mutter/clutter/clutter/clutter-align-constraint.c
Jonas Dreßler 77d359cdc3 clutter/align-constraint: Don't take source actors position into account
ClutterAlignConstraint currently assumes the source actor is positioned
in the same coordinate system as the actor it's attached to and
automatically offsets the adjusted allocation by the origin of the
source actor.

This behavior is only valid though in case the source actor is a sibling
of the constraint actor. If the source actor is somewhere else in the
actor tree, the behavior gets annoying because the constraint actor is
offset by (seemingly) random positions.

To fix this, stop offsetting the constraint actors allocation by the
position of the source.

To still make it possible to align the constraint actors origin with the
origin of the source, no longer override the origin of the allocation
in the AlignConstraint. This allows users to align the origin using a
BindConstraint, binding the actor position to the position of the
source, which is more flexible and also more elegant.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/737
2020-06-10 19:20:32 +00:00

641 lines
19 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2010 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that 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 library. If not, see <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* SECTION:clutter-align-constraint
* @Title: ClutterAlignConstraint
* @Short_Description: A constraint aligning the position of an actor
*
* #ClutterAlignConstraint is a #ClutterConstraint that aligns the position
* of the #ClutterActor to which it is applied to the size of another
* #ClutterActor using an alignment factor
*
* #ClutterAlignConstraint is available since Clutter 1.4
*/
#include "clutter-build-config.h"
#include "clutter-align-constraint.h"
#include "clutter-actor-meta-private.h"
#include "clutter-actor-private.h"
#include "clutter-constraint.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-private.h"
#include <math.h>
#define CLUTTER_ALIGN_CONSTRAINT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), CLUTTER_TYPE_ALIGN_CONSTRAINT, ClutterAlignConstraintClass))
#define CLUTTER_IS_ALIGN_CONSTRAINT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), CLUTTER_TYPE_ALIGN_CONSTRAINT))
#define CLUTTER_ALIGN_CONSTRAINT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), CLUTTER_TYPE_ALIGN_CONSTRAINT, ClutterAlignConstraintClass))
struct _ClutterAlignConstraint
{
ClutterConstraint parent_instance;
ClutterActor *actor;
ClutterActor *source;
ClutterAlignAxis align_axis;
graphene_point_t pivot;
gfloat factor;
};
struct _ClutterAlignConstraintClass
{
ClutterConstraintClass parent_class;
};
enum
{
PROP_0,
PROP_SOURCE,
PROP_ALIGN_AXIS,
PROP_PIVOT_POINT,
PROP_FACTOR,
PROP_LAST
};
static GParamSpec *obj_props[PROP_LAST];
G_DEFINE_TYPE (ClutterAlignConstraint,
clutter_align_constraint,
CLUTTER_TYPE_CONSTRAINT);
static void
source_queue_relayout (ClutterActor *actor,
ClutterAlignConstraint *align)
{
if (align->actor != NULL)
_clutter_actor_queue_only_relayout (align->actor);
}
static void
source_destroyed (ClutterActor *actor,
ClutterAlignConstraint *align)
{
align->source = NULL;
}
static void
clutter_align_constraint_set_actor (ClutterActorMeta *meta,
ClutterActor *new_actor)
{
ClutterAlignConstraint *align = CLUTTER_ALIGN_CONSTRAINT (meta);
ClutterActorMetaClass *parent;
if (new_actor != NULL &&
align->source != NULL &&
clutter_actor_contains (new_actor, align->source))
{
g_warning (G_STRLOC ": The source actor '%s' is contained "
"by the actor '%s' associated to the constraint "
"'%s'",
_clutter_actor_get_debug_name (align->source),
_clutter_actor_get_debug_name (new_actor),
_clutter_actor_meta_get_debug_name (meta));
return;
}
/* store the pointer to the actor, for later use */
align->actor = new_actor;
parent = CLUTTER_ACTOR_META_CLASS (clutter_align_constraint_parent_class);
parent->set_actor (meta, new_actor);
}
static void
clutter_align_constraint_update_allocation (ClutterConstraint *constraint,
ClutterActor *actor,
ClutterActorBox *allocation)
{
ClutterAlignConstraint *align = CLUTTER_ALIGN_CONSTRAINT (constraint);
gfloat source_width, source_height;
gfloat actor_width, actor_height;
gfloat offset_x_start, offset_y_start;
gfloat pivot_x, pivot_y;
if (align->source == NULL)
return;
clutter_actor_box_get_size (allocation, &actor_width, &actor_height);
clutter_actor_get_size (align->source, &source_width, &source_height);
pivot_x = align->pivot.x == -1.f
? align->factor
: align->pivot.x;
pivot_y = align->pivot.y == -1.f
? align->factor
: align->pivot.y;
offset_x_start = pivot_x * -actor_width;
offset_y_start = pivot_y * -actor_height;
switch (align->align_axis)
{
case CLUTTER_ALIGN_X_AXIS:
allocation->x1 += offset_x_start + (source_width * align->factor);
allocation->x2 = allocation->x1 + actor_width;
break;
case CLUTTER_ALIGN_Y_AXIS:
allocation->y1 += offset_y_start + (source_height * align->factor);
allocation->y2 = allocation->y1 + actor_height;
break;
case CLUTTER_ALIGN_BOTH:
allocation->x1 += offset_x_start + (source_width * align->factor);
allocation->y1 += offset_y_start + (source_height * align->factor);
allocation->x2 = allocation->x1 + actor_width;
allocation->y2 = allocation->y1 + actor_height;
break;
default:
g_assert_not_reached ();
break;
}
clutter_actor_box_clamp_to_pixel (allocation);
}
static void
clutter_align_constraint_dispose (GObject *gobject)
{
ClutterAlignConstraint *align = CLUTTER_ALIGN_CONSTRAINT (gobject);
if (align->source != NULL)
{
g_signal_handlers_disconnect_by_func (align->source,
G_CALLBACK (source_destroyed),
align);
g_signal_handlers_disconnect_by_func (align->source,
G_CALLBACK (source_queue_relayout),
align);
align->source = NULL;
}
G_OBJECT_CLASS (clutter_align_constraint_parent_class)->dispose (gobject);
}
static void
clutter_align_constraint_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterAlignConstraint *align = CLUTTER_ALIGN_CONSTRAINT (gobject);
switch (prop_id)
{
case PROP_SOURCE:
clutter_align_constraint_set_source (align, g_value_get_object (value));
break;
case PROP_ALIGN_AXIS:
clutter_align_constraint_set_align_axis (align, g_value_get_enum (value));
break;
case PROP_PIVOT_POINT:
clutter_align_constraint_set_pivot_point (align, g_value_get_boxed (value));
break;
case PROP_FACTOR:
clutter_align_constraint_set_factor (align, g_value_get_float (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_align_constraint_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterAlignConstraint *align = CLUTTER_ALIGN_CONSTRAINT (gobject);
switch (prop_id)
{
case PROP_SOURCE:
g_value_set_object (value, align->source);
break;
case PROP_ALIGN_AXIS:
g_value_set_enum (value, align->align_axis);
break;
case PROP_PIVOT_POINT:
{
graphene_point_t point;
clutter_align_constraint_get_pivot_point (align, &point);
g_value_set_boxed (value, &point);
}
break;
case PROP_FACTOR:
g_value_set_float (value, align->factor);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_align_constraint_class_init (ClutterAlignConstraintClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
ClutterConstraintClass *constraint_class = CLUTTER_CONSTRAINT_CLASS (klass);
meta_class->set_actor = clutter_align_constraint_set_actor;
constraint_class->update_allocation = clutter_align_constraint_update_allocation;
/**
* ClutterAlignConstraint:source:
*
* The #ClutterActor used as the source for the alignment.
*
* The #ClutterActor must not be a child or a grandchild of the actor
* using the constraint.
*
* Since: 1.4
*/
obj_props[PROP_SOURCE] =
g_param_spec_object ("source",
P_("Source"),
P_("The source of the alignment"),
CLUTTER_TYPE_ACTOR,
CLUTTER_PARAM_READWRITE | G_PARAM_CONSTRUCT);
/**
* ClutterAlignConstraint:align-axis:
*
* The axis to be used to compute the alignment
*
* Since: 1.4
*/
obj_props[PROP_ALIGN_AXIS] =
g_param_spec_enum ("align-axis",
P_("Align Axis"),
P_("The axis to align the position to"),
CLUTTER_TYPE_ALIGN_AXIS,
CLUTTER_ALIGN_X_AXIS,
CLUTTER_PARAM_READWRITE | G_PARAM_CONSTRUCT);
/**
* ClutterAlignConstraint:pivot-point:
*
* The pivot point used by the constraint. The pivot point is the
* point in the constraint actor around which the aligning is applied,
* with (0, 0) being the top left corner of the actor and (1, 1) the
* bottom right corner of the actor.
*
* For example, setting the pivot point to (0.5, 0.5) and using a factor
* of 1 for both axes will align the actors horizontal and vertical
* center point with the bottom right corner of the source actor.
*
* By default, the pivot point is set to (-1, -1), which means it's not
* used and the constrained actor will be aligned to always stay inside
* the source actor.
*/
obj_props[PROP_PIVOT_POINT] =
g_param_spec_boxed ("pivot-point",
P_("Pivot point"),
P_("The pivot point"),
GRAPHENE_TYPE_POINT,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS);
/**
* ClutterAlignConstraint:factor:
*
* The alignment factor, as a normalized value between 0.0 and 1.0
*
* The factor depends on the #ClutterAlignConstraint:align-axis property:
* with an align-axis value of %CLUTTER_ALIGN_X_AXIS, 0.0 means left and
* 1.0 means right; with a value of %CLUTTER_ALIGN_Y_AXIS, 0.0 means top
* and 1.0 means bottom.
*
* Since: 1.4
*/
obj_props[PROP_FACTOR] =
g_param_spec_float ("factor",
P_("Factor"),
P_("The alignment factor, between 0.0 and 1.0"),
0.0, 1.0,
0.0,
CLUTTER_PARAM_READWRITE | G_PARAM_CONSTRUCT);
gobject_class->dispose = clutter_align_constraint_dispose;
gobject_class->set_property = clutter_align_constraint_set_property;
gobject_class->get_property = clutter_align_constraint_get_property;
g_object_class_install_properties (gobject_class, PROP_LAST, obj_props);
}
static void
clutter_align_constraint_init (ClutterAlignConstraint *self)
{
self->actor = NULL;
self->source = NULL;
self->align_axis = CLUTTER_ALIGN_X_AXIS;
self->pivot.x = -1.f;
self->pivot.y = -1.f;
self->factor = 0.0f;
}
/**
* clutter_align_constraint_new:
* @source: (allow-none): the #ClutterActor to use as the source of the
* alignment, or %NULL
* @axis: the axis to be used to compute the alignment
* @factor: the alignment factor, between 0.0 and 1.0
*
* Creates a new constraint, aligning a #ClutterActor's position with
* regards of the size of the actor to @source, with the given
* alignment @factor
*
* Return value: the newly created #ClutterAlignConstraint
*
* Since: 1.4
*/
ClutterConstraint *
clutter_align_constraint_new (ClutterActor *source,
ClutterAlignAxis axis,
gfloat factor)
{
g_return_val_if_fail (source == NULL || CLUTTER_IS_ACTOR (source), NULL);
return g_object_new (CLUTTER_TYPE_ALIGN_CONSTRAINT,
"source", source,
"align-axis", axis,
"factor", factor,
NULL);
}
/**
* clutter_align_constraint_set_source:
* @align: a #ClutterAlignConstraint
* @source: (allow-none): a #ClutterActor, or %NULL to unset the source
*
* Sets the source of the alignment constraint
*
* Since: 1.4
*/
void
clutter_align_constraint_set_source (ClutterAlignConstraint *align,
ClutterActor *source)
{
ClutterActor *old_source, *actor;
ClutterActorMeta *meta;
g_return_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align));
g_return_if_fail (source == NULL || CLUTTER_IS_ACTOR (source));
if (align->source == source)
return;
meta = CLUTTER_ACTOR_META (align);
actor = clutter_actor_meta_get_actor (meta);
if (actor != NULL && source != NULL)
{
if (clutter_actor_contains (actor, source))
{
g_warning (G_STRLOC ": The source actor '%s' is contained "
"by the actor '%s' associated to the constraint "
"'%s'",
_clutter_actor_get_debug_name (source),
_clutter_actor_get_debug_name (actor),
_clutter_actor_meta_get_debug_name (meta));
return;
}
}
old_source = align->source;
if (old_source != NULL)
{
g_signal_handlers_disconnect_by_func (old_source,
G_CALLBACK (source_destroyed),
align);
g_signal_handlers_disconnect_by_func (old_source,
G_CALLBACK (source_queue_relayout),
align);
}
align->source = source;
if (align->source != NULL)
{
g_signal_connect (align->source, "queue-relayout",
G_CALLBACK (source_queue_relayout),
align);
g_signal_connect (align->source, "destroy",
G_CALLBACK (source_destroyed),
align);
if (align->actor != NULL)
clutter_actor_queue_relayout (align->actor);
}
g_object_notify_by_pspec (G_OBJECT (align), obj_props[PROP_SOURCE]);
}
/**
* clutter_align_constraint_get_source:
* @align: a #ClutterAlignConstraint
*
* Retrieves the source of the alignment
*
* Return value: (transfer none): the #ClutterActor used as the source
* of the alignment
*
* Since: 1.4
*/
ClutterActor *
clutter_align_constraint_get_source (ClutterAlignConstraint *align)
{
g_return_val_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align), NULL);
return align->source;
}
/**
* clutter_align_constraint_set_align_axis:
* @align: a #ClutterAlignConstraint
* @axis: the axis to which the alignment refers to
*
* Sets the axis to which the alignment refers to
*
* Since: 1.4
*/
void
clutter_align_constraint_set_align_axis (ClutterAlignConstraint *align,
ClutterAlignAxis axis)
{
g_return_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align));
if (align->align_axis == axis)
return;
align->align_axis = axis;
if (align->actor != NULL)
clutter_actor_queue_relayout (align->actor);
g_object_notify_by_pspec (G_OBJECT (align), obj_props[PROP_ALIGN_AXIS]);
}
/**
* clutter_align_constraint_get_align_axis:
* @align: a #ClutterAlignConstraint
*
* Retrieves the value set using clutter_align_constraint_set_align_axis()
*
* Return value: the alignment axis
*
* Since: 1.4
*/
ClutterAlignAxis
clutter_align_constraint_get_align_axis (ClutterAlignConstraint *align)
{
g_return_val_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align),
CLUTTER_ALIGN_X_AXIS);
return align->align_axis;
}
/**
* clutter_align_constraint_set_pivot_point:
* @align: a #ClutterAlignConstraint
* @pivot_point: A #GraphenePoint
*
* Sets the pivot point used by the constraint, the pivot point is the
* point in the constraint actor around which the aligning is applied,
* with (0, 0) being the top left corner of the actor and (1, 1) the
* bottom right corner of the actor.
*
* If -1 is used, the pivot point is unset and the constrained actor
* will be aligned to always stay inside the source actor.
*/
void
clutter_align_constraint_set_pivot_point (ClutterAlignConstraint *align,
const graphene_point_t *pivot_point)
{
g_return_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align));
g_return_if_fail (pivot_point != NULL);
g_return_if_fail (pivot_point->x == -1.f ||
(pivot_point->x >= 0.f && pivot_point->x <= 1.f));
g_return_if_fail (pivot_point->y == -1.f ||
(pivot_point->y >= 0.f && pivot_point->y <= 1.f));
if (graphene_point_equal (&align->pivot, pivot_point))
return;
align->pivot = *pivot_point;
if (align->actor != NULL)
clutter_actor_queue_relayout (align->actor);
g_object_notify_by_pspec (G_OBJECT (align), obj_props[PROP_PIVOT_POINT]);
}
/**
* clutter_align_constraint_get_pivot_point
* @align: a #ClutterAlignConstraint
* @pivot_point: (out caller-allocates): return location for a #GraphenePoint
*
* Gets the pivot point used by the constraint set with
* clutter_align_constraint_set_pivot_point(). If no custom pivot
* point is set, -1 is set.
*/
void
clutter_align_constraint_get_pivot_point (ClutterAlignConstraint *align,
graphene_point_t *pivot_point)
{
g_return_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align));
g_return_if_fail (pivot_point != NULL);
*pivot_point = align->pivot;
}
/**
* clutter_align_constraint_set_factor:
* @align: a #ClutterAlignConstraint
* @factor: the alignment factor, between 0.0 and 1.0
*
* Sets the alignment factor of the constraint
*
* The factor depends on the #ClutterAlignConstraint:align-axis property
* and it is a value between 0.0 (meaning left, when
* #ClutterAlignConstraint:align-axis is set to %CLUTTER_ALIGN_X_AXIS; or
* meaning top, when #ClutterAlignConstraint:align-axis is set to
* %CLUTTER_ALIGN_Y_AXIS) and 1.0 (meaning right, when
* #ClutterAlignConstraint:align-axis is set to %CLUTTER_ALIGN_X_AXIS; or
* meaning bottom, when #ClutterAlignConstraint:align-axis is set to
* %CLUTTER_ALIGN_Y_AXIS). A value of 0.5 aligns in the middle in either
* cases
*
* Since: 1.4
*/
void
clutter_align_constraint_set_factor (ClutterAlignConstraint *align,
gfloat factor)
{
g_return_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align));
align->factor = CLAMP (factor, 0.0, 1.0);
if (align->actor != NULL)
clutter_actor_queue_relayout (align->actor);
g_object_notify_by_pspec (G_OBJECT (align), obj_props[PROP_FACTOR]);
}
/**
* clutter_align_constraint_get_factor:
* @align: a #ClutterAlignConstraint
*
* Retrieves the factor set using clutter_align_constraint_set_factor()
*
* Return value: the alignment factor
*
* Since: 1.4
*/
gfloat
clutter_align_constraint_get_factor (ClutterAlignConstraint *align)
{
g_return_val_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align), 0.0);
return align->factor;
}