Adding upstream version 43.9.upstream/43.9upstream

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

1 files changed, 1013 insertions, 0 deletions

diff --git a/src/st/st-adjustment.c b/src/st/st-adjustment.c
new file mode 100644
index 0000000..d2baa66
--- /dev/null
+++ b/src/st/st-adjustment.c
@@ -0,0 +1,1013 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * st-adjustment.c: Adjustment object
+ *
+ * Copyright 2008 OpenedHand
+ * Copyright 2009 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * SECTION:st-adjustment
+ * @short_description: A GObject representing an adjustable bounded value
+ *
+ * The #StAdjustment object represents a range of values bounded between a
+ * minimum and maximum, together with step and page increments and a page size.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib-object.h>
+#include <clutter/clutter.h>
+#include <math.h>
+
+#include "st-adjustment.h"
+#include "st-private.h"
+
+typedef struct _StAdjustmentPrivate StAdjustmentPrivate;
+
+struct _StAdjustmentPrivate
+{
+  ClutterActor *actor;
+
+  /* Do not sanity-check values while constructing,
+   * not all properties may be set yet. */
+  guint is_constructing : 1;
+
+  GHashTable *transitions;
+
+  gdouble  lower;
+  gdouble  upper;
+  gdouble  value;
+  gdouble  step_increment;
+  gdouble  page_increment;
+  gdouble  page_size;
+};
+
+static void animatable_iface_init (ClutterAnimatableInterface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (StAdjustment, st_adjustment, G_TYPE_OBJECT,
+                         G_ADD_PRIVATE (StAdjustment)
+                         G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_ANIMATABLE,
+                                                animatable_iface_init));
+
+enum
+{
+  PROP_0,
+
+  PROP_ACTOR,
+  PROP_LOWER,
+  PROP_UPPER,
+  PROP_VALUE,
+  PROP_STEP_INC,
+  PROP_PAGE_INC,
+  PROP_PAGE_SIZE,
+
+  N_PROPS
+};
+
+static GParamSpec *props[N_PROPS] = { NULL, };
+
+enum
+{
+  CHANGED,
+
+  LAST_SIGNAL
+};
+
+static guint signals[LAST_SIGNAL] = { 0, };
+
+typedef struct _TransitionClosure
+{
+  StAdjustment *adjustment;
+  ClutterTransition *transition;
+  char *name;
+  gulong completed_id;
+} TransitionClosure;
+
+static gboolean st_adjustment_set_lower          (StAdjustment *adjustment,
+                                                  gdouble       lower);
+static gboolean st_adjustment_set_upper          (StAdjustment *adjustment,
+                                                  gdouble       upper);
+static gboolean st_adjustment_set_step_increment (StAdjustment *adjustment,
+                                                  gdouble       step);
+static gboolean st_adjustment_set_page_increment (StAdjustment *adjustment,
+                                                  gdouble       page);
+static gboolean st_adjustment_set_page_size      (StAdjustment *adjustment,
+                                                  gdouble       size);
+
+static ClutterActor *
+st_adjustment_get_actor (ClutterAnimatable *animatable)
+{
+  StAdjustment *adjustment = ST_ADJUSTMENT (animatable);
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  g_warn_if_fail (priv->actor);
+
+  return priv->actor;
+}
+
+static void
+animatable_iface_init (ClutterAnimatableInterface *iface)
+{
+  iface->get_actor = st_adjustment_get_actor;
+}
+
+static void
+st_adjustment_constructed (GObject *object)
+{
+  GObjectClass *g_class;
+  StAdjustment *self = ST_ADJUSTMENT (object);
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (self);
+
+  g_class = G_OBJECT_CLASS (st_adjustment_parent_class);
+  /* The docs say we're suppose to chain up, but would crash without
+   * some extra care. */
+  if (g_class && g_class->constructed &&
+      g_class->constructed != st_adjustment_constructed)
+    {
+      g_class->constructed (object);
+    }
+
+  priv->is_constructing = FALSE;
+  st_adjustment_clamp_page (self, priv->lower, priv->upper);
+}
+
+static void
+st_adjustment_get_property (GObject    *gobject,
+                            guint       prop_id,
+                            GValue     *value,
+                            GParamSpec *pspec)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (ST_ADJUSTMENT (gobject));
+
+  switch (prop_id)
+    {
+    case PROP_ACTOR:
+      g_value_set_object (value, priv->actor);
+      break;
+
+    case PROP_LOWER:
+      g_value_set_double (value, priv->lower);
+      break;
+
+    case PROP_UPPER:
+      g_value_set_double (value, priv->upper);
+      break;
+
+    case PROP_VALUE:
+      g_value_set_double (value, priv->value);
+      break;
+
+    case PROP_STEP_INC:
+      g_value_set_double (value, priv->step_increment);
+      break;
+
+    case PROP_PAGE_INC:
+      g_value_set_double (value, priv->page_increment);
+      break;
+
+    case PROP_PAGE_SIZE:
+      g_value_set_double (value, priv->page_size);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+actor_destroyed (gpointer  user_data,
+                 GObject  *where_the_object_was)
+{
+  StAdjustment *adj = ST_ADJUSTMENT (user_data);
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adj);
+
+  priv->actor = NULL;
+
+  g_object_notify_by_pspec (G_OBJECT (adj), props[PROP_ACTOR]);
+}
+
+static void
+st_adjustment_set_actor (StAdjustment *adj,
+                         ClutterActor *actor)
+{
+  StAdjustmentPrivate *priv;
+
+  priv = st_adjustment_get_instance_private (adj);
+
+  if (priv->actor == actor)
+    return;
+
+  if (priv->actor)
+    g_object_weak_unref (G_OBJECT (priv->actor), actor_destroyed, adj);
+  priv->actor = actor;
+  if (priv->actor)
+    g_object_weak_ref (G_OBJECT (priv->actor), actor_destroyed, adj);
+
+  g_object_notify_by_pspec (G_OBJECT (adj), props[PROP_ACTOR]);
+}
+
+static void
+st_adjustment_set_property (GObject      *gobject,
+                            guint         prop_id,
+                            const GValue *value,
+                            GParamSpec   *pspec)
+{
+  StAdjustment *adj = ST_ADJUSTMENT (gobject);
+
+  switch (prop_id)
+    {
+    case PROP_ACTOR:
+      st_adjustment_set_actor (adj, g_value_get_object (value));
+      break;
+
+    case PROP_LOWER:
+      st_adjustment_set_lower (adj, g_value_get_double (value));
+      break;
+
+    case PROP_UPPER:
+      st_adjustment_set_upper (adj, g_value_get_double (value));
+      break;
+
+    case PROP_VALUE:
+      st_adjustment_set_value (adj, g_value_get_double (value));
+      break;
+
+    case PROP_STEP_INC:
+      st_adjustment_set_step_increment (adj, g_value_get_double (value));
+      break;
+
+    case PROP_PAGE_INC:
+      st_adjustment_set_page_increment (adj, g_value_get_double (value));
+      break;
+
+    case PROP_PAGE_SIZE:
+      st_adjustment_set_page_size (adj, g_value_get_double (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+st_adjustment_dispose (GObject *object)
+{
+  StAdjustmentPrivate *priv;
+
+  priv = st_adjustment_get_instance_private (ST_ADJUSTMENT (object));
+  if (priv->actor)
+    {
+      g_object_weak_unref (G_OBJECT (priv->actor), actor_destroyed, object);
+      priv->actor = NULL;
+    }
+  g_clear_pointer (&priv->transitions, g_hash_table_unref);
+
+  G_OBJECT_CLASS (st_adjustment_parent_class)->dispose (object);
+}
+
+static void
+st_adjustment_class_init (StAdjustmentClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->constructed = st_adjustment_constructed;
+  object_class->get_property = st_adjustment_get_property;
+  object_class->set_property = st_adjustment_set_property;
+  object_class->dispose = st_adjustment_dispose;
+
+  /**
+   * StAdjustment:actor:
+   *
+   * If the adjustment is used as #ClutterAnimatable for a
+   * #ClutterPropertyTransition, this property is used to determine which
+   * monitor should drive the animation.
+   */
+  props[PROP_ACTOR] =
+    g_param_spec_object ("actor", "Actor", "Actor",
+                         CLUTTER_TYPE_ACTOR,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StAdjustment:lower:
+   *
+   * The minimum value of the adjustment.
+   */
+  props[PROP_LOWER] =
+    g_param_spec_double ("lower", "Lower", "Lower bound",
+                         -G_MAXDOUBLE,  G_MAXDOUBLE, 0.0,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StAdjustment:upper:
+   *
+   * The maximum value of the adjustment.
+   *
+   * Note that values will be restricted by `upper - page-size` if
+   * #StAdjustment:page-size is non-zero.
+   */
+  props[PROP_UPPER] =
+    g_param_spec_double ("upper", "Upper", "Upper bound",
+                         -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StAdjustment:value:
+   *
+   * The value of the adjustment.
+   */
+  props[PROP_VALUE] =
+    g_param_spec_double ("value", "Value", "Current value",
+                         -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StAdjustment:step-increment:
+   *
+   * The step increment of the adjustment.
+   */
+  props[PROP_STEP_INC] =
+    g_param_spec_double ("step-increment", "Step Increment", "Step increment",
+                         0.0, G_MAXDOUBLE, 0.0,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StAdjustment:page-increment:
+   *
+   * The page increment of the adjustment.
+   */
+  props[PROP_PAGE_INC] =
+    g_param_spec_double ("page-increment", "Page Increment", "Page increment",
+                         0.0, G_MAXDOUBLE, 0.0,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StAdjustment:page-size:
+   *
+   * The page size of the adjustment.
+   *
+   * Note that the page-size is irrelevant and should be set to zero if the
+   * adjustment is used for a simple scalar value.
+   */
+  props[PROP_PAGE_SIZE] =
+    g_param_spec_double ("page-size", "Page Size", "Page size",
+                         0.0, G_MAXDOUBLE, 0.0,
+                         ST_PARAM_READWRITE |
+                         G_PARAM_CONSTRUCT |
+                         G_PARAM_EXPLICIT_NOTIFY);
+
+  g_object_class_install_properties (object_class, N_PROPS, props);
+
+  /**
+   * StAdjustment::changed:
+   * @self: the #StAdjustment
+   *
+   * Emitted when any of the adjustment properties have changed, except for
+   * #StAdjustment:value.
+   */
+  signals[CHANGED] =
+    g_signal_new ("changed",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (StAdjustmentClass, changed),
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 0);
+}
+
+static void
+st_adjustment_init (StAdjustment *self)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (self);
+  priv->is_constructing = TRUE;
+}
+
+/**
+ * st_adjustment_new:
+ * @actor: (nullable): a #ClutterActor
+ * @value: the initial value
+ * @lower: the minimum value
+ * @upper: the maximum value
+ * @step_increment: the step increment
+ * @page_increment: the page increment
+ * @page_size: the page size
+ *
+ * Creates a new #StAdjustment
+ *
+ * Returns: a new #StAdjustment
+ */
+StAdjustment *
+st_adjustment_new (ClutterActor *actor,
+                   gdouble value,
+                   gdouble lower,
+                   gdouble upper,
+                   gdouble step_increment,
+                   gdouble page_increment,
+                   gdouble page_size)
+{
+  return g_object_new (ST_TYPE_ADJUSTMENT,
+                       "actor", actor,
+                       "value", value,
+                       "lower", lower,
+                       "upper", upper,
+                       "step-increment", step_increment,
+                       "page-increment", page_increment,
+                       "page-size", page_size,
+                       NULL);
+}
+
+/**
+ * st_adjustment_get_value:
+ * @adjustment: a #StAdjustment
+ *
+ * Gets the current value of the adjustment. See st_adjustment_set_value().
+ *
+ * Returns: The current value of the adjustment
+ */
+gdouble
+st_adjustment_get_value (StAdjustment *adjustment)
+{
+  g_return_val_if_fail (ST_IS_ADJUSTMENT (adjustment), 0);
+
+  return ((StAdjustmentPrivate *)st_adjustment_get_instance_private (adjustment))->value;
+}
+
+/**
+ * st_adjustment_set_value:
+ * @adjustment: a #StAdjustment
+ * @value: the new value
+ *
+ * Sets the #StAdjustment value. The value is clamped to lie between
+ * #StAdjustment:lower and #StAdjustment:upper - #StAdjustment:page-size.
+ */
+void
+st_adjustment_set_value (StAdjustment *adjustment,
+                         gdouble       value)
+{
+  StAdjustmentPrivate *priv;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  /* Defer clamp until after construction. */
+  if (!priv->is_constructing)
+    {
+      value = CLAMP (value,
+                     priv->lower,
+                     MAX (priv->lower, priv->upper - priv->page_size));
+    }
+
+  if (priv->value != value)
+    {
+      priv->value = value;
+
+      g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_VALUE]);
+    }
+}
+
+/**
+ * st_adjustment_clamp_page:
+ * @adjustment: a #StAdjustment
+ * @lower: the lower value
+ * @upper: the upper value
+ *
+ * Set #StAdjustment:value to a value clamped between @lower and @upper. The
+ * clamping described by st_adjustment_set_value() still applies.
+ */
+void
+st_adjustment_clamp_page (StAdjustment *adjustment,
+                          gdouble       lower,
+                          gdouble       upper)
+{
+  StAdjustmentPrivate *priv;
+  gboolean changed;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  lower = CLAMP (lower, priv->lower, priv->upper - priv->page_size);
+  upper = CLAMP (upper, priv->lower + priv->page_size, priv->upper);
+
+  changed = FALSE;
+
+  if (priv->value + priv->page_size > upper)
+    {
+      priv->value = upper - priv->page_size;
+      changed = TRUE;
+    }
+
+  if (priv->value < lower)
+    {
+      priv->value = lower;
+      changed = TRUE;
+    }
+
+  if (changed)
+    g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_VALUE]);
+}
+
+/**
+ * st_adjustment_set_lower:
+ * @adjustment: a #StAdjustment
+ * @lower: the new minimum value
+ *
+ * Sets the minimum value of the adjustment.
+ *
+ * When setting multiple adjustment properties via their individual
+ * setters, multiple #GObject::notify and #StAdjustment::changed
+ * signals will be emitted. However, it’s possible to compress the
+ * #GObject::notify signals into one by calling
+ * g_object_freeze_notify() and g_object_thaw_notify() around the
+ * calls to the individual setters.
+ *
+ * Alternatively, using st_adjustment_set_values() will compress both
+ * #GObject::notify and #StAdjustment::changed emissions.
+ */
+static gboolean
+st_adjustment_set_lower (StAdjustment *adjustment,
+                         gdouble       lower)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->lower != lower)
+    {
+      priv->lower = lower;
+
+      g_signal_emit (adjustment, signals[CHANGED], 0);
+
+      g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_LOWER]);
+
+      /* Defer clamp until after construction. */
+      if (!priv->is_constructing)
+        st_adjustment_clamp_page (adjustment, priv->lower, priv->upper);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+/**
+ * st_adjustment_set_upper:
+ * @adjustment: a #StAdjustment
+ * @upper: the new maximum value
+ *
+ * Sets the maximum value of the adjustment.
+ *
+ * Note that values will be restricted by `upper - page-size`
+ * if the page-size property is nonzero.
+ *
+ * See st_adjustment_set_lower() about how to compress multiple
+ * signal emissions when setting multiple adjustment properties.
+ *
+ * Returns: %TRUE if the value was changed
+ */
+static gboolean
+st_adjustment_set_upper (StAdjustment *adjustment,
+                         gdouble       upper)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->upper != upper)
+    {
+      priv->upper = upper;
+
+      g_signal_emit (adjustment, signals[CHANGED], 0);
+
+      g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_UPPER]);
+
+      /* Defer clamp until after construction. */
+      if (!priv->is_constructing)
+        st_adjustment_clamp_page (adjustment, priv->lower, priv->upper);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+/**
+ * st_adjustment_set_step_increment:
+ * @adjustment: a #StAdjustment
+ * @step: the new step increment
+ *
+ * Sets the step increment of the adjustment.
+ *
+ * See st_adjustment_set_lower() about how to compress multiple
+ * signal emissions when setting multiple adjustment properties.
+ *
+ * Returns: %TRUE if the value was changed
+ */
+static gboolean
+st_adjustment_set_step_increment (StAdjustment *adjustment,
+                                  gdouble       step)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->step_increment != step)
+    {
+      priv->step_increment = step;
+
+      g_signal_emit (adjustment, signals[CHANGED], 0);
+
+      g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_STEP_INC]);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+/**
+ * st_adjustment_set_page_increment:
+ * @adjustment: a #StAdjustment
+ * @page: the new page increment
+ *
+ * Sets the page increment of the adjustment.
+ *
+ * See st_adjustment_set_lower() about how to compress multiple
+ * signal emissions when setting multiple adjustment properties.
+ *
+ * Returns: %TRUE if the value was changed
+ */
+static gboolean
+st_adjustment_set_page_increment (StAdjustment *adjustment,
+                                  gdouble       page)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->page_increment != page)
+    {
+      priv->page_increment = page;
+
+      g_signal_emit (adjustment, signals[CHANGED], 0);
+
+      g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_PAGE_INC]);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+/**
+ * st_adjustment_set_page_size:
+ * @adjustment: a #StAdjustment
+ * @size: the new page size
+ *
+ * Sets the page size of the adjustment.
+ *
+ * See st_adjustment_set_lower() about how to compress multiple
+ * signal emissions when setting multiple adjustment properties.
+ *
+ * Returns: %TRUE if the value was changed
+ */
+static gboolean
+st_adjustment_set_page_size (StAdjustment *adjustment,
+                             gdouble       size)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->page_size != size)
+    {
+      priv->page_size = size;
+
+      g_signal_emit (adjustment, signals[CHANGED], 0);
+
+      g_object_notify_by_pspec (G_OBJECT (adjustment), props[PROP_PAGE_SIZE]);
+
+      /* We'll explicitly clamp after construction. */
+      if (!priv->is_constructing)
+        st_adjustment_clamp_page (adjustment, priv->lower, priv->upper);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+/**
+ * st_adjustment_set_values:
+ * @adjustment: a #StAdjustment
+ * @value: the new value
+ * @lower: the new minimum value
+ * @upper: the new maximum value
+ * @step_increment: the new step increment
+ * @page_increment: the new page increment
+ * @page_size: the new page size
+ *
+ * Sets all properties of the adjustment at once.
+ *
+ * Use this function to avoid multiple emissions of the #GObject::notify and
+ * #StAdjustment::changed signals. See st_adjustment_set_lower() for an
+ * alternative way of compressing multiple emissions of #GObject::notify into
+ * one.
+ */
+void
+st_adjustment_set_values (StAdjustment *adjustment,
+                          gdouble       value,
+                          gdouble       lower,
+                          gdouble       upper,
+                          gdouble       step_increment,
+                          gdouble       page_increment,
+                          gdouble       page_size)
+{
+  StAdjustmentPrivate *priv;
+  gboolean emit_changed = FALSE;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+  g_return_if_fail (page_size >= 0 && page_size <= G_MAXDOUBLE);
+  g_return_if_fail (step_increment >= 0 && step_increment <= G_MAXDOUBLE);
+  g_return_if_fail (page_increment >= 0 && page_increment <= G_MAXDOUBLE);
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  emit_changed = FALSE;
+
+  g_object_freeze_notify (G_OBJECT (adjustment));
+
+  emit_changed |= st_adjustment_set_lower (adjustment, lower);
+  emit_changed |= st_adjustment_set_upper (adjustment, upper);
+  emit_changed |= st_adjustment_set_step_increment (adjustment, step_increment);
+  emit_changed |= st_adjustment_set_page_increment (adjustment, page_increment);
+  emit_changed |= st_adjustment_set_page_size (adjustment, page_size);
+
+  if (value != priv->value)
+    {
+      st_adjustment_set_value (adjustment, value);
+      emit_changed = TRUE;
+    }
+
+  if (emit_changed)
+    g_signal_emit (G_OBJECT (adjustment), signals[CHANGED], 0);
+
+  g_object_thaw_notify (G_OBJECT (adjustment));
+}
+
+/**
+ * st_adjustment_get_values:
+ * @adjustment: an #StAdjustment
+ * @value: (out) (optional): the current value
+ * @lower: (out) (optional): the lower bound
+ * @upper: (out) (optional): the upper bound
+ * @step_increment: (out) (optional): the step increment
+ * @page_increment: (out) (optional): the page increment
+ * @page_size: (out) (optional): the page size
+ *
+ * Gets all of @adjustment's values at once.
+ */
+void
+st_adjustment_get_values (StAdjustment *adjustment,
+                          gdouble      *value,
+                          gdouble      *lower,
+                          gdouble      *upper,
+                          gdouble      *step_increment,
+                          gdouble      *page_increment,
+                          gdouble      *page_size)
+{
+  StAdjustmentPrivate *priv;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  if (lower)
+    *lower = priv->lower;
+
+  if (upper)
+    *upper = priv->upper;
+
+  if (value)
+    *value = st_adjustment_get_value (adjustment);
+
+  if (step_increment)
+    *step_increment = priv->step_increment;
+
+  if (page_increment)
+    *page_increment = priv->page_increment;
+
+  if (page_size)
+    *page_size = priv->page_size;
+}
+
+/**
+ * st_adjustment_adjust_for_scroll_event:
+ * @adjustment: An #StAdjustment
+ * @delta: A delta, retrieved directly from clutter_event_get_scroll_delta()
+ *   or similar.
+ *
+ * Adjusts the adjustment using delta values from a scroll event.
+ * You should use this instead of using st_adjustment_set_value()
+ * as this method will tweak the values directly using the same
+ * math as GTK+, to ensure that scrolling is consistent across
+ * the environment.
+ */
+void
+st_adjustment_adjust_for_scroll_event (StAdjustment *adjustment,
+                                       gdouble       delta)
+{
+  StAdjustmentPrivate *priv;
+  gdouble new_value, scroll_unit;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  scroll_unit = pow (priv->page_size, 2.0 / 3.0);
+
+  new_value = priv->value + delta * scroll_unit;
+  st_adjustment_set_value (adjustment, new_value);
+}
+
+static void
+transition_closure_free (gpointer data)
+{
+  TransitionClosure *clos;
+  ClutterTimeline *timeline;
+
+  if (G_UNLIKELY (data == NULL))
+    return;
+
+  clos = data;
+  timeline = CLUTTER_TIMELINE (clos->transition);
+
+  g_clear_signal_handler (&clos->completed_id, clos->transition);
+
+  if (clutter_timeline_is_playing (timeline))
+    clutter_timeline_stop (timeline);
+
+  g_object_unref (clos->transition);
+  g_free (clos->name);
+  g_free (clos);
+}
+
+static void
+remove_transition (StAdjustment *adjustment,
+                   const char   *name)
+{
+  StAdjustmentPrivate *priv = st_adjustment_get_instance_private (adjustment);
+
+  g_hash_table_remove (priv->transitions, name);
+
+  if (g_hash_table_size (priv->transitions) == 0)
+    g_clear_pointer (&priv->transitions, g_hash_table_unref);
+}
+
+static void
+on_transition_stopped (ClutterTransition *transition,
+                       gboolean           is_finished,
+                       TransitionClosure *clos)
+{
+  StAdjustment *adjustment = clos->adjustment;
+
+  if (!clutter_transition_get_remove_on_complete (transition))
+    return;
+
+  /* Take a reference, because removing the closure will
+   * release the reference on the transition, and we want
+   * it to survive the signal emission; ClutterTransition's
+   * own ::stopped signal closure will release it after all
+   * other handlers have run.
+   */
+  g_object_ref (transition);
+
+  remove_transition (adjustment, clos->name);
+}
+
+/**
+ * st_adjustment_get_transition:
+ * @adjustment: a #StAdjustment
+ * @name: a transition name
+ *
+ * Get the #ClutterTransition for @name previously added with
+ * st_adjustment_add_transition() or %NULL if not found.
+ *
+ * Returns: (transfer none) (nullable): a #ClutterTransition
+ */
+ClutterTransition *
+st_adjustment_get_transition (StAdjustment *adjustment,
+                              const char   *name)
+{
+  StAdjustmentPrivate *priv;
+  TransitionClosure *clos;
+
+  g_return_val_if_fail (ST_IS_ADJUSTMENT (adjustment), NULL);
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->transitions == NULL)
+    return NULL;
+
+  clos = g_hash_table_lookup (priv->transitions, name);
+  if (clos == NULL)
+    return NULL;
+
+  return clos->transition;
+}
+
+/**
+ * st_adjustment_add_transition:
+ * @adjustment: a #StAdjustment
+ * @name: a unique name for the transition
+ * @transition: a #ClutterTransition
+ *
+ * Add a #ClutterTransition for the adjustment. If the transition stops, it will
+ * be automatically removed if #ClutterTransition:remove-on-complete is %TRUE.
+ */
+void
+st_adjustment_add_transition (StAdjustment      *adjustment,
+                              const char        *name,
+                              ClutterTransition *transition)
+{
+  StAdjustmentPrivate *priv;
+  TransitionClosure *clos;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+  g_return_if_fail (name != NULL);
+  g_return_if_fail (CLUTTER_IS_TRANSITION (transition));
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->transitions == NULL)
+    priv->transitions = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                               NULL,
+                                               transition_closure_free);
+
+  if (g_hash_table_lookup (priv->transitions, name) != NULL)
+    {
+      g_warning ("A transition with name '%s' already exists for "
+                 "adjustment '%p'", name, adjustment);
+      return;
+    }
+
+  clutter_transition_set_animatable (transition, CLUTTER_ANIMATABLE (adjustment));
+
+  clos = g_new (TransitionClosure, 1);
+  clos->adjustment = adjustment;
+  clos->transition = g_object_ref (transition);
+  clos->name = g_strdup (name);
+  clos->completed_id = g_signal_connect (transition, "stopped",
+                                         G_CALLBACK (on_transition_stopped),
+                                         clos);
+
+  g_hash_table_insert (priv->transitions, clos->name, clos);
+  clutter_timeline_start (CLUTTER_TIMELINE (transition));
+}
+
+/**
+ * st_adjusmtent_remove_transition:
+ * @adjustment: a #StAdjustment
+ * @name: the name of the transition to remove
+ *
+ * Remove a #ClutterTransition previously added by st_adjustment_add_transtion()
+ * with @name.
+ */
+void
+st_adjustment_remove_transition (StAdjustment *adjustment,
+                                 const char   *name)
+{
+  StAdjustmentPrivate *priv;
+  TransitionClosure *clos;
+
+  g_return_if_fail (ST_IS_ADJUSTMENT (adjustment));
+  g_return_if_fail (name != NULL);
+
+  priv = st_adjustment_get_instance_private (adjustment);
+
+  if (priv->transitions == NULL)
+    return;
+
+  clos = g_hash_table_lookup (priv->transitions, name);
+  if (clos == NULL)
+    return;
+
+  remove_transition (adjustment, name);
+}