Add support for counting to a specific calendar time (absolute time)

5 files changed, 150 insertions, 8 deletions

diff --git a/extras.c b/extras.c
index 37819f5..bde4172 100644
--- a/extras.c
+++ b/extras.c
@@ -132,6 +132,61 @@ static void i3lock_draw_led(cairo_t *cr,
 }
 
 
+static char * i3lock_replace_str(char *to,
+                                 const char *from,
+                                 const char *old_substr,
+                                 const char *new_substr,
+                                 size_t max_length) {
+
+    int offset; /* the offset in the tmp_str after each match */
+
+    /* the offset in from needed to pick up the right side after a match */
+    int from_offset;
+
+    int from_len = strlen(from);
+    int new_substr_len = strlen(new_substr);
+    int old_substr_len = strlen(old_substr);
+    int len_diff = old_substr_len - new_substr_len;
+    size_t free_space = max_length - 1;
+    char tmp_str[max_length];
+    char *tmp_str_ptr;
+
+    /* reserve the last byte for '\0' in case of clipping */
+    strncpy(tmp_str, from, free_space);
+
+    for (int i = 0; ; ++i) {
+        tmp_str_ptr = strstr(tmp_str, old_substr);
+        if (tmp_str_ptr == NULL) {
+            /* no more instances of old_substr */
+            break;
+        }
+
+        offset = tmp_str_ptr - tmp_str;
+        free_space -= offset;
+        if (free_space <= new_substr_len) {
+            strncpy(tmp_str_ptr, new_substr, free_space);
+            break;
+        }
+        strncpy(tmp_str_ptr, new_substr, new_substr_len);
+        free_space -= new_substr_len;
+        /* tmp_str offset -> from_offset mapping */
+        from_offset = offset + old_substr_len + i * len_diff;
+        if (free_space <= from_len - from_offset) {
+            strncpy(tmp_str_ptr + new_substr_len, from + from_offset, free_space);
+            break;
+        }
+        strncpy(tmp_str_ptr + new_substr_len, from + from_offset, from_len - from_offset + 1);
+
+    }
+
+    strncpy(to, tmp_str, max_length - 1);
+    *(to + (max_length - 1)) = '\0';
+
+    return to;
+
+}
+
+
 void i3lock_draw_digital_clock(cairo_t *cr,
                                const i3lock_digital_clock_t *dc,
                                const uint32_t *resolution,
@@ -440,9 +495,56 @@ void i3lock_draw_led_clock(cairo_t *cr,
                             brokentime->tm_sec & 1,
                             lc);
         }
+
         return;
+
     }
 
 }
 
 
+char * i3lock_format_elapsed_time(char *to,
+                                  const char *template,
+                                  int max_size,
+                                  int seconds) {
+
+    char tmp_str[max_size];
+    char int_str[32]; /* more than enough for int */
+    int days = seconds / 86400;
+    int hours = (seconds - days * 86400) / 3600;
+    int minutes = (seconds - days * 86400 - hours * 3600) / 60;
+    int rest_seconds = seconds - days * 86400 - hours * 3600 - minutes * 60;
+
+    strncpy(tmp_str, template, max_size);
+    if (strlen(template) >= max_size) {
+        /* do a proper clipping */
+        *(tmp_str + (max_size - 1)) = '\0';
+    }
+
+    /* days */
+    snprintf(int_str, 32, "%d", days);
+    i3lock_replace_str(to, tmp_str, "%d", int_str, max_size);
+    strcpy(tmp_str, to);
+
+    /* hours */
+    snprintf(int_str, 32, "%d", hours);
+    i3lock_replace_str(to, tmp_str, "%h", int_str, max_size);
+    strcpy(tmp_str, to);
+
+    /* minutes */
+    snprintf(int_str, 32, "%d", minutes);
+    i3lock_replace_str(to, tmp_str, "%m", int_str, max_size);
+    strcpy(tmp_str, to);
+
+    /* rest. seconds */
+    snprintf(int_str, 32, "%d", rest_seconds);
+    i3lock_replace_str(to, tmp_str, "%s", int_str, max_size);
+    strcpy(tmp_str, to);
+
+    /* seconds */
+    snprintf(int_str, 32, "%d", seconds);
+    i3lock_replace_str(to, tmp_str, "%S", int_str, max_size);
+
+    return to;
+
+}
diff --git a/extras.h b/extras.h
index d4a353e..c78ffff 100644
--- a/extras.h
+++ b/extras.h
@@ -88,7 +88,6 @@ void i3lock_draw_elapsed_time(cairo_t *cr,
                               const uint32_t *resolution,
                               const time_t *now);
 
-
 void i3lock_draw_led_clock(cairo_t *cr,
                            const i3lock_led_clock_t *lc,
                            const uint32_t *resolution,
@@ -99,4 +98,9 @@ void i3lock_draw_string(cairo_t *cr,
                         const char *formatted_string,
                         const i3lock_elapsed_time_t *et,
                         const uint32_t *resolution);
+
+char * i3lock_format_elapsed_time(char *to,
+                                  const char *template,
+                                  int max_size,
+                                  int seconds);
 #endif
diff --git a/i3lock-extended.1 b/i3lock-extended.1
index b0f51a7..34ea2a3 100644
--- a/i3lock-extended.1
+++ b/i3lock-extended.1
@@ -8,7 +8,7 @@
 .fi
 ..
 
-.TH i3lock\-extended 1 "MARCH 2020" Linux "User Manuals"
+.TH i3lock\-extended 1 "DECEMBER 2020" Linux "User Manuals"
 
 .SH NAME
 i3lock\-extended \- improved screen locker
@@ -18,6 +18,8 @@ i3lock\-extended \- improved screen locker
 .RB [\|\-B
 .IR color \|]
 .RB [\|\-b\|]
+.RB [\|\-C
+.IR seconds \|]
 .RB [\|\-c
 .IR color \|]
 .RB [\|\-D\|]
@@ -94,6 +96,8 @@ Digital clock
 Elapsed time since activation
 .IP \[bu]
 Display-text
+.IP \[bu]
+Count to a specific calendar time (absolute time)
 
 .SH OPTIONS
 .TP
@@ -112,6 +116,14 @@ Turn the screen into the given color instead of white.
 Color must be given in 3-byte. Default: ffffff (white).
 
 .TP
+.BI \-C\  seconds \fR,\ \fB\-\-count\-until= seconds
+Sets the seconds since the Epoch to count to. date +%s -d ... can be used to
+get the Epoch time. Then the following macros will become available for the
+display-text parameter: %d - days remaining until the time set,
+%h - hours remaining, %m - minutes remaining, %s - seconds remaining,
+%S - total amount of seconds remaining. Default: 0 (count until is off).
+
+.TP
 .B \-D, \-\-digital\-clock
 Display digital clock.
 
diff --git a/i3lock.c b/i3lock.c
index f7c5bdc..d492e5a 100644
--- a/i3lock.c
+++ b/i3lock.c
@@ -84,6 +84,7 @@ static void input_done(void);
 bool digital_clock = false;
 bool led_clock = false;
 bool elapsed_time = false;
+int count_until = 0; /* count seconds until */
 int refresh_rate = 2; /* 2 frames per second */
 i3lock_digital_clock_t i3lock_digital_clock = {28,
                                                "000000",
@@ -1083,6 +1084,7 @@ int main(int argc, char *argv[]) {
         {"dpms", no_argument, NULL, 'd'},
         {"color", required_argument, NULL, 'c'},
 #ifdef EXTRAS
+        {"count-until", no_argument, NULL, 'C'},
         {"digital-clock", no_argument, NULL, 'D'},
         {"digital-clock-color", required_argument, NULL, 'G'},
         {"digital-clock-template", required_argument, NULL, 'T'},
@@ -1122,7 +1124,7 @@ int main(int argc, char *argv[]) {
         errx(EXIT_FAILURE, "i3lock is a program for X11 and does not work on Wayland. Try https://github.com/swaywm/swaylock instead");
 
 #ifdef EXTRAS
-    char *optstring = "hvnbDdELc:B:G:F:J:O:R:r:S:T:W:X:x:Y:y:Z:p:ui:teI:f";
+    char *optstring = "hvnbDdELC:c:B:G:F:J:O:R:r:S:T:W:X:x:Y:y:Z:p:ui:teI:f";
 #else
     char *optstring = "hvnbdc:p:ui:teI:f";
 #endif
@@ -1156,6 +1158,12 @@ int main(int argc, char *argv[]) {
                 break;
             }
 #ifdef EXTRAS
+            case 'C': /* count until */
+                if (optarg != NULL && atoi(optarg) > 0) /* not nice with -1 and 0 */
+                    count_until = atoi(optarg);
+                DEBUG("count_until: %d\n",
+                      count_until);
+                break;
             case 'D':
                 digital_clock = true;
                 break;
diff --git a/unlock_indicator.c b/unlock_indicator.c
index 73320cb..8f69972 100644
--- a/unlock_indicator.c
+++ b/unlock_indicator.c
@@ -58,12 +58,15 @@ extern bool debug_mode;
 
 #ifdef EXTRAS
 /* timekeeping */
+#define I3LOCK_COUNT_UNTIL_BUFFER 128
+char count_until_str[I3LOCK_COUNT_UNTIL_BUFFER];
 time_t now;
 struct tm *brokentime;
 /* enable the digital clock */
 extern bool digital_clock;
 extern bool led_clock;
 extern bool elapsed_time;
+extern int count_until;
 extern i3lock_digital_clock_t i3lock_digital_clock;
 extern i3lock_elapsed_time_t i3lock_elapsed_time;
 extern i3lock_led_clock_t i3lock_led_clock;
@@ -359,17 +362,30 @@ void draw_image(xcb_pixmap_t bg_pixmap, uint32_t *resolution) {
                                   resolution,
                                   brokentime);
     }
-    /* elapsed time or display text */
+    /* elapsed time or counter with display text or only display text */
     if (elapsed_time) {
         i3lock_draw_elapsed_time(xcb_ctx,
                                  &i3lock_elapsed_time,
                                  resolution,
                                  &now);
     } else if (display_text != NULL) {
-        i3lock_draw_string(xcb_ctx,
-                           display_text,
-                           &i3lock_elapsed_time,
-                           resolution);
+        if (count_until) {
+            if (i3lock_format_elapsed_time(
+                    count_until_str,
+                    display_text,
+                    I3LOCK_COUNT_UNTIL_BUFFER,
+                    count_until - (int) now) != NULL) {
+                i3lock_draw_string(xcb_ctx,
+                                   count_until_str,
+                                   &i3lock_elapsed_time,
+                                   resolution);
+            }
+        } else {
+            i3lock_draw_string(xcb_ctx,
+                               display_text,
+                               &i3lock_elapsed_time,
+                               resolution);
+        }
     }
 #endif
     if (xr_screens > 0) {