Липкие окошки

void __fastcall TForm1::wm_windowposchanging(TMessage &msg)
{
     const int sensitivity = 10; //количество пикселей для прилипания
     RECT rcWorkArea = {0};
 
     if(SystemParametersInfo(SPI_GETWORKAREA, 0, &rcWorkArea, FALSE))
     {
         WINDOWPOS *wp = (WINDOWPOS*)msg.LParam;
 
         if(abs(wp->x - rcWorkArea.left) <= sensitivity)
             wp->x = rcWorkArea.left;
         if(abs(wp->y - rcWorkArea.top) <= sensitivity)
             wp->y = rcWorkArea.top;
         if(abs(wp->cx + wp->x - rcWorkArea.right) <= sensitivity)
            wp->x = rcWorkArea.right - wp->cx;
         if(abs(wp->cy + wp->y - rcWorkArea.bottom) <= sensitivity)
             wp->y = rcWorkArea.bottom - wp->cy;
     }
     TForm::Dispatch(&msg);
}

...
private:
        void __fastcall wm_windowposchanging(TMessage &msg);
public:
        ...
        BEGIN_MESSAGE_MAP
        MESSAGE_HANDLER(WM_WINDOWPOSCHANGING, TMessage, wm_windowposchanging)
        END_MESSAGE_MAP(TForm)

case WM_MOVING: {
    RECT rcWorkArea = {0};
    if(SystemParametersInfo(SPI_GETWORKAREA, 0, &rcWorkArea, FALSE)) {
        RECT *wp = (RECT*)Msg.LParam; //собственно рамка
           ....
}