_X_LPARAM(msg->lParam), GET_Y_LPARAM(msg->lParam) };
    ClientToScreen(msg->hwnd, &pt2);

    POINT pt = msg->pt;

    // Don't do anything if another window is capturing the mouse.
    HWND cCapture = ::GetCapture();
    if (cCapture && cCapture != m_captureHwnd && m_current->type != TrackedMenuEntry)
        return TRUE;

    m_movedSinceDown = TRUE;

    m_ptPrev = pt;

    child = WindowFromPoint(pt);

    StackEntry * entry = NULL;
    if (IsTrackedWindow(child, &entry) == S_OK)
    {
        TRACE("MouseMove\n");
    }

    BOOL isTracking = FALSE;
    if (entry && (entry->type == MenuBarEntry || m_current->type != TrackedMenuEntry))
    {
        ScreenToClient(child, &pt);
        iHitTestResult = SendMessageW(child, TB_HITTEST, 0, (LPARAM) &pt);
        isTracking = entry->mb->_IsTracking();

        if (SendMessage(child, WM_USER_ISTRACKEDITEM, iHitTestResult, 0) == S_FALSE)
        {
            // The current tracked item has changed, notify the toolbar

            TRACE("Hot item tracking detected a change (capture=%p / cCapture=%p)...\n", m_captureHwnd, cCapture);
            DisableMouseTrack(NULL, FALSE);
            if (isTracking && iHitTestResult >= 0 && m_current->type == TrackedMenuEntry)
                SendMessage(entry->hwnd, WM_CANCELMODE, 0, 0);
            PostMessage(child, WM_USER_CHANGETRACKEDITEM, iHitTestResult, MAKELPARAM(isTracking, TRUE));
            if (m_current->type == TrackedMenuEntry)
                return FALSE;
        }
    }

    if (m_entryUnderMouse != entry)
    {
        // Mouse moved away from a tracked window
        if (m_entryUnderMouse)
        {
            m_entryUnderMouse->mb->_ChangeHotItem(NULL, -1, HICF_MOUSE);
        }
    }

    if (m_hwndUnderMouse != child)
    {
        if (entry)
        {
            // Mouse moved to a tracked window
            if (m_current->type == MenuPopupEntry)
            {
                ScreenToClient(child, &pt2);
                SendMessage(child, WM_MOUSEMOVE, msg->wParam, MAKELPARAM(pt2.x, pt2.y));
            }
        }

        m_hwndUnderMouse = child;
        m_entryUnderMouse = entry;
    }

    if (m_current->type == MenuPopupEntry)
    {
        HWND parent = GetAncestor(child, GA_ROOT);
        DisableMouseTrack(parent, FALSE);
    }

    return TRUE;
}

LRESULT CMenuFocusManager::ProcessMouseDown(MSG* msg, BOOL isLButton)
{
    HWND child;
    int iHitTestResult = -1;

    TRACE("ProcessMouseDown %d %d %d\n", msg->message, msg->wParam, msg->lParam);

    // Don't do anything if another window is capturing the mouse.
    HWND cCapture = ::GetCapture();
    if (cCapture && cCapture != m_captureHwnd && m_current->type != TrackedMenuEntry)
    {
        TRACE("Foreign capture active.\n");
        return TRUE;
    }

    POINT pt = msg->pt;

    child = WindowFromPoint(pt);

    StackEntry * entry = NULL;
    if (IsTrackedWindow(child, &entry) != S_OK)
    {
        TRACE("Foreign window detected.\n");
        return TRUE;
    }

    if (entry->type == MenuBarEntry)
    {
        if (entry != m_current)
        {
            TRACE("Menubar with popup active.\n");
            return TRUE;
        }
    }

    if (entry)
    {
        ScreenToClient(child, &pt);
        iHitTestResult = SendMessageW(child, TB_HITTEST, 0, (LPARAM) &pt);

        if (iHitTestResult >= 0)
        {
            TRACE("MouseDown send %d\n", iHitTestResult);
            entry->mb->_MenuBarMouseDown(child, iHitTestResult, isLButton);
        }
    }

    msg->message = WM_NULL;

    m_movedSinceDown = FALSE;
    m_windowAtDown = child;

    TRACE("MouseDown end\n");

    return TRUE;
}

LRESULT CMenuFocusManager::ProcessMouseUp(MSG* msg, BOOL isLButton)
{
    HWND child;
    int iHitTestResult = -1;

    TRACE("ProcessMouseUp %d %d %d\n", msg->message, msg->wParam, msg->lParam);

    // Don't do anything if another window is capturing the mouse.
    HWND cCapture = ::GetCapture();
    if (cCapture && cCapture != m_captureHwnd && m_current->type != TrackedMenuEntry)
        return TRUE;

    POINT pt = msg->pt;

    child = WindowFromPoint(pt);

    StackEntry * entry = NULL;
    if (IsTrackedWindow(child, &entry) != S_OK)
        return TRUE;

    if (entry)
    {
        ScreenToClient(child, &pt);
        iHitTestResult = SendMessageW(child, TB_HITTEST, 0, (LPARAM) &pt);

        if (iHitTestResult >= 0)
        {
            TRACE("MouseUp send %d\n", iHitTestResult);
            entry->mb->_MenuBarMouseUp(child, iHitTestResult, isLButton);
        }
    }

    return TRUE;
}

LRESULT CMenuFocusManager::MsgFilterHook(INT nCode, WPARAM hookWParam, LPARAM hookLParam)
{
    if (nCode < 0)
        return CallNextHookEx(m_hMsgFilterHook, nCode, hookWParam, hookLParam);

    if (nCode == MSGF_MENU)
    {
        BOOL callNext = TRUE;
        MSG* msg = reinterpret_cast<MSG*>(hookLParam);

        switch (msg->message)
        {
        case WM_LBUTTONDOWN:
        case WM_RBUTTONDOWN:
            if (m_menuBar && m_current->type == TrackedMenuEntry)
            {
                POINT pt = msg->pt;
                HWND child = WindowFromPoint(pt);
                BOOL hoveringMenuBar = m_menuBar->mb->IsWindowOwner(child) == S_OK;
                if (hoveringMenuBar)
                {
                    m_menuBar->mb->_BeforeCancelPopup();
                }
            }
            break;
        case WM_MOUSEMOVE:
            callNext = ProcessMouseMove(msg);
            break;
        case WM_INITMENUPOPUP:
            TRACE("WM_INITMENUPOPUP %p %p\n", msg->wParam, msg->lParam);
            m_selectedMenu = reinterpret_cast<HMENU>(msg->lParam);
            m_selectedItem = -1;
            m_selectedItemFlags = 0;
            break;
        case WM_MENUSELECT:
            TRACE("WM_MENUSELECT %p %p\n", msg->wParam, msg->lParam);
            m_selectedMenu = reinterpret_cast<HMENU>(msg->lParam);
            m_selectedItem = GET_X_LPARAM(msg->wParam);
            m_selectedItemFlags = HIWORD(msg->wParam);
            break;
        case WM_KEYDOWN:
            switch (msg->wParam)
            {
            case VK_LEFT:
                if (m_current->hmenu == m_selectedMenu)
                {
                    m_parent->mb->_MenuItemSelect(VK_LEFT);
                }
                break;
            case VK_RIGHT:
                if (m_selectedItem < 0 || !(m_selectedItemFlags & MF_POPUP))
                {
                    m_parent->mb->_MenuItemSelect(VK_RIGHT);
                }
                break;
            }
            break;
        }

        if (!callNext)
            return 1;
    }

    return CallNextHookEx(m_hMsgFilterHook, nCode, hookWParam, hookLParam);
}

LRESULT CMenuFocusManager::GetMsgHook(INT nCode, WPARAM hookWParam, LPARAM hookLParam)
{
    BOOL isLButton = FALSE;
    if (nCode < 0)
        return CallNextHookEx(m_hGetMsgHook, nCode, hookWParam, hookLParam);

    if (nCode == HC_ACTION)
    {
        BOOL callNext = TRUE;
        MSG* msg = reinterpret_cast<MSG*>(hookLParam);
        POINT pt = msg->pt;

        switch (msg->message)
        {
        case WM_CAPTURECHANGED:
            if (m_captureHwnd)
            {
                TRACE("Capture lost.\n");
                m_captureHwnd = NULL;
            }
            break;

        case WM_NCLBUTTONDOWN:
        case WM_LBUTTONDBLCLK:
        case WM_LBUTTONDOWN:
            isLButton = TRUE;
            TRACE("LB\n");

            if (m_menuBar && m_current->type == MenuPopupEntry)
            {
                POINT pt = msg->pt;
                HWND child = WindowFromPoint(pt);
                BOOL hoveringMenuBar = m_menuBar->mb->IsWindowOwner(child) == S_OK;
                if (hoveringMenuBar)
                {
                    m_current->mb->_MenuItemSelect(MPOS_FULLCANCEL);
                    break;
                }
            }

            if (m_current->type == MenuPopupEntry)
            {
                HWND child = WindowFromPoint(pt);

                if (IsTrackedWindowOrParent(child) != S_OK)
                {
                    m_current->mb->_MenuItemSelect(MPOS_FULLCANCEL);
                    break;
                }
            }

            ProcessMouseDown(msg, isLButton);

            break;
        case WM_NCRBUTTONUP:
        case WM_RBUTTONUP:
            ProcessMouseUp(msg, isLButton);
            break;
        case WM_NCLBUTTONUP:
        case WM_LBUTTONUP:
            isLButton = TRUE;
            ProcessMouseUp(msg, isLButton);
            break;
        case WM_MOUSEMOVE:
            callNext = ProcessMouseMove(msg);
            break;
        case WM_MOUSELEAVE:
            callNext = ProcessMouseMove(msg);
            //callNext = ProcessMouseLeave(msg);
            break;
        case WM_SYSKEYDOWN:
        case WM_KEYDOWN:
            if (m_current->type == MenuPopupEntry)
            {
                DisableMouseTrack(m_current->hwnd, TRUE);
                switch (msg->wParam)
                {
                case VK_ESCAPE:
                case VK_MENU:
                case VK_LMENU:
                case VK_RMENU:
                    m_current->mb->_MenuItemSelect(MPOS_FULLCANCEL);
                    break;
                case VK_RETURN:
                    m_current->mb->_MenuItemSelect(MPOS_EXECUTE);
                    break;
                case VK_LEFT:
                    m_current->mb->_MenuItemSelect(VK_LEFT);
                    break;
                case VK_RIGHT:
                    m_current->mb->_MenuItemSelect(VK_RIGHT);
                    break;
                case VK_UP:
                    m_current->mb->_MenuItemSelect(VK_UP);
                    break;
                case VK_DOWN:
                    m_current->mb->_MenuItemSelect(VK_DOWN);
                    break;
                }
                msg->message = WM_NULL;
                msg->lParam = 0;
                msg->wParam = 0;
            }
            break;
        }

        if (!callNext)
            return 1;
    }

    return CallNextHookEx(m_hGetMsgHook, nCode, hookWParam, hookLParam);
}

HRESULT CMenuFocusManager::PlaceHooks()
{
    if (m_hGetMsgHook)
    {
        WARN("GETMESSAGE hook already placed!\n");
        return S_OK;
    }
    if (m_hMsgFilterHook)
    {
        WARN("MSGFILTER hook already placed!\n");
        return S_OK;
    }
    if (m_current->type == TrackedMenuEntry)
    {
        TRACE("Entering MSGFILTER hook...\n");
        m_hMsgFilterHook = SetWindowsHookEx(WH_MSGFILTER, s_MsgFilterHook, NULL, m_threadId);
    }
    else
    {
        TRACE("Entering GETMESSAGE hook...\n");
        m_hGetMsgHook = SetWindowsHookEx(WH_GETMESSAGE, s_GetMsgHook, NULL, m_threadId);
    }
    return S_OK;
}

HRESULT CMenuFocusManager::RemoveHooks()
{
    if (m_hMsgFilterHook)
    {
        TRACE("Removing MSGFILTER hook...\n");
        UnhookWindowsHookEx(m_hMsgFilterHook);
        m_hMsgFilterHook = NULL;
    }
    if (m_hGetMsgHook)
    {
        TRACE("Removing GETMESSAGE hook...\n");
        UnhookWindowsHookEx(m_hGetMsgHook);
        m_hGetMsgHook = NULL;
    }
    return S_OK;
}

// Used to update the tracking info to account for a change in the top-level menu
HRESULT CMenuFocusManager::UpdateFocus()
{
    HRESULT hr;
    StackEntry * old = m_current;

    TRACE("UpdateFocus\n");

    // Assign the new current item
    if (m_bandCount > 0)
        m_current = &(m_bandStack[m_bandCount - 1]);
    else
        m_current = NULL;

    // Remove the menu capture if necesary
    if (!m_current || m_current->type != MenuPopupEntry)
    {
        SetMenuCapture(NULL);
        if (old && old->type == MenuPopupEntry && m_PreviousForeground)
        {
            ::SetForegroundWindow(m_PreviousForeground);
            m_PreviousForeground = NULL;
        }
    }

    // Obtain the top-level window for the new active menu
    if (m_current && m_current->type != TrackedMenuEntry)
    {
        hr = m_current->mb->_GetTopLevelWindow(&(m_current->hwnd));
        if (FAILED_UNEXPECTEDLY(hr))
            return hr;
    }

    // Refresh the parent pointer
    if (m_bandCount >= 2)
    {
        m_parent = &(m_bandStack[m_bandCount - 2]);
        _ASSERT(m_parent->type != TrackedMenuEntry);
    }
    else
    {
        m_parent = NULL;
    }

    // Refresh the menubar pointer, if applicable
    if (m_bandCount >= 1 && m_bandStack[0].type == MenuBarEntry)
    {
        m_menuBar = &(m_bandStack[0]);
    }
    else
    {
        m_menuBar = NULL;
    }

    // Remove the old hooks if the menu type changed, or we don't have a menu anymore
    if (old && (!m_current || old->type != m_current->type))
    {
        if (m_current && m_current->type != TrackedMenuEntry)
        {
            DisableMouseTrack(m_current->hwnd, FALSE);
        }

        hr = RemoveHooks();
        if (FAILED_UNEXPECTEDLY(hr))
            return hr;
    }

    // And place new ones if necessary
    if (m_current && (!old || old->type != m_current->type))
    {
        hr = PlaceHooks();
        if (FAILED_UNEXPECTEDLY(hr))
            return hr;
    }

    // Give the user a chance to move the mouse to the new menu
    if (m_parent)
    {
        DisableMouseTrack(m_parent->hwnd, TRUE);
    }

    if (m_current && m_current->type == MenuPopupEntry)
    {
        if (m_captureHwnd == NULL)
        {
            // We need to restore the capture after a non-shell submenu or context menu is shown
            StackEntry * topMenu = m_bandStack;
            if (topMenu->type == MenuBarEntry)
                topMenu++;

            // Get the top-level window from the top popup
            CComPtr<IServiceProvider> bandSite;
            CComPtr<IOleWindow> deskBar;
            hr = topMenu->mb->GetSite(IID_PPV_ARG(IServiceProvider, &bandSite));
            if (FAILED(hr))
                goto NoCapture;
            hr = bandSite->QueryService(SID_SMenuPopup, IID_PPV_ARG(IOleWindow, &deskBar));
            if (FAILED(hr))
                goto NoCapture;

            CComPtr<IOleWindow> deskBarSite;
            hr = IUnknown_GetSite(deskBar, IID_PPV_ARG(IOleWindow, &deskBarSite));
            if (FAILED(hr))
                goto NoCapture;

            // FIXME: Find the correct place for this
            HWND hWndOwner;
            hr = deskBarSite->GetWindow(&hWndOwner);
            if (FAILED(hr))
                goto NoCapture;

            m_PreviousForeground = ::GetForegroundWindow();
            if (m_PreviousForeground != hWndOwner)
                ::SetForegroundWindow(hWndOwner);
            else
                m_PreviousForeground = NULL;

            // Get the HWND of the top-level window
            HWND hWndSite;
            hr = deskBar->GetWindow(&hWndSite);
            if (FAILED(hr))
                goto NoCapture;
            SetMenuCapture(hWndSite);
        }
NoCapture:

        if (!m_parent || m_parent->type == MenuBarEntry)
        {
            if (old && old->type == TrackedMenuEntry)
            {
                // FIXME: Debugging code, probably not right
                POINT pt2;
                RECT rc2;
                GetCursorPos(&pt2);
                ScreenToClient(m_current->hwnd, &pt2);
                GetClientRect(m_current->hwnd, &rc2);
                if (PtInRect(&rc2, pt2))
                    SendMessage(m_current->hwnd, WM_MOUSEMOVE, 0, MAKELPARAM(pt2.x, pt2.y));
                else
                    SendMessage(m_current->hwnd, WM_MOUSELEAVE, 0, 0);
            }
        }
    }

    _ASSERT(!m_parent || m_parent->type != TrackedMenuEntry);

    return S_OK;
}

// Begin tracking top-level menu bar (for file browser windows)
HRESULT CMenuFocusManager::PushMenuBar(CMenuBand * mb)
{
    TRACE("PushMenuBar %p\n", mb);

    mb->AddRef();

    _ASSERT(m_bandCount == 0);

    HRESULT hr = PushToArray(MenuBarEntry, mb, NULL);
    if (FAILED_UNEXPECTEDLY(hr))
        return hr;

    return UpdateFocus();
}

// Begin tracking a shell menu popup (start menu or submenus)
HRESULT CMenuFocusManager::PushMenuPopup(CMenuBand * mb)
{
    TRACE("PushTrackedPopup %p\n", mb);

    mb->AddRef();

    _ASSERT(!m_current || m_current->type != TrackedMenuEntry);

    HRESULT hr = PushToArray(MenuPopupEntry, mb, NULL);
    if (FAILED_UNEXPECTEDLY(hr))
        return hr;

    hr = UpdateFocus();

    m_menuDepth++;

    if (m_parent && m_parent->type != TrackedMenuEntry)
    {
        m_parent->mb->_SetChildBand(mb);
        mb->_SetParentBand(m_parent->mb);
    }

    return hr;
}

// Begin tracking a system popup submenu (submenu of the file browser windows)
HRESULT CMenuFocusManager::PushTrackedPopup(HMENU popup)
{
    TRACE("PushTrackedPopup %p\n", popup);

    _ASSERT(m_bandCount > 0);
    _ASSERT(!m_current || m_current->type != TrackedMenuEntry);

    HRESULT hr = PushToArray(TrackedMenuEntry, NULL, popup);
    if (FAILED_UNEXPECTEDLY(hr))
        return hr;

    TRACE("PushTrackedPopup %p\n", popup);
    m_selectedMenu = popup;
    m_selectedItem = -1;
    m_selectedItemFlags = 0;

    return UpdateFocus();
}

// Stop tracking the menubar
HRESULT CMenuFocusManager::PopMenuBar(CMenuBand * mb)
{
    StackEntryType type;
    CMenuBand * mbc;
    HRESULT hr;

    TRACE("PopMenuBar %p\n", mb);

    if (m_current == m_entryUnderMouse)
    {
        m_entryUnderMouse = NULL;
    }

    hr = PopFromArray(&type, &mbc, NULL);
    if (FAILED_UNEXPECTEDLY(hr))
    {
        UpdateFocus();
        return hr;
    }

    _ASSERT(type == MenuBarEntry);
    if (type != MenuBarEntry)
        return E_FAIL;

    if (!mbc)
        return E_FAIL;

    mbc->_SetParentBand(NULL);

    mbc->Release();

    hr = UpdateFocus();
    if (FAILED_UNEXPECTEDLY(hr))
        return hr;

    if (m_current)
    {
        _ASSERT(m_current->type != TrackedMenuEntry);
        m_current->mb->_SetChildBand(NULL);
    }

    return S_OK;
}

// Stop tracking a shell menu
HRESULT CMenuFocusManager::PopMenuPopup(CMenuBand * mb)
{
    StackEntryType type;
    CMenuBand * mbc;
    HRESULT hr;

    TRACE("PopMenuPopup %p\n", mb);

    if (m_current == m_entryUnderMouse)
    {
        m_entryUnderMouse = NULL;
    }

    m_menuDepth--;

    hr = PopFromArray(&type, &mbc, NULL);
    if (FAILED_UNEXPECTEDLY(hr))
    {
        UpdateFocus();
        return hr;
    }

    _ASSERT(type == MenuPopupEntry);
    if (type != MenuPopupEntry)
        return E_FAIL;

    if (!mbc)
        return E_FAIL;

    mbc->_SetParentBand(NULL);

    mbc->Release();

    hr = UpdateFocus();
    if (FAILED_UNEXPECTEDLY(hr))
        return hr;

    if (m_current)
    {
        _ASSERT(m_current->type != TrackedMenuEntry);
        m_current->mb->_SetChildBand(NULL);
    }

    return S_OK;
}

// Stop tracking a system popup submenu
HRESULT CMenuFocusManager::PopTrackedPopup(HMENU popup)
{
    StackEntryType type;
    HMENU hmenu;
    HRESULT hr;

    TRACE("PopTrackedPopup %p\n", popup);

    hr = PopFromArray(&type, NULL, &hmenu);
    if (FAILED_UNEXPECTEDLY(hr))
    {
        UpdateFocus();
        return hr;
    }

    _ASSERT(type == TrackedMenuEntry);
    if (type != TrackedMenuEntry)
        return E_FAIL;

    if (hmenu != popup)
        return E_FAIL;

    hr = UpdateFocus();
    if (FAILED_UNEXPECTEDLY(hr))
        return hr;

    return S_OK;
}