x11: Fix the _NET_SUPPORTING_WM_CHECK window fetch to be spec compliant

"The child window MUST also have the _NET_SUPPORTING_WM_CHECK property set to
the ID of the child window. […] If the _NET_SUPPORTING_WM_CHECK window on the
client window is missing or not properly set, clients SHOULD assume that no
conforming Window Manager is present."

This commit implements that, which allows us to not have to do a
XGetWindowProperty() every N seconds when running under a compliant WM.

This is also a more correct fix for the bug handled in commit
daf29bffed.

https://bugzilla.gnome.org/show_bug.cgi?id=666921
This commit is contained in:
Rui Matos 2012-01-09 05:54:08 +00:00
parent 608637b562
commit f0a80fa308

View File

@ -1311,17 +1311,45 @@ cleanup_atoms(gpointer data)
g_free (supported_atoms);
}
static void
fetch_net_wm_check_window (GdkScreen *screen)
static Window
get_net_supporting_wm_check (GdkX11Screen *screen,
Window window)
{
GdkX11Screen *x11_screen;
GdkDisplay *display;
Atom type;
gint format;
gulong n_items;
gulong bytes_after;
guchar *data;
Window *xwindow;
Window value;
display = screen->display;
type = None;
data = NULL;
value = None;
gdk_x11_display_error_trap_push (display);
XGetWindowProperty (screen->xdisplay, window,
gdk_x11_get_xatom_by_name_for_display (display, "_NET_SUPPORTING_WM_CHECK"),
0, G_MAXLONG, False, XA_WINDOW, &type, &format,
&n_items, &bytes_after, &data);
gdk_x11_display_error_trap_pop_ignored (display);
if (type == XA_WINDOW)
value = *(Window *)data;
if (data)
XFree (data);
return value;
}
static void
fetch_net_wm_check_window (GdkScreen *screen)
{
GdkX11Screen *x11_screen;
GdkDisplay *display;
Window window;
GTimeVal tv;
gint error;
@ -1330,56 +1358,45 @@ fetch_net_wm_check_window (GdkScreen *screen)
g_return_if_fail (GDK_X11_DISPLAY (display)->trusted_client);
if (x11_screen->wmspec_check_window != None)
return; /* already have it */
g_get_current_time (&tv);
if (ABS (tv.tv_sec - x11_screen->last_wmspec_check_time) < 15)
return; /* we've checked recently */
x11_screen->last_wmspec_check_time = tv.tv_sec;
window = get_net_supporting_wm_check (x11_screen, x11_screen->xroot_window);
if (window == None)
return;
data = NULL;
XGetWindowProperty (x11_screen->xdisplay, x11_screen->xroot_window,
gdk_x11_get_xatom_by_name_for_display (display, "_NET_SUPPORTING_WM_CHECK"),
0, G_MAXLONG, False, XA_WINDOW, &type, &format,
&n_items, &bytes_after, &data);
if (type != XA_WINDOW)
{
if (data)
XFree (data);
return;
}
xwindow = (Window *)data;
if (x11_screen->wmspec_check_window == *xwindow)
{
XFree (xwindow);
return;
}
if (window != get_net_supporting_wm_check (x11_screen, window))
return;
gdk_x11_display_error_trap_push (display);
/* Find out if this WM goes away, so we can reset everything. */
XSelectInput (x11_screen->xdisplay, *xwindow, StructureNotifyMask);
XSelectInput (x11_screen->xdisplay, window, StructureNotifyMask);
error = gdk_x11_display_error_trap_pop (display);
if (!error)
{
x11_screen->wmspec_check_window = *xwindow;
/* We check the window property again because after XGetWindowProperty()
* and before XSelectInput() the window may have been recycled in such a
* way that XSelectInput() doesn't fail but the window is no longer what
* we want.
*/
if (window != get_net_supporting_wm_check (x11_screen, window))
return;
x11_screen->wmspec_check_window = window;
x11_screen->last_wmspec_check_time = tv.tv_sec;
x11_screen->need_refetch_net_supported = TRUE;
x11_screen->need_refetch_wm_name = TRUE;
/* Careful, reentrancy */
_gdk_x11_screen_window_manager_changed (GDK_SCREEN (x11_screen));
_gdk_x11_screen_window_manager_changed (screen);
}
else if (error == BadWindow)
{
/* Leftover property, try again immediately, new wm may be starting up */
x11_screen->last_wmspec_check_time = 0;
}
XFree (xwindow);
}
/**