Add module sway/hide for swaybar integration

This allows auto-showing the bar when the modifier is pressed

Closes Alexays#255

Setup instructions:
- Set the `mode` of the bar to "hide" in sway configuration file
- Set the `layer` of the bar to "overlay" in Waybar configuration file
- Add "sway/hide" into `modules-left` in Waybar configuration file

include/factory.hpp

@@ -6,6 +6,7 @@
 #include "modules/sway/mode.hpp"
 #include "modules/sway/window.hpp"
 #include "modules/sway/workspaces.hpp"
+#include "modules/sway/hide.hpp"
 #endif
 #ifdef HAVE_WLR
 #include "modules/wlr/taskbar.hpp"

include/modules/sway/hide.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <fmt/format.h>
+#include <tuple>
+#include "ALabel.hpp"
+#include "bar.hpp"
+#include "client.hpp"
+#include "modules/sway/ipc/client.hpp"
+#include "util/json.hpp"
+#include "util/sleeper_thread.hpp"
+
+namespace waybar::modules::sway {
+
+class Hide : public ALabel, public sigc::trackable {
+ public:
+  Hide(const std::string&, const waybar::Bar&, const Json::Value&);
+  ~Hide() = default;
+  auto update() -> void;
+
+ private:
+  void onEvent(const struct Ipc::ipc_response&);
+  void worker();
+
+  const Bar&       bar_;
+  std::string      window_;
+  int              windowId_;
+  util::JsonParser parser_;
+
+  util::SleeperThread thread_;
+  Ipc                 ipc_;
+};
+
+}  // namespace waybar::modules::sway

meson.build

@@ -158,7 +158,8 @@ src_files += [
     'src/modules/sway/ipc/client.cpp',
     'src/modules/sway/mode.cpp',
     'src/modules/sway/window.cpp',
-    'src/modules/sway/workspaces.cpp'
+    'src/modules/sway/workspaces.cpp',
+    'src/modules/sway/hide.cpp',
 ]
 
 if true

src/factory.cpp

@@ -22,6 +22,9 @@ waybar::AModule* waybar::Factory::makeModule(const std::string& name) const {
     if (ref == "sway/window") {
       return new waybar::modules::sway::Window(id, bar_, config_[name]);
     }
+    if (ref == "sway/hide") {
+      return new waybar::modules::sway::Hide(id, bar_, config_[name]);
+    }
 #endif
 #ifdef HAVE_WLR
     if (ref == "wlr/taskbar") {

src/modules/sway/hide.cpp

@@ -0,0 +1,38 @@
+#include "modules/sway/hide.hpp"
+#include <spdlog/spdlog.h>
+
+namespace waybar::modules::sway {
+
+Hide::Hide(const std::string& id, const Bar& bar, const Json::Value& config)
+    : ALabel(config, "hide", id, "{}", 0, true), bar_(bar), windowId_(-1) {
+  ipc_.subscribe(R"(["bar_state_update"])");
+  ipc_.signal_event.connect(sigc::mem_fun(*this, &Hide::onEvent));
+  bar_.window.get_style_context()->add_class("hidden");
+  // Launch worker
+  worker();
+}
+
+void Hide::onEvent(const struct Ipc::ipc_response& res) {
+
+  auto payload = parser_.parse(res.payload);
+  if (payload.isMember("visible_by_modifier")) {
+    if (payload["visible_by_modifier"].asBool())
+      bar_.window.get_style_context()->remove_class("hidden");
+    else
+      bar_.window.get_style_context()->add_class("hidden");
+  }
+}
+
+void Hide::worker() {
+  thread_ = [this] {
+    try {
+      ipc_.handleEvent();
+    } catch (const std::exception& e) {
+      spdlog::error("Hide: {}", e.what());
+    }
+  };
+}
+
+auto Hide::update() -> void {
+}
+}  // namespace waybar::modules::sway