add river/window module

include/factory.hpp

@@ -18,6 +18,7 @@
 #endif
 #ifdef HAVE_RIVER
 #include "modules/river/tags.hpp"
+#include "modules/river/window.hpp"
 #endif
 #if defined(__linux__) && !defined(NO_FILESYSTEM)
 #include "modules/battery.hpp"

include/modules/river/window.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <gtkmm/button.h>
+#include <wayland-client.h>
+
+#include "ALabel.hpp"
+#include "bar.hpp"
+#include "river-status-unstable-v1-client-protocol.h"
+#include "xdg-output-unstable-v1-client-protocol.h"
+
+namespace waybar::modules::river {
+
+class Window : public waybar::ALabel {
+ public:
+  Window(const std::string &, const waybar::Bar &, const Json::Value &);
+  ~Window();
+
+  // Handlers for wayland events
+  void handle_focused_view(const char *title);
+  void handle_focused_output(struct wl_output *output);
+  void handle_unfocused_output(struct wl_output *output);
+
+  struct zriver_status_manager_v1 *status_manager_;
+  struct wl_seat *seat_;
+
+ private:
+  const waybar::Bar &bar_;
+  struct wl_output *output_; // stores the output this module belongs to
+  struct wl_output *focused_output_; // stores the currently focused output
+  struct zriver_seat_status_v1 *seat_status_;
+};
+
+} /* namespace waybar::modules::river */

src/factory.cpp

@@ -45,6 +45,9 @@ waybar::AModule* waybar::Factory::makeModule(const std::string& name) const {
     if (ref == "river/tags") {
       return new waybar::modules::river::Tags(id, bar_, config_[name]);
     }
+    if (ref == "river/window") {
+      return new waybar::modules::river::Window(id, bar_, config_[name]);
+    }
 #endif
     if (ref == "idle_inhibitor") {
       return new waybar::modules::IdleInhibitor(id, bar_, config_[name]);

src/modules/river/window.cpp

@@ -0,0 +1,127 @@
+#include "modules/river/window.hpp"
+
+#include <gtkmm/button.h>
+#include <gtkmm/label.h>
+#include <spdlog/spdlog.h>
+#include <wayland-client.h>
+
+#include <algorithm>
+
+#include "client.hpp"
+#include "xdg-output-unstable-v1-client-protocol.h"
+
+namespace waybar::modules::river {
+
+static void listen_focused_view(void *data, struct zriver_seat_status_v1 *zriver_seat_status_v1,
+                                const char *title) {
+  static_cast<Window *>(data)->handle_focused_view(title);
+}
+
+static void listen_focused_output(void *data, struct zriver_seat_status_v1 *zriver_seat_status_v1,
+                                  struct wl_output *output) {
+  static_cast<Window *>(data)->handle_focused_output(output);
+}
+
+static void listen_unfocused_output(void *data, struct zriver_seat_status_v1 *zriver_seat_status_v1,
+                                    struct wl_output *output) {
+  static_cast<Window *>(data)->handle_unfocused_output(output);
+}
+
+static const zriver_seat_status_v1_listener seat_status_listener_impl{
+    .focused_output = listen_focused_output,
+    .unfocused_output = listen_unfocused_output,
+    .focused_view = listen_focused_view,
+};
+
+static void handle_global(void *data, struct wl_registry *registry, uint32_t name,
+                          const char *interface, uint32_t version) {
+  if (std::strcmp(interface, zriver_status_manager_v1_interface.name) == 0) {
+    version = std::min<uint32_t>(version, 2);
+    static_cast<Window *>(data)->status_manager_ = static_cast<struct zriver_status_manager_v1 *>(
+        wl_registry_bind(registry, name, &zriver_status_manager_v1_interface, version));
+  }
+
+  if (std::strcmp(interface, wl_seat_interface.name) == 0) {
+    version = std::min<uint32_t>(version, 1);
+    static_cast<Window *>(data)->seat_ = static_cast<struct wl_seat *>(
+        wl_registry_bind(registry, name, &wl_seat_interface, version));
+  }
+}
+
+static void handle_global_remove(void *data, struct wl_registry *registry, uint32_t name) {
+  /* Ignore event */
+}
+
+static const wl_registry_listener registry_listener_impl = {.global = handle_global,
+                                                            .global_remove = handle_global_remove};
+
+Window::Window(const std::string &id, const waybar::Bar &bar, const Json::Value &config)
+    : waybar::ALabel(config, "window", id, "{}", 30),
+      status_manager_{nullptr},
+      seat_{nullptr},
+      bar_(bar),
+      seat_status_{nullptr} {
+  struct wl_display *display = Client::inst()->wl_display;
+  struct wl_registry *registry = wl_display_get_registry(display);
+  wl_registry_add_listener(registry, &registry_listener_impl, this);
+  wl_display_roundtrip(display);
+
+  output_ = gdk_wayland_monitor_get_wl_output(bar_.output->monitor->gobj());
+
+  if (!status_manager_) {
+    spdlog::error("river_status_manager_v1 not advertised");
+    return;
+  }
+
+  if (!seat_) {
+    spdlog::error("wl_seat not advertised");
+  }
+
+  label_.hide();  // hide the label until populated
+  ALabel::update();
+
+  seat_status_ = zriver_status_manager_v1_get_river_seat_status(status_manager_, seat_);
+  zriver_seat_status_v1_add_listener(seat_status_, &seat_status_listener_impl, this);
+
+  zriver_status_manager_v1_destroy(status_manager_);
+}
+
+Window::~Window() {
+  if (seat_status_) {
+    zriver_seat_status_v1_destroy(seat_status_);
+  }
+}
+
+void Window::handle_focused_view(const char *title) {
+  // don't change the label on unfocused outputs.
+  // this makes the current output report its currently focused view, and unfocused outputs will
+  // report their last focused views. when freshly starting the bar, unfocused outputs don't have a
+  // last focused view, and will get blank labels until they are brought into focus at least once.
+  if (focused_output_ != output_) return;
+
+  if (std::strcmp(title, "") == 0) {
+    label_.hide();  // hide empty labels
+  } else {
+    label_.show();
+    label_.set_markup(title);
+  }
+
+  ALabel::update();
+}
+
+void Window::handle_focused_output(struct wl_output *output) {
+  if (output_ == output) {  // if we focused the output this bar belongs to
+    label_.get_style_context()->add_class("focused");
+    ALabel::update();
+  }
+  focused_output_ = output;
+}
+
+void Window::handle_unfocused_output(struct wl_output *output) {
+  if (output_ == output) {  // if we unfocused the output this bar belongs to
+    label_.get_style_context()->remove_class("focused");
+    ALabel::update();
+  }
+}
+
+} /* namespace waybar::modules::river */