slock

simple X display locker utility
git clone git://git.suckless.org/slock
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commit 9dfe0ce531023bf63c0e518b07ee97cf0cac742a
parent 55e827af0fb94f6c2b9e76a7bfe7e98cf697dc7b
Author: Markus Teich <markus.teich@stusta.mhn.de>
Date:   Mon, 18 Jan 2016 16:49:15 +0100

error messages on grab failure

Diffstat:
slock.c | 30++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/slock.c b/slock.c @@ -230,7 +230,7 @@ lockscreen(Display *dpy, int screen) XSetWindowAttributes wa; Cursor invisible; - if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(Lock)))) + if (!running || dpy == NULL || screen < 0 || !(lock = malloc(sizeof(Lock)))) return NULL; lock->screen = screen; @@ -253,29 +253,31 @@ lockscreen(Display *dpy, int screen) XMapRaised(dpy, lock->win); if (rr) XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask); + + /* Try to grab mouse pointer *and* keyboard, else fail the lock */ for (len = 1000; len; len--) { if (XGrabPointer(dpy, lock->root, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask, GrabModeAsync, GrabModeAsync, None, invisible, CurrentTime) == GrabSuccess) break; usleep(1000); } - if (running && len) { + if (!len) { + fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", screen); + } else { for (len = 1000; len; len--) { - if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess) - break; + if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess) { + /* everything fine, we grabbed both inputs */ + XSelectInput(dpy, lock->root, SubstructureNotifyMask); + return lock; + } usleep(1000); } + fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", screen); } - - running &= (len > 0); - if (!running) { - unlockscreen(dpy, lock); - lock = NULL; - } else { - XSelectInput(dpy, lock->root, SubstructureNotifyMask); - } - - return lock; + /* grabbing one of the inputs failed */ + running = 0; + unlockscreen(dpy, lock); + return NULL; } static void