clutter/actor-box: Allow marking boxes as uninitialized

Add support for an artificial UNINITIALIZED marking for ClutterActorBox,
done by setting the boxes origin to Infinity and its size to -Infinity.
That is a value that's considered an invalid allocation by Clutter and
which can never be set by sane code.

This will allow setting the allocation of ClutterActors to an
UNINITIALIZED box when creating actors or when removing them from the
scenegraph and makes it possible to explicitely detect uninitialized
allocations, which is useful in a few cases.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1290
This commit is contained in:
Jonas Dreßler 2020-06-06 12:55:07 +02:00
parent 932340a989
commit 0bfb995bff
2 changed files with 43 additions and 0 deletions

View File

@ -615,6 +615,32 @@ clutter_actor_box_scale (ClutterActorBox *box,
box->y2 *= scale;
}
/**
* clutter_actor_box_is_initialized:
* @box: a #ClutterActorBox
*
* Checks if @box has been initialized, a #ClutterActorBox is uninitialized
* if it has a size of -1 at an origin of 0, 0.
*
* Returns: %TRUE if the box is uninitialized, %FALSE if it isn't
*/
gboolean
clutter_actor_box_is_initialized (ClutterActorBox *box)
{
gboolean x1_uninitialized, x2_uninitialized;
gboolean y1_uninitialized, y2_uninitialized;
g_return_val_if_fail (box != NULL, TRUE);
x1_uninitialized = isinf (box->x1);
x2_uninitialized = isinf (box->x2) && signbit (box->x2);
y1_uninitialized = isinf (box->y1);
y2_uninitialized = isinf (box->y2) && signbit (box->y2);
return !x1_uninitialized || !x2_uninitialized ||
!y1_uninitialized || !y2_uninitialized;
}
G_DEFINE_BOXED_TYPE_WITH_CODE (ClutterActorBox, clutter_actor_box,
clutter_actor_box_copy,
clutter_actor_box_free,

View File

@ -174,6 +174,20 @@ struct _ClutterActorBox
*/
#define CLUTTER_ACTOR_BOX_INIT_ZERO CLUTTER_ACTOR_BOX_INIT (0.f, 0.f, 0.f, 0.f)
/**
* CLUTTER_ACTOR_BOX_UNINITIALIZED:
*
* A simple macro for creating a #ClutterActorBox with a size of -1 when
* declaring it, e.g.:
*
* |[
* ClutterActorBox box = CLUTTER_ACTOR_BOX_UNINITIALIZED;
* ]|
*/
#define CLUTTER_ACTOR_BOX_UNINITIALIZED { .x1 = INFINITY, .y1 = INFINITY, .x2 = -INFINITY, .y2 = -INFINITY }
CLUTTER_EXPORT
GType clutter_actor_box_get_type (void) G_GNUC_CONST;
CLUTTER_EXPORT
@ -252,6 +266,9 @@ CLUTTER_EXPORT
void clutter_actor_box_scale (ClutterActorBox *box,
gfloat scale);
CLUTTER_EXPORT
gboolean clutter_actor_box_is_initialized (ClutterActorBox *box);
/**
* ClutterKnot:
* @x: X coordinate of the knot