add the regretable timer feature

i3lock.1

@@ -18,6 +18,8 @@ i3lock \- improved screen locker
 .RB [\|\-v\|]
 .RB [\|\-n\|]
 .RB [\|\-b\|]
+.RB [\|\-r
+.IR timeout \|]
 .RB [\|\-i
 .IR image.png \|]
 .RB [\|\-c
@@ -42,6 +44,8 @@ i3lock forks, so you can combine it with an alias to suspend to RAM (run "i3lock
 .IP \[bu]
 You can specify either a background color or a PNG image which will be displayed while your screen is locked.
 .IP \[bu]
+You can cancel the lock by pressing any key within the first few seconds.
+.IP \[bu]
 You can specify whether i3lock should bell upon a wrong password.
 .IP \[bu]
 i3lock uses PAM and therefore is compatible with LDAP, etc.
@@ -62,6 +66,11 @@ Don't fork after starting.
 Enable beeping. Be sure to not do this when you are about to annoy other people,
 like when opening your laptop in a boring lecture.
 
+.TP
+.BI \-r\  timeout \fR,\ \fB\-\-regrettable= timeout
+Specify the regrettable timer in seconds. Within this time period, any key press
+will cancel the lock.
+
 .TP
 .B \-u, \-\-no-unlock-indicator
 Disable the unlock indicator. i3lock will by default show an unlock indicator

i3lock.c

@@ -68,7 +68,10 @@ bool debug_mode = false;
 bool unlock_indicator = true;
 char *modifier_string = NULL;
 static bool dont_fork = false;
+bool regrettable = true;
+int regrettable_timeout = 0;
 struct ev_loop *main_loop;
+static struct ev_timer *regrettable_timer;
 static struct ev_timer *clear_auth_wrong_timeout;
 static struct ev_timer *clear_indicator_timeout;
 static struct ev_timer *discard_passwd_timeout;
@@ -221,6 +224,18 @@ static void finish_input(void) {
     input_done();
 }
 
+/*
+ * Turn regrettable status off (called beyond regrettable_timeout)
+ *
+ */
+static void regrettable_off(EV_P_ ev_timer *w, int revents) {
+    regrettable = false;
+
+    /* Now free this timeout. */
+    STOP_TIMER(w);
+    DEBUG("regrettable off\n");
+}
+
 /*
  * Resets auth_state to STATE_AUTH_IDLE 2 seconds after an unsuccessful
  * authentication event.
@@ -387,6 +402,12 @@ static void handle_key_press(xcb_key_press_event_t *event) {
     bool ctrl;
     bool composed = false;
 
+    /* if a key is pressed within regrettable_timeout, then unlock */
+    if (regrettable) {
+        ev_break(EV_DEFAULT, EVBREAK_ALL);
+        return;
+    }
+
     ksym = xkb_state_key_get_one_sym(xkb_state, event->detail);
     ctrl = xkb_state_mod_name_is_active(xkb_state, XKB_MOD_NAME_CTRL, XKB_STATE_MODS_DEPRESSED);
 
@@ -822,6 +843,7 @@ int main(int argc, char *argv[]) {
         {"version", no_argument, NULL, 'v'},
         {"nofork", no_argument, NULL, 'n'},
         {"beep", no_argument, NULL, 'b'},
+        {"regrettable", required_argument, NULL, 'r'},
         {"dpms", no_argument, NULL, 'd'},
         {"color", required_argument, NULL, 'c'},
         {"pointer", required_argument, NULL, 'p'},
@@ -840,7 +862,7 @@ int main(int argc, char *argv[]) {
     if ((username = pw->pw_name) == NULL)
         errx(EXIT_FAILURE, "pw->pw_name is NULL.\n");
 
-    char *optstring = "hvnbdc:p:ui:teI:f";
+    char *optstring = "hvnbr:dc:p:ui:teI:f";
     while ((o = getopt_long(argc, argv, optstring, longopts, &longoptind)) != -1) {
         switch (o) {
             case 'v':
@@ -851,6 +873,9 @@ int main(int argc, char *argv[]) {
             case 'b':
                 beep = true;
                 break;
+            case 'r':
+                regrettable_timeout = atoi(optarg);
+                break;
             case 'd':
                 fprintf(stderr, "DPMS support has been removed from i3lock. Please see the manpage i3lock(1).\n");
                 break;
@@ -899,7 +924,7 @@ int main(int argc, char *argv[]) {
                 show_failed_attempts = true;
                 break;
             default:
-                errx(EXIT_FAILURE, "Syntax: i3lock [-v] [-n] [-b] [-d] [-c color] [-u] [-p win|default]"
+                errx(EXIT_FAILURE, "Syntax: i3lock [-v] [-n] [-b] [-r timeout] [-d] [-c color] [-u] [-p win|default]"
                                    " [-i image.png] [-t] [-e] [-I timeout] [-f]");
         }
     }
@@ -1064,6 +1089,10 @@ int main(int argc, char *argv[]) {
     if (main_loop == NULL)
         errx(EXIT_FAILURE, "Could not initialize libev. Bad LIBEV_FLAGS?\n");
 
+    /* start the timer to expire the regrettable state */
+    if (regrettable_timeout > 0)
+        START_TIMER(regrettable_timer, TSTAMP_N_SECS(regrettable_timeout), regrettable_off);
+
     /* Explicitly call the screen redraw in case "locking…" message was displayed */
     auth_state = STATE_AUTH_IDLE;
     redraw_screen();