forked from AuroraMiddleware/gtk
615 lines
18 KiB
C
615 lines
18 KiB
C
/* gtkconstraint.c: Constraint between two widgets
|
||
* Copyright 2019 GNOME Foundation
|
||
*
|
||
* 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 2.1 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
|
||
*/
|
||
|
||
/**
|
||
* SECTION:gtkconstraint
|
||
* @Title: GtkConstraint
|
||
* @Short_description: The description of a constraint
|
||
*
|
||
* #GtkConstraint describes a constraint between an attribute on a widget
|
||
* and another attribute on another widget, expressed as a linear equation
|
||
* like:
|
||
*
|
||
* |[
|
||
* target.attr1 = source.attr2 × multiplier + constant
|
||
* ]|
|
||
*
|
||
* Each #GtkConstraint is part of a system that will be solved by a
|
||
* #GtkConstraintLayout in order to allocate and position each child widget.
|
||
*
|
||
* The source and target widgets, as well as their attributes, of a
|
||
* #GtkConstraint instance are immutable after creation.
|
||
*/
|
||
|
||
#include "config.h"
|
||
|
||
#include "gtkconstraintprivate.h"
|
||
#include "gtkconstraintsolverprivate.h"
|
||
#include "gtkintl.h"
|
||
#include "gtktypebuiltins.h"
|
||
#include "gtkwidget.h"
|
||
|
||
enum {
|
||
PROP_TARGET = 1,
|
||
PROP_TARGET_ATTRIBUTE,
|
||
PROP_RELATION,
|
||
PROP_SOURCE,
|
||
PROP_SOURCE_ATTRIBUTE,
|
||
PROP_MULTIPLIER,
|
||
PROP_CONSTANT,
|
||
PROP_STRENGTH,
|
||
|
||
N_PROPERTIES
|
||
};
|
||
|
||
static GParamSpec *obj_props[N_PROPERTIES];
|
||
|
||
G_DEFINE_TYPE (GtkConstraint, gtk_constraint, G_TYPE_OBJECT)
|
||
|
||
static void
|
||
gtk_constraint_set_property (GObject *gobject,
|
||
guint prop_id,
|
||
const GValue *value,
|
||
GParamSpec *pspec)
|
||
{
|
||
GtkConstraint *self = GTK_CONSTRAINT (gobject);
|
||
|
||
switch (prop_id)
|
||
{
|
||
case PROP_TARGET:
|
||
self->target = g_value_get_object (value);
|
||
break;
|
||
|
||
case PROP_TARGET_ATTRIBUTE:
|
||
self->target_attribute = g_value_get_enum (value);
|
||
break;
|
||
|
||
case PROP_RELATION:
|
||
self->relation = g_value_get_enum (value);
|
||
break;
|
||
|
||
case PROP_SOURCE:
|
||
self->source = g_value_get_object (value);
|
||
break;
|
||
|
||
case PROP_SOURCE_ATTRIBUTE:
|
||
self->source_attribute = g_value_get_enum (value);
|
||
break;
|
||
|
||
case PROP_MULTIPLIER:
|
||
self->multiplier = g_value_get_double (value);
|
||
break;
|
||
|
||
case PROP_CONSTANT:
|
||
self->constant = g_value_get_double (value);
|
||
break;
|
||
|
||
case PROP_STRENGTH:
|
||
self->strength = g_value_get_int (value);
|
||
break;
|
||
|
||
default:
|
||
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
|
||
break;
|
||
}
|
||
}
|
||
|
||
static void
|
||
gtk_constraint_get_property (GObject *gobject,
|
||
guint prop_id,
|
||
GValue *value,
|
||
GParamSpec *pspec)
|
||
{
|
||
GtkConstraint *self = GTK_CONSTRAINT (gobject);
|
||
|
||
switch (prop_id)
|
||
{
|
||
case PROP_TARGET:
|
||
g_value_set_object (value, self->target);
|
||
break;
|
||
|
||
case PROP_TARGET_ATTRIBUTE:
|
||
g_value_set_enum (value, self->target_attribute);
|
||
break;
|
||
|
||
case PROP_RELATION:
|
||
g_value_set_enum (value, self->relation);
|
||
break;
|
||
|
||
case PROP_SOURCE:
|
||
g_value_set_object (value, self->source);
|
||
break;
|
||
|
||
case PROP_SOURCE_ATTRIBUTE:
|
||
g_value_set_enum (value, self->source_attribute);
|
||
break;
|
||
|
||
case PROP_MULTIPLIER:
|
||
g_value_set_double (value, self->multiplier);
|
||
break;
|
||
|
||
case PROP_CONSTANT:
|
||
g_value_set_double (value, self->constant);
|
||
break;
|
||
|
||
case PROP_STRENGTH:
|
||
g_value_set_int (value, self->strength);
|
||
break;
|
||
|
||
default:
|
||
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
|
||
break;
|
||
}
|
||
}
|
||
|
||
static void
|
||
gtk_constraint_finalize (GObject *gobject)
|
||
{
|
||
GtkConstraint *self = GTK_CONSTRAINT (gobject);
|
||
|
||
gtk_constraint_detach (self);
|
||
|
||
G_OBJECT_CLASS (gtk_constraint_parent_class)->finalize (gobject);
|
||
}
|
||
|
||
static void
|
||
gtk_constraint_class_init (GtkConstraintClass *klass)
|
||
{
|
||
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
|
||
|
||
gobject_class->set_property = gtk_constraint_set_property;
|
||
gobject_class->get_property = gtk_constraint_get_property;
|
||
gobject_class->finalize = gtk_constraint_finalize;
|
||
|
||
/**
|
||
* GtkConstraint:target:
|
||
*
|
||
* The target of the constraint.
|
||
*
|
||
* The constraint will set the #GtkConstraint:target-attribute of the
|
||
* target using the #GtkConstraint:source-attribute of the source
|
||
* widget.
|
||
*/
|
||
obj_props[PROP_TARGET] =
|
||
g_param_spec_object ("target",
|
||
P_("Target"),
|
||
P_("The target of the constraint"),
|
||
GTK_TYPE_CONSTRAINT_TARGET,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:target-attribute:
|
||
*
|
||
* The attribute of the #GtkConstraint:target set by the constraint.
|
||
*/
|
||
obj_props[PROP_TARGET_ATTRIBUTE] =
|
||
g_param_spec_enum ("target-attribute",
|
||
P_("Target Attribute"),
|
||
P_("The attribute of the target set by the constraint"),
|
||
GTK_TYPE_CONSTRAINT_ATTRIBUTE,
|
||
GTK_CONSTRAINT_ATTRIBUTE_NONE,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:relation:
|
||
*
|
||
* The order relation between the terms of the constraint.
|
||
*/
|
||
obj_props[PROP_RELATION] =
|
||
g_param_spec_enum ("relation",
|
||
P_("Relation"),
|
||
P_("The relation between the source and target attributes"),
|
||
GTK_TYPE_CONSTRAINT_RELATION,
|
||
GTK_CONSTRAINT_RELATION_EQ,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:source:
|
||
*
|
||
* The source of the constraint.
|
||
*
|
||
* The constraint will set the #GtkConstraint:target-attribute of the
|
||
* target using the #GtkConstraint:source-attribute of the source.
|
||
*/
|
||
obj_props[PROP_SOURCE] =
|
||
g_param_spec_object ("source",
|
||
P_("Source"),
|
||
P_("The source of the constraint"),
|
||
GTK_TYPE_CONSTRAINT_TARGET,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:source-attribute:
|
||
*
|
||
* The attribute of the #GtkConstraint:source read by the constraint.
|
||
*/
|
||
obj_props[PROP_SOURCE_ATTRIBUTE] =
|
||
g_param_spec_enum ("source-attribute",
|
||
P_("Source Attribute"),
|
||
P_("The attribute of the source widget set by the constraint"),
|
||
GTK_TYPE_CONSTRAINT_ATTRIBUTE,
|
||
GTK_CONSTRAINT_ATTRIBUTE_NONE,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:multiplier:
|
||
*
|
||
* The multiplication factor to be applied to the
|
||
* #GtkConstraint:source-attribute.
|
||
*/
|
||
obj_props[PROP_MULTIPLIER] =
|
||
g_param_spec_double ("multiplier",
|
||
P_("Multiplier"),
|
||
P_("The multiplication factor to be applied to the source attribute"),
|
||
-G_MAXDOUBLE, G_MAXDOUBLE, 1.0,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:constant:
|
||
*
|
||
* The constant value to be added to the #GtkConstraint:source-attribute.
|
||
*/
|
||
obj_props[PROP_CONSTANT] =
|
||
g_param_spec_double ("constant",
|
||
P_("Constant"),
|
||
P_("The constant to be added to the source attribute"),
|
||
-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
/**
|
||
* GtkConstraint:strength:
|
||
*
|
||
* The strength of the constraint.
|
||
*
|
||
* The strength can be expressed either using one of the symbolic values
|
||
* of the #GtkConstraintStrength enumeration, or any positive integer
|
||
* value.
|
||
*/
|
||
obj_props[PROP_STRENGTH] =
|
||
g_param_spec_int ("strength",
|
||
P_("Strength"),
|
||
P_("The strength of the constraint"),
|
||
0, GTK_CONSTRAINT_STRENGTH_REQUIRED,
|
||
GTK_CONSTRAINT_STRENGTH_REQUIRED,
|
||
G_PARAM_READWRITE |
|
||
G_PARAM_STATIC_STRINGS |
|
||
G_PARAM_CONSTRUCT_ONLY);
|
||
|
||
g_object_class_install_properties (gobject_class, N_PROPERTIES, obj_props);
|
||
}
|
||
|
||
static void
|
||
gtk_constraint_init (GtkConstraint *self)
|
||
{
|
||
self->multiplier = 1.0;
|
||
self->constant = 0.0;
|
||
|
||
self->target_attribute = GTK_CONSTRAINT_ATTRIBUTE_NONE;
|
||
self->source_attribute = GTK_CONSTRAINT_ATTRIBUTE_NONE;
|
||
self->relation = GTK_CONSTRAINT_RELATION_EQ;
|
||
self->strength = GTK_CONSTRAINT_STRENGTH_REQUIRED;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_new:
|
||
* @target: (nullable) (type GtkConstraintTarget): a #GtkConstraintTarget
|
||
* @target_attribute: the attribute of @target to be set
|
||
* @relation: the relation equivalence between @target_attribute and @source_attribute
|
||
* @source: (nullable) (type GtkConstraintTarget): a #GtkConstraintTarget
|
||
* @source_attribute: the attribute of @source to be read
|
||
* @multiplier: a multiplication factor to be applied to @source_attribute
|
||
* @constant: a constant factor to be added to @source_attribute
|
||
* @strength: the strength of the constraint
|
||
*
|
||
* Creates a new #GtkConstraint representing a relation between a layout
|
||
* attribute on a source and a layout attribute on a target.
|
||
*
|
||
* Returns: the newly created #GtkConstraint
|
||
*/
|
||
GtkConstraint *
|
||
gtk_constraint_new (gpointer target,
|
||
GtkConstraintAttribute target_attribute,
|
||
GtkConstraintRelation relation,
|
||
gpointer source,
|
||
GtkConstraintAttribute source_attribute,
|
||
double multiplier,
|
||
double constant,
|
||
int strength)
|
||
{
|
||
g_return_val_if_fail (target == NULL || GTK_IS_CONSTRAINT_TARGET (target), NULL);
|
||
g_return_val_if_fail (source == NULL || GTK_IS_CONSTRAINT_TARGET (source), NULL);
|
||
|
||
return g_object_new (GTK_TYPE_CONSTRAINT,
|
||
"target", target,
|
||
"target-attribute", target_attribute,
|
||
"relation", relation,
|
||
"source", source,
|
||
"source-attribute", source_attribute,
|
||
"multiplier", multiplier,
|
||
"constant", constant,
|
||
"strength", strength,
|
||
NULL);
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_new_constant:
|
||
* @target: (nullable) (type GtkConstraintTarget): a #GtkConstraintTarget
|
||
* @target_attribute: the attribute of @target to be set
|
||
* @relation: the relation equivalence between @target_attribute and @constant
|
||
* @constant: a constant factor to be set on @target_attribute
|
||
* @strength: the strength of the constraint
|
||
*
|
||
* Creates a new #GtkConstraint representing a relation between a layout
|
||
* attribute on a target and a constant value.
|
||
*
|
||
* Returns: the newly created #GtkConstraint
|
||
*/
|
||
GtkConstraint *
|
||
gtk_constraint_new_constant (gpointer target,
|
||
GtkConstraintAttribute target_attribute,
|
||
GtkConstraintRelation relation,
|
||
double constant,
|
||
int strength)
|
||
{
|
||
g_return_val_if_fail (target == NULL || GTK_IS_CONSTRAINT_TARGET (target), NULL);
|
||
|
||
return g_object_new (GTK_TYPE_CONSTRAINT,
|
||
"target", target,
|
||
"target-attribute", target_attribute,
|
||
"relation", relation,
|
||
"source-attribute", GTK_CONSTRAINT_ATTRIBUTE_NONE,
|
||
"constant", constant,
|
||
"strength", strength,
|
||
NULL);
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_target:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the #GtkConstraintTarget used as the target for @constraint.
|
||
*
|
||
* If the #GtkConstraint:target property is set to %NULL, the @constraint
|
||
* will use the #GtkConstraintLayout's widget.
|
||
*
|
||
* Returns: (transfer none) (nullable): a #GtkConstraintTarget
|
||
*/
|
||
GtkConstraintTarget *
|
||
gtk_constraint_get_target (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), NULL);
|
||
|
||
return constraint->target;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_target_attribute:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the attribute of the target to be set by the @constraint.
|
||
*
|
||
* Returns: the target's attribute
|
||
*/
|
||
GtkConstraintAttribute
|
||
gtk_constraint_get_target_attribute (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_ATTRIBUTE_NONE);
|
||
|
||
return constraint->target_attribute;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_source:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the #GtkConstraintTarget used as the source for @constraint.
|
||
*
|
||
* If the #GtkConstraint:source property is set to %NULL, the @constraint
|
||
* will use the #GtkConstraintLayout's widget.
|
||
*
|
||
* Returns: (transfer none) (nullable): a #GtkConstraintTarget
|
||
*/
|
||
GtkConstraintTarget *
|
||
gtk_constraint_get_source (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), NULL);
|
||
|
||
return constraint->source;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_source_attribute:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the attribute of the source to be read by the @constraint.
|
||
*
|
||
* Returns: the target's attribute
|
||
*/
|
||
GtkConstraintAttribute
|
||
gtk_constraint_get_source_attribute (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_ATTRIBUTE_NONE);
|
||
|
||
return constraint->source_attribute;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_relation:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* The order relation between the terms of the @constraint.
|
||
*
|
||
* Returns: a #GtkConstraintRelation value
|
||
*/
|
||
GtkConstraintRelation
|
||
gtk_constraint_get_relation (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_RELATION_EQ);
|
||
|
||
return constraint->relation;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_multiplier:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the multiplication factor applied to the source
|
||
* attribute's value.
|
||
*
|
||
* Returns: a multiplication factor
|
||
*/
|
||
double
|
||
gtk_constraint_get_multiplier (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), 1.0);
|
||
|
||
return constraint->multiplier;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_constant:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the constant factor added to the source attributes' value.
|
||
*
|
||
* Returns: a constant factor
|
||
*/
|
||
double
|
||
gtk_constraint_get_constant (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), 0.0);
|
||
|
||
return constraint->constant;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_get_strength:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Retrieves the strength of the constraint.
|
||
*
|
||
* Returns: the strength of the constraint
|
||
*/
|
||
int
|
||
gtk_constraint_get_strength (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_STRENGTH_REQUIRED);
|
||
|
||
return constraint->strength;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_is_required:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Checks whether the @constraint is a required relation for solving the
|
||
* constraint layout.
|
||
*
|
||
* Returns: %TRUE if the constraint is required
|
||
*/
|
||
gboolean
|
||
gtk_constraint_is_required (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), FALSE);
|
||
|
||
return constraint->strength == GTK_CONSTRAINT_STRENGTH_REQUIRED;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_is_attached:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Checks whether the @constraint is attached to a #GtkConstraintLayout,
|
||
* and it is contributing to the layout.
|
||
*
|
||
* Returns: %TRUE if the constraint is attached
|
||
*/
|
||
gboolean
|
||
gtk_constraint_is_attached (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), FALSE);
|
||
|
||
return constraint->constraint_ref != NULL;
|
||
}
|
||
|
||
/**
|
||
* gtk_constraint_is_constant:
|
||
* @constraint: a #GtkConstraint
|
||
*
|
||
* Checks whether the @constraint describes a relation between an attribute
|
||
* on the #GtkConstraint:target and a constant value.
|
||
*
|
||
* Returns: %TRUE if the constraint is a constant relation
|
||
*/
|
||
gboolean
|
||
gtk_constraint_is_constant (GtkConstraint *constraint)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), FALSE);
|
||
|
||
return constraint->source == NULL &&
|
||
constraint->source_attribute == GTK_CONSTRAINT_ATTRIBUTE_NONE;
|
||
}
|
||
|
||
void
|
||
gtk_constraint_attach (GtkConstraint *constraint,
|
||
GtkConstraintSolver *solver,
|
||
GtkConstraintRef *ref)
|
||
{
|
||
g_return_if_fail (GTK_IS_CONSTRAINT (constraint));
|
||
g_return_if_fail (GTK_IS_CONSTRAINT_SOLVER (solver));
|
||
g_return_if_fail (ref != NULL);
|
||
|
||
constraint->constraint_ref = ref;
|
||
constraint->solver = solver;
|
||
}
|
||
|
||
void
|
||
gtk_constraint_detach (GtkConstraint *constraint)
|
||
{
|
||
g_return_if_fail (GTK_IS_CONSTRAINT (constraint));
|
||
|
||
if (constraint->constraint_ref == NULL)
|
||
return;
|
||
|
||
gtk_constraint_solver_remove_constraint (constraint->solver, constraint->constraint_ref);
|
||
constraint->constraint_ref = NULL;
|
||
constraint->solver = NULL;
|
||
}
|
||
|
||
typedef struct _GtkConstraintTargetInterface GtkConstraintTargetInterface;
|
||
|
||
struct _GtkConstraintTargetInterface
|
||
{
|
||
GTypeInterface g_iface;
|
||
};
|
||
|
||
G_DEFINE_INTERFACE (GtkConstraintTarget, gtk_constraint_target, G_TYPE_OBJECT)
|
||
|
||
static void
|
||
gtk_constraint_target_default_init (GtkConstraintTargetInterface *iface)
|
||
{
|
||
}
|