waybar: expose accessible buttons for interactive modules

Expose clickable label modules and tray items as accessible buttons instead of generic containers.

This adds the accessibility metadata and action wiring needed for a11y AT-SPI to recognize interactive Waybar elements consistently.

Author: awsms

include/ALabel.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <gtkmm/button.h>
 #include <glibmm/markup.h>
 #include <gtkmm/label.h>
 #include <json/json.h>
@@ -20,6 +21,7 @@ class ALabel : public AModule {
 
  protected:
   Gtk::Label label_;
+  Gtk::Button accessible_button_;
   std::string format_;
   const std::chrono::milliseconds interval_;
   bool alt_ = false;

include/AModule.hpp

@@ -42,6 +42,8 @@ class AModule : public IModule {
   Gtk::EventBox event_box_;
 
   virtual void setCursor(Gdk::CursorType const& c);
+  void setupAccessibleButton(Gtk::Button& button);
+  bool usesAccessibleButton() const;
 
   virtual bool handleToggle(GdkEventButton* const& ev);
   virtual bool handleMouseEnter(GdkEventCrossing* const& ev);

include/modules/sni/item.hpp

@@ -3,6 +3,7 @@
 #include <dbus-status-notifier-item.h>
 #include <giomm/dbusproxy.h>
 #include <glibmm/refptr.h>
+#include <gtkmm/button.h>
 #include <gtkmm/eventbox.h>
 #include <gtkmm/icontheme.h>
 #include <gtkmm/image.h>
@@ -39,6 +40,7 @@ class Item : public sigc::trackable {
   int icon_size;
   int effective_icon_size;
   Gtk::Image image;
+  Gtk::Button button;
   Gtk::EventBox event_box;
   std::string category;
   std::string id;
@@ -89,6 +91,7 @@ class Item : public sigc::trackable {
   double getScaledIconSize();
   static void onMenuDestroyed(Item* self, GObject* old_menu_pointer);
   void makeMenu();
+  void updateAccessibleName();
   bool handleClick(GdkEventButton* const& /*ev*/);
   bool handleScroll(GdkEventScroll* const&);
   bool handleMouseEnter(GdkEventCrossing* const&);

src/AIconLabel.cpp

@@ -52,7 +52,10 @@ AIconLabel::AIconLabel(const Json::Value& config, const std::string& name, const
     box_.add(image_);
   }
 
-  event_box_.add(box_);
+  auto& container =
+      usesAccessibleButton() ? static_cast<Gtk::Bin&>(accessible_button_) : static_cast<Gtk::Bin&>(event_box_);
+  container.remove();
+  container.add(box_);
 }
 
 auto AIconLabel::update() -> void {

src/ALabel.cpp

@@ -34,7 +34,6 @@ ALabel::ALabel(const Json::Value& config, const std::string& name, const std::st
     label_.get_style_context()->add_class(id);
   }
   label_.get_style_context()->add_class(MODULE_CLASS);
-  event_box_.add(label_);
   if (config_["max-length"].isUInt()) {
     label_.set_max_width_chars(config_["max-length"].asInt());
     label_.set_ellipsize(Pango::EllipsizeMode::ELLIPSIZE_END);
@@ -135,6 +134,14 @@ ALabel::ALabel(const Json::Value& config, const std::string& name, const std::st
       label_.set_justify(Gtk::Justification::JUSTIFY_CENTER);
     }
   }
+
+  if (usesAccessibleButton()) {
+    setupAccessibleButton(accessible_button_);
+    accessible_button_.add(label_);
+    event_box_.add(accessible_button_);
+  } else {
+    event_box_.add(label_);
+  }
 }
 
 auto ALabel::update() -> void { AModule::update(); }

src/AModule.cpp

@@ -45,12 +45,10 @@ AModule::AModule(const Json::Value& config, const std::string& name, const std::
                config[eventEntry.second].isString();
       }) != eventMap_.cend();
 
-  if (enable_click || hasUserEvents) {
-    hasUserEvents_ = true;
+  hasUserEvents_ = enable_click || hasUserEvents;
+  if (hasUserEvents_) {
     event_box_.add_events(Gdk::BUTTON_PRESS_MASK);
     event_box_.signal_button_press_event().connect(sigc::mem_fun(*this, &AModule::handleToggle));
-  } else {
-    hasUserEvents_ = false;
   }
 
   bool hasReleaseEvent =
@@ -59,13 +57,14 @@ AModule::AModule(const Json::Value& config, const std::string& name, const std::
         return eventEntry.first.second == GdkEventType::GDK_BUTTON_RELEASE &&
                config[eventEntry.second].isString();
       }) != eventMap_.cend();
+  bool hasScrollEvents = config_["on-scroll-up"].isString() || config_["on-scroll-down"].isString() ||
+                         config_["on-scroll-left"].isString() ||
+                         config_["on-scroll-right"].isString() || enable_scroll;
   if (hasReleaseEvent) {
     event_box_.add_events(Gdk::BUTTON_RELEASE_MASK);
     event_box_.signal_button_release_event().connect(sigc::mem_fun(*this, &AModule::handleRelease));
   }
-  if (config_["on-scroll-up"].isString() || config_["on-scroll-down"].isString() ||
-      config_["on-scroll-left"].isString() || config_["on-scroll-right"].isString() ||
-      enable_scroll) {
+  if (hasScrollEvents) {
     event_box_.add_events(Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK);
     event_box_.signal_scroll_event().connect(sigc::mem_fun(*this, &AModule::handleScroll));
   }
@@ -127,6 +126,40 @@ void AModule::setCursor(Gdk::CursorType const& c) {
   }
 }
 
+void AModule::setupAccessibleButton(Gtk::Button& button) {
+  if (!usesAccessibleButton()) {
+    return;
+  }
+
+  auto eventMask = event_box_.get_events();
+  button.set_relief(Gtk::RELIEF_NONE);
+  button.set_focus_on_click(false);
+  button.get_style_context()->add_class("flat");
+
+  if (hasUserEvents_) {
+    button.add_events(Gdk::BUTTON_PRESS_MASK);
+    button.signal_button_press_event().connect(sigc::mem_fun(*this, &AModule::handleToggle), false);
+  }
+
+  if (eventMask & Gdk::BUTTON_RELEASE_MASK) {
+    button.add_events(Gdk::BUTTON_RELEASE_MASK);
+    button.signal_button_release_event().connect(sigc::mem_fun(*this, &AModule::handleRelease), false);
+  }
+
+  if (eventMask & (Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK)) {
+    button.add_events(Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK);
+    button.signal_scroll_event().connect(sigc::mem_fun(*this, &AModule::handleScroll), false);
+  }
+}
+
+bool AModule::usesAccessibleButton() const {
+  if (hasUserEvents_) {
+    return true;
+  }
+
+  return (event_box_.get_events() & Gdk::BUTTON_RELEASE_MASK) != 0;
+}
+
 bool AModule::handleMouseEnter(GdkEventCrossing* const& e) {
   if (auto* module = event_box_.get_child(); module != nullptr) {
     module->set_state_flags(Gtk::StateFlags::STATE_FLAG_PRELIGHT);

src/modules/sni/item.cpp

@@ -1,7 +1,9 @@
 #include "modules/sni/item.hpp"
 
+#include <atk/atk.h>
 #include <gdkmm/general.h>
 #include <glibmm/main.h>
+#include <gtkmm/cssprovider.h>
 #include <gtkmm/tooltip.h>
 #include <spdlog/spdlog.h>
 
@@ -38,6 +40,33 @@ namespace waybar::modules::SNI {
 static const Glib::ustring SNI_INTERFACE_NAME = sn_item_interface_info()->name;
 static const unsigned UPDATE_DEBOUNCE_TIME = 10;
 
+namespace {
+Glib::RefPtr<Gtk::CssProvider> trayButtonCssProvider() {
+  static auto provider = [] {
+    auto css = Gtk::CssProvider::create();
+    css->load_from_data(R"CSS(
+.waybar-accessible-tray-button {
+  padding: 0;
+  margin: 0;
+  min-width: 0;
+  min-height: 0;
+  border-width: 0;
+  border-style: none;
+  border-radius: 0;
+  box-shadow: none;
+}
+
+.waybar-accessible-tray-button > image {
+  padding: 0;
+  margin: 0;
+}
+)CSS");
+    return css;
+  }();
+  return provider;
+}
+}  // namespace
+
 Item::Item(const std::string& bn, const std::string& op, const Json::Value& config, const Bar& bar,
            const std::function<void(Item&)>& on_ready,
            const std::function<void(Item&)>& on_invalidate, const std::function<void()>& on_updated)
@@ -62,12 +91,22 @@ Item::Item(const std::string& bn, const std::string& op, const Json::Value& conf
 
   auto& window = const_cast<Bar&>(bar).window;
   window.signal_configure_event().connect_notify(sigc::mem_fun(*this, &Item::onConfigure));
-  event_box.add(image);
-  event_box.add_events(Gdk::BUTTON_PRESS_MASK | Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK);
-  event_box.signal_button_press_event().connect(sigc::mem_fun(*this, &Item::handleClick));
-  event_box.signal_scroll_event().connect(sigc::mem_fun(*this, &Item::handleScroll));
-  event_box.signal_enter_notify_event().connect(sigc::mem_fun(*this, &Item::handleMouseEnter));
-  event_box.signal_leave_notify_event().connect(sigc::mem_fun(*this, &Item::handleMouseLeave));
+  button.set_relief(Gtk::RELIEF_NONE);
+  button.set_border_width(0);
+  button.set_focus_on_click(false);
+  button.set_can_focus(false);
+  button.get_style_context()->add_class("flat");
+  button.get_style_context()->add_class("waybar-accessible-tray-button");
+  button.get_style_context()->add_provider(trayButtonCssProvider(),
+                                           GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+  button.add(image);
+  event_box.add(button);
+  button.add_events(Gdk::BUTTON_PRESS_MASK | Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK |
+                    Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK);
+  button.signal_button_press_event().connect(sigc::mem_fun(*this, &Item::handleClick));
+  button.signal_scroll_event().connect(sigc::mem_fun(*this, &Item::handleScroll));
+  button.signal_enter_notify_event().connect(sigc::mem_fun(*this, &Item::handleMouseEnter));
+  button.signal_leave_notify_event().connect(sigc::mem_fun(*this, &Item::handleMouseLeave));
   // initial visibility
   event_box.show_all();
   event_box.set_visible(show_passive_);
@@ -182,11 +221,10 @@ void Item::setProperty(const Glib::ustring& name, Glib::VariantBase& value) {
       } else {
         setCustomIcon(id);
       }
+      updateAccessibleName();
     } else if (name == "Title") {
       title = get_variant<std::string>(value);
-      if (tooltip.text.empty()) {
-        event_box.set_tooltip_markup(title);
-      }
+      updateAccessibleName();
     } else if (name == "Status") {
       setStatus(get_variant<Glib::ustring>(value));
     } else if (name == "IconName") {
@@ -205,9 +243,7 @@ void Item::setProperty(const Glib::ustring& name, Glib::VariantBase& value) {
       attention_movie_name = get_variant<std::string>(value);
     } else if (name == "ToolTip") {
       tooltip = get_variant<ToolTip>(value);
-      if (!tooltip.text.empty()) {
-        event_box.set_tooltip_markup(tooltip.text);
-      }
+      updateAccessibleName();
     } else if (name == "IconThemePath") {
       icon_theme_path = get_variant<std::string>(value);
       if (!icon_theme_path.empty()) {
@@ -260,6 +296,29 @@ void Item::invalidate() {
   on_invalidate_(*this);
 }
 
+void Item::updateAccessibleName() {
+  if (!tooltip.text.empty()) {
+    button.set_tooltip_markup(tooltip.text);
+  } else if (!title.empty()) {
+    button.set_tooltip_markup(title);
+  }
+
+  std::string accessible_name;
+  if (!title.empty()) {
+    accessible_name = title;
+  } else if (!id.empty()) {
+    accessible_name = id;
+  } else if (!tooltip.text.empty()) {
+    accessible_name = tooltip.text.raw();
+  } else {
+    accessible_name = bus_name;
+  }
+
+  if (auto* accessible = gtk_widget_get_accessible(GTK_WIDGET(button.gobj())); accessible != nullptr) {
+    atk_object_set_name(accessible, accessible_name.c_str());
+  }
+}
+
 void Item::setCustomIcon(const std::string& id) {
   spdlog::debug("SNI tray id: {}", id);