mutter/clutter/clutter-align-constraint.c

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/*
* 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>
*/
/**
2010-05-19 15:10:05 +00:00
* 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
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-align-constraint.h"
#include "clutter-constraint.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-private.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))
typedef struct _ClutterAlignConstraintClass ClutterAlignConstraintClass;
struct _ClutterAlignConstraint
{
ClutterConstraint parent_instance;
ClutterActor *source;
ClutterAlignAxis align_axis;
gfloat factor;
};
struct _ClutterAlignConstraintClass
{
ClutterConstraintClass parent_class;
};
enum
{
PROP_0,
PROP_SOURCE,
PROP_ALIGN_AXIS,
PROP_FACTOR
};
G_DEFINE_TYPE (ClutterAlignConstraint,
clutter_align_constraint,
CLUTTER_TYPE_CONSTRAINT);
static void
update_actor_position (ClutterAlignConstraint *align)
{
gfloat source_width, source_height;
gfloat actor_width, actor_height;
gfloat source_x, source_y;
gfloat new_position;
ClutterActor *actor;
if (align->source == NULL)
return;
if (!clutter_actor_meta_get_enabled (CLUTTER_ACTOR_META (align)))
return;
actor = clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (align));
if (actor == NULL)
return;
clutter_actor_get_position (align->source, &source_x, &source_y);
clutter_actor_get_size (align->source, &source_width, &source_height);
clutter_actor_get_size (actor, &actor_width, &actor_height);
switch (align->align_axis)
{
case CLUTTER_ALIGN_X_AXIS:
new_position = ((source_width - actor_width) * align->factor)
+ source_x;
clutter_actor_set_x (actor, new_position);
break;
case CLUTTER_ALIGN_Y_AXIS:
new_position = ((source_height - actor_height) * align->factor)
+ source_y;
clutter_actor_set_y (actor, new_position);
break;
}
}
static void
source_position_changed (ClutterActor *actor,
const ClutterActorBox *allocation,
ClutterAllocationFlags flags,
ClutterAlignConstraint *align)
{
update_actor_position (align);
}
static void
source_destroyed (ClutterActor *actor,
ClutterAlignConstraint *align)
{
align->source = NULL;
}
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_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_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);
GParamSpec *pspec;
gobject_class->set_property = clutter_align_constraint_set_property;
gobject_class->get_property = clutter_align_constraint_get_property;
/**
* ClutterAlignConstraint:source:
*
* The #ClutterActor used as the source for the alignment
*
* Since: 1.4
*/
pspec = g_param_spec_object ("source",
P_("Source"),
P_("The source of the alignment"),
CLUTTER_TYPE_ACTOR,
CLUTTER_PARAM_READWRITE |
G_PARAM_CONSTRUCT);
g_object_class_install_property (gobject_class, PROP_SOURCE, pspec);
/**
* ClutterAlignConstraint:align-axis:
*
* The axis to be used to compute the alignment
*
* Since: 1.4
*/
pspec = 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);
g_object_class_install_property (gobject_class, PROP_ALIGN_AXIS, pspec);
/**
* 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
*/
pspec = 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);
g_object_class_install_property (gobject_class, PROP_FACTOR, pspec);
}
static void
clutter_align_constraint_init (ClutterAlignConstraint *self)
{
self->source = NULL;
self->align_axis = CLUTTER_ALIGN_X_AXIS;
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;
g_return_if_fail (CLUTTER_IS_ALIGN_CONSTRAINT (align));
g_return_if_fail (source == NULL || CLUTTER_IS_ACTOR (source));
if (align->source == source)
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_position_changed),
align);
}
align->source = source;
if (align->source != NULL)
{
g_signal_connect (align->source, "allocation-changed",
G_CALLBACK (source_position_changed),
align);
g_signal_connect (align->source, "destroy",
G_CALLBACK (source_destroyed),
align);
update_actor_position (align);
}
g_object_notify (G_OBJECT (align), "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;
update_actor_position (align);
g_object_notify (G_OBJECT (align), "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_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);
update_actor_position (align);
g_object_notify (G_OBJECT (align), "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;
}