https://github.com/Alexays/Waybar/issues/1315. Option to display week number on calendar

include/modules/clock.hpp

@@ -35,6 +35,8 @@ class Clock : public ALabel {
   auto weekdays_header(const date::weekday& first_dow, std::ostream& os) -> void;
   auto first_day_of_week() -> date::weekday;
   const date::time_zone* current_timezone();
+  auto print_iso_weeknum(std::ostream& os,
+                         int weeknum) -> void;
   bool is_timezone_fixed();
   auto timezones_text(std::chrono::system_clock::time_point *now) -> std::string;
 };

src/modules/clock.cpp

@@ -1,4 +1,5 @@
 #include "modules/clock.hpp"
+#include <iomanip>
 
 #include <spdlog/spdlog.h>
 #if FMT_VERSION < 60000
@@ -167,12 +168,32 @@ auto waybar::modules::Clock::calendar_text(const waybar_time& wtime) -> std::str
 
   std::stringstream os;
   const auto        first_dow = first_day_of_week();
+  int ws{0};    // weeks-pos: side(1 - left, 2 - right)
+  int wn{0};    // weeknumber
+  if (config_["week-pos"].isString()) {
+    if (config_["week-pos"].asString() == "left") {
+      ws = 1;
+      // Add paddings before the header
+      os << std::string(4, ' ');
+    } else if (config_["week-pos"].asString() == "right") {
+      ws = 2;
+    }
+  }
+  if (ws > 0){
+    wn = (date::sys_days{date::year_month_day{ym / 1}} - date::sys_days{date::year_month_day{ymd.year() / 1 / 1}}).count() / 7 + 1;
+  }
+
   weekdays_header(first_dow, os);
 
   // First week prefixed with spaces if needed.
   auto wd = date::weekday(ym / 1);
   auto empty_days = (wd - first_dow).count();
   if (empty_days > 0) {
+    if (ws == 1) {
+      print_iso_weeknum(os, wn);
+      os << ' ';
+      ++wn;
+    }
     os << std::string(empty_days * 3 - 1, ' ');
   }
   auto last_day = (ym / date::literals::last).day();
@@ -180,7 +201,19 @@ auto waybar::modules::Clock::calendar_text(const waybar_time& wtime) -> std::str
     if (wd != first_dow) {
       os << ' ';
     } else if (unsigned(d) != 1) {
+      if (ws == 2) {
+        os << ' ';
+        print_iso_weeknum(os, wn);
+        ++wn;
+      }
+
       os << '\n';
+
+      if (ws == 1) {
+        print_iso_weeknum(os, wn);
+        os << ' ';
+        ++wn;
+      }
     }
     if (d == curr_day) {
       if (config_["today-format"].isString()) {
@@ -192,6 +225,12 @@ auto waybar::modules::Clock::calendar_text(const waybar_time& wtime) -> std::str
     } else {
       os << date::format("%e", d);
     }
+    /*Print weeks on the right when the endings with spaces*/
+    if (ws == 2 && d == last_day && wd.c_encoding() < 6) {
+      empty_days = 6 - wd.c_encoding();
+      os << std::string(empty_days * 3 + 1, ' ');
+      print_iso_weeknum(os, wn);
+    }
   }
 
   auto result = os.str();
@@ -239,6 +278,17 @@ auto waybar::modules::Clock::timezones_text(std::chrono::system_clock::time_poin
   return os.str();
 }
 
+auto waybar::modules::Clock::print_iso_weeknum(std::ostream& os,
+                                               int weeknum) -> void {
+  std::stringstream res;
+  res << 'W' << std::setfill('0') << std::setw(2) << weeknum;
+
+  if (config_["week-format"].isString()) {
+    auto week_format = config_["week-format"].asString();
+    os << fmt::format(week_format, res.str());
+  } else os << res.str();
+}
+
 #ifdef HAVE_LANGINFO_1STDAY
 template <auto fn>
 using deleter_from_fn = std::integral_constant<decltype(fn), fn>;