Merge lp:~cimi/overlay-scrollbar/new-thumb-functionalities into lp:overlay-scrollbar

[Andrea Cimitan]

Big changes... are you really sure you want to review that? :-)

[Marco Trevisan (Treviño) (3v1n0)]

I do :)

[Marco Trevisan (Treviño) (3v1n0)]

From an usability point of view I'd reduce the value of TIMEOUT_THUMB_SHOW to 50ms. It seems better here.

[Andrea Cimitan (cimi)]

Marco, I'm thinking about increasing it to 150 :-) Please notice that the timeout is not respected when the thumb is touching the screen edge.

Anyway, the branch is still in progress :-) Not ready for review (see the "Status"!)

[Ted Gould (ted)]

In general, I'm a little uncomfortable with all the bit twittling for the state variable. I think that you should put that into its own function. Two reasons, it's easy to mess up. And it seems to be likely someplace you'll want to put a g_debug() statement when things are going wrong.

Also, the diffs would be a lot smaller if the name changes weren't included with the logic changes. I think next time you should split those out into two different merge requests.

Other than that, it was a big diff! :-) I didn't see anything on a general read through.

review: Approve

=== modified file 'os/Makefile.am'
--- os/Makefile.am	2011-10-05 12:24:21 +0000
+++ os/Makefile.am	2011-10-12 17:16:23 +0000
@@ -16,8 +16,8 @@
 
 source_c = \
 	$(srcdir)/os-animation.c \
+	$(srcdir)/os-bar.c \
 	$(srcdir)/os-log.c \
-	$(srcdir)/os-pager.c \
 	$(srcdir)/os-scrollbar.c \
 	$(srcdir)/os-thumb.c \
 	$(srcdir)/os-utils.c

=== renamed file 'os/os-pager.c' => 'os/os-bar.c'
--- os/os-pager.c	2011-10-05 12:24:21 +0000
+++ os/os-bar.c	2011-10-12 17:16:23 +0000
@@ -29,78 +29,45 @@
 #include <cairo-xlib.h>
 #include <gdk/gdkx.h>
 
-/* Rate of the fade. */
-#define RATE_FADE 30
-
 /* Duration of the fade-in. */
 #define DURATION_FADE_IN 200
 
 /* Duration of the fade-out. */
 #define DURATION_FADE_OUT 400
 
+/* Max duration of the retracting tail. */
+#define MAX_DURATION_TAIL 600
+
+/* Min duration of the retracting tail. */
+#define MIN_DURATION_TAIL 100
+
 #ifdef USE_GTK3
 #define SHAPE_REGION(x) (cairo_region_create_rectangle (x))
 #else
 #define SHAPE_REGION(x) (gdk_region_rectangle (x))
 #endif
 
-struct _OsPagerPrivate {
-  GdkWindow *pager_window;
-  GdkWindow *connection_window;
+struct _OsBarPrivate {
+  GdkRectangle bar_mask;
+  GdkRectangle tail_mask; /* In theory not needed, but easier to read. */
+  GdkRectangle allocation;
+  GdkWindow *bar_window;
+  GdkWindow *tail_window;
   GtkWidget *parent;
-  GdkRectangle mask;
-  GdkRectangle connection_mask; /* In theory not needed, but easier to read. */
-  GdkRectangle allocation;
-  OsAnimation *animation;
+  OsAnimation *state_animation;
+  OsAnimation *tail_animation;
   gboolean active;
   gboolean detached;
   gboolean visible;
   gfloat weight;
-  gulong handler_id;
 };
 
-static void os_pager_dispose (GObject *object);
-static void os_pager_finalize (GObject *object);
-
-/* Draw on the connection_window. */
-static void
-draw_connection (OsPager *pager)
-{
-#ifdef USE_GTK3
-  GdkRGBA color;
-  GtkStyleContext *style_context;
-#else
-  GdkColor color;
-  GtkStyle *style;
-#endif
-  OsPagerPrivate *priv;
-
-  priv = pager->priv;
-
-#ifdef USE_GTK3
-  style_context = gtk_widget_get_style_context (priv->parent);
-
-  gtk_style_context_get_background_color (style_context, GTK_STATE_FLAG_ACTIVE, &color);
-
-  color.alpha = 1.0;
-
-  gdk_window_set_background_rgba (priv->connection_window, &color);
-#else
-  style = gtk_widget_get_style (priv->parent);
-
-  color = style->bg[GTK_STATE_ACTIVE];
-
-  gdk_colormap_alloc_color (gdk_drawable_get_colormap (priv->connection_window), &color, FALSE, TRUE);
-
-  gdk_window_set_background (priv->connection_window, &color);
-#endif
-
-  gdk_window_invalidate_rect (gtk_widget_get_window (priv->parent), &priv->allocation, TRUE);
-}
-
-/* Draw on the pager_window. */
-static void
-draw_pager (OsPager *pager)
+static void os_bar_dispose (GObject *object);
+static void os_bar_finalize (GObject *object);
+
+/* Draw on the bar_window. */
+static void
+draw_bar (OsBar *bar)
 {
 #ifdef USE_GTK3
   GdkRGBA c1, c2, color;
@@ -109,10 +76,10 @@
   GdkColor c1, c2, color;
   GtkStyle *style;
 #endif
-  OsPagerPrivate *priv;
+  OsBarPrivate *priv;
   gfloat weight;
 
-  priv = pager->priv;
+  priv = bar->priv;
 
   weight = priv->weight;
 
@@ -135,7 +102,7 @@
   color.blue  = weight * c1.blue  + (1.0 - weight) * c2.blue;
   color.alpha = 1.0;
 
-  gdk_window_set_background_rgba (priv->pager_window, &color);
+  gdk_window_set_background_rgba (priv->bar_window, &color);
 #else
   style = gtk_widget_get_style (priv->parent);
 
@@ -154,9 +121,45 @@
   color.green = weight * c1.green + (1.0 - weight) * c2.green;
   color.blue  = weight * c1.blue  + (1.0 - weight) * c2.blue;
 
-  gdk_colormap_alloc_color (gdk_drawable_get_colormap (priv->pager_window), &color, FALSE, TRUE);
-
-  gdk_window_set_background (priv->pager_window, &color);
+  gdk_colormap_alloc_color (gdk_drawable_get_colormap (priv->bar_window), &color, FALSE, TRUE);
+
+  gdk_window_set_background (priv->bar_window, &color);
+#endif
+
+  gdk_window_invalidate_rect (gtk_widget_get_window (priv->parent), &priv->allocation, TRUE);
+}
+
+/* Draw on the tail_window. */
+static void
+draw_tail (OsBar *bar)
+{
+#ifdef USE_GTK3
+  GdkRGBA color;
+  GtkStyleContext *style_context;
+#else
+  GdkColor color;
+  GtkStyle *style;
+#endif
+  OsBarPrivate *priv;
+
+  priv = bar->priv;
+
+#ifdef USE_GTK3
+  style_context = gtk_widget_get_style_context (priv->parent);
+
+  gtk_style_context_get_background_color (style_context, GTK_STATE_FLAG_ACTIVE, &color);
+
+  color.alpha = 1.0;
+
+  gdk_window_set_background_rgba (priv->tail_window, &color);
+#else
+  style = gtk_widget_get_style (priv->parent);
+
+  color = style->bg[GTK_STATE_ACTIVE];
+
+  gdk_colormap_alloc_color (gdk_drawable_get_colormap (priv->tail_window), &color, FALSE, TRUE);
+
+  gdk_window_set_background (priv->tail_window, &color);
 #endif
 
   gdk_window_invalidate_rect (gtk_widget_get_window (priv->parent), &priv->allocation, TRUE);
@@ -167,35 +170,35 @@
 change_state_cb (gfloat   weight,
                  gpointer user_data)
 {
-  OsPager *pager;
-  OsPagerPrivate *priv;
-
-  pager = OS_PAGER (user_data);
-
-  priv = pager->priv;
+  OsBar *bar;
+  OsBarPrivate *priv;
+
+  bar = OS_BAR (user_data);
+
+  priv = bar->priv;
 
   priv->weight = weight;
 
   if (priv->parent == NULL)
     return;
 
-  draw_pager (pager);
+  draw_bar (bar);
 }
 
 /* Stop function called by the change-state animation. */
 static void
 change_state_stop_cb (gpointer user_data)
 {
-  OsPager *pager;
-  OsPagerPrivate *priv;
-
-  pager = OS_PAGER (user_data);
-
-  priv = pager->priv;
+  OsBar *bar;
+  OsBarPrivate *priv;
+
+  bar = OS_BAR (user_data);
+
+  priv = bar->priv;
 
   priv->weight = 1.0f;
 
-  draw_pager (pager);
+  draw_bar (bar);
 }
 
 /* Callback called when the Gtk+ theme changes. */
@@ -204,19 +207,19 @@
                           GParamSpec* pspec,
                           gpointer    user_data)
 {
-  OsPager *pager;
-  OsPagerPrivate *priv;
+  OsBar *bar;
+  OsBarPrivate *priv;
 
-  pager = OS_PAGER (user_data);
-  priv = pager->priv;
+  bar = OS_BAR (user_data);
+  priv = bar->priv;
 
   if (priv->parent == NULL ||
-      priv->pager_window == NULL ||
-      priv->connection_window == NULL)
+      priv->bar_window == NULL ||
+      priv->tail_window == NULL)
     return;
 
-  draw_connection (pager);
-  draw_pager (pager);
+  draw_tail (bar);
+  draw_bar (bar);
 }
 
 /* Check if two GdkRectangle are different. */
@@ -232,29 +235,93 @@
   return FALSE;
 }
 
-G_DEFINE_TYPE (OsPager, os_pager, G_TYPE_OBJECT);
-
-static void
-os_pager_class_init (OsPagerClass *class)
+/* Callback called by the retract-tail animation. */
+static void
+retract_tail_cb (gfloat   weight,
+                 gpointer user_data)
+{
+  GdkRectangle tail_mask;
+  OsBar *bar;
+  OsBarPrivate *priv;
+
+  bar = OS_BAR (user_data);
+
+  priv = bar->priv;
+
+  if (priv->parent == NULL)
+    return;
+
+  tail_mask = priv->tail_mask;
+
+  if (priv->allocation.height >= priv->allocation.width)
+    {
+      tail_mask.height = tail_mask.height * (1.0 - weight);
+
+      if (priv->tail_mask.y + priv->tail_mask.height < priv->bar_mask.y + priv->bar_mask.height)
+        tail_mask.y = priv->tail_mask.y + priv->tail_mask.height - tail_mask.height;
+    }
+  else
+    {
+      tail_mask.width = tail_mask.width * (1.0 - weight);
+
+      if (priv->tail_mask.x + priv->tail_mask.width < priv->bar_mask.x + priv->bar_mask.width)
+        tail_mask.x = priv->tail_mask.x + priv->tail_mask.width - tail_mask.width;
+    }
+
+  if (weight < 1.0)
+    gdk_window_shape_combine_region (priv->tail_window,
+                                     SHAPE_REGION(&tail_mask),
+                                     0, 0);
+  else
+    {
+      /* Store the new tail_mask and hide the tail_window. */
+      priv->tail_mask = tail_mask;
+      gdk_window_hide (priv->tail_window);
+    }
+}
+
+/* Stop function called by the retract-tail animation. */
+static void
+retract_tail_stop_cb (gpointer user_data)
+{
+  OsBar *bar;
+  OsBarPrivate *priv;
+
+  bar = OS_BAR (user_data);
+
+  priv = bar->priv;
+
+  if (priv->parent == NULL)
+    return;
+
+  gdk_window_shape_combine_region (priv->tail_window,
+                                   SHAPE_REGION(&priv->tail_mask),
+                                   0, 0);
+}
+
+G_DEFINE_TYPE (OsBar, os_bar, G_TYPE_OBJECT);
+
+static void
+os_bar_class_init (OsBarClass *class)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (class);
 
-  gobject_class->dispose  = os_pager_dispose;
-  gobject_class->finalize = os_pager_finalize;
+  gobject_class->dispose  = os_bar_dispose;
+  gobject_class->finalize = os_bar_finalize;
 
-  g_type_class_add_private (gobject_class, sizeof (OsPagerPrivate));
+  g_type_class_add_private (gobject_class, sizeof (OsBarPrivate));
 }
 
 static void
-os_pager_init (OsPager *pager)
+os_bar_init (OsBar *bar)
 {
   GdkRectangle allocation, mask;
-  OsPagerPrivate *priv;
+  OsBarPrivate *priv;
 
-  pager->priv = G_TYPE_INSTANCE_GET_PRIVATE (pager,
-                                             OS_TYPE_PAGER,
-                                             OsPagerPrivate);
-  priv = pager->priv;
+  bar->priv = G_TYPE_INSTANCE_GET_PRIVATE (bar,
+                                           OS_TYPE_BAR,
+                                           OsBarPrivate);
+  priv = bar->priv;
 
   allocation.x = 0;
   allocation.y = 0;
@@ -268,8 +335,8 @@
   mask.width = 1;
   mask.height = 1;
 
-  priv->connection_mask = mask;
-  priv->mask = mask;
+  priv->bar_mask = mask;
+  priv->tail_mask = mask;
 
   priv->active = FALSE;
   priv->detached = FALSE;
@@ -277,217 +344,227 @@
 
   priv->weight = 1.0f;
 
-  priv->animation = os_animation_new (RATE_FADE, DURATION_FADE_OUT,
-                                      change_state_cb, NULL, pager);
-
-  priv->handler_id = g_signal_connect (gtk_settings_get_default (), "notify::gtk-theme-name",
-                                       G_CALLBACK (notify_gtk_theme_name_cb), pager);
-}
-
-static void
-os_pager_dispose (GObject *object)
-{
-  OsPager *pager;
-  OsPagerPrivate *priv;
-
-  pager = OS_PAGER (object);
-  priv = pager->priv;
-
-  if (priv->animation != NULL)
-    {
-      g_object_unref (priv->animation);
-      priv->animation = NULL;
-    }
-
-  if (priv->connection_window != NULL)
-    {
-      /* From the Gdk documentation:
-       * "Note that a window will not be destroyed
-       *  automatically when its reference count
-       *  reaches zero. You must call
-       *  gdk_window_destroy ()
-       *  yourself before that happens". */
-      gdk_window_destroy (priv->connection_window);
-
-      g_object_unref (priv->connection_window);
-      priv->connection_window = NULL;
-    }
-
-  if (priv->pager_window != NULL)
-    {
-      /* From the Gdk documentation:
-       * "Note that a window will not be destroyed
-       *  automatically when its reference count
-       *  reaches zero. You must call
-       *  gdk_window_destroy ()
-       *  yourself before that happens". */
-      gdk_window_destroy (priv->pager_window);
-
-      g_object_unref (priv->pager_window);
-      priv->pager_window = NULL;
-    }
-
-  os_pager_set_parent (pager, NULL);
-
-  g_signal_handler_disconnect (gtk_settings_get_default (),
-                               priv->handler_id);
-
-  G_OBJECT_CLASS (os_pager_parent_class)->dispose (object);
-}
-
-static void
-os_pager_finalize (GObject *object)
-{
-  G_OBJECT_CLASS (os_pager_parent_class)->finalize (object);
+  priv->state_animation = os_animation_new (RATE_ANIMATION, DURATION_FADE_OUT,
+                                            change_state_cb, NULL, bar);
+  priv->tail_animation = os_animation_new (RATE_ANIMATION, MAX_DURATION_TAIL,
+                                           retract_tail_cb, NULL, bar);
+
+  g_signal_connect (gtk_settings_get_default (), "notify::gtk-theme-name",
+                    G_CALLBACK (notify_gtk_theme_name_cb), bar);
+}
+
+static void
+os_bar_dispose (GObject *object)
+{
+  OsBar *bar;
+  OsBarPrivate *priv;
+
+  bar = OS_BAR (object);
+  priv = bar->priv;
+
+  if (priv->tail_animation != NULL)
+    {
+      g_object_unref (priv->tail_animation);
+      priv->tail_animation = NULL;
+    }
+
+  if (priv->state_animation != NULL)
+    {
+      g_object_unref (priv->state_animation);
+      priv->state_animation = NULL;
+    }
+
+  if (priv->tail_window != NULL)
+    {
+      /* From the Gdk documentation:
+       * "Note that a window will not be destroyed
+       *  automatically when its reference count
+       *  reaches zero. You must call
+       *  gdk_window_destroy ()
+       *  yourself before that happens". */
+      gdk_window_destroy (priv->tail_window);
+
+      g_object_unref (priv->tail_window);
+      priv->tail_window = NULL;
+    }
+
+  if (priv->bar_window != NULL)
+    {
+      /* From the Gdk documentation:
+       * "Note that a window will not be destroyed
+       *  automatically when its reference count
+       *  reaches zero. You must call
+       *  gdk_window_destroy ()
+       *  yourself before that happens". */
+      gdk_window_destroy (priv->bar_window);
+
+      g_object_unref (priv->bar_window);
+      priv->bar_window = NULL;
+    }
+
+  os_bar_set_parent (bar, NULL);
+
+  G_OBJECT_CLASS (os_bar_parent_class)->dispose (object);
+}
+
+static void
+os_bar_finalize (GObject *object)
+{
+  G_OBJECT_CLASS (os_bar_parent_class)->finalize (object);
 }
 
 /* Public functions. */
 
 /**
- * os_pager_new:
- *
- * Creates a new #OsPager instance.
- *
- * Returns: the new #OsPager instance.
+ * os_bar_new:
+ *
+ * Creates a new #OsBar instance.
+ *
+ * Returns: the new #OsBar instance.
  **/
-OsPager*
-os_pager_new (void)
+OsBar*
+os_bar_new (void)
 {
-  return g_object_new (OS_TYPE_PAGER, NULL);
+  return g_object_new (OS_TYPE_BAR, NULL);
 }
 
-/* Move a mask on the connection_window, fake movement. */
+/* Move a mask on the tail_window, fake movement. */
 static void
-mask_connection (OsPager *pager)
+mask_tail (OsBar *bar)
 {
-  OsPagerPrivate *priv;
-
-  priv = pager->priv;
-
-  gdk_window_shape_combine_region (priv->connection_window,
-                                   SHAPE_REGION(&priv->connection_mask),
+  OsBarPrivate *priv;
+
+  priv = bar->priv;
+
+  gdk_window_shape_combine_region (priv->tail_window,
+                                   SHAPE_REGION(&priv->tail_mask),
                                    0, 0);
 }
 
 /**
- * os_pager_connect:
- * @pager: a #OsPager
- * @mask: a #GdkRectangle with the position and dimension of the connection
- *
- * Moves and resizes connection.
- **/
-void
-os_pager_connect (OsPager      *pager,
-                  GdkRectangle  mask)
-{
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
-
-  if (!rectangle_changed (priv->connection_mask, mask))
-    return;
-
-  priv->connection_mask = mask;
-
-  if (priv->parent == NULL)
-    return;
-
-  mask_connection (pager);
-}
-
-/**
- * os_pager_hide:
- * @pager: a #OsPager
- *
- * Hides the #OsPager.
- **/
-void
-os_pager_hide (OsPager *pager)
-{
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
-
-  priv->visible = FALSE;
-
-  if (priv->parent == NULL)
+ * os_bar_connect:
+ * @bar: a #OsBar
+ * @mask: a #GdkRectangle with the position and dimension of the tail
+ *
+ * Moves and resizes tail.
+ **/
+void
+os_bar_connect (OsBar       *bar,
+                GdkRectangle mask)
+{
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
+
+  if (!os_animation_is_running (priv->tail_animation) &&
+      !rectangle_changed (priv->tail_mask, mask))
     return;
 
   /* If there's an animation currently running, stop it. */
-  os_animation_stop (priv->animation, change_state_stop_cb);
-
-  gdk_window_hide (priv->connection_window);
-  gdk_window_hide (priv->pager_window);
-}
-
-/* Move a mask on the pager_window, fake movement. */
+  os_animation_stop (priv->tail_animation, NULL);
+
+  priv->tail_mask = mask;
+
+  if (priv->parent == NULL)
+    return;
+
+  mask_tail (bar);
+}
+
+/**
+ * os_bar_hide:
+ * @bar: a #OsBar
+ *
+ * Hides the #OsBar.
+ **/
+void
+os_bar_hide (OsBar *bar)
+{
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
+
+  priv->visible = FALSE;
+
+  if (priv->parent == NULL)
+    return;
+
+  /* Immediately hide, then stop animations. */
+  gdk_window_hide (priv->tail_window);
+  gdk_window_hide (priv->bar_window);
+
+  os_animation_stop (priv->tail_animation, retract_tail_stop_cb);
+  os_animation_stop (priv->state_animation, change_state_stop_cb);
+}
+
+/* Move a mask on the bar_window, fake movement. */
 static void
-mask_pager (OsPager *pager)
+mask_bar (OsBar *bar)
 {
-  OsPagerPrivate *priv;
-
-  priv = pager->priv;
-
-  gdk_window_shape_combine_region (priv->pager_window,
-                                   SHAPE_REGION(&priv->mask),
+  OsBarPrivate *priv;
+
+  priv = bar->priv;
+
+  gdk_window_shape_combine_region (priv->bar_window,
+                                   SHAPE_REGION(&priv->bar_mask),
                                    0, 0);
 }
 
 /**
- * os_pager_move_resize:
- * @pager: a #OsPager
- * @mask: a #GdkRectangle with the position and dimension of the #OsPager
+ * os_bar_move_resize:
+ * @bar: a #OsBar
+ * @mask: a #GdkRectangle with the position and dimension of the #OsBar
  *
- * Moves and resizes @pager.
+ * Moves and resizes @bar.
  **/
 void
-os_pager_move_resize (OsPager      *pager,
-                      GdkRectangle  mask)
+os_bar_move_resize (OsBar       *bar,
+                    GdkRectangle mask)
 {
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
-
-  if (!rectangle_changed (priv->mask, mask))
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
+
+  if (!rectangle_changed (priv->bar_mask, mask))
     return;
 
-  priv->mask = mask;
+  priv->bar_mask = mask;
 
   if (priv->parent == NULL)
     return;
 
-  mask_pager (pager);
+  mask_bar (bar);
 }
 
 /**
- * os_pager_set_active:
- * @pager: a #OsPager
+ * os_bar_set_active:
+ * @bar: a #OsBar
  * @active: whether is active or not
- * @animation: whether animate it or not
+ * @animate: whether animate it or not
  *
- * Changes the activity state of @pager.
+ * Changes the activity state of @bar.
  **/
 void
-os_pager_set_active (OsPager *pager,
-                     gboolean active,
-                     gboolean animate)
+os_bar_set_active (OsBar   *bar,
+                   gboolean active,
+                   gboolean animate)
 {
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
-
-  /* Set the state and draw even if there's an animation running, that is
-   * (!animate && os_animation_is_running (priv->animation)). */
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
+
+  /* Set the state and draw even if there's a state_animation running, that is
+   * (!animate && os_animation_is_running (priv->state_animation)). */
   if ((priv->active != active) ||
-      (!animate && os_animation_is_running (priv->animation)))
+      (!animate && os_animation_is_running (priv->state_animation)))
     {
       gboolean visible;
 
@@ -496,43 +573,45 @@
       if (priv->parent == NULL)
         return;
 
-      visible = gdk_window_is_visible (priv->pager_window);
+      visible = gdk_window_is_visible (priv->bar_window);
 
       if (visible)
-        os_animation_stop (priv->animation, NULL);
+        os_animation_stop (priv->state_animation, NULL);
 
       if (visible && animate)
         {
-          os_animation_set_duration (priv->animation, priv->active ? DURATION_FADE_IN :
-                                                                     DURATION_FADE_OUT);
-          os_animation_start (priv->animation);
+          os_animation_set_duration (priv->state_animation, priv->active ? DURATION_FADE_IN :
+                                                                           DURATION_FADE_OUT);
+          os_animation_start (priv->state_animation);
         }
 
       if (!visible || !animate)
         {
           priv->weight = 1.0f;
 
-          draw_pager (pager);
+          draw_bar (bar);
         }
     }
 }
 
 /**
- * os_pager_set_detached:
- * @pager: a #OsPager
- * @detached: whether the pager is detached or not
+ * os_bar_set_detached:
+ * @bar: a #OsBar
+ * @detached: whether the bar is detached or not
+ * @animate: whether animate it or not
  *
- * Changes the detached state of @pager.
+ * Changes the detached state of @bar.
  **/
 void
-os_pager_set_detached (OsPager *pager,
-                       gboolean detached)
+os_bar_set_detached (OsBar   *bar,
+                     gboolean detached,
+                     gboolean animate)
 {
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
 
   if (priv->detached != detached)
     {
@@ -543,27 +622,49 @@
 
       if (priv->detached)
         {
-          gdk_window_show (priv->connection_window);
-          gdk_window_raise (priv->pager_window);
+          /* If there's a tail animation currently running, stop it. */
+          os_animation_stop (priv->tail_animation, retract_tail_stop_cb);
+
+          /* No tail connection animation yet. */
+          gdk_window_show (priv->tail_window);
+          gdk_window_raise (priv->bar_window);
+        }
+      else if (animate)
+        {
+          gint32 duration;
+
+          /* The detached state should already stop this. */
+          OS_DCHECK (!os_animation_is_running (priv->tail_animation));
+
+          /* Calculate and set the duration. */
+          if (priv->allocation.height >= priv->allocation.width)
+            duration = MIN_DURATION_TAIL + ((gdouble) priv->tail_mask.height / priv->allocation.height) *
+                                           (MAX_DURATION_TAIL - MIN_DURATION_TAIL);
+          else
+            duration = MIN_DURATION_TAIL + ((gdouble) priv->tail_mask.width / priv->allocation.width) *
+                                           (MAX_DURATION_TAIL - MIN_DURATION_TAIL);
+          os_animation_set_duration (priv->tail_animation, duration);
+
+          os_animation_start (priv->tail_animation);
         }
       else
-        gdk_window_hide (priv->connection_window);
+        gdk_window_hide (priv->tail_window);
     }
 }
 
-/* Create connection_window and pager_window. */
+/* Create tail_window and bar_window. */
 static void
-create_windows (OsPager *pager)
+create_windows (OsBar *bar)
 {
   GdkWindowAttr attributes;
-  OsPagerPrivate *priv;
+  OsBarPrivate *priv;
 
-  priv = pager->priv;
+  priv = bar->priv;
 
   /* Instead reparenting,
    * which doesn't seem to work well,
    * destroy the two windows. */
-  if (priv->connection_window != NULL)
+  if (priv->tail_window != NULL)
     {
       /* From the Gdk documentation:
        * "Note that a window will not be destroyed
@@ -571,13 +672,13 @@
        *  reaches zero. You must call
        *  gdk_window_destroy ()
        *  yourself before that happens". */
-      gdk_window_destroy (priv->connection_window);
+      gdk_window_destroy (priv->tail_window);
 
-      g_object_unref (priv->connection_window);
-      priv->connection_window = NULL;
+      g_object_unref (priv->tail_window);
+      priv->tail_window = NULL;
     }
 
-  if (priv->pager_window != NULL)
+  if (priv->bar_window != NULL)
     {
       /* From the Gdk documentation:
        * "Note that a window will not be destroyed
@@ -585,10 +686,10 @@
        *  reaches zero. You must call
        *  gdk_window_destroy ()
        *  yourself before that happens". */
-      gdk_window_destroy (priv->pager_window);
+      gdk_window_destroy (priv->bar_window);
 
-      g_object_unref (priv->pager_window);
-      priv->pager_window = NULL;
+      g_object_unref (priv->bar_window);
+      priv->bar_window = NULL;
     }
 
   attributes.event_mask = 0;
@@ -601,8 +702,8 @@
   attributes.colormap = gtk_widget_get_colormap (priv->parent);
 #endif
 
-  /* connection_window. */
-  priv->connection_window = gdk_window_new (gtk_widget_get_window (priv->parent),
+  /* tail_window. */
+  priv->tail_window = gdk_window_new (gtk_widget_get_window (priv->parent),
                                             &attributes,
 #ifdef USE_GTK3
                                             GDK_WA_VISUAL);
@@ -610,13 +711,13 @@
                                             GDK_WA_VISUAL | GDK_WA_COLORMAP);
 #endif
 
-  g_object_ref_sink (priv->connection_window);
+  g_object_ref_sink (priv->tail_window);
 
-  gdk_window_set_transient_for (priv->connection_window,
+  gdk_window_set_transient_for (priv->tail_window,
                                 gtk_widget_get_window (priv->parent));
 
   /* FIXME(Cimi) maybe this is not required with 0 as event mask. */
-  gdk_window_input_shape_combine_region (priv->connection_window,
+  gdk_window_input_shape_combine_region (priv->tail_window,
 #ifdef USE_GTK3
                                          cairo_region_create (),
 #else
@@ -624,22 +725,22 @@
 #endif
                                          0, 0);
 
-  /* pager_window. */
-  priv->pager_window = gdk_window_new (gtk_widget_get_window (priv->parent),
-                                       &attributes,
+  /* bar_window. */
+  priv->bar_window = gdk_window_new (gtk_widget_get_window (priv->parent),
+                                     &attributes,
 #ifdef USE_GTK3
-                                       GDK_WA_VISUAL);
+                                     GDK_WA_VISUAL);
 #else
-                                       GDK_WA_VISUAL | GDK_WA_COLORMAP);
+                                     GDK_WA_VISUAL | GDK_WA_COLORMAP);
 #endif 
 
-  g_object_ref_sink (priv->pager_window);
+  g_object_ref_sink (priv->bar_window);
 
-  gdk_window_set_transient_for (priv->pager_window,
+  gdk_window_set_transient_for (priv->bar_window,
                                 gtk_widget_get_window (priv->parent));
 
   /* FIXME(Cimi) maybe this is not required with 0 as event mask. */
-  gdk_window_input_shape_combine_region (priv->pager_window,
+  gdk_window_input_shape_combine_region (priv->bar_window,
 #ifdef USE_GTK3
                                          cairo_region_create (),
 #else
@@ -649,30 +750,30 @@
 }
 
 /**
- * os_pager_set_parent:
- * @pager: a #OsPager
+ * os_bar_set_parent:
+ * @bar: a #OsBar
  * @parent: a #GtkWidget
  *
  * Sets the parent widget
  **/
 void
-os_pager_set_parent (OsPager   *pager,
-                     GtkWidget *parent)
+os_bar_set_parent (OsBar     *bar,
+                   GtkWidget *parent)
 {
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
-
-  /* Stop currently running animation. */
-  if (priv->animation != NULL)
-    os_animation_stop (priv->animation, NULL);
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
+
+  /* Stop currently running animations. */
+  if (priv->tail_animation != NULL)
+    os_animation_stop (priv->tail_animation, retract_tail_stop_cb);
+  if (priv->state_animation != NULL)
+    os_animation_stop (priv->state_animation, NULL);
 
   if (priv->parent != NULL)
-    {
-      g_object_unref (priv->parent);
-    }
+    g_object_unref (priv->parent);
 
   priv->parent = parent;
 
@@ -682,69 +783,67 @@
 
       priv->weight = 1.0f;
 
-      create_windows (pager);
-      draw_connection (pager);
-      draw_pager (pager);
-      mask_pager (pager);
+      create_windows (bar);
+      draw_tail (bar);
+      draw_bar (bar);
+      mask_bar (bar);
 
-      gdk_window_move_resize (priv->connection_window,
+      gdk_window_move_resize (priv->tail_window,
                               priv->allocation.x,
                               priv->allocation.y,
                               priv->allocation.width,
                               priv->allocation.height);
 
-      gdk_window_move_resize (priv->pager_window,
+      gdk_window_move_resize (priv->bar_window,
                               priv->allocation.x,
                               priv->allocation.y,
                               priv->allocation.width,
                               priv->allocation.height);
 
       if (priv->visible)
-        {
-          gdk_window_show (priv->pager_window);
-        }
+        gdk_window_show (priv->bar_window);
     }
 }
 
 /**
- * os_pager_show:
- * @pager: a #OsPager
+ * os_bar_show:
+ * @bar: a #OsBar
  *
- * Shows @pager.
+ * Shows @bar.
  **/
 void
-os_pager_show (OsPager *pager)
+os_bar_show (OsBar *bar)
 {
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
 
   priv->visible = TRUE;
 
   if (priv->parent == NULL)
     return;
 
-  gdk_window_show (priv->pager_window);
+  gdk_window_show (priv->bar_window);
 }
 
 /**
- * os_pager_size_allocate:
- * @pager: a #OsPager
+ * os_bar_size_allocate:
+ * @bar: a #OsBar
  * @rectangle: a #GdkRectangle
  *
  * Sets the position and dimension of the whole area.
  **/
 void
-os_pager_size_allocate (OsPager     *pager,
-                        GdkRectangle rectangle)
+os_bar_size_allocate (OsBar       *bar,
+                      GdkRectangle rectangle)
 {
-  OsPagerPrivate *priv;
-
-  g_return_if_fail (OS_IS_PAGER (pager));
-
-  priv = pager->priv;
+  OsBarPrivate *priv;
+
+  g_return_if_fail (OS_IS_BAR (bar));
+
+  priv = bar->priv;
 
   if (!rectangle_changed (priv->allocation, rectangle))
     return;
@@ -754,13 +853,13 @@
   if (priv->parent == NULL)
     return;
 
-  gdk_window_move_resize (priv->connection_window,
+  gdk_window_move_resize (priv->tail_window,
                           rectangle.x,
                           rectangle.y,
                           rectangle.width,
                           rectangle.height);
 
-  gdk_window_move_resize (priv->pager_window,
+  gdk_window_move_resize (priv->bar_window,
                           rectangle.x,
                           rectangle.y,
                           rectangle.width,

=== modified file 'os/os-private.h'
--- os/os-private.h	2011-10-05 12:24:21 +0000
+++ os/os-private.h	2011-10-12 17:16:23 +0000
@@ -30,7 +30,11 @@
 #pragma GCC visibility push(hidden)
 #endif /* __GNUC__ */
 
+/* Rate of the animations (frames per second). */
+#define RATE_ANIMATION 30
+
 /* Size of the thumb in pixels. */
+#define MIN_THUMB_HEIGHT 35
 #define THUMB_WIDTH  17
 #define THUMB_HEIGHT 69
 
@@ -39,14 +43,19 @@
 
 G_BEGIN_DECLS
 
+typedef struct
+{
+  gint x;
+  gint y;
+} OsCoordinate;
+
 typedef enum
 {
   OS_EVENT_NONE = 0,
   OS_EVENT_BUTTON_PRESS = 1,
   OS_EVENT_ENTER_NOTIFY = 2,
-  OS_EVENT_MOTION_NOTIFY = 4,
-  OS_EVENT_VALUE_CHANGED = 8
-} OsEvent;
+  OS_EVENT_MOTION_NOTIFY = 4
+} OsEventFlags;
 
 /* os-log.c */
 
@@ -150,6 +159,57 @@
 void         os_animation_stop         (OsAnimation        *animation,
                                         OsAnimationStopFunc stop_func);
 
+/* os-bar.c */
+
+#define OS_TYPE_BAR            (os_bar_get_type ())
+#define OS_BAR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), OS_TYPE_BAR, OsBar))
+#define OS_BAR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), OS_TYPE_BAR, OsBarClass))
+#define OS_IS_BAR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), OS_TYPE_BAR))
+#define OS_IS_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), OS_TYPE_BAR))
+#define OS_BAR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), OS_TYPE_BAR, OsBarClass))
+
+typedef struct _OsBar OsBar;
+typedef struct _OsBarClass OsBarClass;
+typedef struct _OsBarPrivate OsBarPrivate;
+
+struct _OsBar {
+  GObject parent_instance;
+
+  OsBarPrivate *priv;
+};
+
+struct _OsBarClass {
+  GObjectClass parent_class;
+};
+
+GType  os_bar_get_type      (void) G_GNUC_CONST;
+
+OsBar* os_bar_new           (void);
+
+void   os_bar_hide          (OsBar *bar);
+
+void   os_bar_connect       (OsBar       *bar,
+                             GdkRectangle mask);
+
+void   os_bar_move_resize   (OsBar       *bar,
+                             GdkRectangle mask);
+
+void   os_bar_set_active    (OsBar   *bar,
+                             gboolean active,
+                             gboolean animate);
+
+void   os_bar_set_detached  (OsBar   *bar,
+                             gboolean detached,
+                             gboolean animate);
+
+void   os_bar_set_parent    (OsBar     *bar,
+                             GtkWidget *parent);
+
+void   os_bar_show          (OsBar *bar);
+
+void   os_bar_size_allocate (OsBar       *bar,
+                             GdkRectangle rectangle);
+
 /* os-thumb.c */
 
 #define OS_TYPE_THUMB (os_thumb_get_type ())
@@ -184,56 +244,6 @@
 void       os_thumb_set_detached (OsThumb *thumb,
                                   gboolean detached);
 
-/* os-pager.c */
-
-#define OS_TYPE_PAGER            (os_pager_get_type ())
-#define OS_PAGER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), OS_TYPE_PAGER, OsPager))
-#define OS_PAGER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), OS_TYPE_PAGER, OsPagerClass))
-#define OS_IS_PAGER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), OS_TYPE_PAGER))
-#define OS_IS_PAGER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), OS_TYPE_PAGER))
-#define OS_PAGER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), OS_TYPE_PAGER, OsPagerClass))
-
-typedef struct _OsPager OsPager;
-typedef struct _OsPagerClass OsPagerClass;
-typedef struct _OsPagerPrivate OsPagerPrivate;
-
-struct _OsPager {
-  GObject parent_instance;
-
-  OsPagerPrivate *priv;
-};
-
-struct _OsPagerClass {
-  GObjectClass parent_class;
-};
-
-GType    os_pager_get_type      (void) G_GNUC_CONST;
-
-OsPager* os_pager_new           (void);
-
-void     os_pager_hide          (OsPager *pager);
-
-void     os_pager_connect       (OsPager     *pager,
-                                 GdkRectangle mask);
-
-void     os_pager_move_resize   (OsPager     *pager,
-                                 GdkRectangle mask);
-
-void     os_pager_set_active    (OsPager *pager,
-                                 gboolean active,
-                                 gboolean animate);
-
-void     os_pager_set_detached  (OsPager *pager,
-                                 gboolean detached);
-
-void     os_pager_set_parent    (OsPager   *pager,
-                                 GtkWidget *parent);
-
-void     os_pager_show          (OsPager *pager);
-
-void     os_pager_size_allocate (OsPager     *pager,
-                                 GdkRectangle rectangle);
-
 G_END_DECLS
 
 #ifdef __GNUC__

=== modified file 'os/os-scrollbar.c'
--- os/os-scrollbar.c	2011-10-05 12:24:21 +0000
+++ os/os-scrollbar.c	2011-10-12 17:16:23 +0000
@@ -34,20 +34,17 @@
 #include <X11/Xutil.h>
 #include <X11/extensions/XInput2.h>
 
-/* Size of the pager in pixels. */
-#define PAGER_SIZE 3
+/* Size of the bar in pixels. */
+#define BAR_SIZE 3
 
 /* Size of the proximity effect in pixels. */
 #define PROXIMITY_SIZE 30
 
-/* Rate of the paging. */
-#define RATE_PAGING 30
-
-/* Max duration of the paging. */
-#define MAX_DURATION_PAGING 1000
-
-/* Min duration of the paging. */
-#define MIN_DURATION_PAGING 250
+/* Max duration of the scrolling. */
+#define MAX_DURATION_SCROLLING 1000
+
+/* Min duration of the scrolling. */
+#define MIN_DURATION_SCROLLING 250
 
 /* Timeout assumed for PropertyNotify _NET_ACTIVE_WINDOW event. */
 #define TIMEOUT_PRESENT_WINDOW 400
@@ -58,6 +55,9 @@
 /* Timeout before hiding in ms, after leaving the thumb. */
 #define TIMEOUT_THUMB_HIDE 200
 
+/* Timeout before showing in ms, after entering the proximity. */
+#define TIMEOUT_THUMB_SHOW 100
+
 /* Timeout before hiding in ms, after leaving the toplevel. */
 #define TIMEOUT_TOPLEVEL_HIDE 200
 
@@ -71,48 +71,60 @@
 
 typedef enum
 {
+  OS_STATE_NONE = 0,
+  OS_STATE_CONNECTED = 1,
+  OS_STATE_DETACHED = 2,
+  OS_STATE_FULLSIZE = 4,
+  OS_STATE_INTERNAL = 8,
+  OS_STATE_LOCKED = 16,
+  OS_STATE_RECONNECTING = 32
+} OsStateFlags;
+
+typedef enum
+{
   OS_STRUT_SIDE_NONE = 0,
   OS_STRUT_SIDE_TOP = 1,
   OS_STRUT_SIDE_BOTTOM = 2,
   OS_STRUT_SIDE_LEFT = 4,
   OS_STRUT_SIDE_RIGHT = 8
-} OsStrutSide;
+} OsStrutSideFlags;
+
+typedef struct
+{
+  gboolean proximity;
+  gboolean running;
+} OsWindowFilter;
 
 struct _OsScrollbarPrivate
 {
   GdkRectangle overlay;
   GdkRectangle slider;
   GdkRectangle trough;
-  GtkAllocation pager_all;
+  GtkAllocation bar_all;
   GtkAllocation thumb_all;
   GtkAdjustment *adjustment;
   GtkOrientation orientation;
   GtkWidget *thumb;
   GtkWindowGroup *window_group;
   OsAnimation *animation;
-  OsPager *pager;
+  OsBar *bar;
+  OsCoordinate pointer;
+  OsCoordinate thumb_win;
+  OsEventFlags event;
+  OsStateFlags state;
   OsSide side;
-  OsEvent event;
+  OsWindowFilter filter;
   gboolean active_window;
-  gboolean can_deactivate_pager;
-  gboolean can_hide;
-  gboolean detached_scroll;
-  gboolean filter;
-  gboolean fullsize;
-  gboolean internal;
-  gboolean lock_position;
-  gboolean proximity;
-  gboolean toplevel_button_press;
+  gboolean deactivable_bar;
+  gboolean hidable_thumb;
+  gboolean window_button_press; /* FIXME(Cimi) to replace with X11 input events. */
   gdouble value;
-  gint win_x;
-  gint win_y;
   gint slide_initial_slider_position;
   gint slide_initial_coordinate;
-  gint pointer_x;
-  gint pointer_y;
   gint64 present_time;
-  guint32 source_deactivate_pager_id;
+  guint32 source_deactivate_bar_id;
   guint32 source_hide_thumb_id;
+  guint32 source_show_thumb_id;
   guint32 source_unlock_thumb_id;
 };
 
@@ -159,10 +171,10 @@
 static void os_scrollbar_dispose (GObject *object);
 static void os_scrollbar_finalize (GObject *object);
 
-/* Calculate pager layout info. */
+/* Calculate bar layout info. */
 static void
-calc_layout_pager (OsScrollbar *scrollbar,
-                   gdouble      adjustment_value)
+calc_layout_bar (OsScrollbar *scrollbar,
+                 gdouble      adjustment_value)
 {
   OsScrollbarPrivate *priv;
 
@@ -279,6 +291,23 @@
     }
 }
 
+/* Calculate the position of the thumb window. */
+static void
+calc_thumb_window_position (OsScrollbar *scrollbar)
+{
+  OsScrollbarPrivate *priv;
+  gint x_pos, y_pos;
+
+  priv = scrollbar->priv;
+
+  /* In reality, I'm storing widget's window, not the toplevel.
+   * Is that the same with gdk_window_get_origin? */
+  gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
+
+  priv->thumb_win.x = x_pos + priv->thumb_all.x;
+  priv->thumb_win.y = y_pos + priv->thumb_all.y;
+}
+
 /* Calculate the workarea using _UNITY_NET_WORKAREA_REGION. */
 static void
 calc_workarea (Display *display,
@@ -327,21 +356,114 @@
     }
 }
 
-/* Deactivate the pager if it's the case. */
-static void
-deactivate_pager (OsScrollbar *scrollbar)
-{
-  OsScrollbarPrivate *priv;
-
-  priv = scrollbar->priv;
-
-  if (priv->pager != NULL && priv->can_deactivate_pager)
-    os_pager_set_active (priv->pager, FALSE, TRUE);
-}
-
-/* Timeout before deactivating the pager. */
+/* Check whether the thumb movement can be considered connected or not. */
+static void
+check_connection (OsScrollbar *scrollbar)
+{
+  OsScrollbarPrivate *priv;
+  gint x_pos, y_pos;
+
+  priv = scrollbar->priv;
+
+  /* This seems to be required to get proper values. */
+  calc_layout_bar (scrollbar, gtk_adjustment_get_value (priv->adjustment));
+  calc_layout_slider (scrollbar, gtk_adjustment_get_value (priv->adjustment));
+
+  gdk_window_get_origin (gtk_widget_get_window (priv->thumb), &x_pos, &y_pos);
+
+  if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+    {
+      if (priv->overlay.height > priv->slider.height)
+        {
+          if (y_pos >= priv->thumb_win.y + priv->overlay.y &&
+              y_pos + priv->slider.height <= priv->thumb_win.y + priv->overlay.y + priv->overlay.height)
+            priv->state |= OS_STATE_CONNECTED;
+          else
+            priv->state &= ~(OS_STATE_CONNECTED);
+        }
+      else
+        {
+          if (y_pos == priv->thumb_win.y + priv->slider.y)
+            priv->state |= OS_STATE_CONNECTED;
+          else
+            priv->state &= ~(OS_STATE_CONNECTED);
+        }
+    }
+  else
+    {
+      if (priv->overlay.width > priv->slider.width)
+        {
+          if (x_pos >= priv->thumb_win.x + priv->overlay.x &&
+              x_pos + priv->slider.width <= priv->thumb_win.x + priv->overlay.x + priv->overlay.width)
+            priv->state |= OS_STATE_CONNECTED;
+          else
+            priv->state &= ~(OS_STATE_CONNECTED);
+        }
+      else
+        {
+          if (x_pos == priv->thumb_win.x + priv->slider.x)
+            priv->state |= OS_STATE_CONNECTED;
+          else
+            priv->state &= ~(OS_STATE_CONNECTED);
+        }
+    }
+}
+
+/* Traduce coordinates into GtkRange values. */
+static gdouble
+coord_to_value (OsScrollbar *scrollbar,
+                gint         coord)
+{
+  OsScrollbarPrivate *priv;
+  gdouble frac;
+  gdouble value;
+  gint    trough_length;
+  gint    slider_length;
+
+  priv = scrollbar->priv;
+
+  if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+    {
+      trough_length = priv->trough.height;
+      slider_length = MAX (priv->slider.height, priv->overlay.height);
+    }
+  else
+    {
+      trough_length = priv->trough.width;
+      slider_length = MAX (priv->slider.width, priv->overlay.width);
+    }
+
+  if (trough_length == slider_length)
+    frac = 1.0;
+  else
+    frac = (MAX (0, coord) / (gdouble) (trough_length - slider_length));
+
+  value = gtk_adjustment_get_lower (priv->adjustment) + frac * (gtk_adjustment_get_upper (priv->adjustment) -
+                                                                gtk_adjustment_get_lower (priv->adjustment) -
+                                                                gtk_adjustment_get_page_size (priv->adjustment));
+
+  value = CLAMP (value,
+                 gtk_adjustment_get_lower (priv->adjustment),
+                 gtk_adjustment_get_upper (priv->adjustment) - gtk_adjustment_get_page_size (priv->adjustment));
+
+  return value;
+}
+
+/* Deactivate the bar if it's the case. */
+static void
+deactivate_bar (OsScrollbar *scrollbar)
+{
+  OsScrollbarPrivate *priv;
+
+  priv = scrollbar->priv;
+
+  if (priv->bar != NULL && priv->deactivable_bar)
+    os_bar_set_active (priv->bar, FALSE, TRUE);
+}
+
+/* Timeout before deactivating the bar. */
 static gboolean
-deactivate_pager_cb (gpointer user_data)
+deactivate_bar_cb (gpointer user_data)
 {
   OsScrollbar *scrollbar;
   OsScrollbarPrivate *priv;
@@ -351,8 +473,8 @@
 
   OS_DCHECK (!priv->active_window);
 
-  deactivate_pager (scrollbar);
-  priv->source_deactivate_pager_id = 0;
+  deactivate_bar (scrollbar);
+  priv->source_deactivate_bar_id = 0;
 
   return FALSE;
 }
@@ -365,7 +487,7 @@
 
   priv = scrollbar->priv;
 
-  if (priv->can_hide)
+  if (priv->hidable_thumb)
     gtk_widget_hide (priv->thumb);
 }
 
@@ -396,9 +518,9 @@
 #endif
 }
 
-/* Move the pager. */
+/* Move the bar. */
 static void
-move_pager (OsScrollbar *scrollbar)
+move_bar (OsScrollbar *scrollbar)
 {
   GdkRectangle mask;
   OsScrollbarPrivate *priv;
@@ -409,7 +531,7 @@
     {
       mask.x = 0;
       mask.y = priv->overlay.y;
-      mask.width = priv->pager_all.width;
+      mask.width = priv->bar_all.width;
       mask.height = priv->overlay.height;
     }
   else
@@ -417,10 +539,10 @@
       mask.x = priv->overlay.x;
       mask.y = 0;
       mask.width = priv->overlay.width;
-      mask.height = priv->pager_all.height;
+      mask.height = priv->bar_all.height;
     }
 
-  os_pager_move_resize (priv->pager, mask);
+  os_bar_move_resize (priv->bar, mask);
 }
 
 /* Sanitize x coordinate of thumb window. */
@@ -481,7 +603,7 @@
 
       for (i = 0; i < cairo_region_num_rectangles (struts_region); i++)
         {
-          OsStrutSide strut_side;
+          OsStrutSideFlags strut_side;
           gint count;
 
           cairo_region_get_rectangle (struts_region, i, &tmp_rect);
@@ -548,7 +670,7 @@
       (n_monitor != gdk_screen_get_monitor_at_point (screen, monitor_x + priv->thumb_all.width, y) ||
        monitor_x + priv->thumb_all.width >= screen_width))
     {
-      priv->internal = TRUE;
+      priv->state |= OS_STATE_INTERNAL;
       return MAX (x - priv->thumb_all.width, screen_width - priv->thumb_all.width);
     }
 
@@ -556,12 +678,12 @@
       (n_monitor != gdk_screen_get_monitor_at_point (screen, monitor_x - priv->thumb_all.width, y) ||
        monitor_x - priv->thumb_all.width <= screen_x))
     {
-      priv->internal = TRUE;
+      priv->state |= OS_STATE_INTERNAL;
       return MAX (x, screen_x);
     }
 
   if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-    priv->internal = FALSE;
+    priv->state &= ~(OS_STATE_INTERNAL);
 
   return x;
 }
@@ -624,7 +746,7 @@
 
       for (i = 0; i < cairo_region_num_rectangles (struts_region); i++)
         {
-          OsStrutSide strut_side;
+          OsStrutSideFlags strut_side;
           gint count;
 
           cairo_region_get_rectangle (struts_region, i, &tmp_rect);
@@ -691,7 +813,7 @@
       (n_monitor != gdk_screen_get_monitor_at_point (screen, x, monitor_y + priv->thumb_all.height) ||
        monitor_y + priv->thumb_all.height >= screen_height))
     {
-      priv->internal = TRUE;
+      priv->state |= OS_STATE_INTERNAL;
       return MAX (y - priv->thumb_all.height, screen_height - priv->thumb_all.height);
     }
 
@@ -699,12 +821,12 @@
       (n_monitor != gdk_screen_get_monitor_at_point (screen, x, monitor_y - priv->thumb_all.height) ||
        monitor_y - priv->thumb_all.height <= screen_y))
     {
-      priv->internal = TRUE;
+      priv->state |= OS_STATE_INTERNAL;
       return MAX (y, screen_y);
     }
 
   if (priv->orientation == GTK_ORIENTATION_HORIZONTAL)
-    priv->internal = FALSE;
+    priv->state &= ~(OS_STATE_INTERNAL);
 
   return y;
 }
@@ -752,10 +874,10 @@
   swap_thumb (scrollbar, os_thumb_new (priv->orientation));
 }
 
-/* Callback called by the paging animation. */
+/* Callback called by the scrolling animation. */
 static void
-paging_cb (gfloat   weight,
-           gpointer user_data)
+scrolling_cb (gfloat   weight,
+              gpointer user_data)
 {
   gdouble new_value;
   OsScrollbar *scrollbar;
@@ -779,6 +901,22 @@
   gtk_adjustment_set_value (priv->adjustment, new_value);
 }
 
+/* End function called by the scrolling animation. */
+static void
+scrolling_end_cb (gpointer user_data)
+{
+  OsScrollbar *scrollbar;
+  OsScrollbarPrivate *priv;
+
+  scrollbar = OS_SCROLLBAR (user_data);
+
+  priv = scrollbar->priv;
+
+  priv->state &= ~(OS_STATE_RECONNECTING);
+
+  check_connection (scrollbar);
+}
+
 /* Swap adjustment pointer. */
 static void
 swap_adjustment (OsScrollbar   *scrollbar,
@@ -879,8 +1017,8 @@
   scrollbar = OS_SCROLLBAR (user_data);
   priv = scrollbar->priv;
 
-  if (priv->can_hide)
-    priv->lock_position = FALSE;
+  if (priv->hidable_thumb)
+    priv->state &= ~(OS_STATE_LOCKED);
 
   priv->source_unlock_thumb_id = 0;
 
@@ -899,43 +1037,43 @@
   scrollbar = OS_SCROLLBAR (user_data);
   priv = scrollbar->priv;
 
-  /* FIXME(Cimi) we should control each time os_pager_show()/hide()
-   * is called here and in map()/unmap().
+  /* FIXME(Cimi) we should control each time os_bar_show ()/hide ()
+   * is called here and in map ()/unmap ().
    * We are arbitrary calling that and I'm frightened we should show or keep
-   * hidden a pager that is meant to be hidden/shown.
-   * I don't want to see pagers reappearing because
-   * of a change in the adjustment of an invisible pager or viceversa. */
+   * hidden a bar that is meant to be hidden/shown.
+   * I don't want to see bars reappearing because
+   * of a change in the adjustment of an invisible bar or viceversa. */
   if (gtk_adjustment_get_upper (adjustment) - gtk_adjustment_get_lower (adjustment) >
       gtk_adjustment_get_page_size (adjustment))
     {
-      priv->fullsize = FALSE;
-      if (priv->proximity != FALSE)
-        os_pager_show (priv->pager);
+      priv->state &= ~(OS_STATE_FULLSIZE);
+      if (priv->filter.proximity)
+        os_bar_show (priv->bar);
     }
   else
     {
-      priv->fullsize = TRUE;
-      if (priv->proximity != FALSE)
+      priv->state |= OS_STATE_FULLSIZE;
+      if (priv->filter.proximity)
         {
-          os_pager_hide (priv->pager);
+          os_bar_hide (priv->bar);
 
           gtk_widget_hide (priv->thumb);
         }
     }
 
-  calc_layout_pager (scrollbar, gtk_adjustment_get_value (adjustment));
+  calc_layout_bar (scrollbar, gtk_adjustment_get_value (adjustment));
   calc_layout_slider (scrollbar, gtk_adjustment_get_value (adjustment));
 
   if (!(priv->event & OS_EVENT_ENTER_NOTIFY) &&
       !(priv->event & OS_EVENT_MOTION_NOTIFY))
     gtk_widget_hide (priv->thumb);
 
-  move_pager (scrollbar);
+  move_bar (scrollbar);
 }
 
-/* Update the visual connection between pager and thumb. */
+/* Update the tail (visual connection) between bar and thumb. */
 static void
-update_visual_connection (OsScrollbar *scrollbar)
+update_tail (OsScrollbar *scrollbar)
 {
   OsScrollbarPrivate *priv;
   gint x_pos, y_pos;
@@ -946,73 +1084,85 @@
 
   if (priv->orientation == GTK_ORIENTATION_VERTICAL)
     {
-      if (priv->win_y + priv->overlay.y >= y_pos + priv->slider.height)
+      if (priv->thumb_win.y + priv->overlay.y >= y_pos + priv->slider.height)
         {
           GdkRectangle mask;
 
           mask.x = 0;
-          mask.y = y_pos + priv->slider.height / 2 - priv->win_y;
-          mask.width = priv->pager_all.width;
+          mask.y = y_pos + priv->slider.height / 2 - priv->thumb_win.y;
+          mask.width = priv->bar_all.width;
           mask.height = priv->overlay.y - mask.y;
 
-          os_pager_connect (priv->pager, mask);
-          os_pager_set_detached (priv->pager, TRUE);
-
+          os_bar_connect (priv->bar, mask);
+
+          priv->state |= OS_STATE_DETACHED;
+
+          os_bar_set_detached (priv->bar, TRUE, FALSE);
           os_thumb_set_detached (OS_THUMB (priv->thumb), TRUE);
         }
-      else if (priv->win_y + priv->overlay.y + priv->overlay.height <= y_pos)
+      else if (priv->thumb_win.y + priv->overlay.y + priv->overlay.height <= y_pos)
         {
           GdkRectangle mask;
 
           mask.x = 0;
           mask.y = priv->overlay.y + priv->overlay.height;
-          mask.width = priv->pager_all.width;
-          mask.height = y_pos + priv->slider.height / 2 - priv->win_y - mask.y;
-
-          os_pager_connect (priv->pager, mask);
-          os_pager_set_detached (priv->pager, TRUE);
-
+          mask.width = priv->bar_all.width;
+          mask.height = y_pos + priv->slider.height / 2 - priv->thumb_win.y - mask.y;
+
+          os_bar_connect (priv->bar, mask);
+
+          priv->state |= OS_STATE_DETACHED;
+
+          os_bar_set_detached (priv->bar, TRUE, FALSE);
           os_thumb_set_detached (OS_THUMB (priv->thumb), TRUE);
         }
-      else 
+      else
         {
-          os_pager_set_detached (priv->pager, FALSE);
+          priv->state &= ~(OS_STATE_DETACHED);
+
+          os_bar_set_detached (priv->bar, FALSE, FALSE);
           os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
         }
     }
   else
     {
-      if (priv->win_x + priv->overlay.x >= x_pos + priv->slider.width)
+      if (priv->thumb_win.x + priv->overlay.x >= x_pos + priv->slider.width)
         {
           GdkRectangle mask;
 
-          mask.x = x_pos + priv->slider.width / 2 - priv->win_x;
+          mask.x = x_pos + priv->slider.width / 2 - priv->thumb_win.x;
           mask.y = 0;
           mask.width = priv->overlay.x - mask.x;
-          mask.height = priv->pager_all.height;
-
-          os_pager_connect (priv->pager, mask);
-          os_pager_set_detached (priv->pager, TRUE);
-
+          mask.height = priv->bar_all.height;
+
+          os_bar_connect (priv->bar, mask);
+
+          priv->state |= OS_STATE_DETACHED;
+
+          os_bar_set_detached (priv->bar, TRUE, FALSE);
           os_thumb_set_detached (OS_THUMB (priv->thumb), TRUE);
         }
-      else if (priv->win_x + priv->overlay.x + priv->overlay.width <= x_pos)
+      else if (priv->thumb_win.x + priv->overlay.x + priv->overlay.width <= x_pos)
         {
           GdkRectangle mask;
 
           mask.x = priv->overlay.x + priv->overlay.width;
           mask.y = 0;
-          mask.width = x_pos + priv->slider.width / 2 - priv->win_x - mask.x;
-          mask.height = priv->pager_all.height;
-
-          os_pager_connect (priv->pager, mask);
-          os_pager_set_detached (priv->pager, TRUE);
-
+          mask.width = x_pos + priv->slider.width / 2 - priv->thumb_win.x - mask.x;
+          mask.height = priv->bar_all.height;
+
+          os_bar_connect (priv->bar, mask);
+
+          priv->state |= OS_STATE_DETACHED;
+
+          os_bar_set_detached (priv->bar, TRUE, FALSE);
           os_thumb_set_detached (OS_THUMB (priv->thumb), TRUE);
         }
       else
         {
-          os_pager_set_detached (priv->pager, FALSE);
+          priv->state &= ~(OS_STATE_DETACHED);
+
+          os_bar_set_detached (priv->bar, FALSE, FALSE);
           os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
         }
     }
@@ -1028,35 +1178,28 @@
   scrollbar = OS_SCROLLBAR (user_data);
   priv = scrollbar->priv;
 
-  calc_layout_pager (scrollbar, gtk_adjustment_get_value (adjustment));
+  calc_layout_bar (scrollbar, gtk_adjustment_get_value (adjustment));
   calc_layout_slider (scrollbar, gtk_adjustment_get_value (adjustment));
 
   if (!(priv->event & OS_EVENT_ENTER_NOTIFY) &&
       !(priv->event & OS_EVENT_MOTION_NOTIFY))
     gtk_widget_hide (priv->thumb);
 
-  if (gtk_widget_get_mapped (priv->thumb))
-    {
-      /* If we're dragging the thumb, it can't be detached. */
-      if (priv->event & OS_EVENT_MOTION_NOTIFY)
-        {
-          os_pager_set_detached (priv->pager, FALSE);
-          os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
-        }
-      else
-        update_visual_connection (scrollbar);
-    }
+  if (gtk_widget_get_mapped (priv->thumb) &&
+      !((priv->event & OS_EVENT_MOTION_NOTIFY) &&
+        (priv->state & OS_STATE_CONNECTED)))
+    update_tail (scrollbar);
 
-  move_pager (scrollbar);
+  move_bar (scrollbar);
 }
 
-/* Pager functions. */
+/* Bar functions. */
 
-/* Set the state of the pager checking mouse position. */
+/* Set the state of the bar checking mouse position. */
 static void
-pager_set_state_from_pointer (OsScrollbar *scrollbar,
-                              gint         x,
-                              gint         y)
+bar_set_state_from_pointer (OsScrollbar *scrollbar,
+                            gint         x,
+                            gint         y)
 {
   GtkAllocation allocation;
   OsScrollbarPrivate *priv;
@@ -1070,13 +1213,13 @@
   if ((x > allocation.x && x < allocation.x + allocation.width) &&
       (y > allocation.y && y < allocation.y + allocation.height))
     {
-      priv->can_deactivate_pager = FALSE;
-      os_pager_set_active (priv->pager, TRUE, TRUE);
+      priv->deactivable_bar = FALSE;
+      os_bar_set_active (priv->bar, TRUE, TRUE);
     }
   else
     {
-      priv->can_deactivate_pager = TRUE;
-      os_pager_set_active (priv->pager, FALSE, TRUE);
+      priv->deactivable_bar = TRUE;
+      os_bar_set_active (priv->bar, FALSE, TRUE);
     }
 }
 
@@ -1105,16 +1248,16 @@
           gdk_screen_get_active_window (gtk_widget_get_screen (GTK_WIDGET (scrollbar))))
         {
           /* Stops potential running timeout. */
-          if (priv->source_deactivate_pager_id != 0)
+          if (priv->source_deactivate_bar_id != 0)
             {
-              g_source_remove (priv->source_deactivate_pager_id);
-              priv->source_deactivate_pager_id = 0;
+              g_source_remove (priv->source_deactivate_bar_id);
+              priv->source_deactivate_bar_id = 0;
             }
 
           priv->active_window = TRUE;
 
-          priv->can_deactivate_pager = FALSE;
-          os_pager_set_active (priv->pager, TRUE, TRUE);
+          priv->deactivable_bar = FALSE;
+          os_bar_set_active (priv->bar, TRUE, TRUE);
         }
       else if (priv->active_window)
         {
@@ -1147,13 +1290,13 @@
               /* When the window is unfocused,
                * check the position of the pointer
                * and set the state accordingly. */
-              pager_set_state_from_pointer (scrollbar, x, y);
+              bar_set_state_from_pointer (scrollbar, x, y);
             }
           else
             {
               /* If the pointer is outside of the window, set it inactive. */
-              priv->can_deactivate_pager = TRUE;
-              os_pager_set_active (priv->pager, FALSE, TRUE);
+              priv->deactivable_bar = TRUE;
+              os_bar_set_active (priv->bar, FALSE, TRUE);
             }
 
           if ((current_time > end_time) && priv->thumb != NULL)
@@ -1251,7 +1394,8 @@
 {
   if (event->type == GDK_BUTTON_PRESS)
     {
-      if (event->button == 1)
+      if (event->button == 1 ||
+          event->button == 2)
         {
           OsScrollbar *scrollbar;
           OsScrollbarPrivate *priv;
@@ -1268,7 +1412,60 @@
           priv->event |= OS_EVENT_BUTTON_PRESS;
           priv->event &= ~(OS_EVENT_MOTION_NOTIFY);
 
-          priv->detached_scroll = FALSE;
+          if (event->button == 2)
+            {
+              /* Reconnect the thumb with the bar. */
+              gdouble new_value;
+              gint c, delta;
+              gint32 duration;
+
+              if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+                {
+                  priv->slide_initial_slider_position = event->y_root - priv->thumb_win.y - event->y;
+                  priv->slide_initial_coordinate = event->y_root;
+
+                  delta = event->y_root - priv->slide_initial_coordinate;
+                }
+              else
+                {
+                  priv->slide_initial_slider_position = event->x_root - priv->thumb_win.x - event->x;
+                  priv->slide_initial_coordinate = event->x_root;
+
+                  delta = event->x_root - priv->slide_initial_coordinate;
+                }
+
+              c = priv->slide_initial_slider_position + delta;
+
+              /* If a scrolling animation is running,
+               * stop it and add the new value. */
+              os_animation_stop (priv->animation, NULL);
+
+              new_value = coord_to_value (scrollbar, c);
+
+              /* Only start the animation if needed. */
+              if (new_value != gtk_adjustment_get_value (priv->adjustment))
+                {
+                  priv->state |= OS_STATE_RECONNECTING;
+
+                  priv->value = new_value;
+
+                  /* Calculate and set the duration. */
+                  if (priv->value > gtk_adjustment_get_value (priv->adjustment))
+                    duration = MIN_DURATION_SCROLLING + ((priv->value - gtk_adjustment_get_value (priv->adjustment)) /
+                                                         (gtk_adjustment_get_upper (priv->adjustment) -
+                                                          gtk_adjustment_get_lower (priv->adjustment))) *
+                                                        (MAX_DURATION_SCROLLING - MIN_DURATION_SCROLLING);
+                  else
+                    duration = MIN_DURATION_SCROLLING + ((gtk_adjustment_get_value (priv->adjustment) - priv->value) /
+                                                         (gtk_adjustment_get_upper (priv->adjustment) -
+                                                          gtk_adjustment_get_lower (priv->adjustment))) *
+                                                        (MAX_DURATION_SCROLLING - MIN_DURATION_SCROLLING);
+                  os_animation_set_duration (priv->animation, duration);
+
+                  /* Start the scrolling animation. */
+                  os_animation_start (priv->animation);
+                }
+            }
 
           if (priv->orientation == GTK_ORIENTATION_VERTICAL)
             {
@@ -1281,8 +1478,8 @@
               priv->slide_initial_coordinate = event->x_root;
             }
 
-          priv->pointer_x = event->x;
-          priv->pointer_y = event->y;
+          priv->pointer.x = event->x;
+          priv->pointer.y = event->y;
         }
     }
 
@@ -1299,7 +1496,7 @@
 
   priv = scrollbar->priv;
 
-  /* If a paging animation is running,
+  /* If a scrolling animation is running,
    * stop it and add the new value. */
   if (os_animation_is_running (priv->animation))
     {
@@ -1314,13 +1511,17 @@
                        gtk_adjustment_get_lower (priv->adjustment),
                        gtk_adjustment_get_upper (priv->adjustment) - gtk_adjustment_get_page_size (priv->adjustment));
 
+  /* There's no need to do start a new animation. */
+  if (priv->value == gtk_adjustment_get_value (priv->adjustment))
+    return;
+
   /* Calculate and set the duration. */
-  duration = MIN_DURATION_PAGING + ((priv->value - gtk_adjustment_get_value (priv->adjustment)) /
-                                    gtk_adjustment_get_page_increment (priv->adjustment)) *
-                                   (MAX_DURATION_PAGING - MIN_DURATION_PAGING);
+  duration = MIN_DURATION_SCROLLING + ((priv->value - gtk_adjustment_get_value (priv->adjustment)) /
+                                       gtk_adjustment_get_page_increment (priv->adjustment)) *
+                                      (MAX_DURATION_SCROLLING - MIN_DURATION_SCROLLING);
   os_animation_set_duration (priv->animation, duration);
 
-  /* Start the paging animation. */
+  /* Start the scrolling animation. */
   os_animation_start (priv->animation);
 }
 
@@ -1334,7 +1535,7 @@
 
   priv = scrollbar->priv;
 
-  /* If a paging animation is running,
+  /* If a scrolling animation is running,
    * stop it and subtract the new value. */
   if (os_animation_is_running (priv->animation))
     {
@@ -1349,13 +1550,17 @@
                        gtk_adjustment_get_lower (priv->adjustment),
                        gtk_adjustment_get_upper (priv->adjustment) - gtk_adjustment_get_page_size (priv->adjustment));
 
+  /* There's no need to do start a new animation. */
+  if (priv->value == gtk_adjustment_get_value (priv->adjustment))
+    return;
+
   /* Calculate and set the duration. */
-  duration = MIN_DURATION_PAGING + ((gtk_adjustment_get_value (priv->adjustment) - priv->value) /
-                                    gtk_adjustment_get_page_increment (priv->adjustment)) *
-                                   (MAX_DURATION_PAGING - MIN_DURATION_PAGING);
+  duration = MIN_DURATION_SCROLLING + ((gtk_adjustment_get_value (priv->adjustment) - priv->value) /
+                                       gtk_adjustment_get_page_increment (priv->adjustment)) *
+                                      (MAX_DURATION_SCROLLING - MIN_DURATION_SCROLLING);
   os_animation_set_duration (priv->animation, duration);
 
-  /* Start the paging animation. */
+  /* Start the scrolling animation. */
   os_animation_start (priv->animation);
 }
 
@@ -1366,7 +1571,8 @@
 {
   if (event->type == GDK_BUTTON_RELEASE)
     {
-      if (event->button == 1)
+      if (event->button == 1 ||
+          event->button == 2)
         {
           OsScrollbar *scrollbar;
           OsScrollbarPrivate *priv;
@@ -1376,24 +1582,23 @@
 
           gtk_window_set_transient_for (GTK_WINDOW (widget), NULL);
 
-          if (!(priv->event & OS_EVENT_MOTION_NOTIFY) && !priv->detached_scroll)
+          if (event->button == 1 &&
+              !(priv->event & OS_EVENT_MOTION_NOTIFY))
             {
               if (priv->orientation == GTK_ORIENTATION_VERTICAL)
                 {
-                  if (priv->pointer_y < priv->slider.height / 2)
+                  if (priv->pointer.y < priv->slider.height / 2)
                     page_up (scrollbar);
                   else
                     page_down (scrollbar);
                 }
               else
                 {
-                  if (priv->pointer_x < priv->slider.width / 2)
+                  if (priv->pointer.x < priv->slider.width / 2)
                     page_up (scrollbar);
                   else
                     page_down (scrollbar);
                 }
-
-              priv->event |= OS_EVENT_VALUE_CHANGED;
             }
 
           priv->event &= ~(OS_EVENT_BUTTON_PRESS | OS_EVENT_MOTION_NOTIFY);
@@ -1416,11 +1621,11 @@
 
   priv->event |= OS_EVENT_ENTER_NOTIFY;
 
-  priv->can_deactivate_pager = FALSE;
-  priv->can_hide = FALSE;
+  priv->deactivable_bar = FALSE;
+  priv->hidable_thumb = FALSE;
 
-  if (priv->internal)
-    priv->lock_position = TRUE;
+  if (priv->state & OS_STATE_INTERNAL)
+    priv->state |= OS_STATE_LOCKED;
 
   return FALSE;
 }
@@ -1440,20 +1645,20 @@
    * not interacting with the thumb. */
   if (!(priv->event & OS_EVENT_BUTTON_PRESS))
     {
-      /* Never deactivate the pager in an active window. */
+      /* Never deactivate the bar in an active window. */
       if (!priv->active_window)
         {
-          priv->can_deactivate_pager = TRUE;
-
-          if (priv->source_deactivate_pager_id != 0)
-            g_source_remove (priv->source_deactivate_pager_id);
-
-          priv->source_deactivate_pager_id = g_timeout_add (TIMEOUT_THUMB_HIDE,
-                                                            deactivate_pager_cb,
-                                                            scrollbar);
+          priv->deactivable_bar = TRUE;
+
+          if (priv->source_deactivate_bar_id != 0)
+            g_source_remove (priv->source_deactivate_bar_id);
+
+          priv->source_deactivate_bar_id = g_timeout_add (TIMEOUT_THUMB_HIDE,
+                                                          deactivate_bar_cb,
+                                                          scrollbar);
         }
 
-      priv->can_hide = TRUE;
+      priv->hidable_thumb = TRUE;
 
       if (priv->source_hide_thumb_id != 0)
         g_source_remove (priv->source_hide_thumb_id);
@@ -1481,9 +1686,9 @@
   scrollbar = OS_SCROLLBAR (user_data);
   priv = scrollbar->priv;
 
-  /* Immediately set the pager to be active. */
-  priv->can_deactivate_pager = FALSE;
-  os_pager_set_active (priv->pager, TRUE, FALSE);
+  /* Immediately set the bar to be active. */
+  priv->deactivable_bar = FALSE;
+  os_bar_set_active (priv->bar, TRUE, FALSE);
 
   xid = GDK_WINDOW_XID (gtk_widget_get_window (widget));
   xid_parent = GDK_WINDOW_XID (gtk_widget_get_window (gtk_widget_get_toplevel (GTK_WIDGET (scrollbar))));
@@ -1542,46 +1747,6 @@
     }
 }
 
-/* Traduce coordinates into GtkRange values. */
-static gdouble
-coord_to_value (OsScrollbar *scrollbar,
-                gint         coord)
-{
-  OsScrollbarPrivate *priv;
-  gdouble frac;
-  gdouble value;
-  gint    trough_length;
-  gint    slider_length;
-
-  priv = scrollbar->priv;
-
-  if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-    {
-      trough_length = priv->trough.height;
-      slider_length = MAX (priv->slider.height, priv->overlay.height);
-    }
-  else
-    {
-      trough_length = priv->trough.width;
-      slider_length = MAX (priv->slider.width, priv->overlay.width);
-    }
-
-  if (trough_length == slider_length)
-    frac = 1.0;
-  else
-    frac = (MAX (0, coord) / (gdouble) (trough_length - slider_length));
-
-  value = gtk_adjustment_get_lower (priv->adjustment) + frac * (gtk_adjustment_get_upper (priv->adjustment) -
-                                                                gtk_adjustment_get_lower (priv->adjustment) -
-                                                                gtk_adjustment_get_page_size (priv->adjustment));
-
-  value = CLAMP (value,
-                 gtk_adjustment_get_lower (priv->adjustment),
-                 gtk_adjustment_get_upper (priv->adjustment) - gtk_adjustment_get_page_size (priv->adjustment));
-
-  return value;
-}
-
 /* From pointer movement, set adjustment value. */
 static void
 capture_movement (OsScrollbar *scrollbar,
@@ -1622,184 +1787,214 @@
     {
       gint x, y;
 
-      /* Thumb and pager are detached.
-       * Detached scroll: keep the thumb detached during the scroll,
-       * update the visual connection when reaching an edge. */
-      if (priv->event & OS_EVENT_VALUE_CHANGED)
-        {
-          /* Return if the mouse movement is small. */
-          if (abs (priv->pointer_x - event->x) <= TOLERANCE_MOTION &&
-              abs (priv->pointer_y - event->y) <= TOLERANCE_MOTION)
-            return FALSE;
-
-          priv->detached_scroll = TRUE;
-
-          /* Stop the paging animation if it's running. */
-          os_animation_stop (priv->animation, NULL);
+      /* Use tolerance at the first calls to this motion notify event. */
+      if (!(priv->event & OS_EVENT_MOTION_NOTIFY) &&
+          abs (priv->pointer.x - event->x) <= TOLERANCE_MOTION &&
+          abs (priv->pointer.y - event->y) <= TOLERANCE_MOTION)
+        return FALSE;
+
+      if (!(priv->event & OS_EVENT_MOTION_NOTIFY))
+        {
+          /* Check if we can consider the thumb movement connected with the overlay. */
+          check_connection (scrollbar);
+
+          priv->event |= OS_EVENT_MOTION_NOTIFY;
+        }
+
+      /* Before stopping the animation,
+       * check if it's reconnecting.
+       * In this case we need to update the slide values
+       * with the current position. */
+      if (os_animation_is_running (priv->animation))
+        {
+          if (priv->state & OS_STATE_RECONNECTING)
+            {
+              /* It's a reconnecting animation. */
+              if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+                {
+                  priv->slide_initial_slider_position = MIN (priv->slider.y, priv->overlay.y);
+                  priv->slide_initial_coordinate = event->y_root;
+                }
+              else
+                {
+                  priv->slide_initial_slider_position = MIN (priv->slider.x, priv->overlay.x);
+                  priv->slide_initial_coordinate = event->x_root;
+                }
+            }
+          else
+            {
+              /* Stop the paging animation now. */
+              os_animation_stop (priv->animation, NULL);
+            }
+        }
+
+      /* Behave differently when the thumb is connected or not. */
+      if (priv->state & OS_STATE_CONNECTED)
+        {
+          /* This is a connected scroll,
+           * the thumb movement is kept in sync with the overlay. */
+
+          if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+            {
+              if (priv->overlay.height > priv->slider.height)
+                {
+                  /* Limit x and y within the overlay. */
+                  x = priv->thumb_win.x;
+                  y = CLAMP (event->y_root - priv->pointer.y,
+                             priv->thumb_win.y + priv->overlay.y,
+                             priv->thumb_win.y + priv->overlay.y + priv->overlay.height - priv->slider.height);
+                }
+              else
+                {
+                  x = priv->thumb_win.x;
+                  y = priv->thumb_win.y + priv->slider.y;
+                }
+            }
+          else
+            {
+              if (priv->overlay.width > priv->slider.width)
+                {
+                  /* Limit x and y within the overlay. */
+                  x = CLAMP (event->x_root - priv->pointer.x,
+                             priv->thumb_win.x + priv->overlay.x,
+                             priv->thumb_win.x + priv->overlay.x + priv->overlay.width - priv->slider.width);
+                  y = priv->thumb_win.y;
+                }
+              else
+                {
+                  x = priv->thumb_win.x + priv->slider.x;
+                  y = priv->thumb_win.y;
+                }
+            }
+
+          /* There's no need to stop animations,
+           * since the reconnecting animation should not have
+           * state OS_STATE_CONNECTED, unless it's ended. 
+           * Just capture the movement and change adjustment's value (scroll). */
+          capture_movement (scrollbar, event->x_root, event->y_root);
+        }
+      else
+        {
+          /* This is a fine scroll, works subtly different.
+           * It has to take care of reconnection,
+           * and scrolling is not allowed when hitting an edge. */
 
           /* Limit x and y within the allocation. */
           if (priv->orientation == GTK_ORIENTATION_VERTICAL)
             {
-              x = priv->win_x;
-              y = CLAMP (event->y_root - priv->pointer_y,
-                         priv->win_y,
-                         priv->win_y + priv->thumb_all.height - priv->slider.height);
+              x = priv->thumb_win.x;
+              y = CLAMP (event->y_root - priv->pointer.y,
+                         priv->thumb_win.y,
+                         priv->thumb_win.y + priv->thumb_all.height - priv->slider.height);
             }
           else
             {
-              x = CLAMP (event->x_root - priv->pointer_x,
-                         priv->win_x,
-                         priv->win_x + priv->thumb_all.width - priv->slider.width);
-              y = priv->win_y;
+              x = CLAMP (event->x_root - priv->pointer.x,
+                         priv->thumb_win.x,
+                         priv->thumb_win.x + priv->thumb_all.width - priv->slider.width);
+              y = priv->thumb_win.y;
             }
 
           /* Fine scroll while detached,
            * do not scroll when hitting an edge. */
           if ((priv->orientation == GTK_ORIENTATION_VERTICAL &&
-               y > priv->win_y &&
-               y < priv->win_y + priv->thumb_all.height - priv->slider.height) ||
+               y > priv->thumb_win.y &&
+               y < priv->thumb_win.y + priv->thumb_all.height - priv->slider.height) ||
               (priv->orientation == GTK_ORIENTATION_HORIZONTAL &&
-               x > priv->win_x &&
-               x < priv->win_x + priv->thumb_all.width - priv->slider.width))
-            capture_movement (scrollbar, event->x_root, event->y_root);
-
-          move_thumb (scrollbar, x, y);
-
-          if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-            {
-              if (gtk_adjustment_get_value (priv->adjustment) == 0)
-                {
-                  update_visual_connection (scrollbar);                
-
-                  if (priv->overlay.height > priv->slider.height)
-                    {
-                      priv->slide_initial_slider_position = 0;
-                      priv->slide_initial_coordinate = MAX (event->y_root, priv->win_y + priv->pointer_y);
-                    }
-                  else
-                    {
-                      priv->slide_initial_slider_position = 0;
-                      priv->slide_initial_coordinate = event->y_root;
-                    }
-                }
-              else if (priv->overlay.y + priv->overlay.height >= priv->trough.height)
-                {
-                  update_visual_connection (scrollbar);
-
-                  if (priv->overlay.height > priv->slider.height)
-                    {
-                      priv->slide_initial_slider_position = priv->trough.height - priv->overlay.height;
-                      priv->slide_initial_coordinate = MAX (event->y_root, priv->win_y + priv->pointer_y);
-                    }
-                  else
-                    {
-                      priv->slide_initial_slider_position = priv->trough.height - priv->slider.height;
-                      priv->slide_initial_coordinate = event->y_root;
-                    }
-                }
-            }
-          else
-            {
-              if (gtk_adjustment_get_value (priv->adjustment) == 0)
-                {
-                  update_visual_connection (scrollbar);                
-
-                  if (priv->overlay.width > priv->slider.width)
-                    {
-                      priv->slide_initial_slider_position = 0;
-                      priv->slide_initial_coordinate = MAX (event->x_root, priv->win_x + priv->pointer_x);
-                    }
-                  else
-                    {
-                      priv->slide_initial_slider_position = 0;
-                      priv->slide_initial_coordinate = event->x_root;
-                    }
-                }
-              else if (priv->overlay.x + priv->overlay.width >= priv->trough.width)
-                {
-                  update_visual_connection (scrollbar);
-
-                  if (priv->overlay.width > priv->slider.width)
-                    {
-                      priv->slide_initial_slider_position = priv->trough.width - priv->overlay.width;
-                      priv->slide_initial_coordinate = MAX (event->x_root, priv->win_x + priv->pointer_x);
-                    }
-                  else
-                    {
-                      priv->slide_initial_slider_position = priv->trough.width - priv->slider.width;
-                      priv->slide_initial_coordinate = event->x_root;
-                    }
-                }
-            }
-
-          return FALSE;            
-        }
-
-      OS_DCHECK (!priv->detached_scroll);
-
-      /* Thumb and pager are connected.
-       * Normal scroll: keep the thumb in sync with the pager,
-       * do not update the visual connection. */
-      priv->event |= OS_EVENT_MOTION_NOTIFY;
-
-      capture_movement (scrollbar, event->x_root, event->y_root);
-
-      if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-        {
-          if (priv->overlay.height > priv->slider.height)
-            {
-              /* Limit x and y within the overlay. */
-              x = priv->win_x;
-              y = CLAMP (event->y_root - priv->pointer_y,
-                         priv->win_y + priv->overlay.y,
-                         priv->win_y + priv->overlay.y + priv->overlay.height - priv->slider.height);
-
-              if (gtk_adjustment_get_value (priv->adjustment) == 0)
-                {
-                  priv->slide_initial_slider_position = 0;
-                  priv->slide_initial_coordinate = MAX (event->y_root, priv->win_y + priv->pointer_y);
-                }
-              else if (priv->overlay.y + priv->overlay.height >= priv->trough.height)
-                {
-                  priv->slide_initial_slider_position = priv->trough.height - priv->overlay.height;
-                  priv->slide_initial_coordinate = MAX (event->y_root, priv->win_y + priv->pointer_y);
-                }
-            }
-          else
-            {
-              x = priv->win_x;
-              y = priv->win_y + priv->slider.y;
-            }
-        }
-      else
-        {
-          if (priv->overlay.width > priv->slider.width)
-            {
-              /* Limit x and y within the overlay. */
-              x = CLAMP (event->x_root - priv->pointer_x,
-                         priv->win_x + priv->overlay.x,
-                         priv->win_x + priv->overlay.x + priv->overlay.width - priv->slider.width);
-              y = priv->win_y;
-
-              if (gtk_adjustment_get_value (priv->adjustment) == 0)
-                {
-                  priv->slide_initial_slider_position = 0;
-                  priv->slide_initial_coordinate = MAX (event->x_root, priv->win_x + priv->pointer_x);
-                }
-              else if (priv->overlay.x + priv->overlay.width >= priv->trough.width)
-                {
-                  priv->slide_initial_slider_position = priv->trough.width - priv->overlay.width;
-                  priv->slide_initial_coordinate = MAX (event->x_root, priv->win_x + priv->pointer_x);
-                }
-            }
-          else
-            {
-              x = priv->win_x + priv->slider.x;
-              y = priv->win_y;
-            }
-        }
-
+               x > priv->thumb_win.x &&
+               x < priv->thumb_win.x + priv->thumb_all.width - priv->slider.width))
+            {
+              /* Stop the animation now.
+               * Only the reconnecting animation can be running now,
+               * because the paging animations were stop before. */
+              os_animation_stop (priv->animation, NULL);
+
+              /* Capture the movement and change adjustment's value (scroll). */
+              capture_movement (scrollbar, event->x_root, event->y_root);
+            }
+          else if (!os_animation_is_running (priv->animation) &&
+                   !(priv->state & OS_STATE_DETACHED))
+            {
+              /* Animate scrolling till reaches the edge. */
+              if ((priv->orientation == GTK_ORIENTATION_VERTICAL && y <= priv->thumb_win.y) ||
+                  (priv->orientation == GTK_ORIENTATION_HORIZONTAL && x <= priv->thumb_win.x))
+                priv->value = gtk_adjustment_get_lower (priv->adjustment);
+              else
+                priv->value = gtk_adjustment_get_upper (priv->adjustment) -
+                              gtk_adjustment_get_page_size (priv->adjustment);
+
+              /* Proceed with the reconnection only if needed. */
+              if (priv->value != gtk_adjustment_get_value (priv->adjustment))
+                {
+                  /* If the thumb is not detached, proceed with reconnection. */
+                  priv->state |= OS_STATE_RECONNECTING;
+
+                  os_animation_set_duration (priv->animation, MIN_DURATION_SCROLLING);
+
+                  /* Start the scrolling animation. */
+                  os_animation_start (priv->animation);
+                }
+            }
+        }
+
+      /* Move the thumb window. */
       move_thumb (scrollbar, x, y);
+
+      /* Adjust slide values in some special situations,
+       * update the tail if the thumb is detached and
+       * check if the movement changed the thumb state to connected. */
+      if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+        {
+          if (gtk_adjustment_get_value (priv->adjustment) <= gtk_adjustment_get_lower (priv->adjustment))
+            {
+              if (priv->state & OS_STATE_DETACHED)
+                update_tail (scrollbar);
+
+              if (!(priv->state & OS_STATE_CONNECTED))
+                check_connection (scrollbar);
+
+              priv->slide_initial_slider_position = 0;
+              priv->slide_initial_coordinate = MAX (event->y_root, priv->thumb_win.y + priv->pointer.y);
+            }
+          else if (priv->overlay.y + priv->overlay.height >= priv->trough.height)
+            {
+              if (priv->state & OS_STATE_DETACHED)
+                update_tail (scrollbar);
+
+              if (!(priv->state & OS_STATE_CONNECTED))
+                check_connection (scrollbar);
+
+              priv->slide_initial_slider_position = priv->trough.height - MAX (priv->overlay.height, priv->slider.height);
+              priv->slide_initial_coordinate = MIN (event->y_root, (priv->thumb_win.y + priv->trough.height -
+                                                                    priv->slider.height + priv->pointer.y));
+            }
+        }
+      else
+        {
+          if (gtk_adjustment_get_value (priv->adjustment) <= gtk_adjustment_get_lower (priv->adjustment))
+            {
+              if (priv->state & OS_STATE_DETACHED)
+                update_tail (scrollbar);
+
+              if (!(priv->state & OS_STATE_CONNECTED))
+                check_connection (scrollbar);
+
+              priv->slide_initial_slider_position = 0;
+              priv->slide_initial_coordinate = MAX (event->x_root, priv->thumb_win.x + priv->pointer.x);
+            }
+          else if (priv->overlay.x + priv->overlay.width >= priv->trough.width)
+            {
+              if (priv->state & OS_STATE_DETACHED)
+                update_tail (scrollbar);
+
+              if (!(priv->state & OS_STATE_CONNECTED))
+                check_connection (scrollbar);
+
+              priv->slide_initial_slider_position = priv->trough.width - MAX (priv->overlay.width, priv->slider.width);
+              priv->slide_initial_coordinate = MIN (event->x_root, (priv->thumb_win.x + priv->trough.width -
+                                                                    priv->slider.width + priv->pointer.x));
+            }
+        }
     }
 
   return FALSE;
@@ -1836,11 +2031,9 @@
   scrollbar = OS_SCROLLBAR (user_data);
   priv = scrollbar->priv;
 
-  /* Stop the paging animation if it's running. */
+  /* Stop the scrolling animation if it's running. */
   os_animation_stop (priv->animation, NULL);
 
-  priv->event |= OS_EVENT_VALUE_CHANGED;
-
   delta = get_wheel_delta (scrollbar, event->direction);
 
   gtk_adjustment_set_value (priv->adjustment,
@@ -1849,6 +2042,25 @@
                                    (gtk_adjustment_get_upper (priv->adjustment) -
                                     gtk_adjustment_get_page_size (priv->adjustment))));
 
+  /* Deal with simultaneous events. */
+  if (priv->event & OS_EVENT_BUTTON_PRESS)
+    {
+      priv->event &= ~(OS_EVENT_MOTION_NOTIFY);
+
+      /* we need to update the slide values
+       * with the current position. */
+      if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+        {
+          priv->slide_initial_slider_position = MIN (priv->slider.y, priv->overlay.y);
+          priv->slide_initial_coordinate = event->y_root;
+        }
+      else
+        {
+          priv->slide_initial_slider_position = MIN (priv->slider.x, priv->overlay.x);
+          priv->slide_initial_coordinate = event->x_root;
+        }
+    }
+
   return FALSE;
 }
 
@@ -1863,31 +2075,28 @@
   priv = scrollbar->priv;
 
   priv->event = OS_EVENT_NONE;
-
-  priv->detached_scroll = FALSE;
-
-  os_pager_set_detached (priv->pager, FALSE);
+  priv->hidable_thumb = TRUE;
+
+  /* Remove running hide timeout, if there is one. */
+  if (priv->source_hide_thumb_id != 0)
+    {
+      g_source_remove (priv->source_hide_thumb_id);
+      priv->source_hide_thumb_id = 0;
+    }
+
+  /* This could hardly still be running,
+   * but it is not impossible. */
+  if (priv->source_show_thumb_id != 0)
+    {
+      g_source_remove (priv->source_show_thumb_id);
+      priv->source_show_thumb_id = 0;
+    }
+
+  os_bar_set_detached (priv->bar, FALSE, TRUE);
 }
 
 /* Toplevel functions. */
 
-/* Store the position of the toplevel window. */
-static void
-store_toplevel_position (OsScrollbar *scrollbar)
-{
-  OsScrollbarPrivate *priv;
-  gint x_pos, y_pos;
-
-  priv = scrollbar->priv;
-
-  /* In reality, I'm storing widget's window, not the toplevel.
-   * Is that the same with gdk_window_get_origin? */
-  gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-  priv->win_x = x_pos + priv->thumb_all.x;
-  priv->win_y = y_pos + priv->thumb_all.y;
-}
-
 static gboolean
 toplevel_configure_event_cb (GtkWidget         *widget,
                              GdkEventConfigure *event,
@@ -1902,7 +2111,7 @@
    * and the configure-event happens after
    * the PropertyNotify _NET_ACTIVE_WINDOW event,
    * see if the mouse pointer is over this window, if TRUE,
-   * proceed with pager_set_state_from_pointer. */
+   * proceed with bar_set_state_from_pointer (). */
   if (!is_insensitive (scrollbar) &&
       (current_time > end_time) &&
       gtk_widget_get_mapped (GTK_WIDGET (scrollbar)))
@@ -1932,34 +2141,67 @@
               /* When the window is resized (maximize/restore),
                * check the position of the pointer
                * and set the state accordingly. */
-              pager_set_state_from_pointer (scrollbar, x, y);
+              bar_set_state_from_pointer (scrollbar, x, y);
             }
         }
       else
         {
-          priv->can_deactivate_pager = FALSE;
-          os_pager_set_active (priv->pager, TRUE, TRUE);
+          priv->deactivable_bar = FALSE;
+          os_bar_set_active (priv->bar, TRUE, TRUE);
         }
     }
 
   if (current_time > end_time)
     gtk_widget_hide (priv->thumb);
 
-  priv->lock_position = FALSE;
+  priv->state &= ~(OS_STATE_LOCKED);
 
-  calc_layout_pager (scrollbar, gtk_adjustment_get_value (priv->adjustment));
+  calc_layout_bar (scrollbar, gtk_adjustment_get_value (priv->adjustment));
   calc_layout_slider (scrollbar, gtk_adjustment_get_value (priv->adjustment));
 
-  store_toplevel_position (scrollbar);
+  calc_thumb_window_position (scrollbar);
 
   return FALSE;
 }
 
+/* widget's window functions. */
+
+/* Move the thumb in the proximity area. */
+static void
+adjust_thumb_position (OsScrollbar *scrollbar,
+                       gdouble      event_x,
+                       gdouble      event_y)
+{
+  OsScrollbarPrivate *priv;
+  gint x, y, x_pos, y_pos;
+
+  priv = scrollbar->priv;
+
+  gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
+
+  if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+    {
+      x = priv->thumb_all.x;
+      y = CLAMP (event_y - priv->slider.height / 2,
+                 priv->thumb_all.y,
+                 priv->thumb_all.y + priv->thumb_all.height - priv->slider.height);
+    }
+  else
+    {
+      x = CLAMP (event_x - priv->slider.width / 2,
+                 priv->thumb_all.x,
+                 priv->thumb_all.x + priv->thumb_all.width - priv->slider.width);
+      y = priv->thumb_all.y;
+    }
+
+  move_thumb (scrollbar, x_pos + x, y_pos + y);
+}
+
 /* Checks if the pointer is in the proximity area. */
 static gboolean
 check_proximity (OsScrollbar *scrollbar,
-                 gint x,
-                 gint y)
+                 gint         x,
+                 gint         y)
 {
   OsScrollbarPrivate *priv;
 
@@ -1968,28 +2210,28 @@
   switch (priv->side)
   {
     case OS_SIDE_RIGHT:
-      return (x >= priv->pager_all.x + priv->pager_all.width - PROXIMITY_SIZE &&
-              x <= priv->pager_all.x + priv->pager_all.width) &&
-             (y >= priv->pager_all.y + priv->overlay.y &&
-              y <= priv->pager_all.y + priv->overlay.y + priv->overlay.height);
+      return (x >= priv->bar_all.x + priv->bar_all.width - PROXIMITY_SIZE &&
+              x <= priv->bar_all.x + priv->bar_all.width) &&
+             (y >= priv->bar_all.y &&
+              y <= priv->bar_all.y + priv->bar_all.height);
       break;
     case OS_SIDE_BOTTOM:
-      return (y >= priv->pager_all.y + priv->pager_all.height - PROXIMITY_SIZE &&
-              y <= priv->pager_all.y + priv->pager_all.height) &&
-             (x >= priv->pager_all.x + priv->overlay.x &&
-              x <= priv->pager_all.x + priv->overlay.x + priv->overlay.width);
+      return (y >= priv->bar_all.y + priv->bar_all.height - PROXIMITY_SIZE &&
+              y <= priv->bar_all.y + priv->bar_all.height) &&
+             (x >= priv->bar_all.x &&
+              x <= priv->bar_all.x + priv->bar_all.width);
       break;
     case OS_SIDE_LEFT:
-      return (x <= priv->pager_all.x + priv->pager_all.width + PROXIMITY_SIZE &&
-              x >= priv->pager_all.x) &&
-             (y >= priv->pager_all.y + priv->overlay.y &&
-              y <= priv->pager_all.y + priv->overlay.y + priv->overlay.height);
+      return (x <= priv->bar_all.x + priv->bar_all.width + PROXIMITY_SIZE &&
+              x >= priv->bar_all.x) &&
+             (y >= priv->bar_all.y &&
+              y <= priv->bar_all.y + priv->bar_all.height);
       break;
     case OS_SIDE_TOP:
-      return (y <= priv->pager_all.y + priv->pager_all.height + PROXIMITY_SIZE &&
-              y >= priv->pager_all.y) &&
-             (x >= priv->pager_all.x + priv->overlay.x &&
-              x <= priv->pager_all.x + priv->overlay.x + priv->overlay.width);
+      return (y <= priv->bar_all.y + priv->bar_all.height + PROXIMITY_SIZE &&
+              y >= priv->bar_all.y) &&
+             (x >= priv->bar_all.x &&
+              x <= priv->bar_all.x + priv->bar_all.width);
       break;
     default:
       break;
@@ -1998,6 +2240,64 @@
   return FALSE;
 }
 
+/* Callback that shows the thumb if it's the case. */
+static gboolean
+show_thumb_cb (gpointer user_data)
+{
+  OsScrollbar *scrollbar;
+  OsScrollbarPrivate *priv;
+
+  scrollbar = OS_SCROLLBAR (user_data);
+  priv = scrollbar->priv;
+
+  if (!priv->hidable_thumb)
+    {
+      gtk_widget_show (priv->thumb);
+
+      update_tail (scrollbar);
+    }
+
+  priv->source_show_thumb_id = 0;
+
+  return FALSE;
+}
+
+/* Adds a timeout to reveal the thumb. */
+static void
+show_thumb (OsScrollbar *scrollbar)
+{
+  OsScrollbarPrivate *priv;
+
+  priv = scrollbar->priv;
+
+  /* Just update the tail if the thumb is already mapped. */
+  if (gtk_widget_get_mapped (priv->thumb))
+    {
+      update_tail (scrollbar);
+      return;
+    }
+
+  if (priv->state & OS_STATE_INTERNAL)
+    {
+      /* If the scrollbar is close to one edge of the screen,
+       * show it immediately, ignoring the timeout,
+       * to preserve Fitts' law. */
+      if (priv->source_show_thumb_id != 0)
+        {
+          g_source_remove (priv->source_show_thumb_id);
+          priv->source_show_thumb_id = 0;
+        }
+
+      gtk_widget_show (priv->thumb);
+
+      update_tail (scrollbar);
+    }
+  else if (priv->source_show_thumb_id == 0)
+    priv->source_show_thumb_id = g_timeout_add (TIMEOUT_THUMB_SHOW,
+                                                show_thumb_cb,
+                                                scrollbar);
+}
+
 /* Filter function applied to the toplevel window. */
 #ifdef USE_GTK3
 typedef enum
@@ -2025,10 +2325,10 @@
 
   xev = gdkxevent;
 
-  g_return_val_if_fail (OS_IS_PAGER (priv->pager), GDK_FILTER_CONTINUE);
+  g_return_val_if_fail (OS_IS_BAR (priv->bar), GDK_FILTER_CONTINUE);
   g_return_val_if_fail (OS_IS_THUMB (priv->thumb), GDK_FILTER_CONTINUE);
 
-  if (!priv->fullsize)
+  if (!(priv->state & OS_STATE_FULLSIZE))
     {
       OsXEvent os_xevent;
       gdouble event_x, event_y;
@@ -2092,101 +2392,72 @@
 
         if (os_xevent == OS_XEVENT_BUTTON_PRESS)
           {
-            priv->toplevel_button_press = TRUE;
+            priv->window_button_press = TRUE;
+
+            if (priv->source_show_thumb_id != 0)
+              {
+                g_source_remove (priv->source_show_thumb_id);
+                priv->source_show_thumb_id = 0;
+              }
+
             gtk_widget_hide (priv->thumb);
           }
 
-        if (priv->toplevel_button_press && os_xevent == OS_XEVENT_BUTTON_RELEASE)
+        if (priv->window_button_press && os_xevent == OS_XEVENT_BUTTON_RELEASE)
           {
-            priv->toplevel_button_press = FALSE;
+            priv->window_button_press = FALSE;
 
             /* Proximity area. */
-            if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-              {
-                if (check_proximity (scrollbar, event_x, event_y))
-                  {
-                    priv->can_hide = FALSE;
-
-                    if (priv->lock_position)
-                      return GDK_FILTER_CONTINUE;
-
-                    if (priv->overlay.height > priv->slider.height)
-                      {
-                        gint x, y, x_pos, y_pos;
-
-                        gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                        x = priv->thumb_all.x;
-                        y = CLAMP (event_y - priv->slider.height / 2,
-                                   priv->thumb_all.y + priv->overlay.y,
-                                   priv->thumb_all.y + priv->overlay.y + priv->overlay.height - priv->slider.height);
-
-                        move_thumb (scrollbar, x_pos + x, y_pos + y);
-                      }
-                    else
-                      {
-                        move_thumb (scrollbar, priv->win_x, priv->win_y + priv->slider.y);
-                      }
-
-                    gtk_widget_show (priv->thumb);
-                  }
-              }
-            else
-              {
-                if (check_proximity (scrollbar, event_x, event_y))
-                  {
-                    priv->can_hide = FALSE;
-
-                    if (priv->lock_position)
-                      return GDK_FILTER_CONTINUE;
-
-                    if (priv->overlay.width > priv->slider.width)
-                      {
-                        gint x, y, x_pos, y_pos;
-
-                        gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                        x = CLAMP (event_x - priv->slider.width / 2,
-                                   priv->thumb_all.x + priv->overlay.x,
-                                   priv->thumb_all.x + priv->overlay.x + priv->overlay.width - priv->slider.width);
-                        y = priv->thumb_all.y;
-
-                        move_thumb (scrollbar, x_pos + x, y_pos + y);
-                      }
-                    else
-                      {
-                        move_thumb (scrollbar, priv->win_x, priv->win_y + priv->slider.y);
-                      }
-
-                    gtk_widget_show (priv->thumb);
-                  }
+            if (check_proximity (scrollbar, event_x, event_y))
+              {
+                priv->hidable_thumb = FALSE;
+
+                if (priv->state & OS_STATE_LOCKED)
+                  return GDK_FILTER_CONTINUE;
+
+                adjust_thumb_position (scrollbar, event_x, event_y);
+
+                gtk_widget_show (priv->thumb);
+
+                update_tail (scrollbar);
               }
           }
 
         if (os_xevent == OS_XEVENT_LEAVE)
           {
-            /* Never deactivate the pager in an active window. */
+            priv->window_button_press = FALSE;
+
+            /* Never deactivate the bar in an active window. */
             if (!priv->active_window)
               {
-                priv->can_deactivate_pager = TRUE;
-
-                if (priv->source_deactivate_pager_id != 0)
-                  g_source_remove (priv->source_deactivate_pager_id);
-
-                priv->source_deactivate_pager_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
-                                                                  deactivate_pager_cb,
-                                                                  scrollbar);
-              }
-
-            priv->toplevel_button_press = FALSE;
-            priv->can_hide = TRUE;
-
-            if (priv->source_hide_thumb_id != 0)
-              g_source_remove (priv->source_hide_thumb_id);
-
-            priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
-                                                        hide_thumb_cb,
-                                                        scrollbar);
+                priv->deactivable_bar = TRUE;
+
+                if (priv->source_deactivate_bar_id != 0)
+                  g_source_remove (priv->source_deactivate_bar_id);
+
+                priv->source_deactivate_bar_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
+                                                                deactivate_bar_cb,
+                                                                scrollbar);
+              }
+
+            if (gtk_widget_get_mapped (priv->thumb) &&
+                !(priv->event & OS_EVENT_BUTTON_PRESS))
+              {
+                priv->hidable_thumb = TRUE;
+
+                if (priv->source_hide_thumb_id != 0)
+                  g_source_remove (priv->source_hide_thumb_id);
+
+                priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
+                                                            hide_thumb_cb,
+                                                            scrollbar);
+              }
+
+            if (priv->source_show_thumb_id != 0)
+              {
+                g_source_remove (priv->source_show_thumb_id);
+                priv->source_show_thumb_id = 0;
+              }
 
             if (priv->source_unlock_thumb_id != 0)
               g_source_remove (priv->source_unlock_thumb_id);
@@ -2197,107 +2468,47 @@
           }
 
         /* Get the motion_notify_event trough XEvent. */
-        if (!priv->toplevel_button_press && os_xevent == OS_XEVENT_MOTION)
+        if (!priv->window_button_press && os_xevent == OS_XEVENT_MOTION)
           {
             /* React to motion_notify_event
              * and set the state accordingly. */
             if (!is_insensitive (scrollbar) && !priv->active_window)
-              pager_set_state_from_pointer (scrollbar, event_x, event_y);
+              bar_set_state_from_pointer (scrollbar, event_x, event_y);
 
             /* Proximity area. */
-            if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+            if (check_proximity (scrollbar, event_x, event_y))
               {
-                if (check_proximity (scrollbar, event_x, event_y))
-                  {
-                    priv->can_hide = FALSE;
-
-                    if (priv->source_hide_thumb_id != 0)
-                      {
-                        g_source_remove (priv->source_hide_thumb_id);
-                        priv->source_hide_thumb_id = 0;
-                      }
-
-                    if (priv->lock_position)
-                      return GDK_FILTER_CONTINUE;
-
-                    if (priv->overlay.height > priv->slider.height)
-                      {
-                        gint x, y, x_pos, y_pos;
-
-                        gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                        x = priv->thumb_all.x;
-                        y = CLAMP (event_y - priv->slider.height / 2,
-                                   priv->thumb_all.y + priv->overlay.y,
-                                   priv->thumb_all.y + priv->overlay.y + priv->overlay.height - priv->slider.height);
-
-                        move_thumb (scrollbar, x_pos + x, y_pos + y);
-                      }
-                    else
-                      {
-                        move_thumb (scrollbar, priv->win_x, priv->win_y + priv->slider.y);
-                      }
-
-                    os_pager_set_detached (priv->pager, FALSE);
-                    os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
-                    gtk_widget_show (priv->thumb);
-                  }
-                else
-                  {
-                    priv->can_hide = TRUE;
-                    priv->lock_position = FALSE;
-
-                    if (gtk_widget_get_mapped (priv->thumb) &&
-                        priv->source_hide_thumb_id == 0)
-                      priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_PROXIMITY_HIDE,
-                                                                  hide_thumb_cb,
-                                                                  scrollbar);
-                  }
+                priv->hidable_thumb = FALSE;
+
+                if (priv->source_hide_thumb_id != 0)
+                  {
+                    g_source_remove (priv->source_hide_thumb_id);
+                    priv->source_hide_thumb_id = 0;
+                  }
+
+                if (priv->state & OS_STATE_LOCKED)
+                  return GDK_FILTER_CONTINUE;
+
+                adjust_thumb_position (scrollbar, event_x, event_y);
+
+                show_thumb (scrollbar);
               }
             else
               {
-                if (check_proximity (scrollbar, event_x, event_y))
+                priv->state &= ~(OS_STATE_LOCKED);
+
+                if (priv->source_show_thumb_id != 0)
                   {
-                    priv->can_hide = FALSE;
-
-                    if (priv->source_hide_thumb_id != 0)
-                      {
-                        g_source_remove (priv->source_hide_thumb_id);
-                        priv->source_hide_thumb_id = 0;
-                      }
-
-                    if (priv->lock_position)
-                      return GDK_FILTER_CONTINUE;
-
-                    if (priv->overlay.width > priv->slider.width)
-                      {
-                        gint x, y, x_pos, y_pos;
-
-                        gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                        x = CLAMP (event_x - priv->slider.width / 2,
-                                   priv->thumb_all.x + priv->overlay.x,
-                                   priv->thumb_all.x + priv->overlay.x + priv->overlay.width - priv->slider.width);
-                        y = priv->thumb_all.y;
-
-                        move_thumb (scrollbar, x_pos + x, y_pos + y);
-                      }
-                    else
-                      {
-                        move_thumb (scrollbar, priv->win_x + priv->slider.x, priv->win_y);
-                      }
-
-                    os_pager_set_detached (priv->pager, FALSE);
-                    os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
-                    gtk_widget_show (priv->thumb);
+                    g_source_remove (priv->source_show_thumb_id);
+                    priv->source_show_thumb_id = 0;
                   }
-                else
+
+                if (gtk_widget_get_mapped (priv->thumb) &&
+                    !(priv->event & OS_EVENT_BUTTON_PRESS))
                   {
-                    priv->can_hide = TRUE;
-                    priv->lock_position = FALSE;
+                    priv->hidable_thumb = TRUE;
 
-                    if (gtk_widget_get_mapped (priv->thumb) &&
-                        priv->source_hide_thumb_id == 0)
+                    if (priv->source_hide_thumb_id == 0)
                       priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_PROXIMITY_HIDE,
                                                                   hide_thumb_cb,
                                                                   scrollbar);
@@ -2325,120 +2536,79 @@
 
   xev = gdkxevent;
 
-  g_return_val_if_fail (OS_IS_PAGER (priv->pager), GDK_FILTER_CONTINUE);
+  g_return_val_if_fail (OS_IS_BAR (priv->bar), GDK_FILTER_CONTINUE);
   g_return_val_if_fail (OS_IS_THUMB (priv->thumb), GDK_FILTER_CONTINUE);
 
-  if (!priv->fullsize)
+  if (!(priv->state & OS_STATE_FULLSIZE))
     {
       if (xev->type == ButtonPress)
         {
-          priv->toplevel_button_press = TRUE;
+          priv->window_button_press = TRUE;
+
+          if (priv->source_show_thumb_id != 0)
+            {
+              g_source_remove (priv->source_show_thumb_id);
+              priv->source_show_thumb_id = 0;
+            }
+
           gtk_widget_hide (priv->thumb);
         }
 
-      if (priv->toplevel_button_press && xev->type == ButtonRelease)
+      if (priv->window_button_press && xev->type == ButtonRelease)
         {
-          priv->toplevel_button_press = FALSE;
+          priv->window_button_press = FALSE;
 
           /* Proximity area. */
-          if (priv->orientation == GTK_ORIENTATION_VERTICAL)
-            {
-              if (check_proximity (scrollbar, xev->xbutton.x, xev->xbutton.y))
-                {
-                  priv->can_hide = FALSE;
-
-                  if (priv->source_hide_thumb_id != 0)
-                    {
-                      g_source_remove (priv->source_hide_thumb_id);
-                      priv->source_hide_thumb_id = 0;
-                    }
-
-                  if (priv->lock_position)
-                    return GDK_FILTER_CONTINUE;
-
-                  if (priv->overlay.height > priv->slider.height)
-                    {
-                      gint x, y, x_pos, y_pos;
-
-                      gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                      x = priv->thumb_all.x;
-                      y = CLAMP (xev->xbutton.y - priv->slider.height / 2,
-                                 priv->thumb_all.y + priv->overlay.y,
-                                 priv->thumb_all.y + priv->overlay.y + priv->overlay.height - priv->slider.height);
-
-                      move_thumb (scrollbar, x_pos + x, y_pos + y);
-                    }
-                  else
-                    {
-                      move_thumb (scrollbar, priv->win_x, priv->win_y + priv->slider.y);
-                    }
-
-                  gtk_widget_show (priv->thumb);
-                }
-            }
-          else
-            {
-              if (check_proximity (scrollbar, xev->xbutton.x, xev->xbutton.y))
-                {
-                  priv->can_hide = FALSE;
-
-                  if (priv->source_hide_thumb_id != 0)
-                    {
-                      g_source_remove (priv->source_hide_thumb_id);
-                      priv->source_hide_thumb_id = 0;
-                    }
-
-                  if (priv->lock_position)
-                    return GDK_FILTER_CONTINUE;
-
-                  if (priv->overlay.width > priv->slider.width)
-                    {
-                      gint x, y, x_pos, y_pos;
-
-                      gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                      x = CLAMP (xev->xbutton.x - priv->slider.width / 2,
-                                 priv->thumb_all.x + priv->overlay.x,
-                                 priv->thumb_all.x + priv->overlay.x + priv->overlay.width - priv->slider.width);
-                      y = priv->thumb_all.y;
-
-                      move_thumb (scrollbar, x_pos + x, y_pos + y);
-                    }
-                  else
-                    {
-                      move_thumb (scrollbar, priv->win_x, priv->win_y + priv->slider.y);
-                    }
-
-                  gtk_widget_show (priv->thumb);
-                }
+          if (check_proximity (scrollbar, xev->xbutton.x, xev->xbutton.y))
+            {
+              priv->hidable_thumb = FALSE;
+
+              if (priv->state & OS_STATE_LOCKED)
+                return GDK_FILTER_CONTINUE;
+
+              adjust_thumb_position (scrollbar, xev->xbutton.x, xev->xbutton.y);
+
+              gtk_widget_show (priv->thumb);
+
+              update_tail (scrollbar);
             }
         }
 
       if (xev->type == LeaveNotify)
         {
-          /* Never deactivate the pager in an active window. */
+          priv->window_button_press = FALSE;
+
+          /* Never deactivate the bar in an active window. */
           if (!priv->active_window)
             {
-              priv->can_deactivate_pager = TRUE;
-
-              if (priv->source_deactivate_pager_id != 0)
-                g_source_remove (priv->source_deactivate_pager_id);
-
-              priv->source_deactivate_pager_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
-                                                                deactivate_pager_cb,
-                                                                scrollbar);
-            }
-
-          priv->toplevel_button_press = FALSE;
-          priv->can_hide = TRUE;
-
-          if (priv->source_hide_thumb_id != 0)
-            g_source_remove (priv->source_hide_thumb_id);
-
-          priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
-                                                      hide_thumb_cb,
-                                                      scrollbar);
+              priv->deactivable_bar = TRUE;
+
+              if (priv->source_deactivate_bar_id != 0)
+                g_source_remove (priv->source_deactivate_bar_id);
+
+              priv->source_deactivate_bar_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
+                                                              deactivate_bar_cb,
+                                                              scrollbar);
+            }
+
+          if (gtk_widget_get_mapped (priv->thumb) &&
+              !(priv->event & OS_EVENT_BUTTON_PRESS))
+            {
+              priv->hidable_thumb = TRUE;
+
+              if (priv->source_hide_thumb_id != 0)
+                g_source_remove (priv->source_hide_thumb_id);
+
+              priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_TOPLEVEL_HIDE,
+                                                          hide_thumb_cb,
+                                                          scrollbar);
+            }
+
+          if (priv->source_show_thumb_id != 0)
+            {
+              g_source_remove (priv->source_show_thumb_id);
+              priv->source_show_thumb_id = 0;
+            }
 
           if (priv->source_unlock_thumb_id != 0)
             g_source_remove (priv->source_unlock_thumb_id);
@@ -2449,95 +2619,47 @@
         }
 
       /* Get the motion_notify_event trough XEvent. */
-      if (!priv->toplevel_button_press && xev->type == MotionNotify)
+      if (!priv->window_button_press && xev->type == MotionNotify)
         {
           /* React to motion_notify_event
            * and set the state accordingly. */
           if (!is_insensitive (scrollbar) && !priv->active_window)
-            pager_set_state_from_pointer (scrollbar, xev->xmotion.x, xev->xmotion.y);
+            bar_set_state_from_pointer (scrollbar, xev->xmotion.x, xev->xmotion.y);
 
           /* Proximity area. */
-          if (priv->orientation == GTK_ORIENTATION_VERTICAL)
+          if (check_proximity (scrollbar, xev->xmotion.x, xev->xmotion.y))
             {
-              if (check_proximity (scrollbar, xev->xmotion.x, xev->xmotion.y))
-                {
-                  priv->can_hide = FALSE;
-
-                  if (priv->lock_position)
-                    return GDK_FILTER_CONTINUE;
-
-                  if (priv->overlay.height > priv->slider.height)
-                    {
-                      gint x, y, x_pos, y_pos;
-
-                      gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                      x = priv->thumb_all.x;
-                      y = CLAMP (xev->xmotion.y - priv->slider.height / 2,
-                                 priv->thumb_all.y + priv->overlay.y,
-                                 priv->thumb_all.y + priv->overlay.y + priv->overlay.height - priv->slider.height);
-
-                      move_thumb (scrollbar, x_pos + x, y_pos + y);
-                    }
-                  else
-                    {
-                      move_thumb (scrollbar, priv->win_x, priv->win_y + priv->slider.y);
-                    }
-
-                  os_pager_set_detached (priv->pager, FALSE);
-                  os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
-                  gtk_widget_show (priv->thumb);
-                }
-              else
-                {
-                  priv->can_hide = TRUE;
-                  priv->lock_position = FALSE;
-
-                  if (gtk_widget_get_mapped (priv->thumb) &&
-                      priv->source_hide_thumb_id == 0)
-                    priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_PROXIMITY_HIDE,
-                                                                hide_thumb_cb,
-                                                                scrollbar);
-                }
+              priv->hidable_thumb = FALSE;
+
+              if (priv->source_hide_thumb_id != 0)
+                {
+                  g_source_remove (priv->source_hide_thumb_id);
+                  priv->source_hide_thumb_id = 0;
+                }
+
+              if (priv->state & OS_STATE_LOCKED)
+                return GDK_FILTER_CONTINUE;
+
+              adjust_thumb_position (scrollbar, xev->xmotion.x, xev->xmotion.y);
+
+              show_thumb (scrollbar);
             }
           else
             {
-              if (check_proximity (scrollbar, xev->xmotion.x, xev->xmotion.y))
+              priv->state &= ~(OS_STATE_LOCKED);
+
+              if (priv->source_show_thumb_id != 0)
                 {
-                  priv->can_hide = FALSE;
-
-                  if (priv->lock_position)
-                    return GDK_FILTER_CONTINUE;
-
-                  if (priv->overlay.width > priv->slider.width)
-                    {
-                      gint x, y, x_pos, y_pos;
-
-                      gdk_window_get_origin (gtk_widget_get_window (GTK_WIDGET (scrollbar)), &x_pos, &y_pos);
-
-                      x = CLAMP (xev->xmotion.x - priv->slider.width / 2,
-                                 priv->thumb_all.x + priv->overlay.x,
-                                 priv->thumb_all.x + priv->overlay.x + priv->overlay.width - priv->slider.width);
-                      y = priv->thumb_all.y;
-
-                      move_thumb (scrollbar, x_pos + x, y_pos + y);
-                    }
-                  else
-                    {
-                      move_thumb (scrollbar, priv->win_x + priv->slider.x, priv->win_y);
-                    }
-
-                  os_pager_set_detached (priv->pager, FALSE);
-                  os_thumb_set_detached (OS_THUMB (priv->thumb), FALSE);
-                  gtk_widget_show (priv->thumb);
+                  g_source_remove (priv->source_show_thumb_id);
+                  priv->source_show_thumb_id = 0;
                 }
-              else
+
+              if (gtk_widget_get_mapped (priv->thumb) &&
+                  !(priv->event & OS_EVENT_BUTTON_PRESS))
                 {
-                  priv->can_hide = TRUE;
-                  priv->lock_position = FALSE;
+                  priv->hidable_thumb = TRUE;
 
-                  if (gtk_widget_get_mapped (priv->thumb) &&
-                      priv->source_hide_thumb_id == 0)
+                  if (priv->source_hide_thumb_id == 0)
                     priv->source_hide_thumb_id = g_timeout_add (TIMEOUT_PROXIMITY_HIDE,
                                                                 hide_thumb_cb,
                                                                 scrollbar);
@@ -2550,6 +2672,44 @@
 }
 #endif
 
+/* Add the window filter function. */
+static void
+add_window_filter (OsScrollbar *scrollbar)
+{
+  OsScrollbarPrivate *priv;
+
+  priv = scrollbar->priv;
+
+  /* Don't add duplicated filters. */
+  if (!priv->filter.running &&
+      gtk_widget_get_realized (GTK_WIDGET (scrollbar)))
+    {
+      priv->filter.running = TRUE;
+      gdk_window_add_filter (gtk_widget_get_window (GTK_WIDGET (scrollbar)),
+                             window_filter_func,
+                             scrollbar);
+    }
+}
+
+/* Remove the window filter function. */
+static void
+remove_window_filter (OsScrollbar *scrollbar)
+{
+  OsScrollbarPrivate *priv;
+
+  priv = scrollbar->priv;
+
+  /* Remove only if the filter is running. */
+  if (priv->filter.running &&
+      gtk_widget_get_realized (GTK_WIDGET (scrollbar)))
+    {
+      priv->filter.running = FALSE;
+      gdk_window_remove_filter (gtk_widget_get_window (GTK_WIDGET (scrollbar)),
+                                window_filter_func,
+                                scrollbar);
+    }
+}
+
 G_DEFINE_TYPE (OsScrollbar, os_scrollbar, GTK_TYPE_SCROLLBAR);
 
 static void
@@ -2634,27 +2794,34 @@
 
   priv->event = OS_EVENT_NONE;
 
+  priv->state = OS_STATE_NONE;
+
+  priv->side = OS_SIDE_RIGHT;
+
+  priv->filter.proximity = FALSE;
+  priv->filter.running = FALSE;
+
   priv->active_window = FALSE;
-  priv->can_deactivate_pager = TRUE;
-  priv->can_hide = TRUE;
-  priv->detached_scroll = FALSE;
-  priv->filter = FALSE;
-  priv->fullsize = FALSE;
-  priv->internal = FALSE;
-  priv->lock_position = FALSE;
-  priv->proximity = FALSE;
-  priv->toplevel_button_press = FALSE;
-  priv->side = OS_SIDE_RIGHT;
-  priv->source_deactivate_pager_id = 0;
+  priv->deactivable_bar = TRUE;
+  priv->hidable_thumb = TRUE;
+  priv->window_button_press = FALSE;
+
+  priv->pointer.x = 0;
+  priv->pointer.y = 0;
+  priv->thumb_win.x = 0;
+  priv->thumb_win.y = 0;
+
+  priv->source_deactivate_bar_id = 0;
   priv->source_hide_thumb_id = 0;
+  priv->source_show_thumb_id = 0;
   priv->source_unlock_thumb_id = 0;
 
-  priv->pager = os_pager_new ();
+  priv->bar = os_bar_new ();
 
   priv->window_group = gtk_window_group_new ();
 
-  priv->animation = os_animation_new (RATE_PAGING, MAX_DURATION_PAGING,
-                                      paging_cb, NULL, scrollbar);
+  priv->animation = os_animation_new (RATE_ANIMATION, MAX_DURATION_SCROLLING,
+                                      scrolling_cb, scrolling_end_cb, scrollbar);
   priv->value = 0;
 
   g_signal_connect (G_OBJECT (scrollbar), "notify::adjustment",
@@ -2673,10 +2840,10 @@
   scrollbar = OS_SCROLLBAR (object);
   priv = scrollbar->priv;
 
-  if (priv->source_deactivate_pager_id != 0)
+  if (priv->source_deactivate_bar_id != 0)
     {
-      g_source_remove (priv->source_deactivate_pager_id);
-      priv->source_deactivate_pager_id = 0;
+      g_source_remove (priv->source_deactivate_bar_id);
+      priv->source_deactivate_bar_id = 0;
     }
 
   if (priv->source_hide_thumb_id != 0)
@@ -2711,10 +2878,10 @@
       priv->animation = NULL;
     }
 
-  if (priv->pager != NULL)
+  if (priv->bar != NULL)
     {
-      g_object_unref (priv->pager);
-      priv->pager = NULL;
+      g_object_unref (priv->bar);
+      priv->bar = NULL;
     }
 
   if (priv->window_group != NULL)
@@ -2767,8 +2934,7 @@
     *minimal_width = *natural_width = 0;
   else
     {
-      /* Smaller than 35 pixels the thumb looks weird. */
-      *minimal_width = 35;
+      *minimal_width = MIN_THUMB_HEIGHT;
       *natural_width = THUMB_HEIGHT;
     }
 }
@@ -2788,8 +2954,7 @@
     *minimal_height = *natural_height = 0;
   else
     {
-      /* Smaller than 35 pixels the thumb looks weird. */
-      *minimal_height = 35;
+      *minimal_height = MIN_THUMB_HEIGHT;
       *natural_height = THUMB_HEIGHT;
     }
 }
@@ -2823,10 +2988,10 @@
       gdk_screen_get_active_window (gtk_widget_get_screen (widget)))
     {
       /* Stops potential running timeout. */
-      if (priv->source_deactivate_pager_id != 0)
+      if (priv->source_deactivate_bar_id != 0)
         {
-          g_source_remove (priv->source_deactivate_pager_id);
-          priv->source_deactivate_pager_id = 0;
+          g_source_remove (priv->source_deactivate_bar_id);
+          priv->source_deactivate_bar_id = 0;
         }
 
       priv->active_window = TRUE;
@@ -2846,29 +3011,24 @@
            * for example when switching notebook page,
            * check the position of the pointer
            * and set the state accordingly. */
-          pager_set_state_from_pointer (scrollbar, x, y);
+          bar_set_state_from_pointer (scrollbar, x, y);
         }
       else
         {
           /* On map-event of an active window,
-           * the pager should be active. */
-          priv->can_deactivate_pager = FALSE;
-          os_pager_set_active (priv->pager, TRUE, FALSE);
+           * the bar should be active. */
+          priv->deactivable_bar = FALSE;
+          os_bar_set_active (priv->bar, TRUE, FALSE);
         }
     }
 
-  if (priv->fullsize == FALSE)
-    os_pager_show (priv->pager);
+  if (!(priv->state & OS_STATE_FULLSIZE))
+    os_bar_show (priv->bar);
 
   if (!is_insensitive (scrollbar))
     {
-      priv->proximity = TRUE;
-
-      if (gtk_widget_get_realized (widget) && priv->filter == FALSE)
-        {
-          priv->filter = TRUE;
-          gdk_window_add_filter (gtk_widget_get_window (widget), window_filter_func, scrollbar);
-        }
+      priv->filter.proximity = TRUE;
+      add_window_filter (scrollbar);
     }
 }
 
@@ -2889,20 +3049,17 @@
                          gdk_window_get_events (gtk_widget_get_window (widget)) |
                          GDK_POINTER_MOTION_MASK);
 
-  if (priv->filter == FALSE && priv->proximity == TRUE)
-    {
-      priv->filter =  TRUE;
-      gdk_window_add_filter (gtk_widget_get_window (widget), window_filter_func, scrollbar);
-    }
+  if (priv->filter.proximity)
+    add_window_filter (scrollbar);
 
   g_signal_connect (G_OBJECT (gtk_widget_get_toplevel (widget)), "configure-event",
                     G_CALLBACK (toplevel_configure_event_cb), scrollbar);
 
-  calc_layout_pager (scrollbar, gtk_adjustment_get_value (priv->adjustment));
-
-  os_pager_set_parent (priv->pager, widget);
-
-  store_toplevel_position (scrollbar);
+  calc_layout_bar (scrollbar, gtk_adjustment_get_value (priv->adjustment));
+
+  os_bar_set_parent (priv->bar, widget);
+
+  calc_thumb_window_position (scrollbar);
 }
 
 static void
@@ -2965,7 +3122,7 @@
   scrollbar = OS_SCROLLBAR (widget);
   priv = scrollbar->priv;
 
-  /* Get the side, then move thumb and pager accordingly. */
+  /* Get the side, then move thumb and bar accordingly. */
   retrieve_side (scrollbar);
 
   priv->trough.x = allocation->x;
@@ -2973,7 +3130,7 @@
   priv->trough.width = allocation->width;
   priv->trough.height = allocation->height;
 
-  priv->pager_all = *allocation;
+  priv->bar_all = *allocation;
   priv->thumb_all = *allocation;
 
   if (priv->orientation == GTK_ORIENTATION_VERTICAL)
@@ -2986,16 +3143,16 @@
         }
 
       if (priv->side == OS_SIDE_RIGHT)
-        priv->pager_all.x = allocation->x - PAGER_SIZE;
+        priv->bar_all.x = allocation->x - BAR_SIZE;
 
-      priv->pager_all.width = PAGER_SIZE;
+      priv->bar_all.width = BAR_SIZE;
 
       priv->thumb_all.width = THUMB_WIDTH;
 
       if (priv->side == OS_SIDE_RIGHT)
-        priv->thumb_all.x = allocation->x - priv->pager_all.width;
+        priv->thumb_all.x = allocation->x - priv->bar_all.width;
       else
-        priv->thumb_all.x = allocation->x + priv->pager_all.width - priv->thumb_all.width;
+        priv->thumb_all.x = allocation->x + priv->bar_all.width - priv->thumb_all.width;
 
       allocation->width = 0;
     }
@@ -3009,32 +3166,32 @@
         }
 
       if (priv->side == OS_SIDE_BOTTOM)
-        priv->pager_all.y = allocation->y - PAGER_SIZE;
+        priv->bar_all.y = allocation->y - BAR_SIZE;
 
-      priv->pager_all.height = PAGER_SIZE;
+      priv->bar_all.height = BAR_SIZE;
 
       priv->thumb_all.height = THUMB_WIDTH;
 
       if (priv->side == OS_SIDE_BOTTOM)
-        priv->thumb_all.y = allocation->y - priv->pager_all.height;
+        priv->thumb_all.y = allocation->y - priv->bar_all.height;
       else
-        priv->thumb_all.y = allocation->y + priv->pager_all.height - priv->thumb_all.height;
+        priv->thumb_all.y = allocation->y + priv->bar_all.height - priv->thumb_all.height;
 
       allocation->height = 0;
     }
 
   if (priv->adjustment != NULL)
     {
-      calc_layout_pager (scrollbar, gtk_adjustment_get_value (priv->adjustment));
+      calc_layout_bar (scrollbar, gtk_adjustment_get_value (priv->adjustment));
       calc_layout_slider (scrollbar, gtk_adjustment_get_value (priv->adjustment));
     }
 
-  os_pager_size_allocate (priv->pager, priv->pager_all);
+  os_bar_size_allocate (priv->bar, priv->bar_all);
 
-  move_pager (scrollbar);
+  move_bar (scrollbar);
 
   if (gtk_widget_get_realized (widget))
-    store_toplevel_position (scrollbar);
+    calc_thumb_window_position (scrollbar);
 
   gtk_widget_set_allocation (widget, allocation);
 }
@@ -3047,15 +3204,10 @@
 
   priv = scrollbar->priv;
 
-  priv->proximity = FALSE;
-
-  if (gtk_widget_get_realized (GTK_WIDGET (scrollbar)) && priv->filter == TRUE)
-    {
-      priv->filter = FALSE;
-      gdk_window_remove_filter (gtk_widget_get_window (GTK_WIDGET (scrollbar)), window_filter_func, scrollbar);
-    }
-
-  os_pager_set_active (priv->pager, FALSE, FALSE);
+  priv->filter.proximity = FALSE;
+  remove_window_filter (scrollbar);
+
+  os_bar_set_active (priv->bar, FALSE, FALSE);
 
   gtk_widget_hide (priv->thumb);
 }
@@ -3068,16 +3220,11 @@
 
   priv = scrollbar->priv;
 
-  priv->proximity = TRUE;
-
-  if (gtk_widget_get_realized (GTK_WIDGET (scrollbar)) && priv->filter == FALSE)
-    {
-      priv->filter = TRUE;
-      gdk_window_add_filter (gtk_widget_get_window (GTK_WIDGET (scrollbar)), window_filter_func, scrollbar);
-    }
+  priv->filter.proximity = TRUE;
+  add_window_filter (scrollbar);
 
   if (priv->active_window)
-    os_pager_set_active (priv->pager, TRUE, FALSE);
+    os_bar_set_active (priv->bar, TRUE, FALSE);
   else
     {
       gint x, y;
@@ -3087,7 +3234,7 @@
       /* When the window is unfocused,
        * check the position of the pointer
        * and set the state accordingly. */
-      pager_set_state_from_pointer (scrollbar, x, y);
+      bar_set_state_from_pointer (scrollbar, x, y);
     }
 }
 
@@ -3150,17 +3297,12 @@
 
   GTK_WIDGET_CLASS (g_type_class_peek (GTK_TYPE_WIDGET))->unmap (widget);
 
-  priv->proximity = FALSE;
-
-  os_pager_hide (priv->pager);
+  os_bar_hide (priv->bar);
 
   gtk_widget_hide (priv->thumb);
 
-  if (gtk_widget_get_realized (widget) && priv->filter == TRUE)
-    {
-      priv->filter = FALSE;
-      gdk_window_remove_filter (gtk_widget_get_window (widget), window_filter_func, scrollbar);
-    }
+  priv->filter.proximity = FALSE;
+  remove_window_filter (scrollbar);
 }
 
 static void
@@ -3172,17 +3314,17 @@
   scrollbar = OS_SCROLLBAR (widget);
   priv = scrollbar->priv;
 
-  os_pager_hide (priv->pager);
+  os_bar_hide (priv->bar);
 
   gtk_widget_hide (priv->thumb);
 
-  priv->filter = FALSE;
+  priv->filter.running = FALSE;
   gdk_window_remove_filter (gtk_widget_get_window (widget), window_filter_func, scrollbar);
 
   g_signal_handlers_disconnect_by_func (G_OBJECT (gtk_widget_get_toplevel (widget)),
                                         G_CALLBACK (toplevel_configure_event_cb), scrollbar);
 
-  os_pager_set_parent (priv->pager, NULL);
+  os_bar_set_parent (priv->bar, NULL);
 
   GTK_WIDGET_CLASS (g_type_class_peek (GTK_TYPE_WIDGET))->unrealize (widget);
 }

=== modified file 'os/os-thumb.c'
--- os/os-thumb.c	2011-10-05 12:24:21 +0000
+++ os/os-thumb.c	2011-10-12 17:16:23 +0000
@@ -29,9 +29,6 @@
 #include <math.h>
 #include <stdlib.h>
 
-/* Rate of the fade-out. */
-#define RATE_FADE_OUT 30
-
 /* Duration of the fade-out. */
 #define DURATION_FADE_OUT 2000
 
@@ -57,14 +54,12 @@
   GtkOrientation orientation;
   GtkWidget *grabbed_widget;
   OsAnimation *animation;
-  OsEvent event;
-  gboolean can_rgba;
+  OsCoordinate pointer;
+  OsCoordinate pointer_root;
+  OsEventFlags event;
+  gboolean rgba;
   gboolean detached;
-  gboolean use_tolerance;
-  gint pointer_x;
-  gint pointer_y;
-  gint pointer_x_root;
-  gint pointer_y_root;
+  gboolean tolerance;
   guint32 source_id;
 };
 
@@ -192,12 +187,17 @@
 
   priv->event = OS_EVENT_NONE;
 
-  priv->can_rgba = FALSE;
+  priv->pointer.x = 0;
+  priv->pointer.y = 0;
+  priv->pointer_root.x = 0;
+  priv->pointer_root.y = 0;
+
+  priv->rgba = FALSE;
   priv->detached = FALSE;
-  priv->use_tolerance = FALSE;
+  priv->tolerance = FALSE;
 
   priv->source_id = 0;
-  priv->animation = os_animation_new (RATE_FADE_OUT, DURATION_FADE_OUT,
+  priv->animation = os_animation_new (RATE_ANIMATION, DURATION_FADE_OUT,
                                       fade_out_cb, NULL, thumb);
 
   gtk_window_set_skip_pager_hint (GTK_WINDOW (thumb), TRUE);
@@ -237,19 +237,20 @@
 
   if (event->type == GDK_BUTTON_PRESS)
     {
-      if (event->button == 1)
+      if (event->button == 1 ||
+          event->button == 2)
         {
           gtk_grab_add (widget);
 
-          priv->pointer_x = event->x;
-          priv->pointer_y = event->y;
-          priv->pointer_x_root = event->x_root;
-          priv->pointer_y_root = event->y_root;
+          priv->pointer.x = event->x;
+          priv->pointer.y = event->y;
+          priv->pointer_root.x = event->x_root;
+          priv->pointer_root.y = event->y_root;
 
           priv->event |= OS_EVENT_BUTTON_PRESS;
           priv->event &= ~(OS_EVENT_MOTION_NOTIFY);
 
-          priv->use_tolerance = TRUE;
+          priv->tolerance = TRUE;
 
           gtk_widget_queue_draw (widget);
         }
@@ -273,7 +274,8 @@
 
   if (event->type == GDK_BUTTON_RELEASE)
     {
-      if (event->button == 1)
+      if (event->button == 1 ||
+          event->button == 2)
         {
           gtk_grab_remove (widget);
 
@@ -295,7 +297,7 @@
   thumb = OS_THUMB (widget);
   priv = thumb->priv;
 
-  priv->can_rgba = FALSE;
+  priv->rgba = FALSE;
 
   if (gdk_screen_is_composited (gtk_widget_get_screen (widget)))
     {
@@ -313,7 +315,7 @@
       if (gdk_visual_get_depth (visual) == 32 && (red_mask   == 0xff0000 &&
                                                   green_mask == 0x00ff00 &&
                                                   blue_mask  == 0x0000ff))   
-        priv->can_rgba = TRUE;
+        priv->rgba = TRUE;
     }
 
   gtk_widget_queue_draw (widget);
@@ -631,7 +633,7 @@
   thumb = OS_THUMB (widget);
   priv = thumb->priv;
 
-  radius = priv->can_rgba ? THUMB_RADIUS : 0;
+  radius = priv->rgba ? THUMB_RADIUS : 0;
 
 #ifdef USE_GTK3
   width = gtk_widget_get_allocated_width (widget);
@@ -690,8 +692,8 @@
   if ((priv->event & OS_EVENT_BUTTON_PRESS) &&
       !(priv->event & OS_EVENT_MOTION_NOTIFY))
     {
-      if ((priv->orientation == GTK_ORIENTATION_VERTICAL && (priv->pointer_y < height / 2)) ||
-          (priv->orientation == GTK_ORIENTATION_HORIZONTAL && (priv->pointer_x < width / 2)))
+      if ((priv->orientation == GTK_ORIENTATION_VERTICAL && (priv->pointer.y < height / 2)) ||
+          (priv->orientation == GTK_ORIENTATION_HORIZONTAL && (priv->pointer.x < width / 2)))
         {
           pattern_add_gdk_rgba_stop (pat, 0.0, &bg_arrow_down, 0.6);
           pattern_add_gdk_rgba_stop (pat, 0.49, &bg_arrow_down, 0.1);
@@ -850,7 +852,7 @@
       os_animation_stop (priv->animation, NULL);
     }
 
-  priv->use_tolerance = FALSE;
+  priv->tolerance = FALSE;
 
   return FALSE;
 }
@@ -906,11 +908,11 @@
    * see code few lines below. */
   if (!(priv->event & OS_EVENT_MOTION_NOTIFY))
   {
-    if (!priv->use_tolerance ||
-        (abs (priv->pointer_x - event->x) > TOLERANCE_FADE ||
-         abs (priv->pointer_y - event->y) > TOLERANCE_FADE))
+    if (!priv->tolerance ||
+        (abs (priv->pointer.x - event->x) > TOLERANCE_FADE ||
+         abs (priv->pointer.y - event->y) > TOLERANCE_FADE))
       {
-        priv->use_tolerance = FALSE;
+        priv->tolerance = FALSE;
         priv->source_id = g_timeout_add (TIMEOUT_FADE_OUT,
                                          timeout_fade_out_cb,
                                          thumb);
@@ -920,8 +922,8 @@
   if (priv->event & OS_EVENT_BUTTON_PRESS &&
       !(priv->event & OS_EVENT_MOTION_NOTIFY))
     {
-      if (abs (priv->pointer_x_root - event->x_root) <= TOLERANCE_MOTION &&
-          abs (priv->pointer_y_root - event->y_root) <= TOLERANCE_MOTION)
+      if (abs (priv->pointer_root.x - event->x_root) <= TOLERANCE_MOTION &&
+          abs (priv->pointer_root.y - event->y_root) <= TOLERANCE_MOTION)
         return FALSE;
 
       priv->event |= OS_EVENT_MOTION_NOTIFY;
@@ -977,6 +979,13 @@
   /* If started, stop the fade-out. */
   os_animation_stop (priv->animation, fade_out_stop_cb);
 
+  if (priv->event & OS_EVENT_MOTION_NOTIFY)
+    {
+      priv->event &= ~(OS_EVENT_MOTION_NOTIFY);
+
+      gtk_widget_queue_draw (widget);
+    }
+
   return FALSE;
 }
 
@@ -991,7 +1000,7 @@
 
   priv->event = OS_EVENT_NONE;
 
-  priv->use_tolerance = FALSE;
+  priv->tolerance = FALSE;
 
   if (priv->grabbed_widget != NULL && gtk_widget_get_mapped (priv->grabbed_widget))
     gtk_grab_add (priv->grabbed_widget);