Adding upstream version 3.38.6.upstream/3.38.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3024 insertions, 0 deletions

diff --git a/src/st/st-widget.c b/src/st/st-widget.c
new file mode 100644
index 0000000..bfce545
--- /dev/null
+++ b/src/st/st-widget.c
@@ -0,0 +1,3024 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * st-widget.c: Base class for St actors
+ *
+ * Copyright 2007 OpenedHand
+ * Copyright 2008, 2009 Intel Corporation.
+ * Copyright 2009, 2010 Red Hat, Inc.
+ * Copyright 2009 Abderrahim Kitouni
+ * Copyright 2009, 2010 Florian Müllner
+ * Copyright 2010 Adel Gadllah
+ * Copyright 2012 Igalia, S.L.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#include <clutter/clutter.h>
+
+#include "st-widget.h"
+
+#include "st-label.h"
+#include "st-private.h"
+#include "st-settings.h"
+#include "st-texture-cache.h"
+#include "st-theme-context.h"
+#include "st-theme-node-transition.h"
+#include "st-theme-node-private.h"
+#include "st-drawing-area.h"
+
+#include "st-widget-accessible.h"
+
+#include <atk/atk-enum-types.h>
+
+/* This is set in stone and also hard-coded in GDK. */
+#define VIRTUAL_CORE_POINTER_ID 2
+
+/*
+ * Forward declaration for sake of StWidgetChild
+ */
+typedef struct _StWidgetPrivate        StWidgetPrivate;
+struct _StWidgetPrivate
+{
+  StThemeNode  *theme_node;
+  gchar        *pseudo_class;
+  gchar        *style_class;
+  gchar        *inline_style;
+
+  StThemeNodeTransition *transition_animation;
+
+  guint is_style_dirty : 1;
+  guint first_child_dirty : 1;
+  guint last_child_dirty : 1;
+  guint draw_bg_color : 1;
+  guint draw_border_internal : 1;
+  guint track_hover : 1;
+  guint hover : 1;
+  guint can_focus : 1;
+
+  gulong texture_file_changed_id;
+  guint update_child_styles_id;
+
+  AtkObject *accessible;
+  AtkRole accessible_role;
+  AtkStateSet *local_state_set;
+
+  ClutterActor *label_actor;
+  gchar        *accessible_name;
+
+  StWidget *last_visible_child;
+  StWidget *first_visible_child;
+
+  StThemeNodePaintState paint_states[2];
+  int current_paint_state : 2;
+};
+
+/**
+ * SECTION:st-widget
+ * @short_description: Base class for stylable actors
+ *
+ * #StWidget is a simple abstract class on top of #ClutterActor. It
+ * provides basic themeing properties.
+ *
+ * Actors in the St library should subclass #StWidget if they plan
+ * to obey to a certain #StStyle.
+ */
+
+enum
+{
+  PROP_0,
+
+  PROP_PSEUDO_CLASS,
+  PROP_STYLE_CLASS,
+  PROP_STYLE,
+  PROP_TRACK_HOVER,
+  PROP_HOVER,
+  PROP_CAN_FOCUS,
+  PROP_LABEL_ACTOR,
+  PROP_ACCESSIBLE_ROLE,
+  PROP_ACCESSIBLE_NAME,
+
+  N_PROPS
+};
+
+static GParamSpec *props[N_PROPS] = { NULL, };
+
+enum
+{
+  STYLE_CHANGED,
+  POPUP_MENU,
+
+  LAST_SIGNAL
+};
+
+static guint signals[LAST_SIGNAL] = { 0, };
+
+G_DEFINE_TYPE_WITH_PRIVATE (StWidget, st_widget, CLUTTER_TYPE_ACTOR);
+#define ST_WIDGET_PRIVATE(w) ((StWidgetPrivate *)st_widget_get_instance_private (w))
+
+static void st_widget_recompute_style (StWidget    *widget,
+                                       StThemeNode *old_theme_node);
+static gboolean st_widget_real_navigate_focus (StWidget         *widget,
+                                               ClutterActor     *from,
+                                               StDirectionType   direction);
+
+static AtkObject * st_widget_get_accessible (ClutterActor *actor);
+static gboolean    st_widget_has_accessible (ClutterActor *actor);
+
+static void
+st_widget_set_property (GObject      *gobject,
+                        guint         prop_id,
+                        const GValue *value,
+                        GParamSpec   *pspec)
+{
+  StWidget *actor = ST_WIDGET (gobject);
+
+  switch (prop_id)
+    {
+    case PROP_PSEUDO_CLASS:
+      st_widget_set_style_pseudo_class (actor, g_value_get_string (value));
+      break;
+
+    case PROP_STYLE_CLASS:
+      st_widget_set_style_class_name (actor, g_value_get_string (value));
+      break;
+
+    case PROP_STYLE:
+      st_widget_set_style (actor, g_value_get_string (value));
+      break;
+
+    case PROP_TRACK_HOVER:
+      st_widget_set_track_hover (actor, g_value_get_boolean (value));
+      break;
+
+    case PROP_HOVER:
+      st_widget_set_hover (actor, g_value_get_boolean (value));
+      break;
+
+    case PROP_CAN_FOCUS:
+      st_widget_set_can_focus (actor, g_value_get_boolean (value));
+      break;
+
+    case PROP_LABEL_ACTOR:
+      st_widget_set_label_actor (actor, g_value_get_object (value));
+      break;
+
+    case PROP_ACCESSIBLE_ROLE:
+      st_widget_set_accessible_role (actor, g_value_get_enum (value));
+      break;
+
+    case PROP_ACCESSIBLE_NAME:
+      st_widget_set_accessible_name (actor, g_value_get_string (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+st_widget_get_property (GObject    *gobject,
+                        guint       prop_id,
+                        GValue     *value,
+                        GParamSpec *pspec)
+{
+  StWidget *actor = ST_WIDGET (gobject);
+  StWidgetPrivate *priv = st_widget_get_instance_private (ST_WIDGET (gobject));
+
+  switch (prop_id)
+    {
+    case PROP_PSEUDO_CLASS:
+      g_value_set_string (value, priv->pseudo_class);
+      break;
+
+    case PROP_STYLE_CLASS:
+      g_value_set_string (value, priv->style_class);
+      break;
+
+    case PROP_STYLE:
+      g_value_set_string (value, priv->inline_style);
+      break;
+
+    case PROP_TRACK_HOVER:
+      g_value_set_boolean (value, priv->track_hover);
+      break;
+
+    case PROP_HOVER:
+      g_value_set_boolean (value, priv->hover);
+      break;
+
+    case PROP_CAN_FOCUS:
+      g_value_set_boolean (value, priv->can_focus);
+      break;
+
+    case PROP_LABEL_ACTOR:
+      g_value_set_object (value, priv->label_actor);
+      break;
+
+    case PROP_ACCESSIBLE_ROLE:
+      g_value_set_enum (value, st_widget_get_accessible_role (actor));
+      break;
+
+    case PROP_ACCESSIBLE_NAME:
+      g_value_set_string (value, priv->accessible_name);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+st_widget_remove_transition (StWidget *widget)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (priv->transition_animation)
+    {
+      g_object_run_dispose (G_OBJECT (priv->transition_animation));
+      g_object_unref (priv->transition_animation);
+      priv->transition_animation = NULL;
+    }
+}
+
+static void
+next_paint_state (StWidget *widget)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  priv->current_paint_state = (priv->current_paint_state + 1) % G_N_ELEMENTS (priv->paint_states);
+}
+
+static StThemeNodePaintState *
+current_paint_state (StWidget *widget)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  return &priv->paint_states[priv->current_paint_state];
+}
+
+static void
+st_widget_texture_cache_changed (StTextureCache *cache,
+                                 GFile          *file,
+                                 gpointer        user_data)
+{
+  StWidget *actor = ST_WIDGET (user_data);
+  StWidgetPrivate *priv = st_widget_get_instance_private (actor);
+  gboolean changed = FALSE;
+  int i;
+
+  for (i = 0; i < G_N_ELEMENTS (priv->paint_states); i++)
+    {
+      StThemeNodePaintState *paint_state = &priv->paint_states[i];
+      changed |= st_theme_node_paint_state_invalidate_for_file (paint_state, file);
+    }
+
+  if (changed && clutter_actor_is_mapped (CLUTTER_ACTOR (actor)))
+    clutter_actor_queue_redraw (CLUTTER_ACTOR (actor));
+}
+
+static void
+st_widget_dispose (GObject *gobject)
+{
+  StWidget *actor = ST_WIDGET (gobject);
+  StWidgetPrivate *priv = st_widget_get_instance_private (actor);
+
+  g_clear_pointer (&priv->theme_node, g_object_unref);
+
+  st_widget_remove_transition (actor);
+
+  g_clear_pointer (&priv->label_actor, g_object_unref);
+
+  g_clear_signal_handler (&priv->texture_file_changed_id,
+                          st_texture_cache_get_default ());
+
+  g_clear_object (&priv->first_visible_child);
+  g_clear_object (&priv->last_visible_child);
+
+  G_OBJECT_CLASS (st_widget_parent_class)->dispose (gobject);
+
+  g_clear_handle_id (&priv->update_child_styles_id, g_source_remove);
+}
+
+static void
+st_widget_finalize (GObject *gobject)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (ST_WIDGET (gobject));
+  guint i;
+
+  g_free (priv->style_class);
+  g_free (priv->pseudo_class);
+  g_object_unref (priv->local_state_set);
+  g_free (priv->accessible_name);
+  g_free (priv->inline_style);
+
+  for (i = 0; i < G_N_ELEMENTS (priv->paint_states); i++)
+    st_theme_node_paint_state_free (&priv->paint_states[i]);
+
+  G_OBJECT_CLASS (st_widget_parent_class)->finalize (gobject);
+}
+
+
+static void
+st_widget_get_preferred_width (ClutterActor *self,
+                               gfloat        for_height,
+                               gfloat       *min_width_p,
+                               gfloat       *natural_width_p)
+{
+  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (self));
+
+  st_theme_node_adjust_for_width (theme_node, &for_height);
+
+  CLUTTER_ACTOR_CLASS (st_widget_parent_class)->get_preferred_width (self, for_height, min_width_p, natural_width_p);
+
+  st_theme_node_adjust_preferred_width (theme_node, min_width_p, natural_width_p);
+}
+
+static void
+st_widget_get_preferred_height (ClutterActor *self,
+                                gfloat        for_width,
+                                gfloat       *min_height_p,
+                                gfloat       *natural_height_p)
+{
+  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (self));
+
+  st_theme_node_adjust_for_width (theme_node, &for_width);
+
+  CLUTTER_ACTOR_CLASS (st_widget_parent_class)->get_preferred_height (self, for_width, min_height_p, natural_height_p);
+
+  st_theme_node_adjust_preferred_height (theme_node, min_height_p, natural_height_p);
+}
+
+static void
+st_widget_allocate (ClutterActor          *actor,
+                    const ClutterActorBox *box)
+{
+  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
+  ClutterActorBox content_box;
+
+  /* Note that we can't just chain up to clutter_actor_real_allocate --
+   * Clutter does some dirty tricks for backwards compatibility.
+   * Clutter also passes the actor's allocation directly to the layout
+   * manager, meaning that we can't modify it for children only.
+   */
+
+  clutter_actor_set_allocation (actor, box);
+
+  st_theme_node_get_content_box (theme_node, box, &content_box);
+
+  /* If we've chained up to here, we want to allocate the children using the
+   * currently installed layout manager */
+  clutter_layout_manager_allocate (clutter_actor_get_layout_manager (actor),
+                                   CLUTTER_CONTAINER (actor),
+                                   &content_box);
+}
+
+/**
+ * st_widget_paint_background:
+ * @widget: The #StWidget
+ *
+ * Paint the background of the widget. This is meant to be called by
+ * subclasses of StWidget that need to paint the background without
+ * painting children.
+ */
+void
+st_widget_paint_background (StWidget            *widget,
+                            ClutterPaintContext *paint_context)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+  CoglFramebuffer *framebuffer;
+  StThemeNode *theme_node;
+  ClutterActorBox allocation;
+  float resource_scale;
+  guint8 opacity;
+
+  resource_scale = clutter_actor_get_resource_scale (CLUTTER_ACTOR (widget));
+
+  framebuffer = clutter_paint_context_get_framebuffer (paint_context);
+  theme_node = st_widget_get_theme_node (widget);
+
+  clutter_actor_get_allocation_box (CLUTTER_ACTOR (widget), &allocation);
+
+  opacity = clutter_actor_get_paint_opacity (CLUTTER_ACTOR (widget));
+
+  if (priv->transition_animation)
+    st_theme_node_transition_paint (priv->transition_animation,
+                                    framebuffer,
+                                    &allocation,
+                                    opacity,
+                                    resource_scale);
+  else
+    st_theme_node_paint (theme_node,
+                         current_paint_state (widget),
+                         framebuffer,
+                         &allocation,
+                         opacity,
+                         resource_scale);
+}
+
+static void
+st_widget_paint (ClutterActor        *actor,
+                 ClutterPaintContext *paint_context)
+{
+  st_widget_paint_background (ST_WIDGET (actor), paint_context);
+
+  /* Chain up so we paint children. */
+  CLUTTER_ACTOR_CLASS (st_widget_parent_class)->paint (actor, paint_context);
+}
+
+static void
+st_widget_parent_set (ClutterActor *widget,
+                      ClutterActor *old_parent)
+{
+  StWidget *self = ST_WIDGET (widget);
+  ClutterActorClass *parent_class;
+
+  parent_class = CLUTTER_ACTOR_CLASS (st_widget_parent_class);
+  if (parent_class->parent_set)
+    parent_class->parent_set (widget, old_parent);
+
+  st_widget_style_changed (self);
+}
+
+static void
+st_widget_map (ClutterActor *actor)
+{
+  StWidget *self = ST_WIDGET (actor);
+
+  CLUTTER_ACTOR_CLASS (st_widget_parent_class)->map (actor);
+
+  st_widget_ensure_style (self);
+}
+
+static void
+st_widget_unmap (ClutterActor *actor)
+{
+  StWidget *self = ST_WIDGET (actor);
+  StWidgetPrivate *priv = st_widget_get_instance_private (self);
+
+  CLUTTER_ACTOR_CLASS (st_widget_parent_class)->unmap (actor);
+
+  if (priv->track_hover && priv->hover)
+    st_widget_set_hover (self, FALSE);
+}
+
+static void
+notify_children_of_style_change (ClutterActor *self)
+{
+  ClutterActorIter iter;
+  ClutterActor *actor;
+
+  clutter_actor_iter_init (&iter, self);
+  while (clutter_actor_iter_next (&iter, &actor))
+    {
+      if (ST_IS_WIDGET (actor))
+        st_widget_style_changed (ST_WIDGET (actor));
+      else
+        notify_children_of_style_change (actor);
+    }
+}
+
+static void
+st_widget_real_style_changed (StWidget *self)
+{
+  clutter_actor_queue_redraw ((ClutterActor *) self);
+}
+
+void
+st_widget_style_changed (StWidget *widget)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+  StThemeNode *old_theme_node = NULL;
+
+  priv->is_style_dirty = TRUE;
+  if (priv->theme_node)
+    {
+      old_theme_node = priv->theme_node;
+      priv->theme_node = NULL;
+    }
+
+  /* update the style only if we are mapped */
+  if (clutter_actor_is_mapped (CLUTTER_ACTOR (widget)))
+    st_widget_recompute_style (widget, old_theme_node);
+
+  /* Descend through all children. If the actor is not mapped,
+   * children will clear their theme node without recomputing style.
+   */
+  notify_children_of_style_change (CLUTTER_ACTOR (widget));
+
+  if (old_theme_node)
+    g_object_unref (old_theme_node);
+}
+
+static void
+on_theme_context_changed (StThemeContext *context,
+                          ClutterStage   *stage)
+{
+  notify_children_of_style_change (CLUTTER_ACTOR (stage));
+}
+
+static StThemeNode *
+get_root_theme_node (ClutterStage *stage)
+{
+  StThemeContext *context = st_theme_context_get_for_stage (stage);
+
+  if (!g_object_get_data (G_OBJECT (context), "st-theme-initialized"))
+    {
+      g_object_set_data (G_OBJECT (context), "st-theme-initialized", GUINT_TO_POINTER (1));
+      g_signal_connect (G_OBJECT (context), "changed",
+                        G_CALLBACK (on_theme_context_changed), stage);
+    }
+
+  return st_theme_context_get_root_node (context);
+}
+
+/**
+ * st_widget_get_theme_node:
+ * @widget: a #StWidget
+ *
+ * Gets the theme node holding style information for the widget.
+ * The theme node is used to access standard and custom CSS
+ * properties of the widget.
+ *
+ * Note: it is a fatal error to call this on a widget that is
+ *  not been added to a stage.
+ *
+ * Returns: (transfer none): the theme node for the widget.
+ *   This is owned by the widget. When attributes of the widget
+ *   or the environment that affect the styling change (for example
+ *   the style_class property of the widget), it will be recreated,
+ *   and the ::style-changed signal will be emitted on the widget.
+ */
+StThemeNode *
+st_widget_get_theme_node (StWidget *widget)
+{
+  StWidgetPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_WIDGET (widget), NULL);
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->theme_node == NULL)
+    {
+      StThemeContext *context;
+      StThemeNode *tmp_node;
+      StThemeNode *parent_node = NULL;
+      ClutterStage *stage = NULL;
+      ClutterActor *parent;
+      char *pseudo_class, *direction_pseudo_class;
+
+      parent = clutter_actor_get_parent (CLUTTER_ACTOR (widget));
+      while (parent != NULL)
+        {
+          if (parent_node == NULL && ST_IS_WIDGET (parent))
+            parent_node = st_widget_get_theme_node (ST_WIDGET (parent));
+          else if (CLUTTER_IS_STAGE (parent))
+            stage = CLUTTER_STAGE (parent);
+
+          parent = clutter_actor_get_parent (parent);
+        }
+
+      if (stage == NULL)
+        {
+          g_autofree char *desc = st_describe_actor (CLUTTER_ACTOR (widget));
+
+          g_critical ("st_widget_get_theme_node called on the widget %s which is not in the stage.",
+                      desc);
+
+          return g_object_new (ST_TYPE_THEME_NODE, NULL);
+        }
+
+      if (parent_node == NULL)
+        parent_node = get_root_theme_node (CLUTTER_STAGE (stage));
+
+      /* Always append a "magic" pseudo class indicating the text
+       * direction, to allow to adapt the CSS when necessary without
+       * requiring separate style sheets.
+       */
+      if (clutter_actor_get_text_direction (CLUTTER_ACTOR (widget)) == CLUTTER_TEXT_DIRECTION_RTL)
+        direction_pseudo_class = (char *)"rtl";
+      else
+        direction_pseudo_class = (char *)"ltr";
+
+      if (priv->pseudo_class)
+        pseudo_class = g_strconcat(priv->pseudo_class, " ",
+                                   direction_pseudo_class, NULL);
+      else
+        pseudo_class = direction_pseudo_class;
+
+      context = st_theme_context_get_for_stage (stage);
+      tmp_node = st_theme_node_new (context, parent_node, NULL,
+                                    G_OBJECT_TYPE (widget),
+                                    clutter_actor_get_name (CLUTTER_ACTOR (widget)),
+                                    priv->style_class,
+                                    pseudo_class,
+                                    priv->inline_style);
+
+      if (pseudo_class != direction_pseudo_class)
+        g_free (pseudo_class);
+
+      priv->theme_node = g_object_ref (st_theme_context_intern_node (context,
+                                                                     tmp_node));
+      g_object_unref (tmp_node);
+    }
+
+  return priv->theme_node;
+}
+
+/**
+ * st_widget_peek_theme_node:
+ * @widget: a #StWidget
+ *
+ * Returns the theme node for the widget if it has already been
+ * computed, %NULL if the widget hasn't been added to a  stage or the theme
+ * node hasn't been computed. If %NULL is returned, then ::style-changed
+ * will be reliably emitted before the widget is allocated or painted.
+ *
+ * Returns: (transfer none): the theme node for the widget.
+ *   This is owned by the widget. When attributes of the widget
+ *   or the environment that affect the styling change (for example
+ *   the style_class property of the widget), it will be recreated,
+ *   and the ::style-changed signal will be emitted on the widget.
+ */
+StThemeNode *
+st_widget_peek_theme_node (StWidget *widget)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), NULL);
+
+  return ST_WIDGET_PRIVATE (widget)->theme_node;
+}
+
+static gboolean
+st_widget_enter (ClutterActor         *actor,
+                 ClutterCrossingEvent *event)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (ST_WIDGET (actor));
+
+  if (priv->track_hover)
+    {
+      if (clutter_actor_contains (actor, event->source))
+        st_widget_set_hover (ST_WIDGET (actor), TRUE);
+      else
+        {
+          /* The widget has a grab and is being told about an
+           * enter-event outside its hierarchy. Hopefully we already
+           * got a leave-event, but if not, handle it now.
+           */
+          st_widget_set_hover (ST_WIDGET (actor), FALSE);
+        }
+    }
+
+  if (CLUTTER_ACTOR_CLASS (st_widget_parent_class)->enter_event)
+    return CLUTTER_ACTOR_CLASS (st_widget_parent_class)->enter_event (actor, event);
+  else
+    return FALSE;
+}
+
+static gboolean
+st_widget_leave (ClutterActor         *actor,
+                 ClutterCrossingEvent *event)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (ST_WIDGET (actor));
+
+  if (priv->track_hover)
+    {
+      if (!event->related || !clutter_actor_contains (actor, event->related))
+        st_widget_set_hover (ST_WIDGET (actor), FALSE);
+    }
+
+  if (CLUTTER_ACTOR_CLASS (st_widget_parent_class)->leave_event)
+    return CLUTTER_ACTOR_CLASS (st_widget_parent_class)->leave_event (actor, event);
+  else
+    return FALSE;
+}
+
+static void
+st_widget_key_focus_in (ClutterActor *actor)
+{
+  StWidget *widget = ST_WIDGET (actor);
+
+  st_widget_add_style_pseudo_class (widget, "focus");
+}
+
+static void
+st_widget_key_focus_out (ClutterActor *actor)
+{
+  StWidget *widget = ST_WIDGET (actor);
+
+  st_widget_remove_style_pseudo_class (widget, "focus");
+}
+
+static gboolean
+st_widget_key_press_event (ClutterActor    *actor,
+                           ClutterKeyEvent *event)
+{
+  if (event->keyval == CLUTTER_KEY_Menu ||
+      (event->keyval == CLUTTER_KEY_F10 &&
+       (event->modifier_state & CLUTTER_SHIFT_MASK)))
+    {
+      st_widget_popup_menu (ST_WIDGET (actor));
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static gboolean
+st_widget_get_paint_volume (ClutterActor *self,
+                            ClutterPaintVolume *volume)
+{
+  ClutterActorBox paint_box, alloc_box;
+  StThemeNode *theme_node;
+  StWidgetPrivate *priv;
+  graphene_point3d_t origin;
+
+  /* Setting the paint volume does not make sense when we don't have any allocation */
+  if (!clutter_actor_has_allocation (self))
+    return FALSE;
+
+  priv = st_widget_get_instance_private (ST_WIDGET (self));
+
+  theme_node = st_widget_get_theme_node (ST_WIDGET (self));
+  clutter_actor_get_allocation_box (self, &alloc_box);
+
+  if (priv->transition_animation)
+    st_theme_node_transition_get_paint_box (priv->transition_animation,
+                                            &alloc_box, &paint_box);
+  else
+    st_theme_node_get_paint_box (theme_node, &alloc_box, &paint_box);
+
+  origin.x = paint_box.x1 - alloc_box.x1;
+  origin.y = paint_box.y1 - alloc_box.y1;
+  origin.z = 0.0f;
+
+  clutter_paint_volume_set_origin (volume, &origin);
+  clutter_paint_volume_set_width (volume, paint_box.x2 - paint_box.x1);
+  clutter_paint_volume_set_height (volume, paint_box.y2 - paint_box.y1);
+
+  if (!clutter_actor_get_clip_to_allocation (self))
+    {
+      ClutterActor *child;
+      /* Based on ClutterGroup/ClutterBox; include the children's
+       * paint volumes, since they may paint outside our allocation.
+       */
+      for (child = clutter_actor_get_first_child (self);
+           child != NULL;
+           child = clutter_actor_get_next_sibling (child))
+        {
+          const ClutterPaintVolume *child_volume;
+
+          if (!clutter_actor_is_visible (child))
+            continue;
+
+          child_volume = clutter_actor_get_transformed_paint_volume (child, self);
+          if (!child_volume)
+            return FALSE;
+
+          clutter_paint_volume_union (volume, child_volume);
+        }
+    }
+
+  return TRUE;
+}
+
+static GList *
+st_widget_real_get_focus_chain (StWidget *widget)
+{
+  GList *children, *l, *visible = NULL;
+
+  children = clutter_actor_get_children (CLUTTER_ACTOR (widget));
+
+  for (l = children; l; l = l->next)
+    {
+      if (clutter_actor_is_visible (CLUTTER_ACTOR (l->data)))
+        visible = g_list_prepend (visible, l->data);
+    }
+
+  g_list_free (children);
+
+  return g_list_reverse (visible);
+}
+
+static void
+st_widget_resource_scale_changed (ClutterActor *actor)
+{
+  StWidget *widget = ST_WIDGET (actor);
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+  int i;
+
+  for (i = 0; i < G_N_ELEMENTS (priv->paint_states); i++)
+    st_theme_node_paint_state_invalidate (&priv->paint_states[i]);
+
+  if (CLUTTER_ACTOR_CLASS (st_widget_parent_class)->resource_scale_changed)
+    CLUTTER_ACTOR_CLASS (st_widget_parent_class)->resource_scale_changed (actor);
+}
+
+static void
+st_widget_class_init (StWidgetClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
+
+  gobject_class->set_property = st_widget_set_property;
+  gobject_class->get_property = st_widget_get_property;
+  gobject_class->dispose = st_widget_dispose;
+  gobject_class->finalize = st_widget_finalize;
+
+  actor_class->get_preferred_width = st_widget_get_preferred_width;
+  actor_class->get_preferred_height = st_widget_get_preferred_height;
+  actor_class->allocate = st_widget_allocate;
+  actor_class->paint = st_widget_paint;
+  actor_class->get_paint_volume = st_widget_get_paint_volume;
+  actor_class->parent_set = st_widget_parent_set;
+  actor_class->map = st_widget_map;
+  actor_class->unmap = st_widget_unmap;
+
+  actor_class->enter_event = st_widget_enter;
+  actor_class->leave_event = st_widget_leave;
+  actor_class->key_focus_in = st_widget_key_focus_in;
+  actor_class->key_focus_out = st_widget_key_focus_out;
+  actor_class->key_press_event = st_widget_key_press_event;
+
+  actor_class->get_accessible = st_widget_get_accessible;
+  actor_class->has_accessible = st_widget_has_accessible;
+
+  actor_class->resource_scale_changed = st_widget_resource_scale_changed;
+
+  klass->style_changed = st_widget_real_style_changed;
+  klass->navigate_focus = st_widget_real_navigate_focus;
+  klass->get_accessible_type = st_widget_accessible_get_type;
+  klass->get_focus_chain = st_widget_real_get_focus_chain;
+
+  /**
+   * StWidget:pseudo-class:
+   *
+   * The pseudo-class of the actor. Typical values include "hover", "active",
+   * "focus".
+   */
+  props[PROP_PSEUDO_CLASS] =
+    g_param_spec_string ("pseudo-class",
+                         "Pseudo Class",
+                         "Pseudo class for styling",
+                         "",
+                         ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:style-class:
+   *
+   * The style-class of the actor for use in styling.
+   */
+  props[PROP_STYLE_CLASS] =
+    g_param_spec_string ("style-class",
+                         "Style Class",
+                         "Style class for styling",
+                         "",
+                         ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:style:
+   *
+   * Inline style information for the actor as a ';'-separated list of
+   * CSS properties.
+   */
+  props[PROP_STYLE] =
+     g_param_spec_string ("style",
+                          "Style",
+                          "Inline style string",
+                          "",
+                          ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:track-hover:
+   *
+   * Determines whether the widget tracks pointer hover state. If
+   * %TRUE (and the widget is visible and reactive), the
+   * #StWidget:hover property and "hover" style pseudo class will be
+   * adjusted automatically as the pointer moves in and out of the
+   * widget.
+   */
+  props[PROP_TRACK_HOVER] =
+     g_param_spec_boolean ("track-hover",
+                           "Track hover",
+                           "Determines whether the widget tracks hover state",
+                           FALSE,
+                           ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:hover:
+   *
+   * Whether or not the pointer is currently hovering over the widget. This is
+   * only tracked automatically if #StWidget:track-hover is %TRUE, but you can
+   * adjust it manually in any case.
+   */
+  props[PROP_HOVER] =
+     g_param_spec_boolean ("hover",
+                           "Hover",
+                           "Whether the pointer is hovering over the widget",
+                           FALSE,
+                           ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:can-focus:
+   *
+   * Whether or not the widget can be focused via keyboard navigation.
+   */
+  props[PROP_CAN_FOCUS] =
+     g_param_spec_boolean ("can-focus",
+                           "Can focus",
+                           "Whether the widget can be focused via keyboard navigation",
+                           FALSE,
+                           ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:label-actor:
+   *
+   * An actor that labels this widget.
+   */
+  props[PROP_LABEL_ACTOR] =
+     g_param_spec_object ("label-actor",
+                          "Label",
+                          "Label that identifies this widget",
+                          CLUTTER_TYPE_ACTOR,
+                          ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:accessible-role:
+   *
+   * The accessible role of this object
+   */
+  props[PROP_ACCESSIBLE_ROLE] =
+     g_param_spec_enum ("accessible-role",
+                        "Accessible Role",
+                        "The accessible role of this object",
+                        ATK_TYPE_ROLE,
+                        ATK_ROLE_INVALID,
+                        ST_PARAM_READWRITE);
+
+  /**
+   * StWidget:accessible-name:
+   *
+   * Object instance's name for assistive technology access.
+   */
+  props[PROP_ACCESSIBLE_NAME] =
+     g_param_spec_string ("accessible-name",
+                          "Accessible name",
+                          "Object instance's name for assistive technology access.",
+                          NULL,
+                          ST_PARAM_READWRITE);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, props);
+
+  /**
+   * StWidget::style-changed:
+   * @widget: the #StWidget
+   *
+   * Emitted when the style information that the widget derives from the
+   * theme changes
+   */
+  signals[STYLE_CHANGED] =
+    g_signal_new ("style-changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (StWidgetClass, style_changed),
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 0);
+
+  /**
+   * StWidget::popup-menu:
+   * @widget: the #StWidget
+   *
+   * Emitted when the user has requested a context menu (eg, via a keybinding)
+   */
+  signals[POPUP_MENU] =
+    g_signal_new ("popup-menu",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (StWidgetClass, popup_menu),
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 0);
+}
+
+static const gchar *
+find_class_name (const gchar *class_list,
+                 const gchar *class_name)
+{
+  gint len = strlen (class_name);
+  const gchar *match;
+
+  if (!class_list)
+    return NULL;
+
+  for (match = strstr (class_list, class_name); match; match = strstr (match + 1, class_name))
+    {
+      if ((match == class_list || g_ascii_isspace (match[-1])) &&
+          (match[len] == '\0' || g_ascii_isspace (match[len])))
+        return match;
+    }
+
+  return NULL;
+}
+
+static gboolean
+set_class_list (gchar       **class_list,
+                const gchar  *new_class_list)
+{
+  if (g_strcmp0 (*class_list, new_class_list) != 0)
+    {
+      g_free (*class_list);
+      *class_list = g_strdup (new_class_list);
+      return TRUE;
+    }
+  else
+    return FALSE;
+}
+
+static gboolean
+add_class_name (gchar       **class_list,
+                const gchar  *class_name)
+{
+  gchar *new_class_list;
+
+  if (*class_list)
+    {
+      if (find_class_name (*class_list, class_name))
+        return FALSE;
+
+      new_class_list = g_strdup_printf ("%s %s", *class_list, class_name);
+      g_free (*class_list);
+      *class_list = new_class_list;
+    }
+  else
+    *class_list = g_strdup (class_name);
+
+  return TRUE;
+}
+
+static gboolean
+remove_class_name (gchar       **class_list,
+                   const gchar  *class_name)
+{
+  const gchar *match, *end;
+  gchar *new_class_list;
+
+  if (!*class_list)
+    return FALSE;
+
+  if (strcmp (*class_list, class_name) == 0)
+    {
+      g_free (*class_list);
+      *class_list = NULL;
+      return TRUE;
+    }
+
+  match = find_class_name (*class_list, class_name);
+  if (!match)
+    return FALSE;
+  end = match + strlen (class_name);
+
+  /* Adjust either match or end to include a space as well.
+   * (One or the other must be possible at this point.)
+   */
+  if (match != *class_list)
+    match--;
+  else
+    end++;
+
+  new_class_list = g_strdup_printf ("%.*s%s", (int)(match - *class_list),
+                                    *class_list, end);
+  g_free (*class_list);
+  *class_list = new_class_list;
+
+  return TRUE;
+}
+
+/**
+ * st_widget_set_style_class_name:
+ * @actor: a #StWidget
+ * @style_class_list: (nullable): a new style class list string
+ *
+ * Set the style class name list. @style_class_list can either be
+ * %NULL, for no classes, or a space-separated list of style class
+ * names. See also st_widget_add_style_class_name() and
+ * st_widget_remove_style_class_name().
+ */
+void
+st_widget_set_style_class_name (StWidget    *actor,
+                                const gchar *style_class_list)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (set_class_list (&priv->style_class, style_class_list))
+    {
+      st_widget_style_changed (actor);
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_STYLE_CLASS]);
+    }
+}
+
+/**
+ * st_widget_add_style_class_name:
+ * @actor: a #StWidget
+ * @style_class: a style class name string
+ *
+ * Adds @style_class to @actor's style class name list, if it is not
+ * already present.
+ */
+void
+st_widget_add_style_class_name (StWidget    *actor,
+                                const gchar *style_class)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+  g_return_if_fail (style_class != NULL);
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (add_class_name (&priv->style_class, style_class))
+    {
+      st_widget_style_changed (actor);
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_STYLE_CLASS]);
+    }
+}
+
+/**
+ * st_widget_remove_style_class_name:
+ * @actor: a #StWidget
+ * @style_class: a style class name string
+ *
+ * Removes @style_class from @actor's style class name, if it is
+ * present.
+ */
+void
+st_widget_remove_style_class_name (StWidget    *actor,
+                                   const gchar *style_class)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+  g_return_if_fail (style_class != NULL);
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (remove_class_name (&priv->style_class, style_class))
+    {
+      st_widget_style_changed (actor);
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_STYLE_CLASS]);
+    }
+}
+
+/**
+ * st_widget_get_style_class_name:
+ * @actor: a #StWidget
+ *
+ * Get the current style class name
+ *
+ * Returns: the class name string. The string is owned by the #StWidget and
+ * should not be modified or freed.
+ */
+const gchar*
+st_widget_get_style_class_name (StWidget *actor)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (actor), NULL);
+
+  return ST_WIDGET_PRIVATE (actor)->style_class;
+}
+
+/**
+ * st_widget_has_style_class_name:
+ * @actor: a #StWidget
+ * @style_class: a style class string
+ *
+ * Tests if @actor's style class list includes @style_class.
+ *
+ * Returns: whether or not @actor's style class list includes
+ * @style_class.
+ */
+gboolean
+st_widget_has_style_class_name (StWidget    *actor,
+                                const gchar *style_class)
+{
+  StWidgetPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_WIDGET (actor), FALSE);
+
+  priv = st_widget_get_instance_private (actor);
+
+  return find_class_name (priv->style_class, style_class) != NULL;
+}
+
+/**
+ * st_widget_get_style_pseudo_class:
+ * @actor: a #StWidget
+ *
+ * Get the current style pseudo class list.
+ *
+ * Note that an actor can have multiple pseudo classes; if you just
+ * want to test for the presence of a specific pseudo class, use
+ * st_widget_has_style_pseudo_class().
+ *
+ * Returns: the pseudo class list string. The string is owned by the
+ * #StWidget and should not be modified or freed.
+ */
+const gchar*
+st_widget_get_style_pseudo_class (StWidget *actor)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (actor), NULL);
+
+  return ST_WIDGET_PRIVATE (actor)->pseudo_class;
+}
+
+/**
+ * st_widget_has_style_pseudo_class:
+ * @actor: a #StWidget
+ * @pseudo_class: a pseudo class string
+ *
+ * Tests if @actor's pseudo class list includes @pseudo_class.
+ *
+ * Returns: whether or not @actor's pseudo class list includes
+ * @pseudo_class.
+ */
+gboolean
+st_widget_has_style_pseudo_class (StWidget    *actor,
+                                  const gchar *pseudo_class)
+{
+  StWidgetPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_WIDGET (actor), FALSE);
+
+  priv = st_widget_get_instance_private (actor);
+
+  return find_class_name (priv->pseudo_class, pseudo_class) != NULL;
+}
+
+/**
+ * st_widget_set_style_pseudo_class:
+ * @actor: a #StWidget
+ * @pseudo_class_list: (nullable): a new pseudo class list string
+ *
+ * Set the style pseudo class list. @pseudo_class_list can either be
+ * %NULL, for no classes, or a space-separated list of pseudo class
+ * names. See also st_widget_add_style_pseudo_class() and
+ * st_widget_remove_style_pseudo_class().
+ */
+void
+st_widget_set_style_pseudo_class (StWidget    *actor,
+                                  const gchar *pseudo_class_list)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (set_class_list (&priv->pseudo_class, pseudo_class_list))
+    {
+      st_widget_style_changed (actor);
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_PSEUDO_CLASS]);
+    }
+}
+
+/**
+ * st_widget_add_style_pseudo_class:
+ * @actor: a #StWidget
+ * @pseudo_class: a pseudo class string
+ *
+ * Adds @pseudo_class to @actor's pseudo class list, if it is not
+ * already present.
+ */
+void
+st_widget_add_style_pseudo_class (StWidget    *actor,
+                                  const gchar *pseudo_class)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+  g_return_if_fail (pseudo_class != NULL);
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (add_class_name (&priv->pseudo_class, pseudo_class))
+    {
+      st_widget_style_changed (actor);
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_PSEUDO_CLASS]);
+    }
+}
+
+/**
+ * st_widget_remove_style_pseudo_class:
+ * @actor: a #StWidget
+ * @pseudo_class: a pseudo class string
+ *
+ * Removes @pseudo_class from @actor's pseudo class, if it is present.
+ */
+void
+st_widget_remove_style_pseudo_class (StWidget    *actor,
+                                     const gchar *pseudo_class)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+  g_return_if_fail (pseudo_class != NULL);
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (remove_class_name (&priv->pseudo_class, pseudo_class))
+    {
+      st_widget_style_changed (actor);
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_PSEUDO_CLASS]);
+    }
+}
+
+/**
+ * st_widget_set_style:
+ * @actor: a #StWidget
+ * @style: (nullable): a inline style string, or %NULL
+ *
+ * Set the inline style string for this widget. The inline style string is an
+ * optional ';'-separated list of CSS properties that override the style as
+ * determined from the stylesheets of the current theme.
+ */
+void
+st_widget_set_style (StWidget  *actor,
+                     const gchar *style)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (actor));
+
+  priv = st_widget_get_instance_private (actor);
+
+  if (g_strcmp0 (style, priv->inline_style))
+    {
+      g_free (priv->inline_style);
+      priv->inline_style = g_strdup (style);
+
+      st_widget_style_changed (actor);
+
+      g_object_notify_by_pspec (G_OBJECT (actor), props[PROP_STYLE]);
+    }
+}
+
+/**
+ * st_widget_get_style:
+ * @actor: a #StWidget
+ *
+ * Get the current inline style string. See st_widget_set_style().
+ *
+ * Returns: (transfer none) (nullable): The inline style string, or %NULL. The
+ *   string is owned by the #StWidget and should not be modified or freed.
+ */
+const gchar*
+st_widget_get_style (StWidget *actor)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (actor), NULL);
+
+  return ST_WIDGET_PRIVATE (actor)->inline_style;
+}
+
+static void
+st_widget_set_first_visible_child (StWidget     *widget,
+                                   ClutterActor *actor)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (priv->first_visible_child == NULL && actor == NULL)
+    return;
+
+  if (priv->first_visible_child != NULL &&
+      CLUTTER_ACTOR (priv->first_visible_child) == actor)
+    return;
+
+  if (priv->first_visible_child != NULL)
+    {
+      st_widget_remove_style_pseudo_class (priv->first_visible_child, "first-child");
+      g_clear_object (&priv->first_visible_child);
+    }
+
+  if (actor == NULL)
+    return;
+
+  if (ST_IS_WIDGET (actor))
+    {
+      st_widget_add_style_pseudo_class (ST_WIDGET (actor), "first-child");
+      priv->first_visible_child = g_object_ref (ST_WIDGET (actor));
+    }
+}
+
+static void
+st_widget_set_last_visible_child (StWidget     *widget,
+                                  ClutterActor *actor)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (priv->last_visible_child == NULL && actor == NULL)
+    return;
+
+  if (priv->last_visible_child != NULL &&
+      CLUTTER_ACTOR (priv->last_visible_child) == actor)
+    return;
+
+  if (priv->last_visible_child != NULL)
+    {
+      st_widget_remove_style_pseudo_class (priv->last_visible_child, "last-child");
+      g_clear_object (&priv->last_visible_child);
+    }
+
+  if (actor == NULL)
+    return;
+
+  if (ST_IS_WIDGET (actor))
+    {
+      st_widget_add_style_pseudo_class (ST_WIDGET (actor), "last-child");
+      priv->last_visible_child = g_object_ref (ST_WIDGET (actor));
+    }
+}
+
+static void
+st_widget_name_notify (StWidget   *widget,
+                       GParamSpec *pspec,
+                       gpointer    data)
+{
+  st_widget_style_changed (widget);
+}
+
+static void
+st_widget_reactive_notify (StWidget   *widget,
+                           GParamSpec *pspec,
+                           gpointer    data)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (clutter_actor_get_reactive (CLUTTER_ACTOR (widget)))
+    st_widget_remove_style_pseudo_class (widget, "insensitive");
+  else
+    st_widget_add_style_pseudo_class (widget, "insensitive");
+
+  if (priv->track_hover)
+    st_widget_sync_hover(widget);
+}
+
+static ClutterActor *
+find_nearest_visible_backwards (ClutterActor *actor)
+{
+  ClutterActor *prev = actor;
+
+  while (prev != NULL && !clutter_actor_is_visible (prev))
+    prev = clutter_actor_get_previous_sibling (prev);
+  return prev;
+}
+
+static ClutterActor *
+find_nearest_visible_forward (ClutterActor *actor)
+{
+  ClutterActor *next = actor;
+
+  while (next != NULL && !clutter_actor_is_visible (next))
+    next = clutter_actor_get_next_sibling (next);
+  return next;
+}
+
+static gboolean
+st_widget_update_child_styles (StWidget *widget)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (priv->first_child_dirty)
+    {
+      ClutterActor *first_child;
+
+      priv->first_child_dirty = FALSE;
+
+      first_child = clutter_actor_get_first_child (CLUTTER_ACTOR (widget));
+      st_widget_set_first_visible_child (widget,
+                                         find_nearest_visible_forward (first_child));
+    }
+
+  if (priv->last_child_dirty)
+    {
+      ClutterActor *last_child;
+
+      priv->last_child_dirty = FALSE;
+
+      last_child = clutter_actor_get_last_child (CLUTTER_ACTOR (widget));
+      st_widget_set_last_visible_child (widget,
+                                        find_nearest_visible_backwards (last_child));
+    }
+
+  priv->update_child_styles_id = 0;
+  return G_SOURCE_REMOVE;
+}
+
+static void
+st_widget_queue_child_styles_update (StWidget *widget)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (priv->update_child_styles_id != 0)
+    return;
+
+  priv->update_child_styles_id = g_idle_add ((GSourceFunc) st_widget_update_child_styles, widget);
+}
+
+static void
+st_widget_visible_notify (StWidget   *widget,
+                          GParamSpec *pspec,
+                          gpointer    data)
+{
+  StWidgetPrivate *parent_priv;
+  ClutterActor *actor = CLUTTER_ACTOR (widget);
+  ClutterActor *parent = clutter_actor_get_parent (actor);
+
+  if (parent == NULL || !ST_IS_WIDGET (parent))
+    return;
+
+  parent_priv = st_widget_get_instance_private (ST_WIDGET (parent));
+
+  if (clutter_actor_is_visible (actor))
+    {
+      ClutterActor *before, *after;
+
+      before = clutter_actor_get_previous_sibling (actor);
+      if (find_nearest_visible_backwards (before) == NULL)
+        parent_priv->first_child_dirty = TRUE;
+
+      after = clutter_actor_get_next_sibling (actor);
+      if (find_nearest_visible_forward (after) == NULL)
+        parent_priv->last_child_dirty = TRUE;
+    }
+  else
+    {
+      if (st_widget_has_style_pseudo_class (widget, "first-child"))
+        parent_priv->first_child_dirty = TRUE;
+
+      if (st_widget_has_style_pseudo_class (widget, "last-child"))
+        parent_priv->last_child_dirty = TRUE;
+    }
+
+  if (parent_priv->first_child_dirty || parent_priv->last_child_dirty)
+    st_widget_queue_child_styles_update (ST_WIDGET (parent));
+}
+
+static void
+st_widget_first_child_notify (StWidget   *widget,
+                              GParamSpec *pspec,
+                              gpointer    data)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  priv->first_child_dirty = TRUE;
+  st_widget_queue_child_styles_update (widget);
+}
+
+static void
+st_widget_last_child_notify (StWidget   *widget,
+                             GParamSpec *pspec,
+                             gpointer    data)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  priv->last_child_dirty = TRUE;
+  st_widget_queue_child_styles_update (widget);
+}
+
+static void
+st_widget_init (StWidget *actor)
+{
+  StWidgetPrivate *priv;
+  guint i;
+
+  priv = st_widget_get_instance_private (actor);
+  priv->transition_animation = NULL;
+  priv->local_state_set = atk_state_set_new ();
+
+  /* connect style changed */
+  g_signal_connect (actor, "notify::name", G_CALLBACK (st_widget_name_notify), NULL);
+  g_signal_connect (actor, "notify::reactive", G_CALLBACK (st_widget_reactive_notify), NULL);
+
+  g_signal_connect (actor, "notify::visible", G_CALLBACK (st_widget_visible_notify), NULL);
+  g_signal_connect (actor, "notify::first-child", G_CALLBACK (st_widget_first_child_notify), NULL);
+  g_signal_connect (actor, "notify::last-child", G_CALLBACK (st_widget_last_child_notify), NULL);
+  priv->texture_file_changed_id = g_signal_connect (st_texture_cache_get_default (), "texture-file-changed",
+                                                    G_CALLBACK (st_widget_texture_cache_changed), actor);
+
+  for (i = 0; i < G_N_ELEMENTS (priv->paint_states); i++)
+    st_theme_node_paint_state_init (&priv->paint_states[i]);
+}
+
+static void
+on_transition_completed (StThemeNodeTransition *transition,
+                         StWidget              *widget)
+{
+  next_paint_state (widget);
+
+  st_theme_node_paint_state_copy (current_paint_state (widget),
+                                  st_theme_node_transition_get_new_paint_state (transition));
+
+  st_widget_remove_transition (widget);
+}
+
+static void
+st_widget_recompute_style (StWidget    *widget,
+                           StThemeNode *old_theme_node)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+  StThemeNode *new_theme_node = st_widget_get_theme_node (widget);
+  int transition_duration;
+  StSettings *settings;
+  gboolean paint_equal, geometry_equal = FALSE;
+  gboolean animations_enabled;
+
+  if (new_theme_node == old_theme_node)
+    {
+      priv->is_style_dirty = FALSE;
+      return;
+    }
+
+  _st_theme_node_apply_margins (new_theme_node, CLUTTER_ACTOR (widget));
+
+  if (old_theme_node)
+    geometry_equal = st_theme_node_geometry_equal (old_theme_node, new_theme_node);
+  if (!geometry_equal)
+    clutter_actor_queue_relayout ((ClutterActor *) widget);
+
+  transition_duration = st_theme_node_get_transition_duration (new_theme_node);
+
+  paint_equal = st_theme_node_paint_equal (old_theme_node, new_theme_node);
+
+  settings = st_settings_get ();
+  g_object_get (settings, "enable-animations", &animations_enabled, NULL);
+
+  if (animations_enabled && transition_duration > 0)
+    {
+      if (priv->transition_animation != NULL)
+        {
+          st_theme_node_transition_update (priv->transition_animation,
+                                           new_theme_node);
+        }
+      else if (old_theme_node && !paint_equal)
+        {
+          /* Since our transitions are only of the painting done by StThemeNode, we
+           * only want to start a transition when what is painted changes; if
+           * other visual aspects like the foreground color of a label change,
+           * we can't animate that anyways.
+           */
+
+          priv->transition_animation =
+            st_theme_node_transition_new (CLUTTER_ACTOR (widget),
+                                          old_theme_node,
+                                          new_theme_node,
+                                          current_paint_state (widget),
+                                          transition_duration);
+
+          g_signal_connect (priv->transition_animation, "completed",
+                            G_CALLBACK (on_transition_completed), widget);
+          g_signal_connect_swapped (priv->transition_animation,
+                                    "new-frame",
+                                    G_CALLBACK (clutter_actor_queue_redraw),
+                                    widget);
+        }
+    }
+  else if (priv->transition_animation)
+    {
+      st_widget_remove_transition (widget);
+    }
+
+  if (!paint_equal)
+    {
+      next_paint_state (widget);
+
+      if (!st_theme_node_paint_equal (new_theme_node, current_paint_state (widget)->node))
+        st_theme_node_paint_state_invalidate (current_paint_state (widget));
+    }
+
+  /* It is very likely that custom CSS properties are used with StDrawingArea
+     to control the custom drawing, so never omit the ::style-changed signal */
+  if (paint_equal)
+    paint_equal = !ST_IS_DRAWING_AREA (widget);
+
+  if (paint_equal && old_theme_node->font_desc != NULL)
+    paint_equal = pango_font_description_equal (old_theme_node->font_desc,
+                                                st_theme_node_get_font (new_theme_node));
+
+  if (paint_equal && old_theme_node->foreground_computed)
+    {
+      ClutterColor col;
+
+      st_theme_node_get_foreground_color (new_theme_node, &col);
+      paint_equal = clutter_color_equal (&old_theme_node->foreground_color, &col);
+    }
+
+  if (paint_equal && old_theme_node->icon_colors)
+    paint_equal = st_icon_colors_equal (old_theme_node->icon_colors,
+                                        st_theme_node_get_icon_colors (new_theme_node));
+
+  if (!paint_equal || !geometry_equal)
+    g_signal_emit (widget, signals[STYLE_CHANGED], 0);
+
+  priv->is_style_dirty = FALSE;
+}
+
+/**
+ * st_widget_ensure_style:
+ * @widget: A #StWidget
+ *
+ * Ensures that @widget has read its style information and propagated any
+ * changes to its children.
+ */
+void
+st_widget_ensure_style (StWidget *widget)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->is_style_dirty)
+    {
+      st_widget_recompute_style (widget, NULL);
+      notify_children_of_style_change (CLUTTER_ACTOR (widget));
+    }
+}
+
+/**
+ * st_widget_set_track_hover:
+ * @widget: A #StWidget
+ * @track_hover: %TRUE if the widget should track the pointer hover state
+ *
+ * Enables hover tracking on the #StWidget.
+ *
+ * If hover tracking is enabled, and the widget is visible and
+ * reactive, then @widget's #StWidget:hover property will be updated
+ * automatically to reflect whether the pointer is in @widget (or one
+ * of its children), and @widget's #StWidget:pseudo-class will have
+ * the "hover" class added and removed from it accordingly.
+ *
+ * Note that currently it is not possible to correctly track the hover
+ * state when another actor has a pointer grab. You can use
+ * st_widget_sync_hover() to update the property manually in this
+ * case.
+ */
+void
+st_widget_set_track_hover (StWidget *widget,
+                           gboolean  track_hover)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->track_hover != track_hover)
+    {
+      priv->track_hover = track_hover;
+      g_object_notify_by_pspec (G_OBJECT (widget), props[PROP_TRACK_HOVER]);
+
+      if (priv->track_hover)
+        st_widget_sync_hover (widget);
+      else
+        st_widget_set_hover (widget, FALSE);
+    }
+}
+
+/**
+ * st_widget_get_track_hover:
+ * @widget: A #StWidget
+ *
+ * Returns the current value of the #StWidget:track-hover property. See
+ * st_widget_set_track_hover() for more information.
+ *
+ * Returns: current value of track-hover on @widget
+ */
+gboolean
+st_widget_get_track_hover (StWidget *widget)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), FALSE);
+
+  return ST_WIDGET_PRIVATE (widget)->track_hover;
+}
+
+/**
+ * st_widget_set_hover:
+ * @widget: A #StWidget
+ * @hover: whether the pointer is hovering over the widget
+ *
+ * Sets @widget's hover property and adds or removes "hover" from its
+ * pseudo class accordingly.
+ *
+ * If you have set #StWidget:track-hover, you should not need to call
+ * this directly. You can call st_widget_sync_hover() if the hover
+ * state might be out of sync due to another actor's pointer grab.
+ */
+void
+st_widget_set_hover (StWidget *widget,
+                     gboolean  hover)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->hover != hover)
+    {
+      priv->hover = hover;
+      if (priv->hover)
+        st_widget_add_style_pseudo_class (widget, "hover");
+      else
+        st_widget_remove_style_pseudo_class (widget, "hover");
+      g_object_notify_by_pspec (G_OBJECT (widget), props[PROP_HOVER]);
+    }
+}
+
+/**
+ * st_widget_sync_hover:
+ * @widget: A #StWidget
+ *
+ * Sets @widget's hover state according to the current pointer
+ * position. This can be used to ensure that it is correct after
+ * (or during) a pointer grab.
+ */
+void
+st_widget_sync_hover (StWidget *widget)
+{
+  ClutterInputDevice *pointer;
+  ClutterActor *pointer_actor;
+  ClutterSeat *seat;
+
+  seat = clutter_backend_get_default_seat (clutter_get_default_backend ());
+  pointer = clutter_seat_get_pointer (seat);
+  pointer_actor = clutter_input_device_get_actor (pointer, NULL);
+  if (pointer_actor && clutter_actor_get_reactive (CLUTTER_ACTOR (widget)))
+    st_widget_set_hover (widget, clutter_actor_contains (CLUTTER_ACTOR (widget), pointer_actor));
+  else
+    st_widget_set_hover (widget, FALSE);
+}
+
+/**
+ * st_widget_get_hover:
+ * @widget: A #StWidget
+ *
+ * If #StWidget:track-hover is set, this returns whether the pointer
+ * is currently over the widget.
+ *
+ * Returns: current value of hover on @widget
+ */
+gboolean
+st_widget_get_hover (StWidget *widget)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), FALSE);
+
+  return ST_WIDGET_PRIVATE (widget)->hover;
+}
+
+/**
+ * st_widget_set_can_focus:
+ * @widget: A #StWidget
+ * @can_focus: %TRUE if the widget can receive keyboard focus
+ *   via keyboard navigation
+ *
+ * Marks @widget as being able to receive keyboard focus via
+ * keyboard navigation.
+ */
+void
+st_widget_set_can_focus (StWidget *widget,
+                         gboolean  can_focus)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->can_focus != can_focus)
+    {
+      priv->can_focus = can_focus;
+      g_object_notify_by_pspec (G_OBJECT (widget), props[PROP_CAN_FOCUS]);
+    }
+}
+
+/**
+ * st_widget_get_can_focus:
+ * @widget: A #StWidget
+ *
+ * Returns the current value of the can-focus property. See
+ * st_widget_set_can_focus() for more information.
+ *
+ * Returns: current value of can-focus on @widget
+ */
+gboolean
+st_widget_get_can_focus (StWidget *widget)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), FALSE);
+
+  return ST_WIDGET_PRIVATE (widget)->can_focus;
+}
+
+/**
+ * st_widget_popup_menu:
+ * @self: A #StWidget
+ *
+ * Asks the widget to pop-up a context menu by emitting #StWidget::popup-menu.
+ */
+void
+st_widget_popup_menu (StWidget *self)
+{
+  g_signal_emit (self, signals[POPUP_MENU], 0);
+}
+
+/* filter @children to contain only only actors that overlap @rbox
+ * when moving in @direction. (Assuming no transformations.)
+ */
+static GList *
+filter_by_position (GList            *children,
+                    ClutterActorBox  *rbox,
+                    StDirectionType   direction)
+{
+  ClutterActorBox cbox;
+  graphene_point3d_t abs_vertices[4];
+  GList *l, *ret;
+  ClutterActor *child;
+
+  for (l = children, ret = NULL; l; l = l->next)
+    {
+      child = l->data;
+      clutter_actor_get_abs_allocation_vertices (child, abs_vertices);
+      clutter_actor_box_from_vertices (&cbox, abs_vertices);
+
+      /* Filter out children if they are in the wrong direction from
+       * @rbox, or if they don't overlap it. To account for floating-
+       * point imprecision, an actor is "down" (etc.) from an another
+       * actor even if it overlaps it by up to 0.1 pixels.
+       */
+      switch (direction)
+        {
+        case ST_DIR_UP:
+          if (cbox.y2 > rbox->y1 + 0.1)
+            continue;
+          break;
+
+        case ST_DIR_DOWN:
+          if (cbox.y1 < rbox->y2 - 0.1)
+            continue;
+          break;
+
+        case ST_DIR_LEFT:
+          if (cbox.x2 > rbox->x1 + 0.1)
+            continue;
+          break;
+
+        case ST_DIR_RIGHT:
+          if (cbox.x1 < rbox->x2 - 0.1)
+            continue;
+          break;
+
+        case ST_DIR_TAB_BACKWARD:
+        case ST_DIR_TAB_FORWARD:
+        default:
+          g_return_val_if_reached (NULL);
+        }
+
+      ret = g_list_prepend (ret, child);
+    }
+
+  g_list_free (children);
+  return ret;
+}
+
+
+static void
+get_midpoint (ClutterActorBox *box,
+              int             *x,
+              int             *y)
+{
+  *x = (box->x1 + box->x2) / 2;
+  *y = (box->y1 + box->y2) / 2;
+}
+
+static double
+get_distance (ClutterActor    *actor,
+              ClutterActorBox *bbox)
+{
+  int ax, ay, bx, by, dx, dy;
+  ClutterActorBox abox;
+  graphene_point3d_t abs_vertices[4];
+
+  clutter_actor_get_abs_allocation_vertices (actor, abs_vertices);
+  clutter_actor_box_from_vertices (&abox, abs_vertices);
+
+  get_midpoint (&abox, &ax, &ay);
+  get_midpoint (bbox, &bx, &by);
+  dx = ax - bx;
+  dy = ay - by;
+
+  /* Not the exact distance, but good enough to sort by. */
+  return dx*dx + dy*dy;
+}
+
+static int
+sort_by_distance (gconstpointer  a,
+                  gconstpointer  b,
+                  gpointer       user_data)
+{
+  ClutterActor *actor_a = (ClutterActor *)a;
+  ClutterActor *actor_b = (ClutterActor *)b;
+  ClutterActorBox *box = user_data;
+
+  return get_distance (actor_a, box) - get_distance (actor_b, box);
+}
+
+static gboolean
+st_widget_real_navigate_focus (StWidget         *widget,
+                               ClutterActor     *from,
+                               StDirectionType   direction)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+  ClutterActor *widget_actor, *focus_child;
+  GList *children, *l;
+
+  widget_actor = CLUTTER_ACTOR (widget);
+  if (from == widget_actor)
+    return FALSE;
+
+  /* Figure out if @from is a descendant of @widget, and if so,
+   * set @focus_child to the immediate child of @widget that
+   * contains (or *is*) @from.
+   */
+  focus_child = from;
+  while (focus_child && clutter_actor_get_parent (focus_child) != widget_actor)
+    focus_child = clutter_actor_get_parent (focus_child);
+
+  if (priv->can_focus)
+    {
+      if (!focus_child)
+        {
+          if (clutter_actor_is_mapped (widget_actor))
+            {
+              /* Accept focus from outside */
+              clutter_actor_grab_key_focus (widget_actor);
+              return TRUE;
+            }
+          else
+            {
+              /* Refuse to set focus on hidden actors */
+              return FALSE;
+            }
+        }
+      else
+        {
+          /* Yield focus from within: since @widget itself is
+           * focusable we don't allow the focus to be navigated
+           * within @widget.
+           */
+          return FALSE;
+        }
+    }
+
+  /* See if we can navigate within @focus_child */
+  if (focus_child && ST_IS_WIDGET (focus_child))
+    {
+      if (st_widget_navigate_focus (ST_WIDGET (focus_child), from, direction, FALSE))
+        return TRUE;
+    }
+
+  children = st_widget_get_focus_chain (widget);
+  if (direction == ST_DIR_TAB_FORWARD ||
+      direction == ST_DIR_TAB_BACKWARD)
+    {
+      /* At this point we know that we want to navigate focus to one of
+       * @widget's immediate children; the next one after @focus_child, or the
+       * first one if @focus_child is %NULL. (With "next" and "first" being
+       * determined by @direction.)
+       */
+      if (direction == ST_DIR_TAB_BACKWARD)
+        children = g_list_reverse (children);
+
+      if (focus_child)
+        {
+          /* Remove focus_child and any earlier children */
+          while (children && children->data != focus_child)
+            children = g_list_delete_link (children, children);
+          if (children)
+            children = g_list_delete_link (children, children);
+        }
+    }
+  else /* direction is an arrow key, not tab */
+    {
+      ClutterActorBox sort_box;
+      graphene_point3d_t abs_vertices[4];
+
+      /* Compute the allocation box of the previous focused actor. If there
+       * was no previous focus, use the coordinates of the appropriate edge of
+       * @widget.
+       *
+       * Note that all of this code assumes the actors are not
+       * transformed (or at most, they are all scaled by the same
+       * amount). If @widget or any of its children is rotated, or
+       * any child is inconsistently scaled, then the focus chain will
+       * probably be unpredictable.
+       */
+      if (from)
+        {
+          clutter_actor_get_abs_allocation_vertices (from, abs_vertices);
+          clutter_actor_box_from_vertices (&sort_box, abs_vertices);
+        }
+      else
+        {
+          clutter_actor_get_abs_allocation_vertices (widget_actor, abs_vertices);
+          clutter_actor_box_from_vertices (&sort_box, abs_vertices);
+          switch (direction)
+            {
+            case ST_DIR_UP:
+              sort_box.y1 = sort_box.y2;
+              break;
+            case ST_DIR_DOWN:
+              sort_box.y2 = sort_box.y1;
+              break;
+            case ST_DIR_LEFT:
+              sort_box.x1 = sort_box.x2;
+              break;
+            case ST_DIR_RIGHT:
+              sort_box.x2 = sort_box.x1;
+              break;
+            case ST_DIR_TAB_FORWARD:
+            case ST_DIR_TAB_BACKWARD:
+            default:
+              g_warn_if_reached ();
+            }
+        }
+
+      if (from)
+        children = filter_by_position (children, &sort_box, direction);
+      if (children)
+        children = g_list_sort_with_data (children, sort_by_distance, &sort_box);
+    }
+
+  /* Now try each child in turn */
+  for (l = children; l; l = l->next)
+    {
+      if (ST_IS_WIDGET (l->data))
+        {
+          if (st_widget_navigate_focus (l->data, from, direction, FALSE))
+            {
+              g_list_free (children);
+              return TRUE;
+            }
+        }
+    }
+
+  g_list_free (children);
+  return FALSE;
+}
+
+
+/**
+ * st_widget_navigate_focus:
+ * @widget: the "top level" container
+ * @from: (nullable): the actor that the focus is coming from
+ * @direction: the direction focus is moving in
+ * @wrap_around: whether focus should wrap around
+ *
+ * Tries to update the keyboard focus within @widget in response to a
+ * keyboard event.
+ *
+ * If @from is a descendant of @widget, this attempts to move the
+ * keyboard focus to the next descendant of @widget (in the order
+ * implied by @direction) that has the #StWidget:can-focus property
+ * set. If @from is %NULL, this attempts to focus either @widget
+ * itself, or its first descendant in the order implied by
+ * @direction. If @from is outside of @widget, it behaves as if it was
+ * a descendant if @direction is one of the directional arrows and as
+ * if it was %NULL otherwise.
+ *
+ * If a container type is marked #StWidget:can-focus, the expected
+ * behavior is that it will only take up a single slot on the focus
+ * chain as a whole, rather than allowing navigation between its child
+ * actors (or having a distinction between itself being focused and
+ * one of its children being focused).
+ *
+ * Some widget classes might have slightly different behavior from the
+ * above, where that would make more sense.
+ *
+ * If @wrap_around is %TRUE and @from is a child of @widget, but the
+ * widget has no further children that can accept the focus in the
+ * given direction, then st_widget_navigate_focus() will try a second
+ * time, using a %NULL @from, which should cause it to reset the focus
+ * to the first available widget in the given direction.
+ *
+ * Returns: %TRUE if clutter_actor_grab_key_focus() has been
+ * called on an actor. %FALSE if not.
+ */
+gboolean
+st_widget_navigate_focus (StWidget         *widget,
+                          ClutterActor     *from,
+                          StDirectionType   direction,
+                          gboolean          wrap_around)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), FALSE);
+
+  if (ST_WIDGET_GET_CLASS (widget)->navigate_focus (widget, from, direction))
+    return TRUE;
+  if (wrap_around && from && clutter_actor_contains (CLUTTER_ACTOR (widget), from))
+    return ST_WIDGET_GET_CLASS (widget)->navigate_focus (widget, NULL, direction);
+  return FALSE;
+}
+
+static gboolean
+append_actor_text (GString      *desc,
+                   ClutterActor *actor)
+{
+  if (CLUTTER_IS_TEXT (actor))
+    {
+      g_string_append_printf (desc, " (\"%s\")",
+                              clutter_text_get_text (CLUTTER_TEXT (actor)));
+      return TRUE;
+    }
+  else if (ST_IS_LABEL (actor))
+    {
+      g_string_append_printf (desc, " (\"%s\")",
+                              st_label_get_text (ST_LABEL (actor)));
+      return TRUE;
+    }
+  else
+    return FALSE;
+}
+
+/**
+ * st_describe_actor:
+ * @actor: a #ClutterActor
+ *
+ * Creates a string describing @actor, for use in debugging. This
+ * includes the class name and actor name (if any), plus if @actor
+ * is an #StWidget, its style class and pseudo class names.
+ *
+ * Returns: the debug name.
+ */
+char *
+st_describe_actor (ClutterActor *actor)
+{
+  GString *desc;
+  const char *name;
+  int i;
+
+  if (!actor)
+    return g_strdup ("[null]");
+
+  desc = g_string_new (NULL);
+  g_string_append_printf (desc, "[%p %s", actor,
+                          G_OBJECT_TYPE_NAME (actor));
+
+  if (ST_IS_WIDGET (actor))
+    {
+      const char *style_class = st_widget_get_style_class_name (ST_WIDGET (actor));
+      const char *pseudo_class = st_widget_get_style_pseudo_class (ST_WIDGET (actor));
+      char **classes;
+
+      if (style_class)
+        {
+          classes = g_strsplit (style_class, ",", -1);
+          for (i = 0; classes[i]; i++)
+            {
+              g_strchug (classes[i]);
+              g_string_append_printf (desc, ".%s", classes[i]);
+            }
+          g_strfreev (classes);
+        }
+
+      if (pseudo_class)
+        {
+          classes = g_strsplit (pseudo_class, ",", -1);
+          for (i = 0; classes[i]; i++)
+            {
+              g_strchug (classes[i]);
+              g_string_append_printf (desc, ":%s", classes[i]);
+            }
+          g_strfreev (classes);
+        }
+    }
+
+  name = clutter_actor_get_name (actor);
+  if (name)
+    g_string_append_printf (desc, " \"%s\"", name);
+
+  if (!append_actor_text (desc, actor))
+    {
+      GList *children, *l;
+
+      /* Do a limited search of @actor's children looking for a label */
+      children = clutter_actor_get_children (actor);
+      for (l = children, i = 0; l && i < 20; l = l->next, i++)
+        {
+          if (append_actor_text (desc, l->data))
+            break;
+          children = g_list_concat (children, clutter_actor_get_children (l->data));
+        }
+      g_list_free (children);
+    }
+
+  g_string_append_c (desc, ']');
+
+  return g_string_free (desc, FALSE);
+}
+
+/**
+ * st_widget_get_label_actor:
+ * @widget: a #StWidget
+ *
+ * Gets the label that identifies @widget if it is defined
+ *
+ * Returns: (transfer none): the label that identifies the widget
+ */
+ClutterActor *
+st_widget_get_label_actor (StWidget *widget)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), NULL);
+
+  return ST_WIDGET_PRIVATE (widget)->label_actor;
+}
+
+/**
+ * st_widget_set_label_actor:
+ * @widget: a #StWidget
+ * @label: a #ClutterActor
+ *
+ * Sets @label as the #ClutterActor that identifies (labels)
+ * @widget. @label can be %NULL to indicate that @widget is not
+ * labelled any more
+ */
+
+void
+st_widget_set_label_actor (StWidget     *widget,
+                           ClutterActor *label)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->label_actor != label)
+    {
+      if (priv->label_actor)
+        g_object_unref (priv->label_actor);
+
+      if (label != NULL)
+        priv->label_actor = g_object_ref (label);
+      else
+        priv->label_actor = NULL;
+
+      g_object_notify_by_pspec (G_OBJECT (widget), props[PROP_LABEL_ACTOR]);
+    }
+}
+
+/**
+ * st_widget_set_accessible_name:
+ * @widget: widget to set the accessible name for
+ * @name: (nullable): a character string to be set as the accessible name
+ *
+ * This method sets @name as the accessible name for @widget.
+ *
+ * Usually you will have no need to set the accessible name for an
+ * object, as usually there is a label for most of the interface
+ * elements. So in general it is better to just use
+ * @st_widget_set_label_actor. This method is only required when you
+ * need to set an accessible name and there is no available label
+ * object.
+ *
+ */
+void
+st_widget_set_accessible_name (StWidget    *widget,
+                               const gchar *name)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->accessible_name != NULL)
+    g_free (priv->accessible_name);
+
+  priv->accessible_name = g_strdup (name);
+  g_object_notify_by_pspec (G_OBJECT (widget), props[PROP_ACCESSIBLE_NAME]);
+}
+
+/**
+ * st_widget_get_accessible_name:
+ * @widget: widget to get the accessible name for
+ *
+ * Gets the accessible name for this widget. See
+ * st_widget_set_accessible_name() for more information.
+ *
+ * Returns: a character string representing the accessible name
+ * of the widget.
+ */
+const gchar *
+st_widget_get_accessible_name (StWidget    *widget)
+{
+  g_return_val_if_fail (ST_IS_WIDGET (widget), NULL);
+
+  return ST_WIDGET_PRIVATE (widget)->accessible_name;
+}
+
+/**
+ * st_widget_set_accessible_role:
+ * @widget: widget to set the accessible role for
+ * @role: The role to use
+ *
+ * This method sets @role as the accessible role for @widget. This
+ * role describes what kind of user interface element @widget is and
+ * is provided so that assistive technologies know how to present
+ * @widget to the user.
+ *
+ * Usually you will have no need to set the accessible role for an
+ * object, as this information is extracted from the context of the
+ * object (ie: a #StButton has by default a push button role). This
+ * method is only required when you need to redefine the role
+ * currently associated with the widget, for instance if it is being
+ * used in an unusual way (ie: a #StButton used as a togglebutton), or
+ * if a generic object is used directly (ie: a container as a menu
+ * item).
+ *
+ * If @role is #ATK_ROLE_INVALID, the role will not be changed
+ * and the accessible's default role will be used instead.
+ */
+void
+st_widget_set_accessible_role (StWidget *widget,
+                               AtkRole   role)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+  priv->accessible_role = role;
+
+  g_object_notify_by_pspec (G_OBJECT (widget), props[PROP_ACCESSIBLE_ROLE]);
+}
+
+
+/**
+ * st_widget_get_accessible_role:
+ * @widget: widget to get the accessible role for
+ *
+ * Gets the #AtkRole for this widget. See
+ * st_widget_set_accessible_role() for more information.
+ *
+ * Returns: accessible #AtkRole for this widget
+ */
+AtkRole
+st_widget_get_accessible_role (StWidget *widget)
+{
+  StWidgetPrivate *priv;
+  AtkRole role = ATK_ROLE_INVALID;
+
+  g_return_val_if_fail (ST_IS_WIDGET (widget), ATK_ROLE_INVALID);
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->accessible_role != ATK_ROLE_INVALID)
+    role = priv->accessible_role;
+  else if (priv->accessible != NULL)
+    role = atk_object_get_role (priv->accessible);
+
+  return role;
+}
+
+static void
+notify_accessible_state_change (StWidget     *widget,
+                                AtkStateType  state,
+                                gboolean      value)
+{
+  StWidgetPrivate *priv = st_widget_get_instance_private (widget);
+
+  if (priv->accessible != NULL)
+    atk_object_notify_state_change (priv->accessible, state, value);
+}
+
+/**
+ * st_widget_add_accessible_state:
+ * @widget: A #StWidget
+ * @state: #AtkStateType state to add
+ *
+ * This method adds @state as one of the accessible states for
+ * @widget. The list of states of a widget describes the current state
+ * of user interface element @widget and is provided so that assistive
+ * technologies know how to present @widget to the user.
+ *
+ * Usually you will have no need to add accessible states for an
+ * object, as the accessible object can extract most of the states
+ * from the object itself (ie: a #StButton knows when it is pressed).
+ * This method is only required when one cannot extract the
+ * information automatically from the object itself (i.e.: a generic
+ * container used as a toggle menu item will not automatically include
+ * the toggled state).
+ *
+ */
+void
+st_widget_add_accessible_state (StWidget    *widget,
+                                AtkStateType state)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (atk_state_set_add_state (priv->local_state_set, state))
+    notify_accessible_state_change (widget, state, TRUE);
+}
+
+/**
+ * st_widget_remove_accessible_state:
+ * @widget: A #StWidget
+ * @state: #AtkState state to remove
+ *
+ * This method removes @state as on of the accessible states for
+ * @widget. See st_widget_add_accessible_state() for more information.
+ *
+ */
+void
+st_widget_remove_accessible_state (StWidget    *widget,
+                                   AtkStateType state)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (atk_state_set_remove_state (priv->local_state_set, state))
+    notify_accessible_state_change (widget, state, FALSE);
+}
+
+/******************************************************************************/
+/*************************** ACCESSIBILITY SUPPORT ****************************/
+/******************************************************************************/
+
+/* GObject */
+
+static void st_widget_accessible_dispose    (GObject *gobject);
+
+/* AtkObject */
+static AtkStateSet *st_widget_accessible_ref_state_set (AtkObject *obj);
+static void         st_widget_accessible_initialize    (AtkObject *obj,
+                                                        gpointer   data);
+static AtkRole      st_widget_accessible_get_role      (AtkObject *obj);
+
+/* Private methods */
+static void on_pseudo_class_notify (GObject    *gobject,
+                                    GParamSpec *pspec,
+                                    gpointer    data);
+static void on_can_focus_notify    (GObject    *gobject,
+                                    GParamSpec *pspec,
+                                    gpointer    data);
+static void on_label_notify        (GObject    *gobject,
+                                    GParamSpec *pspec,
+                                    gpointer    data);
+static void check_pseudo_class     (StWidgetAccessible *self,
+                                    StWidget *widget);
+static void check_labels           (StWidgetAccessible *self,
+                                    StWidget *widget);
+
+struct _StWidgetAccessiblePrivate
+{
+  /* Cached values (used to avoid extra notifications) */
+  gboolean selected;
+  gboolean checked;
+
+  /* The current_label. Right now there are the proper atk
+   * relationships between this object and the label
+   */
+  AtkObject *current_label;
+};
+
+G_DEFINE_TYPE_WITH_PRIVATE (StWidgetAccessible, st_widget_accessible, CALLY_TYPE_ACTOR)
+
+static gboolean
+st_widget_has_accessible (ClutterActor *actor)
+{
+  StWidget *widget;
+  StWidgetPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_WIDGET (actor), FALSE);
+
+  widget = ST_WIDGET (actor);
+  priv = st_widget_get_instance_private (widget);
+
+  return priv->accessible != NULL;
+}
+
+static AtkObject *
+st_widget_get_accessible (ClutterActor *actor)
+{
+  StWidget *widget = NULL;
+  StWidgetPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_WIDGET (actor), NULL);
+
+  widget = ST_WIDGET (actor);
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->accessible == NULL)
+    {
+      priv->accessible =
+        g_object_new (ST_WIDGET_GET_CLASS (widget)->get_accessible_type (),
+                      NULL);
+
+      atk_object_initialize (priv->accessible, actor);
+
+      /* AtkGObjectAccessible, which StWidgetAccessible derives from, clears
+       * the back reference to the object in a weak notify for the object;
+       * weak-ref notification, which occurs during g_object_real_dispose(),
+       * is then the optimal time to clear the forward reference. We
+       * can't clear the reference in dispose() before chaining up, since
+       * clutter_actor_dispose() causes notifications to be sent out, which
+       * will result in a new accessible object being created.
+       */
+      g_object_add_weak_pointer (G_OBJECT (actor),
+                                 (gpointer *)&priv->accessible);
+    }
+
+  return priv->accessible;
+}
+
+/**
+ * st_widget_set_accessible:
+ * @widget: A #StWidget
+ * @accessible: an accessible (#AtkObject)
+ *
+ * This method allows to set a customly created accessible object to
+ * this widget. For example if you define a new subclass of
+ * #StWidgetAccessible at the javascript code.
+ *
+ * NULL is a valid value for @accessible. That contemplates the
+ * hypothetical case of not needing anymore a custom accessible object
+ * for the widget. Next call of st_widget_get_accessible() would
+ * create and return a default accessible.
+ *
+ * It assumes that the call to atk_object_initialize that bound the
+ * gobject with the custom accessible object was already called, so
+ * not a responsibility of this method.
+ *
+ */
+void
+st_widget_set_accessible (StWidget    *widget,
+                          AtkObject   *accessible)
+{
+  StWidgetPrivate *priv;
+
+  g_return_if_fail (ST_IS_WIDGET (widget));
+  g_return_if_fail (accessible == NULL || ATK_IS_GOBJECT_ACCESSIBLE (accessible));
+
+  priv = st_widget_get_instance_private (widget);
+
+  if (priv->accessible != accessible)
+    {
+      if (priv->accessible)
+        {
+          g_object_remove_weak_pointer (G_OBJECT (widget),
+                                        (gpointer *)&priv->accessible);
+          g_object_unref (priv->accessible);
+          priv->accessible = NULL;
+        }
+
+      if (accessible)
+        {
+          priv->accessible =  g_object_ref (accessible);
+          /* See note in st_widget_get_accessible() */
+          g_object_add_weak_pointer (G_OBJECT (widget),
+                                     (gpointer *)&priv->accessible);
+        }
+      else
+        priv->accessible = NULL;
+    }
+}
+
+static const gchar *
+st_widget_accessible_get_name (AtkObject *obj)
+{
+  const gchar* name = NULL;
+
+  g_return_val_if_fail (ST_IS_WIDGET_ACCESSIBLE (obj), NULL);
+
+  name = ATK_OBJECT_CLASS (st_widget_accessible_parent_class)->get_name (obj);
+  if (name == NULL)
+    {
+      StWidget *widget = NULL;
+
+      widget = ST_WIDGET (atk_gobject_accessible_get_object (ATK_GOBJECT_ACCESSIBLE (obj)));
+
+      if (widget == NULL)
+        name = NULL;
+      else
+        name = st_widget_get_accessible_name (widget);
+    }
+
+  return name;
+}
+
+static void
+st_widget_accessible_class_init (StWidgetAccessibleClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  AtkObjectClass *atk_class = ATK_OBJECT_CLASS (klass);
+
+  gobject_class->dispose = st_widget_accessible_dispose;
+
+  atk_class->ref_state_set = st_widget_accessible_ref_state_set;
+  atk_class->initialize = st_widget_accessible_initialize;
+  atk_class->get_role = st_widget_accessible_get_role;
+  atk_class->get_name = st_widget_accessible_get_name;
+}
+
+static void
+st_widget_accessible_init (StWidgetAccessible *self)
+{
+  StWidgetAccessiblePrivate *priv = st_widget_accessible_get_instance_private (self);
+
+  self->priv = priv;
+}
+
+static void
+st_widget_accessible_dispose (GObject *gobject)
+{
+  StWidgetAccessible *self = ST_WIDGET_ACCESSIBLE (gobject);
+
+  if (self->priv->current_label)
+    {
+      g_object_unref (self->priv->current_label);
+      self->priv->current_label = NULL;
+    }
+
+  G_OBJECT_CLASS (st_widget_accessible_parent_class)->dispose (gobject);
+}
+
+static void
+on_accessible_name_notify (GObject    *gobject,
+                           GParamSpec *pspec,
+                           AtkObject  *accessible)
+{
+  g_object_notify (G_OBJECT (accessible), "accessible-name");
+}
+
+static void
+st_widget_accessible_initialize (AtkObject *obj,
+                                 gpointer   data)
+{
+  ATK_OBJECT_CLASS (st_widget_accessible_parent_class)->initialize (obj, data);
+
+  g_signal_connect (data, "notify::pseudo-class",
+                    G_CALLBACK (on_pseudo_class_notify),
+                    obj);
+
+  g_signal_connect (data, "notify::can-focus",
+                    G_CALLBACK (on_can_focus_notify),
+                    obj);
+
+  g_signal_connect (data, "notify::label-actor",
+                    G_CALLBACK (on_label_notify),
+                    obj);
+
+  g_signal_connect (data, "notify::accessible-name",
+                    G_CALLBACK (on_accessible_name_notify),
+                    obj);
+
+  /* Check the cached selected state and notify the first selection.
+   * Ie: it is required to ensure a first notification when Alt+Tab
+   * popup appears
+   */
+  check_pseudo_class (ST_WIDGET_ACCESSIBLE (obj), ST_WIDGET (data));
+  check_labels (ST_WIDGET_ACCESSIBLE (obj), ST_WIDGET (data));
+}
+
+static AtkStateSet *
+st_widget_accessible_ref_state_set (AtkObject *obj)
+{
+  AtkStateSet *result = NULL;
+  AtkStateSet *aux_set = NULL;
+  ClutterActor *actor = NULL;
+  StWidget *widget = NULL;
+  StWidgetPrivate *widget_priv;
+  StWidgetAccessible *self = NULL;
+
+  result = ATK_OBJECT_CLASS (st_widget_accessible_parent_class)->ref_state_set (obj);
+
+  actor = CLUTTER_ACTOR (atk_gobject_accessible_get_object (ATK_GOBJECT_ACCESSIBLE (obj)));
+
+  if (actor == NULL) /* State is defunct */
+    return result;
+
+  widget = ST_WIDGET (actor);
+  self = ST_WIDGET_ACCESSIBLE (obj);
+  widget_priv = st_widget_get_instance_private (widget);
+
+  /* priv->selected should be properly updated on the
+   * ATK_STATE_SELECTED notification callbacks
+   */
+  if (self->priv->selected)
+    atk_state_set_add_state (result, ATK_STATE_SELECTED);
+
+  if (self->priv->checked)
+    atk_state_set_add_state (result, ATK_STATE_CHECKED);
+
+  /* On clutter there isn't any tip to know if a actor is focusable or
+   * not, anyone can receive the key_focus. For this reason
+   * cally_actor sets any actor as FOCUSABLE. This is not the case on
+   * St, where we have can_focus. But this means that we need to
+   * remove the state FOCUSABLE if it is not focusable
+   */
+  if (st_widget_get_can_focus (widget))
+    atk_state_set_add_state (result, ATK_STATE_FOCUSABLE);
+  else
+    atk_state_set_remove_state (result, ATK_STATE_FOCUSABLE);
+
+  /* We add the states added externally if required */
+  if (!atk_state_set_is_empty (widget_priv->local_state_set))
+    {
+      aux_set = atk_state_set_or_sets (result, widget_priv->local_state_set);
+
+      g_object_unref (result); /* previous result will not be used */
+      result = aux_set;
+    }
+
+  return result;
+}
+
+static AtkRole
+st_widget_accessible_get_role (AtkObject *obj)
+{
+  StWidget *widget = NULL;
+  StWidgetPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_WIDGET_ACCESSIBLE (obj), ATK_ROLE_INVALID);
+
+  widget = ST_WIDGET (atk_gobject_accessible_get_object (ATK_GOBJECT_ACCESSIBLE (obj)));
+
+  if (widget == NULL)
+    return ATK_ROLE_INVALID;
+
+  priv = st_widget_get_instance_private (widget);
+  if (priv->accessible_role != ATK_ROLE_INVALID)
+    return priv->accessible_role;
+
+  return ATK_OBJECT_CLASS (st_widget_accessible_parent_class)->get_role (obj);
+}
+
+static void
+on_pseudo_class_notify (GObject    *gobject,
+                        GParamSpec *pspec,
+                        gpointer    data)
+{
+  check_pseudo_class (ST_WIDGET_ACCESSIBLE (data),
+                      ST_WIDGET (gobject));
+}
+
+/*
+ * In some cases the only way to check some states are checking the
+ * pseudo-class. Like if the object is selected (see bug 637830) or if
+ * the object is toggled. This method also notifies a state change if
+ * the value is different to the one cached.
+ *
+ * We also assume that if the object uses that pseudo-class, it makes
+ * sense to notify that state change. It would be possible to refine
+ * that behaviour checking the role (ie: notify CHECKED changes only
+ * for CHECK_BUTTON roles).
+ *
+ * In a ideal world we would have a more standard way to get the
+ * state, like the widget-context (as in the case of
+ * gtktreeview-cells), or something like the property "can-focus". But
+ * for the moment this is enough, and we can update that in the future
+ * if required.
+ */
+static void
+check_pseudo_class (StWidgetAccessible *self,
+                    StWidget *widget)
+{
+  gboolean found = FALSE;
+
+  found = st_widget_has_style_pseudo_class (widget,
+                                            "selected");
+
+  if (found != self->priv->selected)
+    {
+      self->priv->selected = found;
+      atk_object_notify_state_change (ATK_OBJECT (self),
+                                      ATK_STATE_SELECTED,
+                                      found);
+    }
+
+  found = st_widget_has_style_pseudo_class (widget,
+                                            "checked");
+  if (found != self->priv->checked)
+    {
+      self->priv->checked = found;
+      atk_object_notify_state_change (ATK_OBJECT (self),
+                                      ATK_STATE_CHECKED,
+                                      found);
+    }
+}
+
+static void
+on_can_focus_notify (GObject    *gobject,
+                     GParamSpec *pspec,
+                     gpointer    data)
+{
+  gboolean can_focus = st_widget_get_can_focus (ST_WIDGET (gobject));
+
+  atk_object_notify_state_change (ATK_OBJECT (data),
+                                  ATK_STATE_FOCUSABLE, can_focus);
+}
+
+static void
+on_label_notify (GObject    *gobject,
+                 GParamSpec *pspec,
+                 gpointer    data)
+{
+  check_labels (ST_WIDGET_ACCESSIBLE (data), ST_WIDGET (gobject));
+}
+
+static void
+check_labels (StWidgetAccessible *widget_accessible,
+              StWidget           *widget)
+{
+  ClutterActor *label = NULL;
+  AtkObject *label_accessible = NULL;
+
+  /* We only call this method at startup, and when the label changes,
+   * so it is fine to remove the previous relationships if we have the
+   * current_label by default
+   */
+  if (widget_accessible->priv->current_label != NULL)
+    {
+      AtkObject *previous_label = widget_accessible->priv->current_label;
+
+      atk_object_remove_relationship (ATK_OBJECT (widget_accessible),
+                                      ATK_RELATION_LABELLED_BY,
+                                      previous_label);
+
+      atk_object_remove_relationship (previous_label,
+                                      ATK_RELATION_LABEL_FOR,
+                                      ATK_OBJECT (widget_accessible));
+
+      g_object_unref (previous_label);
+    }
+
+  label = st_widget_get_label_actor (widget);
+  if (label == NULL)
+    {
+      widget_accessible->priv->current_label = NULL;
+    }
+  else
+    {
+      label_accessible = clutter_actor_get_accessible (label);
+      widget_accessible->priv->current_label = g_object_ref (label_accessible);
+
+      atk_object_add_relationship (ATK_OBJECT (widget_accessible),
+                                   ATK_RELATION_LABELLED_BY,
+                                   label_accessible);
+
+      atk_object_add_relationship (label_accessible,
+                                   ATK_RELATION_LABEL_FOR,
+                                   ATK_OBJECT (widget_accessible));
+    }
+}
+
+/**
+ * st_widget_get_focus_chain:
+ * @widget: An #StWidget
+ *
+ * Gets a list of the focusable children of @widget, in "Tab"
+ * order. By default, this returns all visible
+ * (as in clutter_actor_is_visible()) children of @widget.
+ *
+ * Returns: (element-type Clutter.Actor) (transfer container):
+ *   @widget's focusable children
+ */
+GList *
+st_widget_get_focus_chain (StWidget *widget)
+{
+  return ST_WIDGET_GET_CLASS (widget)->get_focus_chain (widget);
+}