Idempotent bar show/hide via configurable user kill signals

include/bar.hpp

@@ -14,6 +14,7 @@
 
 #include "AModule.hpp"
 #include "group.hpp"
+#include "util/kill_signal.hpp"
 #include "xdg-output-unstable-v1-client-protocol.h"
 
 namespace waybar {
@@ -68,7 +69,11 @@ class Bar : public sigc::trackable {
   void setMode(const std::string &mode);
   void setVisible(bool value);
   void toggle();
+  void show();
+  void hide();
   void handleSignal(int);
+  util::KillSignalAction getOnSigusr1Action();
+  util::KillSignalAction getOnSigusr2Action();
 
   struct waybar_output *output;
   Json::Value config;
@@ -118,6 +123,9 @@ class Bar : public sigc::trackable {
   std::unique_ptr<BarIpcClient> _ipc_client;
 #endif
   std::vector<std::shared_ptr<waybar::AModule>> modules_all_;
+
+  waybar::util::KillSignalAction onSigusr1;
+  waybar::util::KillSignalAction onSigusr2;
 };
 
 }  // namespace waybar

include/util/kill_signal.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <json/value.h>
+
+#include <cstdint>
+
+namespace waybar::util {
+
+enum class KillSignalAction : std::uint8_t {
+  TOGGLE,
+  RELOAD,
+  SHOW,
+  HIDE,
+  NOOP,
+};
+const std::map<std::string, KillSignalAction> userKillSignalActions = {
+    {"TOGGLE", KillSignalAction::TOGGLE},
+    {"RELOAD", KillSignalAction::RELOAD},
+    {"SHOW", KillSignalAction::SHOW},
+    {"HIDE", KillSignalAction::HIDE},
+    {"NOOP", KillSignalAction::NOOP}};
+
+const KillSignalAction SIGNALACTION_DEFAULT_SIGUSR1 = KillSignalAction::TOGGLE;
+const KillSignalAction SIGNALACTION_DEFAULT_SIGUSR2 = KillSignalAction::RELOAD;
+
+};  // namespace waybar::util

src/bar.cpp

@@ -8,6 +8,8 @@
 #include "client.hpp"
 #include "factory.hpp"
 #include "group.hpp"
+#include "util/enum.hpp"
+#include "util/kill_signal.hpp"
 
 #ifdef HAVE_SWAY
 #include "modules/sway/bar.hpp"
@@ -277,6 +279,30 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
   }
 #endif
 
+  waybar::util::EnumParser<util::KillSignalAction> m_signalActionEnumParser;
+  const auto& configSigusr1 = config["on_sigusr1"];
+  if (configSigusr1.isString()) {
+    auto strSigusr1 = configSigusr1.asString();
+    try {
+      onSigusr1 =
+          m_signalActionEnumParser.parseStringToEnum(strSigusr1, util::userKillSignalActions);
+    } catch (const std::invalid_argument& e) {
+      onSigusr1 = util::SIGNALACTION_DEFAULT_SIGUSR1;
+      spdlog::warn("Invalid string representation for on_sigusr1. Falling back to default mode.");
+    }
+  }
+  const auto& configSigusr2 = config["on_sigusr2"];
+  if (configSigusr2.isString()) {
+    auto strSigusr2 = configSigusr2.asString();
+    try {
+      onSigusr2 =
+          m_signalActionEnumParser.parseStringToEnum(strSigusr2, util::userKillSignalActions);
+    } catch (const std::invalid_argument& e) {
+      onSigusr2 = util::SIGNALACTION_DEFAULT_SIGUSR2;
+      spdlog::warn("Invalid string representation for on_sigusr2. Falling back to default mode.");
+    }
+  }
+
   setupWidgets();
   window.show_all();
 
@@ -422,6 +448,8 @@ void waybar::Bar::setVisible(bool value) {
 }
 
 void waybar::Bar::toggle() { setVisible(!visible); }
+void waybar::Bar::show() { setVisible(true); }
+void waybar::Bar::hide() { setVisible(false); }
 
 // Converting string to button code rn as to avoid doing it later
 void waybar::Bar::setupAltFormatKeyForModule(const std::string& module_name) {
@@ -479,6 +507,9 @@ void waybar::Bar::handleSignal(int signal) {
   }
 }
 
+waybar::util::KillSignalAction waybar::Bar::getOnSigusr1Action() { return this->onSigusr1; }
+waybar::util::KillSignalAction waybar::Bar::getOnSigusr2Action() { return this->onSigusr2; }
+
 void waybar::Bar::getModules(const Factory& factory, const std::string& pos,
                              waybar::Group* group = nullptr) {
   auto module_list = group != nullptr ? config[pos]["modules"] : config[pos];

src/main.cpp

@@ -7,8 +7,10 @@
 #include <list>
 #include <mutex>
 
+#include "bar.hpp"
 #include "client.hpp"
 #include "util/SafeSignal.hpp"
+#include "util/backend_common.hpp"
 
 std::mutex reap_mtx;
 std::list<pid_t> reap;
@@ -71,6 +73,45 @@ static void catchSignals(waybar::SafeSignal<int>& signal_handler) {
   }
 }
 
+waybar::util::KillSignalAction getActionForBar(waybar::Bar* bar, int signal) {
+  switch (signal) {
+    case SIGUSR1:
+      return bar->getOnSigusr1Action();
+    case SIGUSR2:
+      return bar->getOnSigusr2Action();
+    default:
+      return waybar::util::KillSignalAction::NOOP;
+  }
+}
+
+void handleUserSignal(int signal, bool& reload) {
+  int i = 0;
+  for (auto& bar : waybar::Client::inst()->bars) {
+    switch (getActionForBar(bar.get(), signal)) {
+      case waybar::util::KillSignalAction::HIDE:
+        spdlog::debug("Visibility 'hide' for bar ", i);
+        bar->hide();
+        break;
+      case waybar::util::KillSignalAction::SHOW:
+        spdlog::debug("Visibility 'show' for bar ", i);
+        bar->show();
+        break;
+      case waybar::util::KillSignalAction::TOGGLE:
+        spdlog::debug("Visibility 'toggle' for bar ", i);
+        bar->toggle();
+        break;
+      case waybar::util::KillSignalAction::RELOAD:
+        spdlog::info("Reloading...");
+        reload = true;
+        waybar::Client::inst()->reset();
+        return;
+      case waybar::util::KillSignalAction::NOOP:
+        break;
+    }
+    i++;
+  }
+}
+
 // Must be called on the main thread.
 //
 // If this signal should restart or close the bar, this function will write
@@ -80,21 +121,15 @@ static void handleSignalMainThread(int signum, bool& reload) {
     for (auto& bar : waybar::Client::inst()->bars) {
       bar->handleSignal(signum);
     }
-
     return;
   }
 
   switch (signum) {
     case SIGUSR1:
-      spdlog::debug("Visibility toggled");
-      for (auto& bar : waybar::Client::inst()->bars) {
-        bar->toggle();
-      }
+      handleUserSignal(SIGUSR1, reload);
       break;
     case SIGUSR2:
-      spdlog::info("Reloading...");
-      reload = true;
-      waybar::Client::inst()->reset();
+      handleUserSignal(SIGUSR2, reload);
       break;
     case SIGINT:
       spdlog::info("Quitting.");

src/util/enum.cpp

@@ -41,5 +41,6 @@ EnumType EnumParser<EnumType>::parseStringToEnum(const std::string& str,
 // Explicit instantiations for specific EnumType types you intend to use
 // Add explicit instantiations for all relevant EnumType types
 template struct EnumParser<modules::hyprland::Workspaces::SortMethod>;
+template struct EnumParser<util::KillSignalAction>;
 
 }  // namespace waybar::util