Delay to turn off the screen after wrong passwd

Also add flag for number of seconds to wait for it.

When user cancels the password or enters a wrong one, i3lock will wait
for some time before putting the monitors back to sleep. By default it's
30 seconds, but this flag allows to control that.

i3lock.1

@@ -28,6 +28,7 @@ i3lock \- improved screen locker
 .IR pointer\|]
 .RB [\|\-u\|]
 .RB [\|\-e\|]
+.RB [\|\-I\|]
 
 .SH DESCRIPTION
 .B i3lock
@@ -68,6 +69,13 @@ Enable turning off your screen using DPMS. Note that, when you do not specify th
 option, DPMS will turn off your screen after 15 minutes of inactivity anyways (if
 you did not disable this in your X server).
 
+.TP
+.B \-I, \-\-inactivity-timeout
+Specifies the number of seconds i3lock will wait for another password before
+turning off the monitors, in case you entered a wrong password or canceled by
+pressing Escape. Only makes sense together with \-d. If omitted, the default is
+30 seconds.
+
 .TP
 .B \-u, \-\-no-unlock-indicator
 Disable the unlock indicator. i3lock will by default show an unlock indicator

i3lock.c

@@ -34,6 +34,7 @@
 #include "unlock_indicator.h"
 #include "xinerama.h"
 
+#define TSTAMP_N_SECS(n) (n * 1.0)
 #define START_TIMER(timer_obj, timeout, callback) \
     timer_obj = start_timer(timer_obj, timeout, callback)
 #define STOP_TIMER(timer_obj) \
@@ -44,6 +45,7 @@ typedef void (*ev_callback_t)(EV_P_ ev_timer *w, int revents);
 /* We need this for libxkbfile */
 static Display *display;
 char color[7] = "ffffff";
+int inactivity_timeout = 30;
 uint32_t last_resolution[2];
 xcb_window_t win;
 static xcb_cursor_t cursor;
@@ -59,6 +61,7 @@ static bool dont_fork = false;
 struct ev_loop *main_loop;
 static struct ev_timer *clear_pam_wrong_timeout;
 static struct ev_timer *clear_indicator_timeout;
+static struct ev_timer *dpms_timeout;
 extern unlock_state_t unlock_state;
 extern pam_state_t pam_state;
 
@@ -246,6 +249,13 @@ static void clear_input(void) {
     unlock_state = STATE_KEY_PRESSED;
 }
 
+static void turn_off_monitors_cb(EV_P_ ev_timer *w, int revents) {
+    if (input_position == 0)
+        turn_monitors_off();
+
+    STOP_TIMER(dpms_timeout);
+}
+
 static void input_done(void) {
     if (clear_pam_wrong_timeout) {
         ev_timer_stop(main_loop, clear_pam_wrong_timeout);
@@ -545,10 +555,11 @@ static void xcb_check_cb(EV_P_ ev_check *w, int revents) {
                 handle_key_release((xcb_key_release_event_t*)event);
 
                 /* If this was the backspace or escape key we are back at an
-                 * empty input, so turn off the screen if DPMS is enabled */
-                if (input_position == 0)
-                    turn_monitors_off();
-
+                 * empty input, so turn off the screen if DPMS is enabled, but
+                 * only do that after some timeout: maybe user mistyped and
+                 * will type again right away */
+                START_TIMER(dpms_timeout, TSTAMP_N_SECS(inactivity_timeout),
+                            turn_off_monitors_cb);
                 break;
 
             case XCB_VISIBILITY_NOTIFY:
@@ -660,13 +671,15 @@ int main(int argc, char *argv[]) {
         {"image", required_argument, NULL, 'i'},
         {"tiling", no_argument, NULL, 't'},
         {"ignore-empty-password", no_argument, NULL, 'e'},
+        {"inactivity-timeout", required_argument, NULL, 'I'},
         {NULL, no_argument, NULL, 0}
     };
 
     if ((username = getenv("USER")) == NULL)
         errx(EXIT_FAILURE, "USER environment variable not set, please set it.\n");
 
-    while ((o = getopt_long(argc, argv, "hvnbdc:p:ui:te", longopts, &optind)) != -1) {
+    char *optstring = "hvnbdc:p:ui:teI:";
+    while ((o = getopt_long(argc, argv, optstring, longopts, &optind)) != -1) {
         switch (o) {
         case 'v':
             errx(EXIT_SUCCESS, "version " VERSION " © 2010-2012 Michael Stapelberg");
@@ -679,6 +692,13 @@ int main(int argc, char *argv[]) {
         case 'd':
             dpms = true;
             break;
+        case 'I': {
+            int time = 0;
+            if (sscanf(optarg, "%d", &time) != 1 || time < 0)
+                errx(EXIT_FAILURE, "invalid timeout, it must be a positive integer\n");
+            inactivity_timeout = time;
+            break;
+        }
         case 'c': {
             char *arg = optarg;
 
@@ -718,7 +738,7 @@ int main(int argc, char *argv[]) {
             break;
         default:
             errx(EXIT_FAILURE, "Syntax: i3lock [-v] [-n] [-b] [-d] [-c color] [-u] [-p win|default]"
-            " [-i image.png] [-t] [-e]"
+            " [-i image.png] [-t] [-e] [-I]"
             );
         }
     }