Simplify handling of adjustments

The relationship between adjustments and scrollbars and
scrollable widgets was much more complex than it needed to be.

StScrollView: Have the scroll view own a pair of adjustments,
  set them on the child on add(), remove unnecessary
  change notification signal connections.
StBoxLayout: Remove auto-create of adjustments, just take the
  adjustments from the scrollbars and set them on the scrollable
  child. Notify for hadjustment/vadjustment properties.
StScrollBar: Notify adjustment property.
StScrollable: Document how adjustment setting works.

https://bugzilla.gnome.org/show_bug.cgi?id=611740
This commit is contained in:
Owen W. Taylor 2010-03-10 18:32:10 -05:00
parent 163b2d0403
commit 89173544d4
4 changed files with 84 additions and 230 deletions

View File

@ -111,6 +111,8 @@ scrollable_set_adjustments (StScrollable *scrollable,
{
StBoxLayoutPrivate *priv = ST_BOX_LAYOUT (scrollable)->priv;
g_object_freeze_notify (G_OBJECT (scrollable));
if (hadjustment != priv->hadjustment)
{
if (priv->hadjustment)
@ -130,6 +132,7 @@ scrollable_set_adjustments (StScrollable *scrollable,
}
priv->hadjustment = hadjustment;
g_object_notify (G_OBJECT (scrollable), "hadjustment");
}
if (vadjustment != priv->vadjustment)
@ -151,7 +154,10 @@ scrollable_set_adjustments (StScrollable *scrollable,
}
priv->vadjustment = vadjustment;
g_object_notify (G_OBJECT (scrollable), "vadjustment");
}
g_object_thaw_notify (G_OBJECT (scrollable));
}
static void
@ -160,82 +166,14 @@ scrollable_get_adjustments (StScrollable *scrollable,
StAdjustment **vadjustment)
{
StBoxLayoutPrivate *priv;
ClutterActor *actor, *stage;
priv = (ST_BOX_LAYOUT (scrollable))->priv;
actor = CLUTTER_ACTOR (scrollable);
stage = clutter_actor_get_stage (actor);
if (hadjustment)
{
if (priv->hadjustment)
*hadjustment = priv->hadjustment;
else
{
StAdjustment *adjustment;
gdouble width, stage_width, increment;
if (stage)
{
width = clutter_actor_get_width (actor);
stage_width = clutter_actor_get_width (stage);
increment = MAX (1.0, MIN (stage_width, width));
}
else
{
width = increment = 1.0;
}
adjustment = st_adjustment_new (0,
0,
width,
1.0,
increment,
increment);
scrollable_set_adjustments (scrollable,
adjustment,
priv->vadjustment);
*hadjustment = adjustment;
}
}
if (priv->hadjustment)
*hadjustment = priv->hadjustment;
if (vadjustment)
{
if (priv->vadjustment)
*vadjustment = priv->vadjustment;
else
{
StAdjustment *adjustment;
gdouble height, stage_height, increment;
if (stage)
{
height = clutter_actor_get_height (actor);
stage_height = clutter_actor_get_height (stage);
increment = MAX (1.0, MIN (stage_height, height));
}
else
{
height = increment = 1.0;
}
adjustment = st_adjustment_new (0,
0,
height,
1.0,
increment,
increment);
scrollable_set_adjustments (scrollable,
priv->hadjustment,
adjustment);
*vadjustment = adjustment;
}
}
*vadjustment = priv->vadjustment;
}

View File

@ -1143,6 +1143,10 @@ st_scroll_bar_set_adjustment (StScrollBar *bar,
g_return_if_fail (ST_IS_SCROLL_BAR (bar));
priv = bar->priv;
if (adjustment == priv->adjustment)
return;
if (priv->adjustment)
{
g_signal_handlers_disconnect_by_func (priv->adjustment,
@ -1168,6 +1172,8 @@ st_scroll_bar_set_adjustment (StScrollBar *bar,
clutter_actor_queue_relayout (CLUTTER_ACTOR (bar));
}
g_object_notify (G_OBJECT (bar), "adjustment");
}
/**

View File

@ -91,11 +91,10 @@ struct _StScrollViewPrivate
*/
ClutterActor *child;
ClutterActor *hscroll;
ClutterActor *vscroll;
StAdjustment *hadjustment;
ClutterActor *hscroll;
StAdjustment *vadjustment;
ClutterActor *vscroll;
GtkPolicyType hscrollbar_policy;
GtkPolicyType vscrollbar_policy;
@ -165,7 +164,7 @@ update_shadow_visibility (StScrollView *scroll)
{
StScrollViewPrivate *priv = scroll->priv;
if (priv->vshadows && priv->vadjustment)
if (priv->vshadows)
{
gdouble value, lower, upper, page_size;
@ -272,6 +271,25 @@ st_scroll_view_dispose (GObject *object)
if (priv->hscroll)
clutter_actor_destroy (priv->hscroll);
/* For most reliable freeing of memory, an object with signals
* like StAdjustment should be explicitly disposed. Since we own
* the adjustments, we take care of that. This also disconnects
* the signal handlers that we established on creation.
*/
if (priv->hadjustment)
{
g_object_run_dispose (G_OBJECT (priv->hadjustment));
g_object_unref (priv->hadjustment);
priv->hadjustment = NULL;
}
if (priv->vadjustment)
{
g_object_run_dispose (G_OBJECT (priv->vadjustment));
g_object_unref (priv->vadjustment);
priv->hadjustment = NULL;
}
/* since it's impossible to get a handle to these actors, we can
* just directly unparent them and not go through destroy/remove */
if (priv->top_shadow)
@ -712,40 +730,30 @@ st_scroll_view_scroll_event (ClutterActor *self,
{
StScrollViewPrivate *priv = ST_SCROLL_VIEW (self)->priv;
gdouble lower, value, upper, step;
StAdjustment *vadjustment, *hadjustment;
/* don't handle scroll events if requested not to */
if (!priv->mouse_scroll)
return FALSE;
hadjustment = st_scroll_bar_get_adjustment (ST_SCROLL_BAR (priv->hscroll));
vadjustment = st_scroll_bar_get_adjustment (ST_SCROLL_BAR (priv->vscroll));
switch (event->direction)
{
case CLUTTER_SCROLL_UP:
case CLUTTER_SCROLL_DOWN:
if (vadjustment)
g_object_get (vadjustment,
"lower", &lower,
"step-increment", &step,
"value", &value,
"upper", &upper,
NULL);
else
return FALSE;
g_object_get (priv->vadjustment,
"lower", &lower,
"step-increment", &step,
"value", &value,
"upper", &upper,
NULL);
break;
case CLUTTER_SCROLL_LEFT:
case CLUTTER_SCROLL_RIGHT:
if (vadjustment)
g_object_get (hadjustment,
"lower", &lower,
"step-increment", &step,
"value", &value,
"upper", &upper,
NULL);
else
return FALSE;
g_object_get (priv->hadjustment,
"lower", &lower,
"step-increment", &step,
"value", &value,
"upper", &upper,
NULL);
break;
}
@ -755,25 +763,25 @@ st_scroll_view_scroll_event (ClutterActor *self,
if (value == lower)
return FALSE;
else
st_adjustment_set_value (vadjustment, value - step);
st_adjustment_set_value (priv->vadjustment, value - step);
break;
case CLUTTER_SCROLL_DOWN:
if (value == upper)
return FALSE;
else
st_adjustment_set_value (vadjustment, value + step);
st_adjustment_set_value (priv->vadjustment, value + step);
break;
case CLUTTER_SCROLL_LEFT:
if (value == lower)
return FALSE;
else
st_adjustment_set_value (hadjustment, value - step);
st_adjustment_set_value (priv->hadjustment, value - step);
break;
case CLUTTER_SCROLL_RIGHT:
if (value == upper)
return FALSE;
else
st_adjustment_set_value (hadjustment, value + step);
st_adjustment_set_value (priv->hadjustment, value + step);
break;
}
@ -855,14 +863,6 @@ st_scroll_view_class_init (StScrollViewClass *klass)
pspec);
}
static void
disconnect_hadjustment (StScrollView *scroll)
{
StScrollViewPrivate *priv = scroll->priv;
priv->hadjustment = NULL;
}
static void
child_adjustment_changed_cb (StAdjustment *adjustment,
StScrollView *scroll)
@ -878,80 +878,6 @@ child_adjustment_notify_value (GObject *gobject,
update_shadow_visibility (scroll);
}
static void
disconnect_vadjustment (StScrollView *scroll)
{
StScrollViewPrivate *priv = scroll->priv;
if (priv->vadjustment)
{
g_signal_handlers_disconnect_by_func (priv->vadjustment,
child_adjustment_notify_value,
scroll);
g_signal_handlers_disconnect_by_func (priv->vadjustment,
child_adjustment_changed_cb,
scroll);
priv->vadjustment = NULL;
}
}
static void
child_hadjustment_notify_cb (GObject *gobject,
GParamSpec *arg1,
StScrollView *scroll)
{
ClutterActor *actor = CLUTTER_ACTOR (gobject);
StScrollViewPrivate *priv = scroll->priv;
disconnect_hadjustment (scroll);
st_scrollable_get_adjustments (ST_SCROLLABLE (actor), &priv->hadjustment, NULL);
st_scroll_bar_set_adjustment (ST_SCROLL_BAR (priv->hscroll), priv->hadjustment);
if (priv->hadjustment)
{
/* Force scroll step if needed. */
if (priv->column_size_set)
{
g_object_set (priv->hadjustment,
"step-increment", priv->column_size,
NULL);
}
}
}
static void
child_vadjustment_notify_cb (GObject *gobject,
GParamSpec *arg1,
gpointer user_data)
{
StScrollView *scroll = ST_SCROLL_VIEW (user_data);
StScrollViewPrivate *priv = scroll->priv;
disconnect_vadjustment (scroll);
st_scrollable_get_adjustments (ST_SCROLLABLE (priv->child), NULL, &priv->vadjustment);
st_scroll_bar_set_adjustment (ST_SCROLL_BAR (priv->vscroll), priv->vadjustment);
if (priv->vadjustment)
{
/* Force scroll step if needed. */
if (priv->row_size_set)
{
g_object_set (priv->vadjustment,
"step-increment", priv->row_size,
NULL);
}
g_signal_connect (priv->vadjustment, "changed",
G_CALLBACK (child_adjustment_changed_cb), scroll);
g_signal_connect (priv->vadjustment, "notify::value",
G_CALLBACK (child_adjustment_notify_value), scroll);
}
update_shadow_visibility (scroll);
}
static void
st_scroll_view_init (StScrollView *self)
{
@ -960,8 +886,21 @@ st_scroll_view_init (StScrollView *self)
priv->hscrollbar_policy = GTK_POLICY_AUTOMATIC;
priv->vscrollbar_policy = GTK_POLICY_AUTOMATIC;
priv->hscroll = CLUTTER_ACTOR (st_scroll_bar_new (NULL));
priv->vscroll = g_object_new (ST_TYPE_SCROLL_BAR, "vertical", TRUE, NULL);
priv->hadjustment = g_object_new (ST_TYPE_ADJUSTMENT, NULL);
priv->hscroll = g_object_new (ST_TYPE_SCROLL_BAR,
"adjustment", priv->hadjustment,
"vertical", FALSE,
NULL);
priv->vadjustment = g_object_new (ST_TYPE_ADJUSTMENT, NULL);
g_signal_connect (priv->vadjustment, "changed",
G_CALLBACK (child_adjustment_changed_cb), self);
g_signal_connect (priv->vadjustment, "notify::value",
G_CALLBACK (child_adjustment_notify_value), self);
priv->vscroll = g_object_new (ST_TYPE_SCROLL_BAR,
"adjustment", priv->vadjustment,
"vertical", TRUE,
NULL);
clutter_actor_set_parent (priv->hscroll, CLUTTER_ACTOR (self));
clutter_actor_set_parent (priv->vscroll, CLUTTER_ACTOR (self));
@ -985,15 +924,8 @@ st_scroll_view_add (ClutterContainer *container,
/* chain up to StBin::add() */
st_scroll_view_parent_iface->add (container, actor);
/* Get adjustments for scroll-bars */
g_signal_connect (actor, "notify::hadjustment",
G_CALLBACK (child_hadjustment_notify_cb),
container);
g_signal_connect (actor, "notify::vadjustment",
G_CALLBACK (child_vadjustment_notify_cb),
container);
child_hadjustment_notify_cb (G_OBJECT (actor), NULL, self);
child_vadjustment_notify_cb (G_OBJECT (actor), NULL, self);
st_scrollable_set_adjustments (ST_SCROLLABLE (actor),
priv->hadjustment, priv->vadjustment);
}
else
{
@ -1018,15 +950,8 @@ st_scroll_view_remove (ClutterContainer *container,
/* chain up to StBin::remove() */
st_scroll_view_parent_iface->remove (container, actor);
disconnect_hadjustment (self);
disconnect_vadjustment (self);
g_signal_handlers_disconnect_by_func (priv->child,
child_hadjustment_notify_cb,
container);
g_signal_handlers_disconnect_by_func (priv->child,
child_vadjustment_notify_cb,
container);
st_scrollable_set_adjustments (ST_SCROLLABLE (priv->child),
NULL, NULL);
g_object_unref (priv->child);
priv->child = NULL;
@ -1122,14 +1047,11 @@ st_scroll_view_get_vscroll_bar (StScrollView *scroll)
gfloat
st_scroll_view_get_column_size (StScrollView *scroll)
{
StAdjustment *adjustment;
gdouble column_size;
g_return_val_if_fail (scroll, 0);
adjustment = st_scroll_bar_get_adjustment (
ST_SCROLL_BAR (scroll->priv->hscroll));
g_object_get (adjustment,
g_object_get (scroll->priv->hadjustment,
"step-increment", &column_size,
NULL);
@ -1140,8 +1062,6 @@ void
st_scroll_view_set_column_size (StScrollView *scroll,
gfloat column_size)
{
StAdjustment *adjustment;
g_return_if_fail (scroll);
if (column_size < 0)
@ -1154,27 +1074,20 @@ st_scroll_view_set_column_size (StScrollView *scroll,
scroll->priv->column_size_set = TRUE;
scroll->priv->column_size = column_size;
adjustment = st_scroll_bar_get_adjustment (
ST_SCROLL_BAR (scroll->priv->hscroll));
if (adjustment)
g_object_set (adjustment,
"step-increment", (gdouble) scroll->priv->column_size,
NULL);
g_object_set (scroll->priv->hadjustment,
"step-increment", (gdouble) scroll->priv->column_size,
NULL);
}
}
gfloat
st_scroll_view_get_row_size (StScrollView *scroll)
{
StAdjustment *adjustment;
gdouble row_size;
g_return_val_if_fail (scroll, 0);
adjustment = st_scroll_bar_get_adjustment (
ST_SCROLL_BAR (scroll->priv->vscroll));
g_object_get (adjustment,
g_object_get (scroll->priv->vadjustment,
"step-increment", &row_size,
NULL);
@ -1185,8 +1098,6 @@ void
st_scroll_view_set_row_size (StScrollView *scroll,
gfloat row_size)
{
StAdjustment *adjustment;
g_return_if_fail (scroll);
if (row_size < 0)
@ -1199,13 +1110,9 @@ st_scroll_view_set_row_size (StScrollView *scroll,
scroll->priv->row_size_set = TRUE;
scroll->priv->row_size = row_size;
adjustment = st_scroll_bar_get_adjustment (
ST_SCROLL_BAR (scroll->priv->vscroll));
if (adjustment)
g_object_set (adjustment,
"step-increment", (gdouble) scroll->priv->row_size,
NULL);
g_object_set (scroll->priv->vadjustment,
"step-increment", (gdouble) scroll->priv->row_size,
NULL);
}
}

View File

@ -33,7 +33,10 @@
*
* The interface contains methods for getting and setting the adjustments
* for scrolling; these adjustments will be used to hook the scrolled
* position up to scrollbars or other external controls.
* position up to scrollbars or other external controls. When a #StScrollable
* is added to a parent container, the parent container is responsible
* for setting the adjustments. The parent container then sets the adjustments
* back to %NULL when the scrollable is removed.
*
* For #StScrollable supporting height-for-width size negotation, size
* negotation works as follows: