Add ext-workspaces scroll support

include/modules/ext/workspace_manager.hpp

@@ -35,6 +35,7 @@ class WorkspaceManager final : public AModule {
 
   // wl requests
   void commit() const;
+  bool handleScroll(GdkEventScroll* e) override;
 
  private:
   void update() override;
@@ -100,6 +101,7 @@ class Workspace {
   std::vector<u_int32_t>& coordinates() { return coordinates_; }
   Gtk::Button& button() { return button_; }
   void update();
+  bool is_active() const { return has_state(EXT_WORKSPACE_HANDLE_V1_STATE_ACTIVE); }
 
   // wl events
   void handle_id(const std::string& id);

man/waybar-ext-workspaces.5.scd

@@ -54,6 +54,16 @@ Addressed by *ext/workspaces*
 	default: false ++
 	If set to true only active or urgent workspaces will be shown.
 
+*disable-scroll*: ++
+	typeof: bool ++
+	default: false ++
+	If set to true, scrolling is disabled for this module.
+
+*enable-bar-scroll*: ++
+	typeof: bool ++
+	default: false ++
+	If set to true, scrolling anywhere on the bar switches to the previous or next workspace. By default, scrolling only works when the pointer is over the workspaces module
+
 *ignore-hidden*: ++
 	typeof: bool ++
 	default: true ++

src/modules/ext/workspace_manager.cpp

@@ -22,7 +22,9 @@ std::map<std::string, std::string> Workspace::icon_map_;
 
 WorkspaceManager::WorkspaceManager(const std::string& id, const waybar::Bar& bar,
                                    const Json::Value& config)
-    : waybar::AModule(config, "workspaces", id, false, false), bar_(bar), box_(bar.orientation, 0) {
+    : waybar::AModule(config, "workspaces", id, false, !config["disable-scroll"].asBool()),
+      bar_(bar),
+      box_(bar.orientation, 0) {
   add_registry_listener(this);
 
   // parse configuration
@@ -61,6 +63,11 @@ WorkspaceManager::WorkspaceManager(const std::string& id, const waybar::Bar& bar
   }
   box_.get_style_context()->add_class(MODULE_CLASS);
   event_box_.add(box_);
+  if (!config_["disable-scroll"].asBool() && config_["enable-bar-scroll"].asBool()) {
+    auto& window = const_cast<Bar&>(bar_).window;
+    window.add_events(Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK);
+    window.signal_scroll_event().connect(sigc::mem_fun(*this, &WorkspaceManager::handleScroll));
+  }
 
   spdlog::debug("[ext/workspaces]: Workspace manager created");
 }
@@ -147,6 +154,46 @@ void WorkspaceManager::commit() const {
   if (ext_manager_) ext_workspace_manager_v1_commit(ext_manager_);
 }
 
+bool WorkspaceManager::handleScroll(GdkEventScroll* e) {
+  if (gdk_event_get_pointer_emulated(reinterpret_cast<GdkEvent*>(e)) != 0) {
+    return false;
+  }
+
+  const auto dir = getScrollDir(e);
+  if (dir == SCROLL_DIR::NONE) {
+    return true;
+  }
+
+  auto active = std::find_if(workspaces_.begin(), workspaces_.end(), [](const auto& workspace) {
+    return workspace->is_active() && workspace->button().get_visible();
+  });
+  if (active == workspaces_.end()) {
+    return true;
+  }
+
+  auto target = active;
+  do {
+    if (dir == SCROLL_DIR::DOWN || dir == SCROLL_DIR::RIGHT) {
+      ++target;
+      if (target == workspaces_.end()) {
+        target = workspaces_.begin();
+      }
+    } else {
+      if (target == workspaces_.begin()) {
+        target = workspaces_.end();
+      }
+      --target;
+    }
+  } while (target != active && !(*target)->button().get_visible());
+
+  if (target != active) {
+    ext_workspace_handle_v1_activate((*target)->handle());
+    commit();
+  }
+
+  return true;
+}
+
 void WorkspaceManager::update() {
   spdlog::debug("[ext/workspaces]: Updating state");