Adding upstream version 43.9.upstream/43.9upstream

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

1 files changed, 1327 insertions, 0 deletions

diff --git a/src/st/st-scroll-view.c b/src/st/st-scroll-view.c
new file mode 100644
index 0000000..50de481
--- /dev/null
+++ b/src/st/st-scroll-view.c
@@ -0,0 +1,1327 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * st-scroll-view.h: Container with scroll-bars
+ *
+ * Copyright 2008 OpenedHand
+ * Copyright 2009 Intel Corporation.
+ * Copyright 2009, 2010 Red Hat, Inc.
+ * Copyright 2010 Maxim Ermilov
+ *
+ * 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/>.
+ */
+
+/**
+ * SECTION:st-scroll-view
+ * @short_description: a container for scrollable children
+ *
+ * #StScrollView is a single child container for actors that implement
+ * #StScrollable. It provides scrollbars around the edge of the child to
+ * allow the user to move around the scrollable area.
+ */
+
+/* TODO: The code here currently only deals with height-for-width
+ * allocation; width-for-height allocation would need a second set of
+ * code paths through get_preferred_height()/get_preferred_width()/allocate()
+ * that reverse the roles of the horizontal and vertical scrollbars.
+ *
+ * TODO: The multiple layout passes with and without scrollbars when
+ * using the automatic policy causes considerable inefficiency because
+ * it breaks request caching; we should saved the last size passed
+ * into allocate() and if it's the same as previous size not repeat
+ * the determination of scrollbar visibility. This requires overriding
+ * queue_relayout() so we know when to discard the saved value.
+ *
+ * The size negotiation between the #StScrollView and the child is
+ * described in the documentation for #StScrollable; the significant
+ * part to note there is that reported minimum sizes for a scrolled
+ * child are the minimum sizes when no scrollbar is needed. This allows
+ * us to determine what scrollbars are visible without a need to look
+ * inside the #StAdjustment.
+ *
+ * The second simplification that we make that allows us to implement
+ * a straightforward height-for-width negotiation without multiple
+ * allocate passes is that when the scrollbar policy is
+ * AUTO, we always reserve space for the scrollbar in the
+ * reported minimum and natural size.
+ *
+ * See https://bugzilla.gnome.org/show_bug.cgi?id=611740 for a more
+ * detailed description of the considerations involved.
+ */
+
+#include "st-enum-types.h"
+#include "st-private.h"
+#include "st-scroll-view.h"
+#include "st-scroll-bar.h"
+#include "st-scrollable.h"
+#include "st-scroll-view-fade.h"
+#include <clutter/clutter.h>
+#include <math.h>
+
+static void clutter_container_iface_init (ClutterContainerIface *iface);
+
+static ClutterContainerIface *st_scroll_view_parent_iface = NULL;
+
+struct _StScrollViewPrivate
+{
+  /* a pointer to the child; this is actually stored
+   * inside StBin:child, but we keep it to avoid
+   * calling st_bin_get_child() every time we need it
+   */
+  ClutterActor *child;
+
+  StAdjustment *hadjustment;
+  ClutterActor *hscroll;
+  StAdjustment *vadjustment;
+  ClutterActor *vscroll;
+
+  StPolicyType hscrollbar_policy;
+  StPolicyType vscrollbar_policy;
+
+  gfloat        row_size;
+  gfloat        column_size;
+
+  StScrollViewFade *fade_effect;
+
+  guint         row_size_set : 1;
+  guint         column_size_set : 1;
+  guint         mouse_scroll : 1;
+  guint         overlay_scrollbars : 1;
+  guint         hscrollbar_visible : 1;
+  guint         vscrollbar_visible : 1;
+};
+
+G_DEFINE_TYPE_WITH_CODE (StScrollView, st_scroll_view, ST_TYPE_BIN,
+                         G_ADD_PRIVATE (StScrollView)
+                         G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_CONTAINER,
+                                                clutter_container_iface_init))
+
+enum {
+  PROP_0,
+
+  PROP_HSCROLL,
+  PROP_VSCROLL,
+  PROP_HSCROLLBAR_POLICY,
+  PROP_VSCROLLBAR_POLICY,
+  PROP_HSCROLLBAR_VISIBLE,
+  PROP_VSCROLLBAR_VISIBLE,
+  PROP_MOUSE_SCROLL,
+  PROP_OVERLAY_SCROLLBARS,
+
+  N_PROPS
+};
+
+static GParamSpec *props[N_PROPS] = { NULL, };
+
+static void
+st_scroll_view_get_property (GObject    *object,
+                             guint       property_id,
+                             GValue     *value,
+                             GParamSpec *pspec)
+{
+  StScrollViewPrivate *priv = ((StScrollView *) object)->priv;
+
+  switch (property_id)
+    {
+    case PROP_HSCROLL:
+      g_value_set_object (value, priv->hscroll);
+      break;
+    case PROP_VSCROLL:
+      g_value_set_object (value, priv->vscroll);
+      break;
+    case PROP_HSCROLLBAR_POLICY:
+      g_value_set_enum (value, priv->hscrollbar_policy);
+      break;
+    case PROP_VSCROLLBAR_POLICY:
+      g_value_set_enum (value, priv->vscrollbar_policy);
+      break;
+    case PROP_HSCROLLBAR_VISIBLE:
+      g_value_set_boolean (value, priv->hscrollbar_visible);
+      break;
+    case PROP_VSCROLLBAR_VISIBLE:
+      g_value_set_boolean (value, priv->vscrollbar_visible);
+      break;
+    case PROP_MOUSE_SCROLL:
+      g_value_set_boolean (value, priv->mouse_scroll);
+      break;
+    case PROP_OVERLAY_SCROLLBARS:
+      g_value_set_boolean (value, priv->overlay_scrollbars);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    }
+}
+
+/**
+ * st_scroll_view_update_fade_effect:
+ * @scroll: a #StScrollView
+ * @fade_margins: a #ClutterMargin defining the vertical fade effects, in pixels.
+ *
+ * Sets the fade effects in all four edges of the view. A value of 0
+ * disables the effect.
+ */
+void
+st_scroll_view_update_fade_effect (StScrollView  *scroll,
+                                   ClutterMargin *fade_margins)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (scroll)->priv;
+
+  /* A fade amount of other than 0 enables the effect. */
+  if (fade_margins->left != 0. || fade_margins->right != 0. ||
+      fade_margins->top != 0. || fade_margins->bottom != 0.)
+    {
+      if (priv->fade_effect == NULL)
+        {
+          priv->fade_effect = g_object_new (ST_TYPE_SCROLL_VIEW_FADE, NULL);
+
+          clutter_actor_add_effect_with_name (CLUTTER_ACTOR (scroll), "fade",
+                                              CLUTTER_EFFECT (priv->fade_effect));
+        }
+
+      g_object_set (priv->fade_effect,
+                    "fade-margins", fade_margins,
+                    NULL);
+    }
+   else
+    {
+      if (priv->fade_effect != NULL)
+        {
+          clutter_actor_remove_effect (CLUTTER_ACTOR (scroll),
+                                       CLUTTER_EFFECT (priv->fade_effect));
+          priv->fade_effect = NULL;
+        }
+    }
+}
+
+static void
+st_scroll_view_set_property (GObject      *object,
+                             guint         property_id,
+                             const GValue *value,
+                             GParamSpec   *pspec)
+{
+  StScrollView *self = ST_SCROLL_VIEW (object);
+  StScrollViewPrivate *priv = self->priv;
+
+  switch (property_id)
+    {
+    case PROP_MOUSE_SCROLL:
+      st_scroll_view_set_mouse_scrolling (self,
+                                          g_value_get_boolean (value));
+      break;
+    case PROP_OVERLAY_SCROLLBARS:
+      st_scroll_view_set_overlay_scrollbars (self,
+                                             g_value_get_boolean (value));
+      break;
+    case PROP_HSCROLLBAR_POLICY:
+      st_scroll_view_set_policy (self,
+                                 g_value_get_enum (value),
+                                 priv->vscrollbar_policy);
+      break;
+    case PROP_VSCROLLBAR_POLICY:
+      st_scroll_view_set_policy (self,
+                                 priv->hscrollbar_policy,
+                                 g_value_get_enum (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+    }
+}
+
+static void
+st_scroll_view_dispose (GObject *object)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (object)->priv;
+
+  if (priv->fade_effect)
+    {
+      clutter_actor_remove_effect (CLUTTER_ACTOR (object), CLUTTER_EFFECT (priv->fade_effect));
+      priv->fade_effect = NULL;
+    }
+
+  g_clear_pointer (&priv->vscroll, clutter_actor_destroy);
+  g_clear_pointer (&priv->hscroll, clutter_actor_destroy);
+
+  /* For most reliable freeing of memory, an object with signals
+   * like StAdjustment should be explicitly disposed. Since we own
+   * the adjustments, we take care of that. This also disconnects
+   * the signal handlers that we established on creation.
+   */
+  if (priv->hadjustment)
+    {
+      g_object_run_dispose (G_OBJECT (priv->hadjustment));
+      g_object_unref (priv->hadjustment);
+      priv->hadjustment = NULL;
+    }
+
+  if (priv->vadjustment)
+    {
+      g_object_run_dispose (G_OBJECT (priv->vadjustment));
+      g_object_unref (priv->vadjustment);
+      priv->vadjustment = NULL;
+    }
+
+  G_OBJECT_CLASS (st_scroll_view_parent_class)->dispose (object);
+}
+
+static void
+st_scroll_view_paint (ClutterActor        *actor,
+                      ClutterPaintContext *paint_context)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (actor)->priv;
+
+  st_widget_paint_background (ST_WIDGET (actor), paint_context);
+
+  if (priv->child)
+    clutter_actor_paint (priv->child, paint_context);
+  if (priv->hscrollbar_visible)
+    clutter_actor_paint (priv->hscroll, paint_context);
+  if (priv->vscrollbar_visible)
+    clutter_actor_paint (priv->vscroll, paint_context);
+}
+
+static void
+st_scroll_view_pick (ClutterActor       *actor,
+                     ClutterPickContext *pick_context)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (actor)->priv;
+
+  /* Chain up so we get a bounding box pained (if we are reactive) */
+  CLUTTER_ACTOR_CLASS (st_scroll_view_parent_class)->pick (actor, pick_context);
+
+  if (priv->child)
+    clutter_actor_pick (priv->child, pick_context);
+  if (priv->hscrollbar_visible)
+    clutter_actor_pick (priv->hscroll, pick_context);
+  if (priv->vscrollbar_visible)
+    clutter_actor_pick (priv->vscroll, pick_context);
+}
+
+static gboolean
+st_scroll_view_get_paint_volume (ClutterActor       *actor,
+                                 ClutterPaintVolume *volume)
+{
+  return clutter_paint_volume_set_from_allocation (volume, actor);
+}
+
+static double
+get_scrollbar_width (StScrollView *scroll,
+                     gfloat        for_height)
+{
+  StScrollViewPrivate *priv = scroll->priv;
+
+  if (clutter_actor_is_visible (priv->vscroll))
+    {
+      gfloat min_size;
+
+      clutter_actor_get_preferred_width (CLUTTER_ACTOR (priv->vscroll), for_height,
+                                         &min_size, NULL);
+      return min_size;
+    }
+  else
+    return 0;
+}
+
+static double
+get_scrollbar_height (StScrollView *scroll,
+                      gfloat        for_width)
+{
+  StScrollViewPrivate *priv = scroll->priv;
+
+  if (clutter_actor_is_visible (priv->hscroll))
+    {
+      gfloat min_size;
+
+      clutter_actor_get_preferred_height (CLUTTER_ACTOR (priv->hscroll), for_width,
+                                          &min_size, NULL);
+
+      return min_size;
+    }
+  else
+    return 0;
+}
+
+static void
+st_scroll_view_get_preferred_width (ClutterActor *actor,
+                                    gfloat        for_height,
+                                    gfloat       *min_width_p,
+                                    gfloat       *natural_width_p)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (actor)->priv;
+  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
+  gboolean account_for_vscrollbar = FALSE;
+  gfloat min_width = 0, natural_width;
+  gfloat child_min_width, child_natural_width;
+
+  if (!priv->child)
+    return;
+
+  st_theme_node_adjust_for_height (theme_node, &for_height);
+
+  clutter_actor_get_preferred_width (priv->child, -1,
+                                     &child_min_width, &child_natural_width);
+
+  natural_width = child_natural_width;
+
+  switch (priv->hscrollbar_policy)
+    {
+    case ST_POLICY_NEVER:
+      min_width = child_min_width;
+      break;
+    case ST_POLICY_ALWAYS:
+    case ST_POLICY_AUTOMATIC:
+    case ST_POLICY_EXTERNAL:
+      /* Should theoretically use the min width of the hscrollbar,
+       * but that's not cleanly defined at the moment */
+      min_width = 0;
+      break;
+    default:
+      g_warn_if_reached();
+      break;
+    }
+
+  switch (priv->vscrollbar_policy)
+    {
+    case ST_POLICY_NEVER:
+    case ST_POLICY_EXTERNAL:
+      account_for_vscrollbar = FALSE;
+      break;
+    case ST_POLICY_ALWAYS:
+      account_for_vscrollbar = !priv->overlay_scrollbars;
+      break;
+    case ST_POLICY_AUTOMATIC:
+      /* For automatic scrollbars, we always request space for the vertical
+       * scrollbar; we won't know whether we actually need one until our
+       * height is assigned in allocate().
+       */
+      account_for_vscrollbar = !priv->overlay_scrollbars;
+      break;
+    default:
+      g_warn_if_reached();
+      break;
+    }
+
+  if (account_for_vscrollbar)
+    {
+      float sb_width = get_scrollbar_width (ST_SCROLL_VIEW (actor), for_height);
+
+      min_width += sb_width;
+      natural_width += sb_width;
+    }
+
+  if (min_width_p)
+    *min_width_p = min_width;
+
+  if (natural_width_p)
+    *natural_width_p = natural_width;
+
+  st_theme_node_adjust_preferred_width (theme_node, min_width_p, natural_width_p);
+}
+
+static void
+st_scroll_view_get_preferred_height (ClutterActor *actor,
+                                     gfloat        for_width,
+                                     gfloat       *min_height_p,
+                                     gfloat       *natural_height_p)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (actor)->priv;
+  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
+  gboolean account_for_hscrollbar = FALSE;
+  gfloat min_height = 0, natural_height;
+  gfloat child_min_height, child_natural_height;
+  gfloat child_min_width;
+  gfloat sb_width;
+
+  if (!priv->child)
+    return;
+
+  st_theme_node_adjust_for_width (theme_node, &for_width);
+
+  clutter_actor_get_preferred_width (priv->child, -1,
+                                     &child_min_width, NULL);
+
+  if (min_height_p)
+    *min_height_p = 0;
+
+  sb_width = get_scrollbar_width (ST_SCROLL_VIEW (actor), -1);
+
+  switch (priv->vscrollbar_policy)
+    {
+    case ST_POLICY_NEVER:
+    case ST_POLICY_EXTERNAL:
+      break;
+    case ST_POLICY_ALWAYS:
+    case ST_POLICY_AUTOMATIC:
+      /* We've requested space for the scrollbar, subtract it back out */
+      for_width -= sb_width;
+      break;
+    default:
+      g_warn_if_reached();
+      break;
+    }
+
+  switch (priv->hscrollbar_policy)
+    {
+    case ST_POLICY_NEVER:
+    case ST_POLICY_EXTERNAL:
+      account_for_hscrollbar = FALSE;
+      break;
+    case ST_POLICY_ALWAYS:
+      account_for_hscrollbar = !priv->overlay_scrollbars;
+      break;
+    case ST_POLICY_AUTOMATIC:
+      /* For automatic scrollbars, we always request space for the horizontal
+       * scrollbar; we won't know whether we actually need one until our
+       * width is assigned in allocate().
+       */
+      account_for_hscrollbar = !priv->overlay_scrollbars;
+      break;
+    default:
+      g_warn_if_reached();
+      break;
+    }
+
+  clutter_actor_get_preferred_height (priv->child, for_width,
+                                      &child_min_height, &child_natural_height);
+
+  natural_height = child_natural_height;
+
+  switch (priv->vscrollbar_policy)
+    {
+    case ST_POLICY_NEVER:
+      min_height = child_min_height;
+      break;
+    case ST_POLICY_ALWAYS:
+    case ST_POLICY_AUTOMATIC:
+    case ST_POLICY_EXTERNAL:
+      /* Should theoretically use the min height of the vscrollbar,
+       * but that's not cleanly defined at the moment */
+      min_height = 0;
+      break;
+    default:
+      g_warn_if_reached();
+      break;
+    }
+
+  if (account_for_hscrollbar)
+    {
+      float sb_height = get_scrollbar_height (ST_SCROLL_VIEW (actor), for_width);
+
+      min_height += sb_height;
+      natural_height += sb_height;
+    }
+
+  if (min_height_p)
+    *min_height_p = min_height;
+
+  if (natural_height_p)
+    *natural_height_p = natural_height;
+
+  st_theme_node_adjust_preferred_height (theme_node, min_height_p, natural_height_p);
+}
+
+static void
+st_scroll_view_allocate (ClutterActor          *actor,
+                         const ClutterActorBox *box)
+{
+  ClutterActorBox content_box, child_box;
+  gfloat avail_width, avail_height, sb_width, sb_height;
+  gboolean hscrollbar_visible, vscrollbar_visible;
+
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (actor)->priv;
+  StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (actor));
+
+  clutter_actor_set_allocation (actor, box);
+
+  st_theme_node_get_content_box (theme_node, box, &content_box);
+
+  avail_width = content_box.x2 - content_box.x1;
+  avail_height = content_box.y2 - content_box.y1;
+
+  if (clutter_actor_get_request_mode (actor) == CLUTTER_REQUEST_HEIGHT_FOR_WIDTH)
+    {
+      sb_width = get_scrollbar_width (ST_SCROLL_VIEW (actor), -1);
+      sb_height = get_scrollbar_height (ST_SCROLL_VIEW (actor), sb_width);
+    }
+  else
+    {
+      sb_height = get_scrollbar_height (ST_SCROLL_VIEW (actor), -1);
+      sb_width = get_scrollbar_width (ST_SCROLL_VIEW (actor), sb_height);
+    }
+
+  /* Determine what scrollbars are visible. The basic idea of the
+   * handling of an automatic scrollbars is that we start off with the
+   * assumption that we don't need any scrollbars, see if that works,
+   * and if not add horizontal and vertical scrollbars until we are no
+   * longer overflowing.
+   */
+  if (priv->child)
+    {
+      gfloat child_min_width;
+      gfloat child_min_height;
+
+      clutter_actor_get_preferred_width (priv->child, -1,
+                                         &child_min_width, NULL);
+
+      if (priv->vscrollbar_policy == ST_POLICY_AUTOMATIC)
+        {
+          if (priv->hscrollbar_policy == ST_POLICY_AUTOMATIC)
+            {
+              /* Pass one, try without a vertical scrollbar */
+              clutter_actor_get_preferred_height (priv->child, avail_width, &child_min_height, NULL);
+              vscrollbar_visible = child_min_height > avail_height;
+              hscrollbar_visible = child_min_width > avail_width - (vscrollbar_visible ? sb_width : 0);
+              vscrollbar_visible = child_min_height > avail_height - (hscrollbar_visible ? sb_height : 0);
+
+              /* Pass two - if we needed a vertical scrollbar, get a new preferred height */
+              if (vscrollbar_visible)
+                {
+                  clutter_actor_get_preferred_height (priv->child, MAX (avail_width - sb_width, 0),
+                                                      &child_min_height, NULL);
+                  hscrollbar_visible = child_min_width > avail_width - sb_width;
+                }
+            }
+          else
+            {
+              hscrollbar_visible = priv->hscrollbar_policy == ST_POLICY_ALWAYS;
+
+              /* try without a vertical scrollbar */
+              clutter_actor_get_preferred_height (priv->child, avail_width, &child_min_height, NULL);
+              vscrollbar_visible = child_min_height > avail_height - (hscrollbar_visible ? sb_height : 0);
+            }
+        }
+      else
+        {
+          vscrollbar_visible = priv->vscrollbar_policy == ST_POLICY_ALWAYS;
+
+          if (priv->hscrollbar_policy == ST_POLICY_AUTOMATIC)
+            hscrollbar_visible = child_min_width > avail_height - (vscrollbar_visible ? 0 : sb_width);
+          else
+            hscrollbar_visible = priv->hscrollbar_policy == ST_POLICY_ALWAYS;
+        }
+    }
+  else
+    {
+      hscrollbar_visible = priv->hscrollbar_policy != ST_POLICY_NEVER &&
+                           priv->hscrollbar_policy != ST_POLICY_EXTERNAL;
+      vscrollbar_visible = priv->vscrollbar_policy != ST_POLICY_NEVER &&
+                           priv->vscrollbar_policy != ST_POLICY_EXTERNAL;
+    }
+
+  /* Whether or not we show the scrollbars, if the scrollbars are visible
+   * actors, we need to give them some allocation, so we unconditionally
+   * give them the "right" allocation; that might overlap the child when
+   * the scrollbars are not visible, but it doesn't matter because we
+   * don't include them in pick or paint.
+   */
+
+  /* Vertical scrollbar */
+  if (clutter_actor_get_text_direction (actor) == CLUTTER_TEXT_DIRECTION_RTL)
+    {
+      child_box.x1 = content_box.x1;
+      child_box.x2 = content_box.x1 + sb_width;
+    }
+  else
+    {
+      child_box.x1 = content_box.x2 - sb_width;
+      child_box.x2 = content_box.x2;
+    }
+  child_box.y1 = content_box.y1;
+  child_box.y2 = content_box.y2 - (hscrollbar_visible ? sb_height : 0);
+
+  clutter_actor_allocate (priv->vscroll, &child_box);
+
+  /* Horizontal scrollbar */
+  if (clutter_actor_get_text_direction (actor) == CLUTTER_TEXT_DIRECTION_RTL)
+    {
+      child_box.x1 = content_box.x1 + (vscrollbar_visible ? sb_width : 0);
+      child_box.x2 = content_box.x2;
+    }
+  else
+    {
+      child_box.x1 = content_box.x1;
+      child_box.x2 = content_box.x2 - (vscrollbar_visible ? sb_width : 0);
+    }
+  child_box.y1 = content_box.y2 - sb_height;
+  child_box.y2 = content_box.y2;
+
+  clutter_actor_allocate (priv->hscroll, &child_box);
+
+  /* In case the scrollbar policy is NEVER or EXTERNAL or scrollbars
+   * should be overlaid, we don't trim the content box allocation by
+   * the scrollbar size.
+   * Fold this into the scrollbar sizes to simplify the rest of the
+   * computations.
+   */
+  if (priv->hscrollbar_policy == ST_POLICY_NEVER ||
+      priv->hscrollbar_policy == ST_POLICY_EXTERNAL ||
+      priv->overlay_scrollbars)
+    sb_height = 0;
+  if (priv->vscrollbar_policy == ST_POLICY_NEVER ||
+      priv->vscrollbar_policy == ST_POLICY_EXTERNAL ||
+      priv->overlay_scrollbars)
+    sb_width = 0;
+
+  /* Child */
+  if (clutter_actor_get_text_direction (actor) == CLUTTER_TEXT_DIRECTION_RTL)
+    {
+      child_box.x1 = content_box.x1 + sb_width;
+      child_box.x2 = content_box.x2;
+    }
+  else
+    {
+      child_box.x1 = content_box.x1;
+      child_box.x2 = content_box.x2 - sb_width;
+    }
+  child_box.y1 = content_box.y1;
+  child_box.y2 = content_box.y2 - sb_height;
+
+  if (priv->child)
+    clutter_actor_allocate (priv->child, &child_box);
+
+  if (priv->hscrollbar_visible != hscrollbar_visible)
+    {
+      g_object_freeze_notify (G_OBJECT (actor));
+      priv->hscrollbar_visible = hscrollbar_visible;
+      g_object_notify_by_pspec (G_OBJECT (actor),
+                                props[PROP_HSCROLLBAR_VISIBLE]);
+      g_object_thaw_notify (G_OBJECT (actor));
+    }
+
+  if (priv->vscrollbar_visible != vscrollbar_visible)
+    {
+      g_object_freeze_notify (G_OBJECT (actor));
+      priv->vscrollbar_visible = vscrollbar_visible;
+      g_object_notify_by_pspec (G_OBJECT (actor),
+                                props[PROP_VSCROLLBAR_VISIBLE]);
+      g_object_thaw_notify (G_OBJECT (actor));
+    }
+
+}
+
+static void
+adjust_with_direction (StAdjustment           *adj,
+                       ClutterScrollDirection  direction)
+{
+  gdouble delta;
+
+  switch (direction)
+    {
+    case CLUTTER_SCROLL_UP:
+    case CLUTTER_SCROLL_LEFT:
+      delta = -1.0;
+      break;
+    case CLUTTER_SCROLL_RIGHT:
+    case CLUTTER_SCROLL_DOWN:
+      delta = 1.0;
+      break;
+    case CLUTTER_SCROLL_SMOOTH:
+    default:
+      g_assert_not_reached ();
+      break;
+    }
+
+  st_adjustment_adjust_for_scroll_event (adj, delta);
+}
+
+static void
+st_scroll_view_style_changed (StWidget *widget)
+{
+  StScrollView *self = ST_SCROLL_VIEW (widget);
+  gboolean has_vfade, has_hfade;
+  double vfade_offset = 0.0;
+  double hfade_offset = 0.0;
+
+  StThemeNode *theme_node = st_widget_get_theme_node (widget);
+
+  has_vfade = st_theme_node_lookup_length (theme_node, "-st-vfade-offset", FALSE, &vfade_offset);
+  has_hfade = st_theme_node_lookup_length (theme_node, "-st-hfade-offset", FALSE, &hfade_offset);
+  if (has_vfade || has_hfade)
+    {
+      st_scroll_view_update_fade_effect (self,
+                                         &(ClutterMargin) {
+                                           .top = vfade_offset,
+                                           .bottom = vfade_offset,
+                                           .left = hfade_offset,
+                                           .right = hfade_offset,
+                                         });
+    }
+
+  ST_WIDGET_CLASS (st_scroll_view_parent_class)->style_changed (widget);
+}
+
+static gboolean
+st_scroll_view_scroll_event (ClutterActor       *self,
+                             ClutterScrollEvent *event)
+{
+  StScrollViewPrivate *priv = ST_SCROLL_VIEW (self)->priv;
+  ClutterTextDirection direction;
+
+  /* don't handle scroll events if requested not to */
+  if (!priv->mouse_scroll)
+    return FALSE;
+
+  if (clutter_event_is_pointer_emulated ((ClutterEvent *) event))
+    return TRUE;
+
+  direction = clutter_actor_get_text_direction (self);
+
+  switch (event->direction)
+    {
+    case CLUTTER_SCROLL_SMOOTH:
+      {
+        gdouble delta_x, delta_y;
+        clutter_event_get_scroll_delta ((ClutterEvent *)event, &delta_x, &delta_y);
+
+        if (direction == CLUTTER_TEXT_DIRECTION_RTL)
+          delta_x *= -1;
+
+        st_adjustment_adjust_for_scroll_event (priv->hadjustment, delta_x);
+        st_adjustment_adjust_for_scroll_event (priv->vadjustment, delta_y);
+      }
+      break;
+    case CLUTTER_SCROLL_UP:
+    case CLUTTER_SCROLL_DOWN:
+      adjust_with_direction (priv->vadjustment, event->direction);
+      break;
+    case CLUTTER_SCROLL_LEFT:
+    case CLUTTER_SCROLL_RIGHT:
+      if (direction == CLUTTER_TEXT_DIRECTION_RTL)
+        {
+          ClutterScrollDirection dir;
+
+          dir = event->direction == CLUTTER_SCROLL_LEFT ? CLUTTER_SCROLL_RIGHT
+                                                        : CLUTTER_SCROLL_LEFT;
+          adjust_with_direction (priv->hadjustment, dir);
+        }
+      else
+        {
+          adjust_with_direction (priv->hadjustment, event->direction);
+        }
+      break;
+    default:
+      g_warn_if_reached();
+      break;
+    }
+
+  return TRUE;
+}
+
+static void
+st_scroll_view_class_init (StScrollViewClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
+  StWidgetClass *widget_class = ST_WIDGET_CLASS (klass);
+
+  object_class->get_property = st_scroll_view_get_property;
+  object_class->set_property = st_scroll_view_set_property;
+  object_class->dispose = st_scroll_view_dispose;
+
+  actor_class->paint = st_scroll_view_paint;
+  actor_class->pick = st_scroll_view_pick;
+  actor_class->get_paint_volume = st_scroll_view_get_paint_volume;
+  actor_class->get_preferred_width = st_scroll_view_get_preferred_width;
+  actor_class->get_preferred_height = st_scroll_view_get_preferred_height;
+  actor_class->allocate = st_scroll_view_allocate;
+  actor_class->scroll_event = st_scroll_view_scroll_event;
+
+  widget_class->style_changed = st_scroll_view_style_changed;
+
+  /**
+   * StScrollView:hscroll:
+   *
+   * The horizontal #StScrollBar for the #StScrollView.
+   */
+  props[PROP_HSCROLL] =
+    g_param_spec_object ("hscroll",
+                         "StScrollBar",
+                         "Horizontal scroll indicator",
+                         ST_TYPE_SCROLL_BAR,
+                         ST_PARAM_READABLE);
+
+  /**
+   * StScrollView:vscroll:
+   *
+   * The vertical #StScrollBar for the #StScrollView.
+   */
+  props[PROP_VSCROLL] =
+    g_param_spec_object ("vscroll",
+                         "StScrollBar",
+                         "Vertical scroll indicator",
+                         ST_TYPE_SCROLL_BAR,
+                         ST_PARAM_READABLE);
+
+  /**
+   * StScrollView:vscrollbar-policy:
+   *
+   * The #StPolicyType for when to show the vertical #StScrollBar.
+   */
+  props[PROP_VSCROLLBAR_POLICY] =
+    g_param_spec_enum ("vscrollbar-policy",
+                       "Vertical Scrollbar Policy",
+                       "When the vertical scrollbar is displayed",
+                       ST_TYPE_POLICY_TYPE,
+                       ST_POLICY_AUTOMATIC,
+                       ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StScrollView:hscrollbar-policy:
+   *
+   * The #StPolicyType for when to show the horizontal #StScrollBar.
+   */
+  props[PROP_HSCROLLBAR_POLICY] =
+    g_param_spec_enum ("hscrollbar-policy",
+                       "Horizontal Scrollbar Policy",
+                       "When the horizontal scrollbar is displayed",
+                       ST_TYPE_POLICY_TYPE,
+                       ST_POLICY_AUTOMATIC,
+                       ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StScrollView:hscrollbar-visible:
+   *
+   * Whether the horizontal #StScrollBar is visible.
+   */
+  props[PROP_HSCROLLBAR_VISIBLE] =
+    g_param_spec_boolean ("hscrollbar-visible",
+                          "Horizontal Scrollbar Visibility",
+                          "Whether the horizontal scrollbar is visible",
+                          TRUE,
+                          ST_PARAM_READABLE);
+
+  /**
+   * StScrollView:vscrollbar-visible:
+   *
+   * Whether the vertical #StScrollBar is visible.
+   */
+  props[PROP_VSCROLLBAR_VISIBLE] =
+    g_param_spec_boolean ("vscrollbar-visible",
+                          "Vertical Scrollbar Visibility",
+                          "Whether the vertical scrollbar is visible",
+                          TRUE,
+                          ST_PARAM_READABLE);
+
+  /**
+   * StScrollView:enable-mouse-scrolling:
+   *
+   * Whether to enable automatic mouse wheel scrolling.
+   */
+  props[PROP_MOUSE_SCROLL] =
+    g_param_spec_boolean ("enable-mouse-scrolling",
+                          "Enable Mouse Scrolling",
+                          "Enable automatic mouse wheel scrolling",
+                          TRUE,
+                          ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StScrollView:overlay-scrollbars:
+   *
+   * Whether scrollbars are painted on top of the content.
+   */
+  props[PROP_OVERLAY_SCROLLBARS] =
+    g_param_spec_boolean ("overlay-scrollbars",
+                          "Use Overlay Scrollbars",
+                          "Overlay scrollbars over the content",
+                          FALSE,
+                          ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  g_object_class_install_properties (object_class, N_PROPS, props);
+}
+
+static void
+st_scroll_view_init (StScrollView *self)
+{
+  StScrollViewPrivate *priv = self->priv = st_scroll_view_get_instance_private (self);
+
+  priv->hscrollbar_policy = ST_POLICY_AUTOMATIC;
+  priv->vscrollbar_policy = ST_POLICY_AUTOMATIC;
+
+  priv->hadjustment = g_object_new (ST_TYPE_ADJUSTMENT,
+                                    "actor", self,
+                                    NULL);
+  priv->hscroll = g_object_new (ST_TYPE_SCROLL_BAR,
+                                "adjustment", priv->hadjustment,
+                                "vertical", FALSE,
+                                NULL);
+
+  priv->vadjustment = g_object_new (ST_TYPE_ADJUSTMENT,
+                                    "actor", self,
+                                    NULL);
+  priv->vscroll = g_object_new (ST_TYPE_SCROLL_BAR,
+                                "adjustment", priv->vadjustment,
+                                "vertical", TRUE,
+                                NULL);
+
+  clutter_actor_add_child (CLUTTER_ACTOR (self), priv->hscroll);
+  clutter_actor_add_child (CLUTTER_ACTOR (self), priv->vscroll);
+
+  /* mouse scroll is enabled by default, so we also need to be reactive */
+  priv->mouse_scroll = TRUE;
+  g_object_set (G_OBJECT (self), "reactive", TRUE, NULL);
+}
+
+static void
+st_scroll_view_add (ClutterContainer *container,
+                    ClutterActor     *actor)
+{
+  StScrollView *self = ST_SCROLL_VIEW (container);
+  StScrollViewPrivate *priv = self->priv;
+
+  if (ST_IS_SCROLLABLE (actor))
+    {
+      priv->child = actor;
+
+      /* chain up to StBin::add() */
+      st_scroll_view_parent_iface->add (container, actor);
+
+      st_scrollable_set_adjustments (ST_SCROLLABLE (actor),
+                                     priv->hadjustment, priv->vadjustment);
+    }
+  else
+    {
+      g_warning ("Attempting to add an actor of type %s to "
+                 "a StScrollView, but the actor does "
+                 "not implement StScrollable.",
+                 g_type_name (G_OBJECT_TYPE (actor)));
+    }
+}
+
+static void
+st_scroll_view_remove (ClutterContainer *container,
+                       ClutterActor     *actor)
+{
+  StScrollView *self = ST_SCROLL_VIEW (container);
+  StScrollViewPrivate *priv = self->priv;
+
+  if (actor == priv->child)
+    {
+      g_object_ref (priv->child);
+
+      /* chain up to StBin::remove() */
+      st_scroll_view_parent_iface->remove (container, actor);
+
+      st_scrollable_set_adjustments (ST_SCROLLABLE (priv->child),
+                                     NULL, NULL);
+
+      g_object_unref (priv->child);
+      priv->child = NULL;
+    }
+  else
+    {
+      if (actor == priv->vscroll)
+        priv->vscroll = NULL;
+      else if (actor == priv->hscroll)
+        priv->hscroll = NULL;
+      else
+        g_assert ("Unknown child removed from StScrollView");
+
+      clutter_actor_remove_child (CLUTTER_ACTOR (container), actor);
+    }
+}
+
+static void
+clutter_container_iface_init (ClutterContainerIface *iface)
+{
+  /* store a pointer to the StBin implementation of
+   * ClutterContainer so that we can chain up when
+   * overriding the methods
+   */
+  st_scroll_view_parent_iface = g_type_interface_peek_parent (iface);
+
+  iface->add = st_scroll_view_add;
+  iface->remove = st_scroll_view_remove;
+}
+
+/**
+ * st_scroll_view_new:
+ *
+ * Create a new #StScrollView.
+ *
+ * Returns: (transfer full): a new #StScrollView
+ */
+StWidget *
+st_scroll_view_new (void)
+{
+  return g_object_new (ST_TYPE_SCROLL_VIEW, NULL);
+}
+
+/**
+ * st_scroll_view_get_hscroll_bar:
+ * @scroll: a #StScrollView
+ *
+ * Gets the horizontal #StScrollBar of the #StScrollView.
+ *
+ * Returns: (transfer none): the horizontal scrollbar
+ */
+ClutterActor *
+st_scroll_view_get_hscroll_bar (StScrollView *scroll)
+{
+  g_return_val_if_fail (ST_IS_SCROLL_VIEW (scroll), NULL);
+
+  return scroll->priv->hscroll;
+}
+
+/**
+ * st_scroll_view_get_vscroll_bar:
+ * @scroll: a #StScrollView
+ *
+ * Gets the vertical scrollbar of the #StScrollView.
+ *
+ * Returns: (transfer none): the vertical #StScrollBar
+ */
+ClutterActor *
+st_scroll_view_get_vscroll_bar (StScrollView *scroll)
+{
+  g_return_val_if_fail (ST_IS_SCROLL_VIEW (scroll), NULL);
+
+  return scroll->priv->vscroll;
+}
+
+/**
+ * st_scroll_view_get_column_size:
+ * @scroll: a #StScrollView
+ *
+ * Get the step increment of the horizontal plane.
+ *
+ * Returns: the horizontal step increment
+ */
+gfloat
+st_scroll_view_get_column_size (StScrollView *scroll)
+{
+  gdouble column_size;
+
+  g_return_val_if_fail (scroll, 0);
+
+  g_object_get (scroll->priv->hadjustment,
+                "step-increment", &column_size,
+                NULL);
+
+  return column_size;
+}
+
+/**
+ * st_scroll_view_set_column_size:
+ * @scroll: a #StScrollView
+ * @column_size: horizontal step increment
+ *
+ * Set the step increment of the horizontal plane to @column_size.
+ */
+void
+st_scroll_view_set_column_size (StScrollView *scroll,
+                                gfloat        column_size)
+{
+  g_return_if_fail (scroll);
+
+  if (column_size < 0)
+    {
+      scroll->priv->column_size_set = FALSE;
+      scroll->priv->column_size = -1;
+    }
+  else
+    {
+      scroll->priv->column_size_set = TRUE;
+      scroll->priv->column_size = column_size;
+
+      g_object_set (scroll->priv->hadjustment,
+                    "step-increment", (gdouble) scroll->priv->column_size,
+                    NULL);
+    }
+}
+
+/**
+ * st_scroll_view_get_row_size:
+ * @scroll: a #StScrollView
+ *
+ * Get the step increment of the vertical plane.
+ *
+ * Returns: the vertical step increment
+ */
+gfloat
+st_scroll_view_get_row_size (StScrollView *scroll)
+{
+  gdouble row_size;
+
+  g_return_val_if_fail (scroll, 0);
+
+  g_object_get (scroll->priv->vadjustment,
+                "step-increment", &row_size,
+                NULL);
+
+  return row_size;
+}
+
+/**
+ * st_scroll_view_set_row_size:
+ * @scroll: a #StScrollView
+ * @row_size: vertical step increment
+ *
+ * Set the step increment of the vertical plane to @row_size.
+ */
+void
+st_scroll_view_set_row_size (StScrollView *scroll,
+                             gfloat        row_size)
+{
+  g_return_if_fail (scroll);
+
+  if (row_size < 0)
+    {
+      scroll->priv->row_size_set = FALSE;
+      scroll->priv->row_size = -1;
+    }
+  else
+    {
+      scroll->priv->row_size_set = TRUE;
+      scroll->priv->row_size = row_size;
+
+      g_object_set (scroll->priv->vadjustment,
+                    "step-increment", (gdouble) scroll->priv->row_size,
+                    NULL);
+    }
+}
+
+/**
+ * st_scroll_view_set_mouse_scrolling:
+ * @scroll: a #StScrollView
+ * @enabled: %TRUE or %FALSE
+ *
+ * Sets automatic mouse wheel scrolling to enabled or disabled.
+ */
+void
+st_scroll_view_set_mouse_scrolling (StScrollView *scroll,
+                                    gboolean      enabled)
+{
+  StScrollViewPrivate *priv;
+
+  g_return_if_fail (ST_IS_SCROLL_VIEW (scroll));
+
+  priv = ST_SCROLL_VIEW (scroll)->priv;
+
+  if (priv->mouse_scroll != enabled)
+    {
+      priv->mouse_scroll = enabled;
+
+      /* make sure we can receive mouse wheel events */
+      if (enabled)
+        clutter_actor_set_reactive ((ClutterActor *) scroll, TRUE);
+
+      g_object_notify_by_pspec (G_OBJECT (scroll), props[PROP_MOUSE_SCROLL]);
+    }
+}
+
+/**
+ * st_scroll_view_get_mouse_scrolling:
+ * @scroll: a #StScrollView
+ *
+ * Get whether automatic mouse wheel scrolling is enabled or disabled.
+ *
+ * Returns: %TRUE if enabled, %FALSE otherwise
+ */
+gboolean
+st_scroll_view_get_mouse_scrolling (StScrollView *scroll)
+{
+  StScrollViewPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_SCROLL_VIEW (scroll), FALSE);
+
+  priv = ST_SCROLL_VIEW (scroll)->priv;
+
+  return priv->mouse_scroll;
+}
+
+/**
+ * st_scroll_view_set_overlay_scrollbars:
+ * @scroll: A #StScrollView
+ * @enabled: Whether to enable overlay scrollbars
+ *
+ * Sets whether scrollbars are painted on top of the content.
+ */
+void
+st_scroll_view_set_overlay_scrollbars (StScrollView *scroll,
+                                       gboolean      enabled)
+{
+  StScrollViewPrivate *priv;
+
+  g_return_if_fail (ST_IS_SCROLL_VIEW (scroll));
+
+  priv = ST_SCROLL_VIEW (scroll)->priv;
+
+  if (priv->overlay_scrollbars != enabled)
+    {
+      priv->overlay_scrollbars = enabled;
+      g_object_notify_by_pspec (G_OBJECT (scroll),
+                                props[PROP_OVERLAY_SCROLLBARS]);
+      clutter_actor_queue_relayout (CLUTTER_ACTOR (scroll));
+    }
+}
+
+/**
+ * st_scroll_view_get_overlay_scrollbars:
+ * @scroll: A #StScrollView
+ *
+ * Gets whether scrollbars are painted on top of the content.
+ *
+ * Returns: %TRUE if enabled, %FALSE otherwise
+ */
+gboolean
+st_scroll_view_get_overlay_scrollbars (StScrollView *scroll)
+{
+  StScrollViewPrivate *priv;
+
+  g_return_val_if_fail (ST_IS_SCROLL_VIEW (scroll), FALSE);
+
+  priv = ST_SCROLL_VIEW (scroll)->priv;
+
+  return priv->overlay_scrollbars;
+}
+
+/**
+ * st_scroll_view_set_policy:
+ * @scroll: A #StScrollView
+ * @hscroll: Whether to enable horizontal scrolling
+ * @vscroll: Whether to enable vertical scrolling
+ *
+ * Set the scroll policy.
+ */
+void
+st_scroll_view_set_policy (StScrollView   *scroll,
+                           StPolicyType    hscroll,
+                           StPolicyType    vscroll)
+{
+  StScrollViewPrivate *priv;
+
+  g_return_if_fail (ST_IS_SCROLL_VIEW (scroll));
+
+  priv = ST_SCROLL_VIEW (scroll)->priv;
+
+  if (priv->hscrollbar_policy == hscroll && priv->vscrollbar_policy == vscroll)
+    return;
+
+  g_object_freeze_notify ((GObject *) scroll);
+
+  if (priv->hscrollbar_policy != hscroll)
+    {
+      priv->hscrollbar_policy = hscroll;
+      g_object_notify_by_pspec ((GObject *) scroll,
+                                props[PROP_HSCROLLBAR_POLICY]);
+    }
+
+  if (priv->vscrollbar_policy != vscroll)
+    {
+      priv->vscrollbar_policy = vscroll;
+      g_object_notify_by_pspec ((GObject *) scroll,
+                                props[PROP_VSCROLLBAR_POLICY]);
+    }
+
+  clutter_actor_queue_relayout (CLUTTER_ACTOR (scroll));
+
+  g_object_thaw_notify ((GObject *) scroll);
+}