C / C++ / MFC

TRACKMOUSEEVENT t_MouseEvent;
t_MouseEvent.cbSize      = sizeof(TRACKMOUSEEVENT);
t_MouseEvent.dwFlags     = TME_LEAVE | TME_HOVER;
t_MouseEvent.hwndTrack   = m_hWnd;
t_MouseEvent.dwHoverTime = 1;

// We Tell Windows we want to receive WM_MOUSEHOVER and WM_MOUSELEAVE
::_TrackMouseEvent(&t_MouseEvent);

/** Returns true if the mouse cursor is positioned over the Output Windows 'Close' button.
 *  @internal
 *  @caller CanClose()
 */
BOOL
CDockTabsView::MouseOnCloseButton()
{
BOOL bStat = FALSE;

        // During startup/close (Project Open?) the Output Window isn't actually visible and we
        // don't want to nor need to check any further.
    if ( IsWindowVisible() )
    {
    CWnd* pDockFrame;
    POINT point;

            // note: By the time we get here the LMB is no longer down.
        // TRACE( "In CDockTabsView::CanClose() and IsLButtonDown(): %d\n", IsLButtonDown() );

            // Was the click on the Output Window Frame (ie. Title Bar)
        GetCursorPos( &point );
        if ( ( pDockFrame = WindowFromPoint( point ) )->IsChild( this ) )
        {
                // Can't call pDockFrame->OnNcHitTest( point ) as its protected so use WM_NCHITTEST
            UINT nHitPos = pDockFrame->SendMessage( WM_NCHITTEST, 0, MAKELPARAM( point.x, point.y ) );
            // TRACE( "In CDockTabsView::MouseOnCloseButton() and Click in Parent of CDockTabsView: %x, NcHitTest: %x\n", m_hWnd, nHitPos );
            bStat = nHitPos eq HTCLOSE;    // Over 'Close Button'
        }
    }
    return bStat;
}

/** Returns true of the Left Mouse Button is down now, else false.
 */
BOOL
IsLButtonDown()   // rem: also a #define in windowsx.h but that doesn't checked for swapped buttons.
{
        // GetAsyncKeyState() checks on the state of the physical mouse buttons, not
        // on the logical mouse buttons that the physical buttons are mapped to.
        // Checking SM_SWAPBUTTON resolves this. GetAsyncKeyState() will return the
        // current key state even if a window in another thread or process currently has the keyboard focus.
    return KEY_DOWN( GetAsyncKeyState( GetSystemMetrics( SM_SWAPBUTTON ) ? VK_RBUTTON : VK_LBUTTON ) ) ne 0;
}