Yet another swaybar ipc implementation

.github/workflows/freebsd.yml

@@ -13,6 +13,7 @@ jobs:
     - name: Test in FreeBSD VM
       uses: vmactions/[email protected] # aka FreeBSD 13.0
       with:
+        mem: 2048
         usesh: true
         prepare: |
           export CPPFLAGS=-isystem/usr/local/include LDFLAGS=-L/usr/local/lib # sndio

include/bar.hpp

@@ -8,6 +8,9 @@
 #include <gtkmm/window.h>
 #include <json/json.h>
 
+#include <memory>
+#include <vector>
+
 #include "AModule.hpp"
 #include "xdg-output-unstable-v1-client-protocol.h"
 
@@ -36,6 +39,19 @@ struct bar_margins {
   int left = 0;
 };
 
+struct bar_mode {
+  bar_layer layer;
+  bool      exclusive;
+  bool      passthrough;
+  bool      visible;
+};
+
+#ifdef HAVE_SWAY
+namespace modules::sway {
+class BarIpcClient;
+}
+#endif  // HAVE_SWAY
+
 class BarSurface {
  protected:
   BarSurface() = default;
@@ -54,38 +70,55 @@ class BarSurface {
 
 class Bar {
  public:
+  using bar_mode_map = std::map<std::string_view, struct bar_mode>;
+  static const bar_mode_map     PRESET_MODES;
+  static const std::string_view MODE_DEFAULT;
+  static const std::string_view MODE_INVISIBLE;
+
   Bar(struct waybar_output *w_output, const Json::Value &);
   Bar(const Bar &) = delete;
-  ~Bar() = default;
+  ~Bar();
 
+  void setMode(const std::string_view &);
   void setVisible(bool visible);
   void toggle();
   void handleSignal(int);
 
   struct waybar_output *output;
   Json::Value           config;
-  struct wl_surface *   surface;
-  bool                  exclusive = true;
+  struct wl_surface    *surface;
   bool                  visible = true;
   bool                  vertical = false;
   Gtk::Window           window;
 
+#ifdef HAVE_SWAY
+  std::string bar_id;
+#endif
+
  private:
   void onMap(GdkEventAny *);
   auto setupWidgets() -> void;
   void getModules(const Factory &, const std::string &, Gtk::Box*);
   void setupAltFormatKeyForModule(const std::string &module_name);
   void setupAltFormatKeyForModuleList(const char *module_list_name);
+  void setMode(const bar_mode &);
+
+  /* Copy initial set of modes to allow customization */
+  bar_mode_map configured_modes = PRESET_MODES;
+  std::string  last_mode_{MODE_DEFAULT};
 
   std::unique_ptr<BarSurface>                   surface_impl_;
-  bar_layer                                     layer_;
   Gtk::Box                                      left_;
   Gtk::Box                                      center_;
   Gtk::Box                                      right_;
   Gtk::Box                                      box_;
   std::vector<std::unique_ptr<waybar::AModule>> modules_left_;
   std::vector<std::unique_ptr<waybar::AModule>> modules_center_;
   std::vector<std::unique_ptr<waybar::AModule>> modules_right_;
+#ifdef HAVE_SWAY
+  using BarIpcClient = modules::sway::BarIpcClient;
+  std::unique_ptr<BarIpcClient> _ipc_client;
+#endif
   std::vector<std::unique_ptr<waybar::AModule>> modules_all_;
 };
 

include/client.hpp

@@ -29,6 +29,7 @@ class Client {
   struct zwp_idle_inhibit_manager_v1 *idle_inhibit_manager = nullptr;
   std::vector<std::unique_ptr<Bar>>   bars;
   Config                              config;
+  std::string                         bar_id;
 
  private:
   Client() = default;

include/modules/sway/bar.hpp

@@ -0,0 +1,49 @@
+#pragma once
+#include <string>
+
+#include "modules/sway/ipc/client.hpp"
+#include "util/SafeSignal.hpp"
+#include "util/json.hpp"
+
+namespace waybar {
+
+class Bar;
+
+namespace modules::sway {
+
+/*
+ * Supported subset of i3/sway IPC barconfig object
+ */
+struct swaybar_config {
+  std::string id;
+  std::string mode;
+  std::string hidden_state;
+};
+
+/**
+ * swaybar IPC client
+ */
+class BarIpcClient {
+ public:
+  BarIpcClient(waybar::Bar& bar);
+
+ private:
+  void onInitialConfig(const struct Ipc::ipc_response& res);
+  void onIpcEvent(const struct Ipc::ipc_response&);
+  void onConfigUpdate(const swaybar_config& config);
+  void onVisibilityUpdate(bool visible_by_modifier);
+  void update();
+
+  Bar&             bar_;
+  util::JsonParser parser_;
+  Ipc              ipc_;
+
+  swaybar_config bar_config_;
+  bool           visible_by_modifier_ = false;
+
+  SafeSignal<bool>           signal_visible_;
+  SafeSignal<swaybar_config> signal_config_;
+};
+
+}  // namespace modules::sway
+}  // namespace waybar

include/util/SafeSignal.hpp

@@ -0,0 +1,75 @@
+#pragma once
+
+#include <glibmm/dispatcher.h>
+#include <sigc++/signal.h>
+
+#include <functional>
+#include <mutex>
+#include <queue>
+#include <thread>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+
+namespace waybar {
+
+/**
+ * Thread-safe signal wrapper.
+ * Uses Glib::Dispatcher to pass events to another thread and locked queue to pass the arguments.
+ */
+template <typename... Args>
+struct SafeSignal : sigc::signal<void(std::decay_t<Args>...)> {
+ public:
+  SafeSignal() { dp_.connect(sigc::mem_fun(*this, &SafeSignal::handle_event)); }
+
+  template <typename... EmitArgs>
+  void emit(EmitArgs&&... args) {
+    if (main_tid_ == std::this_thread::get_id()) {
+      /*
+       * Bypass the queue if the method is called the main thread.
+       * Ensures that events emitted from the main thread are processed synchronously and saves a
+       * few CPU cycles on locking/queuing.
+       * As a downside, this makes main thread events prioritized over the other threads and
+       * disrupts chronological order.
+       */
+      signal_t::emit(std::forward<EmitArgs>(args)...);
+    } else {
+      {
+        std::unique_lock lock(mutex_);
+        queue_.emplace(std::forward<EmitArgs>(args)...);
+      }
+      dp_.emit();
+    }
+  }
+
+  template <typename... EmitArgs>
+  inline void operator()(EmitArgs&&... args) {
+    emit(std::forward<EmitArgs>(args)...);
+  }
+
+ protected:
+  using signal_t = sigc::signal<void(std::decay_t<Args>...)>;
+  using slot_t = decltype(std::declval<signal_t>().make_slot());
+  using arg_tuple_t = std::tuple<std::decay_t<Args>...>;
+  // ensure that unwrapped methods are not accessible
+  using signal_t::emit_reverse;
+  using signal_t::make_slot;
+
+  void handle_event() {
+    for (std::unique_lock lock(mutex_); !queue_.empty(); lock.lock()) {
+      auto args = queue_.front();
+      queue_.pop();
+      lock.unlock();
+      std::apply(cached_fn_, args);
+    }
+  }
+
+  Glib::Dispatcher        dp_;
+  std::mutex              mutex_;
+  std::queue<arg_tuple_t> queue_;
+  const std::thread::id   main_tid_ = std::this_thread::get_id();
+  // cache functor for signal emission to avoid recreating it on each event
+  const slot_t cached_fn_ = make_slot();
+};
+
+}  // namespace waybar

man/waybar.5.scd.in

@@ -72,14 +72,19 @@ Also a minimal example configuration can be found on the at the bottom of this m
 	typeof: string ++
 	Optional name added as a CSS class, for styling multiple waybars.
 
+*mode* ++
+	typeof: string ++
+	Selects one of the preconfigured display modes. This is an equivalent of the sway-bar(5) *mode* command and supports the same values: *dock*, *hide*, *invisible*, *overlay*. ++
+	Note: *hide* and *invisible* modes may be not as useful without Sway IPC.
+
 *exclusive* ++
 	typeof: bool ++
-	default: *true* unless the layer is set to *overlay* ++
+	default: *true* ++
 	Option to request an exclusive zone from the compositor. Disable this to allow drawing application windows underneath or on top of the bar.
 
 *passthrough* ++
 	typeof: bool ++
-	default: *false* unless the layer is set to *overlay* ++
+	default: *false* ++
 	Option to pass any pointer events to the window under the bar.
 	Intended to be used with either *top* or *overlay* layers and without exclusive zone.
 
@@ -89,6 +94,16 @@ Also a minimal example configuration can be found on the at the bottom of this m
 	Option to disable the use of gtk-layer-shell for popups.
 	Only functional if compiled with gtk-layer-shell support.
 
+*ipc* ++
+	typeof: bool ++
+	default: false ++
+	Option to subscribe to the Sway IPC bar configuration and visibility events and control waybar with *swaymsg bar* commands. ++
+	Requires *bar_id* value from sway configuration to be either passed with the *-b* commandline argument or specified with the *id* option.
+
+*id* ++
+	typeof: string ++
+	*bar_id* for the Sway IPC. Use this if you need to override the value passed with the *-b bar_id* commandline argument for the specific bar instance.
+
 *include* ++
 	typeof: string|array ++
 	Paths to additional configuration files.

meson.build

@@ -178,6 +178,7 @@ endif
 add_project_arguments('-DHAVE_SWAY', language: 'cpp')
 src_files += [
     'src/modules/sway/ipc/client.cpp',
+    'src/modules/sway/bar.cpp',
     'src/modules/sway/mode.cpp',
     'src/modules/sway/language.cpp',
     'src/modules/sway/window.cpp',