Not really, as long as you give yourself focus you should be fine.

The only reason I can think of for doing keyboard or pointer grabs is
either popup menus which need to capture clicks outside their window area
without those clicks passing through to other applications or need to
capture all keystrokes without taking focus. Some games also take grabs so
that they can limit mouse movement to their own window.

However, if you want to care about gaining and losing focus in a
non-window-manager environment, then maybe you might want a grab. On the
contrary, I think that the non-window-manager usecase is not really worth
supporting either - if someone wants to ship standalone XBMC there is
negligible overhead from running a small EWMH/ICCCM compliant
non-compositing window manager along side it.


On Mon, Oct 28, 2013 at 8:41 PM, Rainer Hochecker
<notifications@github.com>wrote:

> In xbmc/windowing/X11/WinSystemX11.cpp:
>
> > +}
> > +
> > +void CWinSystemX11::NotifyMouseCoverage(bool covered)
> > +{
> > +  if (!m_bFullScreen || !m_mainWindow)
> > +    return;
> > +
> > +  if (covered && !m_bIsGrabbed)
> > +  {
> > +    int result = -1;
> > +    while (result != GrabSuccess && result != AlreadyGrabbed)
> > +    {
> > +      result = XGrabPointer(m_dpy, m_mainWindow, True, ButtonPressMask, GrabModeAsync, GrabModeAsync, None, None, CurrentTime);
> > +      XbmcThreads::ThreadSleep(100);
> > +    }
> > +    XGrabKeyboard(m_dpy, m_mainWindow, True, GrabModeAsync, GrabModeAsync, CurrentTime);
>
> You may be right. SDL did so which is the reason why it's here. Do we need
> to grab the keyboard when running without WM?
>
> —
> Reply to this email directly or view it on GitHub<https://github.com/xbmc/xbmc/pull/3505/files#r7246277>
> .
>



-- 
Sam Spilsbury