From 9dfe0ce531023bf63c0e518b07ee97cf0cac742a Mon Sep 17 00:00:00 2001
From: Markus Teich <markus.teich@stusta.mhn.de>
Date: Mon, 18 Jan 2016 16:49:15 +0100
Subject: [PATCH] error messages on grab failure
---
slock.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/slock.c b/slock.c
index d2c3729..df2d3c6 100644
--- 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