init hs project

11 files changed, 1820 insertions, 0 deletions

diff --git a/csrc/widgets/panel/meson.build b/csrc/widgets/panel/meson.build
new file mode 100644
index 0000000..10afc94
--- /dev/null
+++ b/csrc/widgets/panel/meson.build
@@ -0,0 +1,7 @@
+foobar_sources += files(
+  'panel-item.c',
+  'panel-item-icon.c',
+  'panel-item-clock.c',
+  'panel-item-workspaces.c',
+  'panel-item-status.c',
+)
diff --git a/csrc/widgets/panel/panel-item-clock.c b/csrc/widgets/panel/panel-item-clock.c
new file mode 100644
index 0000000..00b2cc5
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-clock.c
@@ -0,0 +1,152 @@
+#include "widgets/panel/panel-item-clock.h"
+
+//
+// FoobarPanelItemClock:
+//
+// A panel item displaying the current time in the format configured by the user.
+//
+
+struct _FoobarPanelItemClock
+{
+	FoobarPanelItem       parent_instance;
+	gchar*                format;
+	FoobarPanelItemAction action;
+	GtkWidget*            label;
+	GtkWidget*            button;
+	FoobarClockService*   clock_service;
+};
+
+static void   foobar_panel_item_clock_class_init    ( FoobarPanelItemClockClass* klass );
+static void   foobar_panel_item_clock_init          ( FoobarPanelItemClock*      self );
+static void   foobar_panel_item_clock_finalize      ( GObject*                   object );
+static void   foobar_panel_item_clock_handle_clicked( GtkButton*                 button,
+                                                      gpointer                   userdata );
+static gchar* foobar_panel_item_clock_compute_label ( GtkExpression*             expression,
+                                                      GDateTime*                 time,
+                                                      gpointer                   userdata );
+
+G_DEFINE_FINAL_TYPE( FoobarPanelItemClock, foobar_panel_item_clock, FOOBAR_TYPE_PANEL_ITEM )
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Panel Item Implementation
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Static initialization for clock panel items.
+//
+void foobar_panel_item_clock_class_init( FoobarPanelItemClockClass* klass )
+{
+	GObjectClass* object_klass = G_OBJECT_CLASS( klass );
+	object_klass->finalize = foobar_panel_item_clock_finalize;
+}
+
+//
+// Instance initialization for clock panel items.
+//
+void foobar_panel_item_clock_init( FoobarPanelItemClock* self )
+{
+	self->label = gtk_label_new( NULL );
+	gtk_label_set_justify( GTK_LABEL( self->label ), GTK_JUSTIFY_CENTER );
+
+	self->button = gtk_button_new( );
+	gtk_button_set_has_frame( GTK_BUTTON( self->button ), FALSE );
+	gtk_button_set_child( GTK_BUTTON( self->button ), self->label );
+	gtk_widget_set_halign( self->button, GTK_ALIGN_CENTER );
+	gtk_widget_set_valign( self->button, GTK_ALIGN_CENTER );
+	g_signal_connect(
+		self->button,
+		"clicked",
+		G_CALLBACK( foobar_panel_item_clock_handle_clicked ),
+		self );
+
+	gtk_widget_add_css_class( GTK_WIDGET( self ), "clock" );
+	foobar_panel_item_set_child( FOOBAR_PANEL_ITEM( self ), self->button );
+}
+
+//
+// Instance cleanup for clock panel items.
+//
+void foobar_panel_item_clock_finalize( GObject* object )
+{
+	FoobarPanelItemClock* self = (FoobarPanelItemClock*)object;
+
+	g_clear_pointer( &self->format, g_free );
+	g_clear_object( &self->clock_service );
+
+	G_OBJECT_CLASS( foobar_panel_item_clock_parent_class )->finalize( object );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Create a new clock panel item with the given configuration.
+//
+FoobarPanelItem* foobar_panel_item_clock_new(
+	FoobarPanelItemConfiguration const* config,
+	FoobarClockService*                 clock_service )
+{
+	g_return_val_if_fail( config != NULL, NULL );
+	g_return_val_if_fail( foobar_panel_item_configuration_get_kind( config ) == FOOBAR_PANEL_ITEM_KIND_CLOCK, NULL );
+	g_return_val_if_fail( FOOBAR_IS_CLOCK_SERVICE( clock_service ), NULL );
+
+	FoobarPanelItemClock* self = g_object_new( FOOBAR_TYPE_PANEL_ITEM_CLOCK, NULL );
+	self->format = g_strdup( foobar_panel_item_clock_configuration_get_format( config ) );
+	self->action = foobar_panel_item_configuration_get_action( config );
+	self->clock_service = g_object_ref( clock_service );
+
+	gtk_widget_set_sensitive( self->button, self->action != FOOBAR_PANEL_ITEM_ACTION_NONE );
+
+	{
+		GtkExpression* service_expr = gtk_constant_expression_new( FOOBAR_TYPE_CLOCK_SERVICE, self->clock_service );
+		GtkExpression* time_expr = gtk_property_expression_new( FOOBAR_TYPE_CLOCK_SERVICE, service_expr, "time" );
+		GtkExpression* label_params[] = { time_expr };
+		GtkExpression* label_expr = gtk_cclosure_expression_new(
+			G_TYPE_STRING,
+			NULL,
+			G_N_ELEMENTS( label_params ),
+			label_params,
+			G_CALLBACK( foobar_panel_item_clock_compute_label ),
+			self,
+			NULL );
+		gtk_expression_bind( label_expr, self->label, "label", NULL );
+	}
+
+	return FOOBAR_PANEL_ITEM( self );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Signal Handlers
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Called when the button was clicked.
+//
+void foobar_panel_item_clock_handle_clicked(
+	GtkButton* button,
+	gpointer   userdata )
+{
+	(void)button;
+	FoobarPanelItemClock* self = (FoobarPanelItemClock*)userdata;
+
+	foobar_panel_item_invoke_action( FOOBAR_PANEL_ITEM( self ), self->action );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Value Converters
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Derive the label from a timestamp, depending on the configured time format.
+//
+gchar* foobar_panel_item_clock_compute_label(
+	GtkExpression* expression,
+	GDateTime*     time,
+	gpointer       userdata )
+{
+	(void)expression;
+	FoobarPanelItemClock* self = (FoobarPanelItemClock*)userdata;
+
+	return g_date_time_format( time, self->format );
+}
diff --git a/csrc/widgets/panel/panel-item-clock.h b/csrc/widgets/panel/panel-item-clock.h
new file mode 100644
index 0000000..5ff7e5b
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-clock.h
@@ -0,0 +1,15 @@
+#pragma once
+
+#include "widgets/panel/panel-item.h"
+#include "services/clock-service.h"
+
+G_BEGIN_DECLS
+
+#define FOOBAR_TYPE_PANEL_ITEM_CLOCK foobar_panel_item_clock_get_type( )
+
+G_DECLARE_FINAL_TYPE( FoobarPanelItemClock, foobar_panel_item_clock, FOOBAR, PANEL_ITEM_CLOCK, FoobarPanelItem )
+
+FoobarPanelItem* foobar_panel_item_clock_new( FoobarPanelItemConfiguration const* config,
+                                              FoobarClockService*                 clock_service );
+
+G_END_DECLS
diff --git a/csrc/widgets/panel/panel-item-icon.c b/csrc/widgets/panel/panel-item-icon.c
new file mode 100644
index 0000000..0a3b4e9
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-icon.c
@@ -0,0 +1,92 @@
+#include "widgets/panel/panel-item-icon.h"
+
+//
+// FoobarPanelItemIcon:
+//
+// Simple item implementation displaying an icon.
+//
+
+struct _FoobarPanelItemIcon
+{
+	FoobarPanelItem       parent_instance;
+	GtkWidget*            button;
+	FoobarPanelItemAction action;
+};
+
+static void foobar_panel_item_icon_class_init    ( FoobarPanelItemIconClass* klass );
+static void foobar_panel_item_icon_init          ( FoobarPanelItemIcon*      self );
+static void foobar_panel_item_icon_handle_clicked( GtkButton*                button,
+                                                   gpointer                  userdata );
+
+G_DEFINE_FINAL_TYPE( FoobarPanelItemIcon, foobar_panel_item_icon, FOOBAR_TYPE_PANEL_ITEM )
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Panel Item Implementation
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Static initialization for icon panel items.
+//
+void foobar_panel_item_icon_class_init( FoobarPanelItemIconClass* klass )
+{
+	(void)klass;
+}
+
+//
+// Instance initialization for icon panel items.
+//
+void foobar_panel_item_icon_init( FoobarPanelItemIcon* self )
+{
+	self->button = gtk_button_new( );
+	gtk_button_set_has_frame( GTK_BUTTON( self->button ), FALSE );
+	gtk_widget_set_halign( self->button, GTK_ALIGN_CENTER );
+	gtk_widget_set_valign( self->button, GTK_ALIGN_CENTER );
+	g_signal_connect(
+		self->button,
+		"clicked",
+		G_CALLBACK( foobar_panel_item_icon_handle_clicked ),
+		self );
+
+	gtk_widget_add_css_class( GTK_WIDGET( self ), "icon" );
+	foobar_panel_item_set_child( FOOBAR_PANEL_ITEM( self ), self->button );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Create a new icon panel item with the given configuration.
+//
+FoobarPanelItem* foobar_panel_item_icon_new( FoobarPanelItemConfiguration const* config )
+{
+	g_return_val_if_fail( config != NULL, NULL );
+	g_return_val_if_fail( foobar_panel_item_configuration_get_kind( config ) == FOOBAR_PANEL_ITEM_KIND_ICON, NULL );
+
+	FoobarPanelItemIcon* self = g_object_new( FOOBAR_TYPE_PANEL_ITEM_ICON, NULL );
+	self->action = foobar_panel_item_configuration_get_action( config );
+
+	gtk_widget_set_sensitive( self->button, self->action != FOOBAR_PANEL_ITEM_ACTION_NONE );
+	gtk_button_set_icon_name(
+		GTK_BUTTON( self->button ),
+		foobar_panel_item_icon_configuration_get_icon_name( config ) );
+
+	return FOOBAR_PANEL_ITEM( self );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Signal Handlers
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Called when the button was clicked.
+//
+void foobar_panel_item_icon_handle_clicked(
+	GtkButton* button,
+	gpointer   userdata )
+{
+	(void)button;
+	FoobarPanelItemIcon* self = (FoobarPanelItemIcon*)userdata;
+
+	foobar_panel_item_invoke_action( FOOBAR_PANEL_ITEM( self ), self->action );
+}
diff --git a/csrc/widgets/panel/panel-item-icon.h b/csrc/widgets/panel/panel-item-icon.h
new file mode 100644
index 0000000..2b4ac1f
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-icon.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include "widgets/panel/panel-item.h"
+
+G_BEGIN_DECLS
+
+#define FOOBAR_TYPE_PANEL_ITEM_ICON foobar_panel_item_icon_get_type( )
+
+G_DECLARE_FINAL_TYPE( FoobarPanelItemIcon, foobar_panel_item_icon, FOOBAR, PANEL_ITEM_ICON, FoobarPanelItem )
+
+FoobarPanelItem* foobar_panel_item_icon_new( FoobarPanelItemConfiguration const* config );
+
+G_END_DECLS
diff --git a/csrc/widgets/panel/panel-item-status.c b/csrc/widgets/panel/panel-item-status.c
new file mode 100644
index 0000000..f06bb68
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-status.c
@@ -0,0 +1,955 @@
+#include "widgets/panel/panel-item-status.h"
+
+//
+// FoobarPanelItemStatus:
+//
+// A panel item showing status indicators for various things such as network state, audio volume, screen brightness,
+// battery level, etc.
+//
+
+struct _FoobarPanelItemStatus
+{
+	FoobarPanelItem            parent_instance;
+	FoobarPanelItemAction      action;
+	GtkWidget*                 button;
+	GtkWidget*                 layout;
+	FoobarBatteryService*      battery_service;
+	FoobarBrightnessService*   brightness_service;
+	FoobarAudioService*        audio_service;
+	FoobarNetworkService*      network_service;
+	FoobarBluetoothService*    bluetooth_service;
+	FoobarNotificationService* notification_service;
+	GtkWidget*                 network_icon;
+	GtkWidget*                 network_label;
+	GtkExpression*             network_icon_expr;
+	FoobarNetwork*             network;
+	gulong                     network_handler_id;
+	gulong                     network_strength_handler_id;
+};
+
+enum
+{
+	PROP_ORIENTATION = 1,
+	N_PROPS,
+};
+
+static GParamSpec* props[N_PROPS] = { 0 };
+
+static void       foobar_panel_item_status_class_init                    ( FoobarPanelItemStatusClass* klass );
+static void       foobar_panel_item_status_init                          ( FoobarPanelItemStatus*      self );
+static void       foobar_panel_item_status_get_property                  ( GObject*                    object,
+                                                                           guint                       prop_id,
+                                                                           GValue*                     value,
+                                                                           GParamSpec*                 pspec );
+static void       foobar_panel_item_status_set_property                  ( GObject*                    object,
+                                                                           guint                       prop_id,
+                                                                           GValue const*               value,
+                                                                           GParamSpec*                 pspec );
+static void       foobar_panel_item_status_finalize                      ( GObject*                    object );
+static void       foobar_panel_item_status_handle_network_change         ( FoobarNetworkAdapterWifi*   adapter,
+                                                                           GParamSpec*                 pspec,
+                                                                           gpointer                    userdata );
+static void       foobar_panel_item_status_handle_network_strength_change( GObject*                    object,
+                                                                           GParamSpec*                 pspec,
+                                                                           gpointer                    userdata );
+static void       foobar_panel_item_status_handle_clicked                ( GtkButton*                  button,
+                                                                           gpointer                    userdata );
+static gboolean   foobar_panel_item_status_handle_brightness_scroll      ( GtkEventControllerScroll*   controller,
+                                                                           gdouble                     dx,
+                                                                           gdouble                     dy,
+                                                                           gpointer                    userdata );
+static gboolean   foobar_panel_item_status_handle_audio_scroll           ( GtkEventControllerScroll*   controller,
+                                                                           gdouble                     dx,
+                                                                           gdouble                     dy,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_network_icon          ( GtkExpression*              expression,
+                                                                           FoobarNetworkAdapter*       adapter,
+                                                                           FoobarNetworkAdapterState   state,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_bluetooth_icon        ( GtkExpression*              expression,
+                                                                           gboolean                    is_enabled,
+                                                                           guint                       connected_device_count,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_battery_icon          ( GtkExpression*              expression,
+                                                                           FoobarBatteryState const*   state,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_battery_label         ( GtkExpression*              expression,
+                                                                           FoobarBatteryState const*   state,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_brightness_icon       ( GtkExpression*              expression,
+                                                                           gint                        percentage,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_brightness_label      ( GtkExpression*              expression,
+                                                                           gint                        percentage,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_audio_icon            ( GtkExpression*              expression,
+                                                                           gboolean                    is_available,
+                                                                           gint                        volume,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_audio_label           ( GtkExpression*              expression,
+                                                                           gboolean                    is_available,
+                                                                           gint                        volume,
+                                                                           gpointer                    userdata );
+static gchar*     foobar_panel_item_status_compute_notifications_icon    ( GtkExpression*              expression,
+                                                                           guint                       count,
+                                                                           gpointer                    userdata );
+static GtkWidget* foobar_panel_item_status_create_item                   ( FoobarPanelItemStatus*      self,
+                                                                           FoobarStatusItem            item,
+                                                                           gboolean                    show_labels,
+                                                                           gboolean                    enable_scrolling );
+static void       foobar_panel_item_status_reevaluate_network            ( FoobarPanelItemStatus*      self );
+
+G_DEFINE_FINAL_TYPE_WITH_CODE(
+	FoobarPanelItemStatus,
+	foobar_panel_item_status,
+	FOOBAR_TYPE_PANEL_ITEM,
+	G_IMPLEMENT_INTERFACE( GTK_TYPE_ORIENTABLE, NULL ) )
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Panel Item Implementation
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Static initialization for status panel items.
+//
+void foobar_panel_item_status_class_init( FoobarPanelItemStatusClass* klass )
+{
+	GObjectClass* object_klass = G_OBJECT_CLASS( klass );
+	object_klass->get_property = foobar_panel_item_status_get_property;
+	object_klass->set_property = foobar_panel_item_status_set_property;
+	object_klass->finalize = foobar_panel_item_status_finalize;
+
+	gpointer orientable_iface = g_type_default_interface_peek( GTK_TYPE_ORIENTABLE );
+	props[PROP_ORIENTATION] = g_param_spec_override(
+		"orientation",
+		g_object_interface_find_property( orientable_iface, "orientation" ) );
+	g_object_class_install_properties( object_klass, N_PROPS, props );
+}
+
+//
+// Instance initialization for status panel items.
+//
+void foobar_panel_item_status_init( FoobarPanelItemStatus* self )
+{
+	self->layout = gtk_box_new( GTK_ORIENTATION_VERTICAL, 0 );
+
+	self->button = gtk_button_new( );
+	gtk_button_set_has_frame( GTK_BUTTON( self->button ), FALSE );
+	gtk_button_set_child( GTK_BUTTON( self->button ), self->layout );
+	gtk_widget_set_halign( self->button, GTK_ALIGN_CENTER );
+	gtk_widget_set_valign( self->button, GTK_ALIGN_CENTER );
+	g_signal_connect(
+		self->button,
+		"clicked",
+		G_CALLBACK( foobar_panel_item_status_handle_clicked ),
+		self );
+
+	gtk_widget_add_css_class( GTK_WIDGET( self ), "status" );
+	foobar_panel_item_set_child( FOOBAR_PANEL_ITEM( self ), self->button );
+}
+
+//
+// Property getter implementation, mapping a property id to a method.
+//
+void foobar_panel_item_status_get_property(
+	GObject*    object,
+	guint       prop_id,
+	GValue*     value,
+	GParamSpec* pspec )
+{
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)object;
+
+	switch ( prop_id )
+	{
+		case PROP_ORIENTATION:
+			g_value_set_enum( value, gtk_orientable_get_orientation( GTK_ORIENTABLE( self->layout ) ) );
+			break;
+		default:
+			G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec );
+			break;
+	}
+}
+
+//
+// Property setter implementation, mapping a property id to a method.
+//
+void foobar_panel_item_status_set_property(
+	GObject*      object,
+	guint         prop_id,
+	GValue const* value,
+	GParamSpec*   pspec )
+{
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)object;
+
+	switch ( prop_id )
+	{
+		case PROP_ORIENTATION:
+			gtk_orientable_set_orientation( GTK_ORIENTABLE( self->layout ), g_value_get_enum( value ) );
+			g_object_notify_by_pspec( G_OBJECT( self ), props[PROP_ORIENTATION] );
+			break;
+		default:
+			G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec );
+			break;
+	}
+}
+
+//
+// Instance cleanup for status panel items.
+//
+void foobar_panel_item_status_finalize( GObject* object )
+{
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)object;
+
+	FoobarNetworkAdapterWifi* adapter = foobar_network_service_get_wifi( self->network_service );
+	g_clear_signal_handler( &self->network_handler_id, adapter );
+	g_clear_signal_handler( &self->network_strength_handler_id, self->network );
+	g_clear_object( &self->network );
+	g_clear_object( &self->battery_service );
+	g_clear_object( &self->brightness_service );
+	g_clear_object( &self->audio_service );
+	g_clear_object( &self->network_service );
+	g_clear_object( &self->bluetooth_service );
+	g_clear_object( &self->notification_service );
+	g_clear_pointer( &self->network_icon_expr, gtk_expression_unref );
+
+	G_OBJECT_CLASS( foobar_panel_item_status_parent_class )->finalize( object );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Create a new status panel item with the given configuration.
+//
+FoobarPanelItem* foobar_panel_item_status_new(
+	FoobarPanelItemConfiguration const* config,
+	FoobarBatteryService*               battery_service,
+	FoobarBrightnessService*            brightness_service,
+	FoobarAudioService*                 audio_service,
+	FoobarNetworkService*               network_service,
+	FoobarBluetoothService*             bluetooth_service,
+	FoobarNotificationService*          notification_service )
+{
+	g_return_val_if_fail( config != NULL, NULL );
+	g_return_val_if_fail( foobar_panel_item_configuration_get_kind( config ) == FOOBAR_PANEL_ITEM_KIND_STATUS, NULL );
+	g_return_val_if_fail( FOOBAR_IS_BATTERY_SERVICE( battery_service ), NULL );
+	g_return_val_if_fail( FOOBAR_IS_BRIGHTNESS_SERVICE( brightness_service ), NULL );
+	g_return_val_if_fail( FOOBAR_IS_AUDIO_SERVICE( audio_service ), NULL );
+	g_return_val_if_fail( FOOBAR_IS_NETWORK_SERVICE( network_service ), NULL );
+	g_return_val_if_fail( FOOBAR_IS_BLUETOOTH_SERVICE( bluetooth_service ), NULL );
+	g_return_val_if_fail( FOOBAR_IS_NOTIFICATION_SERVICE( notification_service ), NULL );
+
+	FoobarPanelItemStatus* self = g_object_new( FOOBAR_TYPE_PANEL_ITEM_STATUS, NULL );
+	self->action = foobar_panel_item_configuration_get_action( config );
+	self->battery_service = g_object_ref( battery_service );
+	self->brightness_service = g_object_ref( brightness_service );
+	self->audio_service = g_object_ref( audio_service );
+	self->network_service = g_object_ref( network_service );
+	self->bluetooth_service = g_object_ref( bluetooth_service );
+	self->notification_service = g_object_ref( notification_service );
+
+	gtk_widget_set_sensitive( self->button, self->action != FOOBAR_PANEL_ITEM_ACTION_NONE );
+
+	gtk_box_set_spacing( GTK_BOX( self->layout ), foobar_panel_item_status_configuration_get_spacing( config ) );
+	gboolean show_labels = foobar_panel_item_status_configuration_get_show_labels( config );
+	gboolean enable_scrolling = foobar_panel_item_status_configuration_get_enable_scrolling( config );
+	gsize items_count;
+	FoobarStatusItem const* items = foobar_panel_item_status_configuration_get_items( config, &items_count );
+	for ( gsize i = 0; i < items_count; ++i )
+	{
+		GtkWidget* widget = foobar_panel_item_status_create_item( self, items[i], show_labels, enable_scrolling );
+		if ( widget )
+		{
+			gtk_widget_set_halign( widget, GTK_ALIGN_CENTER );
+			gtk_box_append( GTK_BOX( self->layout ), widget );
+		}
+	}
+
+	return FOOBAR_PANEL_ITEM( self );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Signal Handlers
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Called when the wi-fi adapter's active network changes.
+//
+// This is used to then subscribe to changes to the active network's strength. Unfortunately, we can't just use
+// GtkExpressions here because the active network may be NULL in which case the strength expression would fail. If one
+// expression fails to evaluate, then the closure expression used to derive the network icon/label also does not get
+// updated.
+//
+// In addition, this method also updates the network label to show the active network's name or become invisible.
+//
+void foobar_panel_item_status_handle_network_change(
+	FoobarNetworkAdapterWifi* adapter,
+	GParamSpec*               pspec,
+	gpointer                  userdata )
+{
+	(void)pspec;
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)userdata;
+
+	FoobarNetwork* network = foobar_network_adapter_wifi_get_active( adapter );
+	if ( self->network != network )
+	{
+		g_clear_signal_handler( &self->network_strength_handler_id, self->network );
+		g_clear_object( &self->network );
+
+		if ( network )
+		{
+			self->network = g_object_ref( network );
+			self->network_strength_handler_id = g_signal_connect(
+				self->network,
+				"notify::strength",
+				G_CALLBACK( foobar_panel_item_status_handle_network_strength_change ),
+				self );
+		}
+
+		if ( self->network_label )
+		{
+			gtk_label_set_label(
+				GTK_LABEL( self->network_label ), self->network ? foobar_network_get_name( self->network ) : NULL );
+			gtk_widget_set_visible( GTK_WIDGET( self->network_label ), self->network != NULL );
+		}
+
+		foobar_panel_item_status_reevaluate_network( self );
+	}
+}
+
+//
+// Called when the wi-fi adapter's active network strength changes.
+//
+// This just forces re-evaluation of the network icon expression for reasons mentioned in
+// foobar_panel_item_status_handle_network_change.
+//
+void foobar_panel_item_status_handle_network_strength_change(
+	GObject*    object,
+	GParamSpec* pspec,
+	gpointer    userdata )
+{
+	(void)object;
+	(void)pspec;
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)userdata;
+	foobar_panel_item_status_reevaluate_network( self );
+}
+
+//
+// Called when the button was clicked.
+//
+void foobar_panel_item_status_handle_clicked(
+	GtkButton* button,
+	gpointer   userdata )
+{
+	(void)button;
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)userdata;
+
+	foobar_panel_item_invoke_action( FOOBAR_PANEL_ITEM( self ), self->action );
+}
+
+//
+// Called when the user has scrolled over the brightness item, used to adjust the brightness level.
+//
+gboolean foobar_panel_item_status_handle_brightness_scroll(
+	GtkEventControllerScroll* controller,
+	gdouble                   dx,
+	gdouble                   dy,
+	gpointer                  userdata )
+{
+	(void)controller;
+	(void)dx;
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)userdata;
+
+	gint new_brightness = foobar_brightness_service_get_percentage( self->brightness_service ) + (gint)dy;
+	foobar_brightness_service_set_percentage( self->brightness_service, new_brightness );
+
+	return TRUE;
+}
+
+//
+// Called when the user has scrolled over the audio item, used to adjust the volume.
+//
+gboolean foobar_panel_item_status_handle_audio_scroll(
+	GtkEventControllerScroll* controller,
+	gdouble                   dx,
+	gdouble                   dy,
+	gpointer                  userdata )
+{
+	(void)controller;
+	(void)dx;
+	FoobarPanelItemStatus* self = (FoobarPanelItemStatus*)userdata;
+
+	FoobarAudioDevice* device = foobar_audio_service_get_default_output( self->audio_service );
+	gint new_volume = foobar_audio_device_get_volume( device ) + (gint)dy;
+	foobar_audio_device_set_volume( device, new_volume );
+
+	return TRUE;
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Value Converters
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Derive the network icon from the active network adapter and its state.
+//
+// In addition, this also uses the wi-fi adapter's active network strength which is monitored separately (see
+// foobar_panel_item_status_handle_network_change).
+//
+gchar* foobar_panel_item_status_compute_network_icon(
+	GtkExpression*            expression,
+	FoobarNetworkAdapter*     adapter,
+	FoobarNetworkAdapterState state,
+	gpointer                  userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if ( FOOBAR_IS_NETWORK_ADAPTER_WIFI( adapter ) )
+	{
+		if ( state == FOOBAR_NETWORK_ADAPTER_STATE_DISCONNECTED ) { return g_strdup( "fluent-wifi-off-symbolic" ); }
+		if ( state != FOOBAR_NETWORK_ADAPTER_STATE_CONNECTED ) { return g_strdup( "fluent-wifi-warning-symbolic" ); }
+
+		FoobarNetwork* network = foobar_network_adapter_wifi_get_active( FOOBAR_NETWORK_ADAPTER_WIFI( adapter ) );
+		gint strength = network ? foobar_network_get_strength( network ) : 0;
+		if ( strength <= 25 ) { return g_strdup( "fluent-wifi-4-symbolic" ); }
+		if ( strength <= 50 ) { return g_strdup( "fluent-wifi-3-symbolic" ); }
+		if ( strength <= 75 ) { return g_strdup( "fluent-wifi-2-symbolic" ); }
+		return g_strdup( "fluent-wifi-1-symbolic" );
+	}
+	else
+	{
+		return g_strdup( "fluent-virtual-network-symbolic" );
+	}
+}
+
+//
+// Derive the bluetooth icon from the bluetooth adapter's state and the number of currently connected devices.
+//
+gchar* foobar_panel_item_status_compute_bluetooth_icon(
+	GtkExpression* expression,
+	gboolean       is_enabled,
+	guint          connected_device_count,
+	gpointer       userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if (is_enabled)
+	{
+		return ( connected_device_count > 0 )
+			? g_strdup( "fluent-bluetooth-connected-symbolic" )
+			: g_strdup( "fluent-bluetooth-symbolic" );
+	}
+	else
+	{
+		return g_strdup( "fluent-bluetooth-off-symbolic" );
+	}
+}
+
+//
+// Derive the battery icon from the current state structure.
+//
+gchar* foobar_panel_item_status_compute_battery_icon(
+	GtkExpression*            expression,
+	FoobarBatteryState const* state,
+	gpointer                  userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if ( state )
+	{
+		gint percentage = foobar_battery_state_get_percentage( state );
+		if ( foobar_battery_state_is_charging( state ) ) { return g_strdup( "fluent-battery-charge-symbolic" ); }
+		if ( percentage <= 5 ) { return g_strdup( "fluent-battery-0-symbolic" ); }
+		if ( percentage <= 15 ) { return g_strdup( "fluent-battery-1-symbolic" ); }
+		if ( percentage <= 25 ) { return g_strdup( "fluent-battery-2-symbolic" ); }
+		if ( percentage <= 35 ) { return g_strdup( "fluent-battery-3-symbolic" ); }
+		if ( percentage <= 45 ) { return g_strdup( "fluent-battery-4-symbolic" ); }
+		if ( percentage <= 55 ) { return g_strdup( "fluent-battery-5-symbolic" ); }
+		if ( percentage <= 65 ) { return g_strdup( "fluent-battery-6-symbolic" ); }
+		if ( percentage <= 75 ) { return g_strdup( "fluent-battery-7-symbolic" ); }
+		if ( percentage <= 85 ) { return g_strdup( "fluent-battery-8-symbolic" ); }
+		if ( percentage <= 95 ) { return g_strdup( "fluent-battery-9-symbolic" ); }
+		return g_strdup( "fluent-battery-10-symbolic" );
+	}
+	else
+	{
+		return g_strdup( "fluent-plug-connected-symbolic" );
+	}
+}
+
+//
+// Derive the battery label from the current state structure, showing the percentage if available.
+//
+gchar* foobar_panel_item_status_compute_battery_label(
+	GtkExpression*            expression,
+	FoobarBatteryState const* state,
+	gpointer                  userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if ( state )
+	{
+		return g_strdup_printf( "%d%%", foobar_battery_state_get_percentage( state ) );
+	}
+	else
+	{
+		return g_strdup( "n/a" );
+	}
+}
+
+//
+// Derive the brightness icon from the current percentage value.
+//
+gchar* foobar_panel_item_status_compute_brightness_icon(
+	GtkExpression* expression,
+	gint           percentage,
+	gpointer       userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if ( percentage <= 50 )
+	{
+		return g_strdup( "fluent-brightness-low-symbolic" );
+	}
+	else
+	{
+		return g_strdup( "fluent-brightness-high-symbolic" );
+	}
+}
+
+//
+// Derive the brightness label from the current percentage value.
+//
+gchar* foobar_panel_item_status_compute_brightness_label(
+	GtkExpression* expression,
+	gint           percentage,
+	gpointer       userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	return g_strdup_printf( "%d%%", percentage );
+}
+
+//
+// Derive the audio icon from the current state and volume of the default output device.
+//
+gchar* foobar_panel_item_status_compute_audio_icon(
+	GtkExpression* expression,
+	gboolean       is_available,
+	gint           volume,
+	gpointer       userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if ( is_available )
+	{
+		if ( volume == 0 ) { return g_strdup( "fluent-speaker-mute-symbolic" ); }
+		if ( volume <= 33 ) { return g_strdup( "fluent-speaker-0-symbolic" ); }
+		if ( volume <= 67 ) { return g_strdup( "fluent-speaker-1-symbolic" ); }
+		return g_strdup( "fluent-speaker-2-symbolic" );
+	}
+	else
+	{
+		return g_strdup( "fluent-speaker-off-symbolic" );
+	}
+}
+
+//
+// Derive the audio label from the current state and volume of the default output device.
+//
+gchar* foobar_panel_item_status_compute_audio_label(
+	GtkExpression* expression,
+	gboolean       is_available,
+	gint           volume,
+	gpointer       userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	if ( is_available )
+	{
+		return g_strdup_printf( "%d%%", volume );
+	}
+	else
+	{
+		return g_strdup( "n/a" );
+	}
+}
+
+//
+// Derive the notification icon from the current number of notifications.
+//
+gchar* foobar_panel_item_status_compute_notifications_icon(
+	GtkExpression* expression,
+	guint          count,
+	gpointer       userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	switch ( count )
+	{
+		case 0:
+			return g_strdup( "fluent-checkmark-circle-symbolic" );
+		case 1:
+			return g_strdup( "fluent-number-circle-1-symbolic" );
+		case 2:
+			return g_strdup( "fluent-number-circle-2-symbolic" );
+		case 3:
+			return g_strdup( "fluent-number-circle-3-symbolic" );
+		case 4:
+			return g_strdup( "fluent-number-circle-4-symbolic" );
+		case 5:
+			return g_strdup( "fluent-number-circle-5-symbolic" );
+		case 6:
+			return g_strdup( "fluent-number-circle-6-symbolic" );
+		case 7:
+			return g_strdup( "fluent-number-circle-7-symbolic" );
+		case 8:
+			return g_strdup( "fluent-number-circle-8-symbolic" );
+		case 9:
+			return g_strdup( "fluent-number-circle-9-symbolic" );
+		default:
+			return g_strdup( "fluent-more-circle-symbolic" );
+	}
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Helper Methods
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Create a new icon displaying the specified status item, optionally adding a label to it (if supported).
+//
+GtkWidget* foobar_panel_item_status_create_item(
+	FoobarPanelItemStatus* self,
+	FoobarStatusItem       item,
+	gboolean               show_labels,
+	gboolean               enable_scrolling )
+{
+	switch ( item )
+	{
+		case FOOBAR_STATUS_ITEM_NETWORK:
+		{
+			GtkWidget* box = gtk_box_new( GTK_ORIENTATION_HORIZONTAL, 0 );
+			gtk_widget_set_valign( box, GTK_ALIGN_FILL );
+
+			GtkExpression* service_expr = gtk_constant_expression_new(
+				FOOBAR_TYPE_NETWORK_SERVICE,
+				self->network_service );
+			GtkExpression* active_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_NETWORK_SERVICE,
+				service_expr,
+				"active" );
+			GtkExpression* state_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_NETWORK_ADAPTER,
+				gtk_expression_ref( active_expr ),
+				"state" );
+			GtkExpression* icon_params[] = { active_expr, state_expr };
+			self->network_icon_expr = gtk_cclosure_expression_new(
+				G_TYPE_STRING,
+				NULL,
+				G_N_ELEMENTS( icon_params ),
+				icon_params,
+				G_CALLBACK( foobar_panel_item_status_compute_network_icon ),
+				self,
+				NULL );
+			self->network_icon = gtk_image_new( );
+			gtk_widget_set_valign( self->network_icon, GTK_ALIGN_CENTER );
+			gtk_expression_bind( gtk_expression_ref( self->network_icon_expr ), self->network_icon, "icon-name", NULL );
+			gtk_box_append( GTK_BOX( box ), self->network_icon );
+
+			if ( show_labels )
+			{
+				self->network_label = gtk_label_new( NULL );
+				gtk_widget_set_valign( self->network_label, GTK_ALIGN_CENTER );
+				gtk_label_set_max_width_chars( GTK_LABEL( self->network_label ), 16 );
+				gtk_label_set_ellipsize( GTK_LABEL( self->network_label ), PANGO_ELLIPSIZE_END );
+				gtk_box_append( GTK_BOX( box ), self->network_label );
+			}
+
+			// Manually subscribe to network (/strength) because evaluation might fail.
+
+			FoobarNetworkAdapterWifi* adapter = foobar_network_service_get_wifi( self->network_service );
+			if ( adapter )
+			{
+				self->network_handler_id = g_signal_connect(
+					adapter,
+					"notify::active",
+					G_CALLBACK( foobar_panel_item_status_handle_network_change ),
+					self );
+				if ( foobar_network_adapter_wifi_get_active( adapter ) )
+				{
+					self->network = g_object_ref( foobar_network_adapter_wifi_get_active( adapter ) );
+					self->network_strength_handler_id = g_signal_connect(
+						self->network,
+						"notify::strength",
+						G_CALLBACK( foobar_panel_item_status_handle_network_strength_change ),
+						self );
+				}
+				if ( self->network_label )
+				{
+					gtk_label_set_label(
+						GTK_LABEL( self->network_label ),
+						self->network ? foobar_network_get_name( self->network ) : NULL );
+					gtk_widget_set_visible( GTK_WIDGET( self->network_label ), self->network != NULL );
+				}
+			}
+
+			return box;
+		}
+		case FOOBAR_STATUS_ITEM_BLUETOOTH:
+		{
+			GtkWidget* icon = gtk_image_new( );
+			gtk_widget_set_valign( icon, GTK_ALIGN_CENTER );
+
+			GtkExpression* service_expr = gtk_constant_expression_new(
+				FOOBAR_TYPE_BLUETOOTH_SERVICE,
+				self->bluetooth_service );
+			GtkExpression* enabled_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_BLUETOOTH_SERVICE,
+				gtk_expression_ref( service_expr ),
+				"is-enabled" );
+			GtkExpression* connected_devices_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_BLUETOOTH_SERVICE,
+				service_expr,
+				"connected-devices" );
+			GtkExpression* connected_device_count_expr = gtk_property_expression_new(
+				GTK_TYPE_FILTER_LIST_MODEL,
+				connected_devices_expr,
+				"n-items" );
+			GtkExpression* icon_params[] = { enabled_expr, connected_device_count_expr };
+			GtkExpression* icon_expr = gtk_cclosure_expression_new(
+				G_TYPE_STRING,
+				NULL,
+				G_N_ELEMENTS( icon_params ),
+				icon_params,
+				G_CALLBACK( foobar_panel_item_status_compute_bluetooth_icon ),
+				NULL,
+				NULL );
+			gtk_expression_bind( icon_expr, icon, "icon-name", NULL );
+
+			return icon;
+		}
+		case FOOBAR_STATUS_ITEM_BATTERY:
+		{
+			GtkWidget* box = gtk_box_new( GTK_ORIENTATION_HORIZONTAL, 0 );
+			gtk_widget_set_valign( box, GTK_ALIGN_FILL );
+
+			GtkExpression* service_expr = gtk_constant_expression_new(
+				FOOBAR_TYPE_BATTERY_SERVICE,
+				self->battery_service );
+			GtkExpression* state_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_BATTERY_SERVICE,
+				service_expr,
+				"state" );
+
+			GtkExpression* icon_params[] = { state_expr };
+			GtkExpression* icon_expr = gtk_cclosure_expression_new(
+				G_TYPE_STRING,
+				NULL,
+				G_N_ELEMENTS( icon_params ),
+				icon_params,
+				G_CALLBACK( foobar_panel_item_status_compute_battery_icon ),
+				NULL,
+				NULL );
+			GtkWidget* icon = gtk_image_new( );
+			gtk_widget_set_valign( icon, GTK_ALIGN_CENTER );
+			gtk_expression_bind( icon_expr, icon, "icon-name", NULL );
+			gtk_box_append( GTK_BOX( box ), icon );
+
+			if ( show_labels )
+			{
+				GtkExpression* label_params[] = { gtk_expression_ref( state_expr ) };
+				GtkExpression* label_expr = gtk_cclosure_expression_new(
+					G_TYPE_STRING,
+					NULL,
+					G_N_ELEMENTS( label_params ),
+					label_params,
+					G_CALLBACK( foobar_panel_item_status_compute_battery_label ),
+					NULL,
+					NULL );
+				GtkWidget* label = gtk_label_new( NULL );
+				gtk_widget_set_valign( label, GTK_ALIGN_CENTER );
+				gtk_expression_bind( label_expr, label, "label", NULL );
+				gtk_box_append( GTK_BOX( box ), label );
+			}
+
+			return box;
+		}
+		case FOOBAR_STATUS_ITEM_BRIGHTNESS:
+		{
+			GtkWidget* box = gtk_box_new( GTK_ORIENTATION_HORIZONTAL, 0 );
+			gtk_widget_set_valign( box, GTK_ALIGN_FILL );
+
+			if ( enable_scrolling )
+			{
+				GtkEventController* scroll_controller = gtk_event_controller_scroll_new(
+					GTK_EVENT_CONTROLLER_SCROLL_VERTICAL | GTK_EVENT_CONTROLLER_SCROLL_DISCRETE );
+				g_signal_connect(
+					scroll_controller,
+					"scroll",
+					G_CALLBACK( foobar_panel_item_status_handle_brightness_scroll ),
+					self );
+				gtk_widget_add_controller( box, scroll_controller );
+			}
+
+			GtkExpression* service_expr = gtk_constant_expression_new(
+				FOOBAR_TYPE_BRIGHTNESS_SERVICE,
+				self->brightness_service );
+			GtkExpression* percentage_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_BRIGHTNESS_SERVICE,
+				service_expr,
+				"percentage" );
+
+			GtkExpression* icon_params[] = { percentage_expr };
+			GtkExpression* icon_expr = gtk_cclosure_expression_new(
+				G_TYPE_STRING,
+				NULL,
+				G_N_ELEMENTS( icon_params ),
+				icon_params,
+				G_CALLBACK( foobar_panel_item_status_compute_brightness_icon ),
+				NULL,
+				NULL );
+			GtkWidget* icon = gtk_image_new( );
+			gtk_widget_set_valign( icon, GTK_ALIGN_CENTER );
+			gtk_expression_bind( icon_expr, icon, "icon-name", NULL );
+			gtk_box_append( GTK_BOX( box ), icon );
+
+			if ( show_labels )
+			{
+				GtkExpression* label_params[] = { gtk_expression_ref( percentage_expr ) };
+				GtkExpression* label_expr = gtk_cclosure_expression_new(
+					G_TYPE_STRING,
+					NULL,
+					G_N_ELEMENTS( label_params ),
+					label_params,
+					G_CALLBACK( foobar_panel_item_status_compute_brightness_label ),
+					NULL,
+					NULL );
+				GtkWidget* label = gtk_label_new( NULL );
+				gtk_widget_set_valign( label, GTK_ALIGN_CENTER );
+				gtk_expression_bind( label_expr, label, "label", NULL );
+				gtk_box_append( GTK_BOX( box ), label );
+			}
+
+			return box;
+		}
+		case FOOBAR_STATUS_ITEM_AUDIO:
+		{
+			GtkWidget* box = gtk_box_new( GTK_ORIENTATION_HORIZONTAL, 0 );
+			gtk_widget_set_valign( box, GTK_ALIGN_FILL );
+
+			if ( enable_scrolling )
+			{
+				GtkEventController* scroll_controller = gtk_event_controller_scroll_new(
+					GTK_EVENT_CONTROLLER_SCROLL_VERTICAL | GTK_EVENT_CONTROLLER_SCROLL_DISCRETE );
+				g_signal_connect(
+					scroll_controller,
+					"scroll",
+					G_CALLBACK( foobar_panel_item_status_handle_audio_scroll ),
+					self );
+				gtk_widget_add_controller( box, scroll_controller );
+			}
+
+			GtkExpression* device_expr = gtk_constant_expression_new(
+				FOOBAR_TYPE_AUDIO_DEVICE,
+				foobar_audio_service_get_default_output( self->audio_service ) );
+			GtkExpression* available_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_AUDIO_DEVICE,
+				gtk_expression_ref( device_expr ),
+				"is-available" );
+			GtkExpression* volume_expr = gtk_property_expression_new(
+				FOOBAR_TYPE_AUDIO_DEVICE,
+				gtk_expression_ref( device_expr ),
+				"volume" );
+
+			GtkExpression* icon_params[] = { available_expr, volume_expr };
+			GtkExpression* icon_expr = gtk_cclosure_expression_new(
+				G_TYPE_STRING,
+				NULL,
+				G_N_ELEMENTS( icon_params ),
+				icon_params,
+				G_CALLBACK( foobar_panel_item_status_compute_audio_icon ),
+				NULL,
+				NULL );
+			GtkWidget* icon = gtk_image_new( );
+			gtk_widget_set_valign( icon, GTK_ALIGN_CENTER );
+			gtk_expression_bind( icon_expr, icon, "icon-name", NULL );
+			gtk_box_append( GTK_BOX( box ), icon );
+
+			if ( show_labels )
+			{
+				GtkExpression* label_params[] = { gtk_expression_ref( available_expr ), gtk_expression_ref( volume_expr ) };
+				GtkExpression* label_expr = gtk_cclosure_expression_new(
+					G_TYPE_STRING,
+					NULL,
+					G_N_ELEMENTS( label_params ),
+					label_params,
+					G_CALLBACK( foobar_panel_item_status_compute_audio_label ),
+					NULL,
+					NULL );
+				GtkWidget* label = gtk_label_new( NULL );
+				gtk_widget_set_valign( label, GTK_ALIGN_CENTER );
+				gtk_expression_bind( label_expr, label, "label", NULL );
+				gtk_box_append( GTK_BOX( box ), label );
+			}
+
+			return box;
+		}
+		case FOOBAR_STATUS_ITEM_NOTIFICATIONS:
+		{
+			GtkWidget* icon = gtk_image_new( );
+			gtk_widget_set_valign( icon, GTK_ALIGN_CENTER );
+
+			GtkExpression* list_expr = gtk_constant_expression_new(
+				G_TYPE_LIST_MODEL,
+				foobar_notification_service_get_notifications( self->notification_service ) );
+			GtkExpression* count_expr = gtk_property_expression_new(
+				GTK_TYPE_SORT_LIST_MODEL,
+				list_expr,
+				"n-items" );
+			GtkExpression* icon_params[] = { count_expr };
+			GtkExpression* icon_expr = gtk_cclosure_expression_new(
+				G_TYPE_STRING,
+				NULL,
+				G_N_ELEMENTS( icon_params ),
+				icon_params,
+				G_CALLBACK( foobar_panel_item_status_compute_notifications_icon ),
+				NULL,
+				NULL );
+			gtk_expression_bind( icon_expr, icon, "icon-name", NULL );
+
+			return icon;
+		}
+		default:
+			g_warn_if_reached( );
+			return NULL;
+	}
+}
+
+//
+// Force re-evaluation of the network icon expression.
+//
+// This is used whenever the active network or its strength changes.
+//
+void foobar_panel_item_status_reevaluate_network( FoobarPanelItemStatus* self )
+{
+	if ( self->network_icon && self->network_icon_expr )
+	{
+		GValue value = G_VALUE_INIT;
+		if ( gtk_expression_evaluate( self->network_icon_expr, NULL, &value ) )
+		{
+			gtk_image_set_from_icon_name( GTK_IMAGE( self->network_icon ), g_value_get_string( &value ) );
+		}
+		g_value_unset( &value );
+	}
+}
diff --git a/csrc/widgets/panel/panel-item-status.h b/csrc/widgets/panel/panel-item-status.h
new file mode 100644
index 0000000..0f1cfdb
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-status.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include "widgets/panel/panel-item.h"
+#include "services/battery-service.h"
+#include "services/brightness-service.h"
+#include "services/audio-service.h"
+#include "services/network-service.h"
+#include "services/bluetooth-service.h"
+#include "services/notification-service.h"
+
+G_BEGIN_DECLS
+
+#define FOOBAR_TYPE_PANEL_ITEM_STATUS foobar_panel_item_status_get_type( )
+
+G_DECLARE_FINAL_TYPE( FoobarPanelItemStatus, foobar_panel_item_status, FOOBAR, PANEL_ITEM_STATUS, FoobarPanelItem )
+
+FoobarPanelItem* foobar_panel_item_status_new( FoobarPanelItemConfiguration const* config,
+                                               FoobarBatteryService*               battery_service,
+                                               FoobarBrightnessService*            brightness_service,
+                                               FoobarAudioService*                 audio_service,
+                                               FoobarNetworkService*               network_service,
+                                               FoobarBluetoothService*             bluetooth_service,
+                                               FoobarNotificationService*          notification_service );
+
+G_END_DECLS
diff --git a/csrc/widgets/panel/panel-item-workspaces.c b/csrc/widgets/panel/panel-item-workspaces.c
new file mode 100644
index 0000000..dff629b
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-workspaces.c
@@ -0,0 +1,327 @@
+#include "widgets/panel/panel-item-workspaces.h"
+#include "widgets/inset-container.h"
+
+//
+// FoobarPanelItemWorkspaces:
+//
+// A panel item showing all workspaces for the current monitor (if multi-monitor mode is enabled) as buttons, indicating
+// the current state of the workspace (i.e., whether it's active, visible, special, etc.).
+//
+
+struct _FoobarPanelItemWorkspaces
+{
+	FoobarPanelItem         parent_instance;
+	GtkWidget*              list_view;
+	GtkWidget*              inset_container;
+	FoobarWorkspaceService* workspace_service;
+	gint                    button_size;
+	gint                    spacing;
+	GtkFilter*              monitor_filter;
+	gulong                  monitor_configuration_handler_id;
+};
+
+enum
+{
+	PROP_ORIENTATION = 1,
+	N_PROPS,
+};
+
+static GParamSpec* props[N_PROPS] = { 0 };
+
+static void     foobar_panel_item_workspaces_class_init                          ( FoobarPanelItemWorkspacesClass* klass );
+static void     foobar_panel_item_workspaces_init                                ( FoobarPanelItemWorkspaces*      self );
+static void     foobar_panel_item_workspaces_get_property                        ( GObject*                        object,
+                                                                                   guint                           prop_id,
+                                                                                   GValue*                         value,
+                                                                                   GParamSpec*                     pspec );
+static void     foobar_panel_item_workspaces_set_property                        ( GObject*                        object,
+                                                                                   guint                           prop_id,
+                                                                                   GValue const*                   value,
+                                                                                   GParamSpec*                     pspec );
+static void     foobar_panel_item_workspaces_finalize                            ( GObject*                        object );
+static void     foobar_panel_item_workspaces_handle_item_setup                   ( GtkListItemFactory*             factory,
+                                                                                   GtkListItem*                    list_item,
+                                                                                   gpointer                        userdata );
+static void     foobar_panel_item_workspaces_handle_item_clicked                 ( GtkButton*                      button,
+                                                                                   gpointer                        userdata );
+static void     foobar_panel_item_workspaces_handle_monitor_configuration_changed( FoobarWorkspaceService*         service,
+                                                                                   gpointer                        userdata );
+static gchar**  foobar_panel_item_workspaces_compute_css_classes                 ( GtkExpression*                  expression,
+                                                                                   FoobarWorkspaceFlags            flags,
+                                                                                   gpointer                        userdata );
+static gboolean foobar_panel_item_workspaces_monitor_filter_func                 ( gpointer                        item,
+                                                                                   gpointer                        userdata );
+
+G_DEFINE_FINAL_TYPE_WITH_CODE(
+	FoobarPanelItemWorkspaces,
+	foobar_panel_item_workspaces,
+	FOOBAR_TYPE_PANEL_ITEM,
+	G_IMPLEMENT_INTERFACE( GTK_TYPE_ORIENTABLE, NULL ) )
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Panel Item Implementation
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Static initialization for workspace panel items.
+//
+void foobar_panel_item_workspaces_class_init( FoobarPanelItemWorkspacesClass* klass )
+{
+	GObjectClass* object_klass = G_OBJECT_CLASS( klass );
+	object_klass->get_property = foobar_panel_item_workspaces_get_property;
+	object_klass->set_property = foobar_panel_item_workspaces_set_property;
+	object_klass->finalize = foobar_panel_item_workspaces_finalize;
+
+	gpointer orientable_iface = g_type_default_interface_peek( GTK_TYPE_ORIENTABLE );
+	props[PROP_ORIENTATION] = g_param_spec_override(
+		"orientation",
+		g_object_interface_find_property( orientable_iface, "orientation" ) );
+	g_object_class_install_properties( object_klass, N_PROPS, props );
+}
+
+//
+// Instance initialization for workspace panel items.
+//
+void foobar_panel_item_workspaces_init( FoobarPanelItemWorkspaces* self )
+{
+	GtkListItemFactory* item_factory = gtk_signal_list_item_factory_new( );
+	g_signal_connect( item_factory, "setup", G_CALLBACK( foobar_panel_item_workspaces_handle_item_setup ), self );
+
+	self->list_view = gtk_list_view_new( NULL, item_factory );
+	gtk_widget_set_halign( self->list_view, GTK_ALIGN_CENTER );
+	gtk_widget_set_valign( self->list_view, GTK_ALIGN_CENTER );
+	gtk_list_view_set_single_click_activate( GTK_LIST_VIEW( self->list_view ), TRUE );
+
+	self->inset_container = foobar_inset_container_new( );
+	foobar_inset_container_set_child( FOOBAR_INSET_CONTAINER( self->inset_container ), GTK_WIDGET( self->list_view ) );
+
+	gtk_widget_add_css_class( GTK_WIDGET( self ), "workspaces" );
+	foobar_panel_item_set_child( FOOBAR_PANEL_ITEM( self ), GTK_WIDGET( self->inset_container ) );
+}
+
+//
+// Property getter implementation, mapping a property id to a method.
+//
+void foobar_panel_item_workspaces_get_property(
+	GObject*    object,
+	guint       prop_id,
+	GValue*     value,
+	GParamSpec* pspec )
+{
+	FoobarPanelItemWorkspaces* self = (FoobarPanelItemWorkspaces*)object;
+
+	switch ( prop_id )
+	{
+		case PROP_ORIENTATION:
+			g_value_set_enum( value, gtk_orientable_get_orientation( GTK_ORIENTABLE( self->list_view ) ) );
+			break;
+		default:
+			G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec );
+			break;
+	}
+}
+
+//
+// Property setter implementation, mapping a property id to a method.
+//
+void foobar_panel_item_workspaces_set_property(
+	GObject*      object,
+	guint         prop_id,
+	GValue const* value,
+	GParamSpec*   pspec )
+{
+	FoobarPanelItemWorkspaces* self = (FoobarPanelItemWorkspaces*)object;
+
+	switch ( prop_id )
+	{
+		case PROP_ORIENTATION:
+			gtk_orientable_set_orientation( GTK_ORIENTABLE( self->list_view ), g_value_get_enum( value ) );
+			g_object_notify_by_pspec( G_OBJECT( self ), props[PROP_ORIENTATION] );
+			break;
+		default:
+			G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec );
+			break;
+	}
+}
+
+//
+// Instance cleanup for workspace panel items.
+//
+void foobar_panel_item_workspaces_finalize( GObject* object )
+{
+	FoobarPanelItemWorkspaces* self = (FoobarPanelItemWorkspaces*)object;
+
+	g_clear_signal_handler( &self->monitor_configuration_handler_id, self->workspace_service );
+	g_clear_object( &self->workspace_service );
+	g_clear_object( &self->monitor_filter );
+
+	G_OBJECT_CLASS( foobar_panel_item_workspaces_parent_class )->finalize( object );
+}
+
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Create a new workspaces panel item with the given configuration.
+//
+// If monitor is not NULL, only workspaces on this monitor will be shown.
+//
+FoobarPanelItem* foobar_panel_item_workspaces_new(
+	FoobarPanelItemConfiguration const* config,
+	GdkMonitor*                         monitor,
+	FoobarWorkspaceService*             workspace_service )
+{
+	g_return_val_if_fail( config != NULL, NULL );
+	g_return_val_if_fail( foobar_panel_item_configuration_get_kind( config ) == FOOBAR_PANEL_ITEM_KIND_WORKSPACES, NULL );
+	g_return_val_if_fail( monitor == NULL || GDK_IS_MONITOR( monitor ), NULL );
+	g_return_val_if_fail( FOOBAR_IS_WORKSPACE_SERVICE( workspace_service ), NULL );
+
+	FoobarPanelItemWorkspaces* self = g_object_new( FOOBAR_TYPE_PANEL_ITEM_WORKSPACES, NULL );
+	self->button_size = foobar_panel_item_workspaces_configuration_get_button_size( config );
+	self->spacing = foobar_panel_item_workspaces_configuration_get_spacing( config );
+	self->workspace_service = g_object_ref( workspace_service );
+
+	// Set up the source model, optionally enabling filtering.
+
+	GListModel* source_model = g_object_ref( foobar_workspace_service_get_workspaces( self->workspace_service ) );
+	if ( monitor )
+	{
+		GtkCustomFilter* filter = gtk_custom_filter_new(
+			foobar_panel_item_workspaces_monitor_filter_func,
+			g_object_ref( monitor ),
+			g_object_unref );
+		self->monitor_filter = GTK_FILTER( filter );
+		source_model = G_LIST_MODEL( gtk_filter_list_model_new( source_model, g_object_ref( self->monitor_filter ) ) );
+
+		self->monitor_configuration_handler_id = g_signal_connect(
+			self->workspace_service,
+			"monitor-configuration-changed",
+			G_CALLBACK( foobar_panel_item_workspaces_handle_monitor_configuration_changed ),
+			self );
+	}
+	GtkNoSelection* selection_model = gtk_no_selection_new( source_model );
+	gtk_list_view_set_model( GTK_LIST_VIEW( self->list_view ), GTK_SELECTION_MODEL( selection_model ) );
+
+	// Wrap the list in an inset container to remove the outer margin from the items.
+
+	foobar_inset_container_set_inset_horizontal( FOOBAR_INSET_CONTAINER( self->inset_container ), -self->spacing / 2 );
+	foobar_inset_container_set_inset_vertical( FOOBAR_INSET_CONTAINER( self->inset_container ), -self->spacing / 2 );
+
+	return FOOBAR_PANEL_ITEM( self );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Signal Handlers
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Called by the list view to create a widget for displaying a workspace.
+//
+void foobar_panel_item_workspaces_handle_item_setup(
+	GtkListItemFactory* factory,
+	GtkListItem*        list_item,
+	gpointer            userdata )
+{
+	(void)factory;
+	FoobarPanelItemWorkspaces* self = (FoobarPanelItemWorkspaces*)userdata;
+
+	GtkWidget* button = gtk_button_new( );
+	gtk_widget_set_size_request( button, self->button_size, self->button_size );
+	gtk_widget_set_margin_top( button, self->spacing / 2 );
+	gtk_widget_set_margin_bottom( button, self->spacing / 2 );
+	gtk_widget_set_margin_start( button, self->spacing / 2 );
+	gtk_widget_set_margin_end( button, self->spacing / 2 );
+	g_signal_connect(
+		button,
+		"clicked",
+		G_CALLBACK( foobar_panel_item_workspaces_handle_item_clicked ),
+		list_item );
+
+	gtk_list_item_set_child( list_item, button );
+
+	{
+		GtkExpression* item_expr = gtk_property_expression_new( GTK_TYPE_LIST_ITEM, NULL, "item" );
+		GtkExpression* active_expr = gtk_property_expression_new( FOOBAR_TYPE_WORKSPACE, item_expr, "flags" );
+		GtkExpression* params[] = { active_expr };
+		GtkExpression* css_expr = gtk_cclosure_expression_new(
+			G_TYPE_STRV,
+			NULL,
+			G_N_ELEMENTS( params ),
+			params,
+			G_CALLBACK( foobar_panel_item_workspaces_compute_css_classes ),
+			NULL,
+			NULL );
+		gtk_expression_bind( css_expr, button, "css-classes", list_item );
+	}
+}
+
+//
+// Called by the workspace service when the monitor for any workspace has changed.
+//
+// This is needed because the GtkFilterListModel does not track changes to the item properties and needs to be
+// re-evaluated manually.
+//
+void foobar_panel_item_workspaces_handle_monitor_configuration_changed(
+	FoobarWorkspaceService* service,
+	gpointer                userdata )
+{
+	(void)service;
+	FoobarPanelItemWorkspaces* self = (FoobarPanelItemWorkspaces*)userdata;
+
+	gtk_filter_changed( self->monitor_filter, GTK_FILTER_CHANGE_DIFFERENT );
+}
+
+//
+// Called when a workspace button was clicked, activating that workspace.
+//
+void foobar_panel_item_workspaces_handle_item_clicked( GtkButton* button, gpointer userdata )
+{
+	(void)button;
+	GtkListItem* item = (GtkListItem*)userdata;
+
+	FoobarWorkspace* workspace = gtk_list_item_get_item( item );
+	if ( workspace ) { foobar_workspace_activate( workspace ); }
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Value Converters
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Derive the list of CSS classes for a workspace button from the workspace's current flags.
+//
+gchar** foobar_panel_item_workspaces_compute_css_classes(
+	GtkExpression*       expression,
+	FoobarWorkspaceFlags flags,
+	gpointer             userdata )
+{
+	(void)expression;
+	(void)userdata;
+
+	GStrvBuilder* builder = g_strv_builder_new( );
+	if ( flags & FOOBAR_WORKSPACE_FLAGS_ACTIVE ) { g_strv_builder_add( builder, "active" ); }
+	if ( flags & FOOBAR_WORKSPACE_FLAGS_VISIBLE ) { g_strv_builder_add( builder, "visible" ); }
+	if ( flags & FOOBAR_WORKSPACE_FLAGS_SPECIAL ) { g_strv_builder_add( builder, "special" ); }
+	if ( flags & FOOBAR_WORKSPACE_FLAGS_URGENT ) { g_strv_builder_add( builder, "urgent" ); }
+	if ( flags & FOOBAR_WORKSPACE_FLAGS_PERSISTENT ) { g_strv_builder_add( builder, "persistent" ); }
+	return g_strv_builder_end( builder );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Helper Methods
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Check if a workspace is on the panel's monitor.
+//
+gboolean foobar_panel_item_workspaces_monitor_filter_func( gpointer item, gpointer userdata )
+{
+	FoobarWorkspace* workspace = (FoobarWorkspace*)item;
+	GdkMonitor* monitor = (GdkMonitor*)userdata;
+
+	gchar const* expected = gdk_monitor_get_connector( monitor );
+	gchar const* actual = foobar_workspace_get_monitor( workspace );
+	return !expected || !g_strcmp0( expected, actual );
+}
diff --git a/csrc/widgets/panel/panel-item-workspaces.h b/csrc/widgets/panel/panel-item-workspaces.h
new file mode 100644
index 0000000..d179217
--- /dev/null
+++ b/csrc/widgets/panel/panel-item-workspaces.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "widgets/panel/panel-item.h"
+#include "services/workspace-service.h"
+
+G_BEGIN_DECLS
+
+#define FOOBAR_TYPE_PANEL_ITEM_WORKSPACES foobar_panel_item_workspaces_get_type( )
+
+G_DECLARE_FINAL_TYPE( FoobarPanelItemWorkspaces, foobar_panel_item_workspaces, FOOBAR, PANEL_ITEM_WORKSPACES, FoobarPanelItem )
+
+FoobarPanelItem* foobar_panel_item_workspaces_new( FoobarPanelItemConfiguration const* config,
+                                                   GdkMonitor*                         monitor,
+                                                   FoobarWorkspaceService*             workspace_service );
+
+G_END_DECLS
diff --git a/csrc/widgets/panel/panel-item.c b/csrc/widgets/panel/panel-item.c
new file mode 100644
index 0000000..918d9f5
--- /dev/null
+++ b/csrc/widgets/panel/panel-item.c
@@ -0,0 +1,195 @@
+#include "widgets/panel/panel-item.h"
+#include "application.h"
+
+//
+// FoobarPanelItem:
+//
+// Base class for all panel items. This is basically a bin layout where the subclass usually sets the child widget.
+//
+
+typedef struct _FoobarPanelItemPrivate
+{
+	GtkWidget* child;
+} FoobarPanelItemPrivate;
+
+enum
+{
+	PROP_CHILD = 1,
+	N_PROPS,
+};
+
+static GParamSpec* props[N_PROPS] = { 0 };
+
+static void foobar_panel_item_class_init  ( FoobarPanelItemClass* klass );
+static void foobar_panel_item_init        ( FoobarPanelItem*      self );
+static void foobar_panel_item_get_property( GObject*              object,
+                                            guint                 prop_id,
+                                            GValue*               value,
+                                            GParamSpec*           pspec );
+static void foobar_panel_item_set_property( GObject*              object,
+                                            guint                 prop_id,
+                                            GValue const*         value,
+                                            GParamSpec*           pspec );
+static void foobar_panel_item_dispose     ( GObject*              object );
+
+G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE( FoobarPanelItem, foobar_panel_item, GTK_TYPE_WIDGET )
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Widget Implementation
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Static initialization for panel items.
+//
+void foobar_panel_item_class_init( FoobarPanelItemClass* klass )
+{
+	GtkWidgetClass* widget_klass = GTK_WIDGET_CLASS( klass );
+	gtk_widget_class_set_css_name( widget_klass, "panel-item" );
+	gtk_widget_class_set_layout_manager_type( widget_klass, GTK_TYPE_BIN_LAYOUT );
+
+	GObjectClass* object_klass = G_OBJECT_CLASS( klass );
+	object_klass->get_property = foobar_panel_item_get_property;
+	object_klass->set_property = foobar_panel_item_set_property;
+	object_klass->dispose = foobar_panel_item_dispose;
+
+	props[PROP_CHILD] = g_param_spec_object(
+		"child",
+		"Child",
+		"Child widget for the panel item.",
+		GTK_TYPE_WIDGET,
+		G_PARAM_READWRITE );
+	g_object_class_install_properties( object_klass, N_PROPS, props );
+}
+
+//
+// Instance initialization for panel items.
+//
+void foobar_panel_item_init( FoobarPanelItem* self )
+{
+	(void)self;
+}
+
+//
+// Property getter implementation, mapping a property id to a method.
+//
+void foobar_panel_item_get_property(
+	GObject*    object,
+	guint       prop_id,
+	GValue*     value,
+	GParamSpec* pspec )
+{
+	FoobarPanelItem* self = (FoobarPanelItem*)object;
+
+	switch ( prop_id )
+	{
+		case PROP_CHILD:
+			g_value_set_object( value, foobar_panel_item_get_child( self ) );
+			break;
+		default:
+			G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec );
+			break;
+	}
+}
+
+//
+// Property setter implementation, mapping a property id to a method.
+//
+void foobar_panel_item_set_property(
+	GObject*      object,
+	guint         prop_id,
+	GValue const* value,
+	GParamSpec*   pspec )
+{
+	FoobarPanelItem* self = (FoobarPanelItem*)object;
+
+	switch ( prop_id )
+	{
+		case PROP_CHILD:
+			foobar_panel_item_set_child( self, g_value_get_object( value ) );
+			break;
+		default:
+			G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec );
+			break;
+	}
+}
+
+//
+// Instance de-initialization for panel items.
+//
+void foobar_panel_item_dispose( GObject* object )
+{
+	FoobarPanelItem*        self = (FoobarPanelItem*)object;
+	FoobarPanelItemPrivate* priv = foobar_panel_item_get_instance_private( self );
+
+	g_clear_pointer( &priv->child, gtk_widget_unparent );
+
+	G_OBJECT_CLASS( foobar_panel_item_parent_class )->dispose( object );
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------------------------------------------------
+
+//
+// Get the child widget for the panel item.
+//
+GtkWidget* foobar_panel_item_get_child( FoobarPanelItem* self )
+{
+	g_return_val_if_fail( FOOBAR_IS_PANEL_ITEM( self ), NULL );
+	FoobarPanelItemPrivate* priv = foobar_panel_item_get_instance_private( self );
+
+	return priv->child;
+}
+
+//
+// Update the child widget for the panel item.
+//
+void foobar_panel_item_set_child(
+	FoobarPanelItem* self,
+	GtkWidget*       child )
+{
+	g_return_if_fail( FOOBAR_IS_PANEL_ITEM( self ) );
+	FoobarPanelItemPrivate* priv = foobar_panel_item_get_instance_private( self );
+	g_return_if_fail( child == NULL || priv->child == child || gtk_widget_get_parent( child ) == NULL );
+
+	if ( priv->child != child )
+	{
+		g_clear_pointer( &priv->child, gtk_widget_unparent );
+
+		if ( child )
+		{
+			priv->child = child;
+			gtk_widget_set_parent( child, GTK_WIDGET( self ) );
+		}
+
+		g_object_notify_by_pspec( G_OBJECT( self ), props[PROP_CHILD] );
+	}
+}
+
+//
+// Invoke the action for the panel item.
+//
+// This needs to be triggered by a subclass, for example by adding a button to the item. Support for panel item actions
+// is opt-in and subclasses have to explicitly implement it. This is just a helper for implementing the action.
+//
+void foobar_panel_item_invoke_action(
+	FoobarPanelItem*      self,
+	FoobarPanelItemAction action )
+{
+	g_return_if_fail( FOOBAR_IS_PANEL_ITEM( self ) );
+
+	switch ( action )
+	{
+		case FOOBAR_PANEL_ITEM_ACTION_NONE:
+			break;
+		case FOOBAR_PANEL_ITEM_ACTION_LAUNCHER:
+			foobar_application_toggle_launcher( FOOBAR_APPLICATION_DEFAULT );
+			break;
+		case FOOBAR_PANEL_ITEM_ACTION_CONTROL_CENTER:
+			foobar_application_toggle_control_center( FOOBAR_APPLICATION_DEFAULT );
+			break;
+		default:
+			g_warn_if_reached( );
+			break;
+	}
+}
diff --git a/csrc/widgets/panel/panel-item.h b/csrc/widgets/panel/panel-item.h
new file mode 100644
index 0000000..12a7e35
--- /dev/null
+++ b/csrc/widgets/panel/panel-item.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <gtk/gtk.h>
+#include "services/configuration-service.h"
+
+G_BEGIN_DECLS
+
+#define FOOBAR_TYPE_PANEL_ITEM foobar_panel_item_get_type( )
+
+G_DECLARE_DERIVABLE_TYPE( FoobarPanelItem, foobar_panel_item, FOOBAR, PANEL_ITEM, GtkWidget )
+
+struct _FoobarPanelItemClass
+{
+	GtkWidgetClass parent_class;
+};
+
+GtkWidget* foobar_panel_item_get_child    ( FoobarPanelItem*      self );
+void       foobar_panel_item_set_child    ( FoobarPanelItem*      self,
+                                            GtkWidget*            child );
+void       foobar_panel_item_invoke_action( FoobarPanelItem*      self,
+                                            FoobarPanelItemAction action );
+
+G_END_DECLS