X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=driver%2Fwindows.c;h=471a8a7c049f6df7b377bbaa66a2040a987a403a;hp=29e046190fed02b12ece386ba3a496c2c3d875bf;hb=3c58fb6311db49c46f1670922933b27c6ea0c065;hpb=585e1a6717d1dd9b90fbb53acaaae82106354d33 diff --git a/driver/windows.c b/driver/windows.c index 29e04619..471a8a7c 100644 --- a/driver/windows.c +++ b/driver/windows.c @@ -68,6 +68,8 @@ Atom XA_SCREENSAVER_STATUS; extern saver_info *global_si_kludge; /* I hate C so much... */ +static void maybe_transfer_grabs (saver_screen_info *ssi, + Window old_w, Window new_w); #define ALL_POINTER_EVENTS \ (ButtonPressMask | ButtonReleaseMask | EnterWindowMask | \ @@ -957,6 +959,80 @@ get_screen_viewport (saver_screen_info *ssi, } +static Bool error_handler_hit_p = False; + +static int +ignore_all_errors_ehandler (Display *dpy, XErrorEvent *error) +{ + error_handler_hit_p = True; + return 0; +} + + +/* Returns True if successful, False if an X error occurred. + We need this because other programs might have done things to + our window that will cause XChangeWindowAttributes() to fail: + if that happens, we give up, destroy the window, and re-create + it. + */ +static Bool +safe_XChangeWindowAttributes (Display *dpy, Window window, + unsigned long mask, + XSetWindowAttributes *attrs) +{ + XErrorHandler old_handler; + XSync (dpy, False); + error_handler_hit_p = False; + old_handler = XSetErrorHandler (ignore_all_errors_ehandler); + + XChangeWindowAttributes (dpy, window, mask, attrs); + + XSync (dpy, False); + XSetErrorHandler (old_handler); + XSync (dpy, False); + + return (!error_handler_hit_p); +} + + +/* This might not be necessary, but just in case. */ +static Bool +safe_XConfigureWindow (Display *dpy, Window window, + unsigned long mask, XWindowChanges *changes) +{ + XErrorHandler old_handler; + XSync (dpy, False); + error_handler_hit_p = False; + old_handler = XSetErrorHandler (ignore_all_errors_ehandler); + + XConfigureWindow (dpy, window, mask, changes); + + XSync (dpy, False); + XSetErrorHandler (old_handler); + XSync (dpy, False); + + return (!error_handler_hit_p); +} + +/* This might not be necessary, but just in case. */ +static Bool +safe_XDestroyWindow (Display *dpy, Window window) +{ + XErrorHandler old_handler; + XSync (dpy, False); + error_handler_hit_p = False; + old_handler = XSetErrorHandler (ignore_all_errors_ehandler); + + XDestroyWindow (dpy, window); + + XSync (dpy, False); + XSetErrorHandler (old_handler); + XSync (dpy, False); + + return (!error_handler_hit_p); +} + + static void initialize_screensaver_window_1 (saver_screen_info *ssi) { @@ -974,6 +1050,7 @@ initialize_screensaver_window_1 (saver_screen_info *ssi) unsigned long attrmask; int x, y, width, height; static Bool printed_visual_info = False; /* only print the message once. */ + Window horked_window = 0; get_screen_viewport (ssi, &x, &y, &width, &height, (p->verbose_p && !si->screen_blanked_p)); @@ -1113,12 +1190,17 @@ initialize_screensaver_window_1 (saver_screen_info *ssi) changes.height = height; changes.border_width = 0; - XConfigureWindow (si->dpy, ssi->screensaver_window, - changesmask, &changes); - XChangeWindowAttributes (si->dpy, ssi->screensaver_window, - attrmask, &attrs); + if (! (safe_XConfigureWindow (si->dpy, ssi->screensaver_window, + changesmask, &changes) && + safe_XChangeWindowAttributes (si->dpy, ssi->screensaver_window, + attrmask, &attrs))) + { + horked_window = ssi->screensaver_window; + ssi->screensaver_window = 0; + } } - else + + if (!ssi->screensaver_window) { ssi->screensaver_window = XCreateWindow (si->dpy, RootWindowOfScreen (ssi->screen), @@ -1127,6 +1209,17 @@ initialize_screensaver_window_1 (saver_screen_info *ssi) ssi->current_visual, attrmask, &attrs); reset_stderr (ssi); + + if (horked_window) + { + fprintf (stderr, + "%s: someone horked our saver window (0x%lx)! Recreating it...\n", + blurb(), (unsigned long) horked_window); + maybe_transfer_grabs (ssi, horked_window, ssi->screensaver_window); + safe_XDestroyWindow (si->dpy, horked_window); + horked_window = 0; + } + if (p->verbose_p) fprintf (stderr, "%s: saver window is 0x%lx.\n", blurb(), (unsigned long) ssi->screensaver_window); @@ -1450,6 +1543,47 @@ unblank_screen (saver_info *si) } +/* Transfer any grabs from the old window to the new. + Actually I think none of this is necessary, since we always + hold our grabs on the root window, but I wrote this before + re-discovering that... + */ +static void +maybe_transfer_grabs (saver_screen_info *ssi, + Window old_w, Window new_w) +{ + saver_info *si = ssi->global; + + /* If the old window held our mouse grab, transfer the grab to the new + window. (Grab the server while so doing, to avoid a race condition.) + */ + if (old_w == si->mouse_grab_window) + { + XGrabServer (si->dpy); /* ############ DANGER! */ + ungrab_mouse (si); + grab_mouse (si, ssi->screensaver_window, + (si->demoing_p + ? 0 + : ssi->cursor)); + XUngrabServer (si->dpy); + XSync (si->dpy, False); /* ###### (danger over) */ + } + + /* If the old window held our keyboard grab, transfer the grab to the new + window. (Grab the server while so doing, to avoid a race condition.) + */ + if (old_w == si->keyboard_grab_window) + { + XGrabServer (si->dpy); /* ############ DANGER! */ + ungrab_kbd(si); + grab_kbd(si, ssi->screensaver_window); + XUngrabServer (si->dpy); + XSync (si->dpy, False); /* ###### (danger over) */ + } +} + + + Bool select_visual (saver_screen_info *ssi, const char *visual_name) { @@ -1538,45 +1672,10 @@ select_visual (saver_screen_info *ssi, const char *visual_name) store_vroot_property (si->dpy, ssi->screensaver_window, ssi->screensaver_window); + /* Transfer any grabs from the old window to the new. */ + maybe_transfer_grabs (ssi, old_w, ssi->screensaver_window); - /* Transfer the grabs from the old window to the new. - Actually I think none of this is necessary, since we always - hold our grabs on the root window, but I wrote this before - re-discovering that... - */ - - - /* If we're destroying the window that holds our mouse grab, - transfer the grab to the new window. (Grab the server while - so doing, to avoid a race condition.) - */ - if (old_w == si->mouse_grab_window) - { - XGrabServer (si->dpy); /* ############ DANGER! */ - ungrab_mouse (si); - grab_mouse (si, ssi->screensaver_window, - (si->demoing_p - ? 0 - : ssi->cursor)); - XUngrabServer (si->dpy); - XSync (si->dpy, False); /* ###### (danger over) */ - } - - /* If we're destroying the window that holds our keyboard grab, - transfer the grab to the new window. (Grab the server while - so doing, to avoid a race condition.) - */ - if (old_w == si->keyboard_grab_window) - { - XGrabServer (si->dpy); /* ############ DANGER! */ - ungrab_kbd(si); - grab_kbd(si, ssi->screensaver_window); - XUngrabServer (si->dpy); - XSync (si->dpy, False); /* ###### (danger over) */ - } - - /* Now we can destroy this window without horking our grabs. */ - + /* Now we can destroy the old window without horking our grabs. */ XDestroyWindow (si->dpy, old_w); if (p->verbose_p)