forked from AuroraMiddleware/gtk
e8b6e6cad0
The documentation engine will use the first paragraph as the summary for a type or constant.
617 lines
18 KiB
C
617 lines
18 KiB
C
/* gtkconstraint.c: Constraint between two widgets
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* Copyright 2019 GNOME Foundation
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see <http://www.gnu.org/licenses/>.
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*
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* Author: Emmanuele Bassi
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*/
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/**
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* SECTION:gtkconstraint
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* @Title: GtkConstraint
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* @Short_description: The description of a constraint
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*
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* `GtkConstraint` describes a constraint between an attribute on a widget
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* and another attribute on another widget, expressed as a linear equation.
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*
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* For instance:
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*
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* ```
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* target.attr1 = source.attr2 × multiplier + constant
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* ```
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*
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* Each `GtkConstraint` is part of a system that will be solved by a
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* [class@Gtk.ConstraintLayout] in order to allocate and position each
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* child widget or guide.
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*
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* The source and target, as well as their attributes, of a `GtkConstraint`
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* instance are immutable after creation.
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*/
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#include "config.h"
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#include "gtkconstraintprivate.h"
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#include "gtkconstraintsolverprivate.h"
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#include "gtkintl.h"
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#include "gtktypebuiltins.h"
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#include "gtkwidget.h"
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enum {
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PROP_TARGET = 1,
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PROP_TARGET_ATTRIBUTE,
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PROP_RELATION,
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PROP_SOURCE,
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PROP_SOURCE_ATTRIBUTE,
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PROP_MULTIPLIER,
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PROP_CONSTANT,
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PROP_STRENGTH,
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N_PROPERTIES
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};
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static GParamSpec *obj_props[N_PROPERTIES];
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G_DEFINE_TYPE (GtkConstraint, gtk_constraint, G_TYPE_OBJECT)
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static void
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gtk_constraint_set_property (GObject *gobject,
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guint prop_id,
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const GValue *value,
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GParamSpec *pspec)
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{
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GtkConstraint *self = GTK_CONSTRAINT (gobject);
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switch (prop_id)
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{
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case PROP_TARGET:
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self->target = g_value_get_object (value);
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break;
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case PROP_TARGET_ATTRIBUTE:
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self->target_attribute = g_value_get_enum (value);
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break;
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case PROP_RELATION:
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self->relation = g_value_get_enum (value);
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break;
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case PROP_SOURCE:
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self->source = g_value_get_object (value);
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break;
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case PROP_SOURCE_ATTRIBUTE:
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self->source_attribute = g_value_get_enum (value);
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break;
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case PROP_MULTIPLIER:
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self->multiplier = g_value_get_double (value);
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break;
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case PROP_CONSTANT:
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self->constant = g_value_get_double (value);
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break;
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case PROP_STRENGTH:
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self->strength = g_value_get_int (value);
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break;
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default:
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G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
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break;
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}
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}
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static void
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gtk_constraint_get_property (GObject *gobject,
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guint prop_id,
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GValue *value,
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GParamSpec *pspec)
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{
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GtkConstraint *self = GTK_CONSTRAINT (gobject);
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switch (prop_id)
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{
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case PROP_TARGET:
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g_value_set_object (value, self->target);
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break;
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case PROP_TARGET_ATTRIBUTE:
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g_value_set_enum (value, self->target_attribute);
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break;
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case PROP_RELATION:
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g_value_set_enum (value, self->relation);
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break;
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case PROP_SOURCE:
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g_value_set_object (value, self->source);
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break;
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case PROP_SOURCE_ATTRIBUTE:
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g_value_set_enum (value, self->source_attribute);
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break;
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case PROP_MULTIPLIER:
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g_value_set_double (value, self->multiplier);
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break;
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case PROP_CONSTANT:
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g_value_set_double (value, self->constant);
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break;
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case PROP_STRENGTH:
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g_value_set_int (value, self->strength);
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break;
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default:
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G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
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break;
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}
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}
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static void
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gtk_constraint_finalize (GObject *gobject)
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{
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GtkConstraint *self = GTK_CONSTRAINT (gobject);
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gtk_constraint_detach (self);
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G_OBJECT_CLASS (gtk_constraint_parent_class)->finalize (gobject);
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}
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static void
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gtk_constraint_class_init (GtkConstraintClass *klass)
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{
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GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
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gobject_class->set_property = gtk_constraint_set_property;
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gobject_class->get_property = gtk_constraint_get_property;
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gobject_class->finalize = gtk_constraint_finalize;
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/**
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* GtkConstraint:target:
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*
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* The target of the constraint.
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*
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* The constraint will set the #GtkConstraint:target-attribute of the
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* target using the #GtkConstraint:source-attribute of the source
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* widget.
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*/
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obj_props[PROP_TARGET] =
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g_param_spec_object ("target",
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P_("Target"),
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P_("The target of the constraint"),
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GTK_TYPE_CONSTRAINT_TARGET,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:target-attribute:
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*
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* The attribute of the #GtkConstraint:target set by the constraint.
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*/
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obj_props[PROP_TARGET_ATTRIBUTE] =
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g_param_spec_enum ("target-attribute",
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P_("Target Attribute"),
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P_("The attribute of the target set by the constraint"),
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GTK_TYPE_CONSTRAINT_ATTRIBUTE,
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GTK_CONSTRAINT_ATTRIBUTE_NONE,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:relation:
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*
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* The order relation between the terms of the constraint.
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*/
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obj_props[PROP_RELATION] =
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g_param_spec_enum ("relation",
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P_("Relation"),
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P_("The relation between the source and target attributes"),
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GTK_TYPE_CONSTRAINT_RELATION,
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GTK_CONSTRAINT_RELATION_EQ,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:source:
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*
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* The source of the constraint.
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*
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* The constraint will set the #GtkConstraint:target-attribute of the
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* target using the #GtkConstraint:source-attribute of the source.
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*/
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obj_props[PROP_SOURCE] =
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g_param_spec_object ("source",
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P_("Source"),
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P_("The source of the constraint"),
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GTK_TYPE_CONSTRAINT_TARGET,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:source-attribute:
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*
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* The attribute of the #GtkConstraint:source read by the constraint.
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*/
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obj_props[PROP_SOURCE_ATTRIBUTE] =
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g_param_spec_enum ("source-attribute",
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P_("Source Attribute"),
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P_("The attribute of the source widget set by the constraint"),
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GTK_TYPE_CONSTRAINT_ATTRIBUTE,
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GTK_CONSTRAINT_ATTRIBUTE_NONE,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:multiplier:
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*
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* The multiplication factor to be applied to the
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* #GtkConstraint:source-attribute.
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*/
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obj_props[PROP_MULTIPLIER] =
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g_param_spec_double ("multiplier",
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P_("Multiplier"),
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P_("The multiplication factor to be applied to the source attribute"),
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-G_MAXDOUBLE, G_MAXDOUBLE, 1.0,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:constant:
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*
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* The constant value to be added to the #GtkConstraint:source-attribute.
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*/
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obj_props[PROP_CONSTANT] =
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g_param_spec_double ("constant",
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P_("Constant"),
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P_("The constant to be added to the source attribute"),
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-G_MAXDOUBLE, G_MAXDOUBLE, 0.0,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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/**
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* GtkConstraint:strength:
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*
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* The strength of the constraint.
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*
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* The strength can be expressed either using one of the symbolic values
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* of the #GtkConstraintStrength enumeration, or any positive integer
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* value.
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*/
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obj_props[PROP_STRENGTH] =
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g_param_spec_int ("strength",
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P_("Strength"),
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P_("The strength of the constraint"),
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0, GTK_CONSTRAINT_STRENGTH_REQUIRED,
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GTK_CONSTRAINT_STRENGTH_REQUIRED,
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G_PARAM_READWRITE |
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G_PARAM_STATIC_STRINGS |
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G_PARAM_CONSTRUCT_ONLY);
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g_object_class_install_properties (gobject_class, N_PROPERTIES, obj_props);
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}
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static void
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gtk_constraint_init (GtkConstraint *self)
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{
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self->multiplier = 1.0;
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self->constant = 0.0;
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self->target_attribute = GTK_CONSTRAINT_ATTRIBUTE_NONE;
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self->source_attribute = GTK_CONSTRAINT_ATTRIBUTE_NONE;
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self->relation = GTK_CONSTRAINT_RELATION_EQ;
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self->strength = GTK_CONSTRAINT_STRENGTH_REQUIRED;
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}
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/**
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* gtk_constraint_new:
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* @target: (nullable) (type GtkConstraintTarget): a #GtkConstraintTarget
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* @target_attribute: the attribute of @target to be set
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* @relation: the relation equivalence between @target_attribute and @source_attribute
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* @source: (nullable) (type GtkConstraintTarget): a #GtkConstraintTarget
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* @source_attribute: the attribute of @source to be read
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* @multiplier: a multiplication factor to be applied to @source_attribute
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* @constant: a constant factor to be added to @source_attribute
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* @strength: the strength of the constraint
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*
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* Creates a new #GtkConstraint representing a relation between a layout
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* attribute on a source and a layout attribute on a target.
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*
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* Returns: the newly created #GtkConstraint
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*/
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GtkConstraint *
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gtk_constraint_new (gpointer target,
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GtkConstraintAttribute target_attribute,
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GtkConstraintRelation relation,
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gpointer source,
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GtkConstraintAttribute source_attribute,
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double multiplier,
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double constant,
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int strength)
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{
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g_return_val_if_fail (target == NULL || GTK_IS_CONSTRAINT_TARGET (target), NULL);
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g_return_val_if_fail (source == NULL || GTK_IS_CONSTRAINT_TARGET (source), NULL);
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return g_object_new (GTK_TYPE_CONSTRAINT,
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"target", target,
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"target-attribute", target_attribute,
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"relation", relation,
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"source", source,
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"source-attribute", source_attribute,
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"multiplier", multiplier,
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"constant", constant,
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"strength", strength,
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NULL);
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}
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/**
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* gtk_constraint_new_constant:
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* @target: (nullable) (type GtkConstraintTarget): a #GtkConstraintTarget
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* @target_attribute: the attribute of @target to be set
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* @relation: the relation equivalence between @target_attribute and @constant
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* @constant: a constant factor to be set on @target_attribute
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* @strength: the strength of the constraint
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*
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* Creates a new #GtkConstraint representing a relation between a layout
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* attribute on a target and a constant value.
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*
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* Returns: the newly created #GtkConstraint
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*/
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GtkConstraint *
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gtk_constraint_new_constant (gpointer target,
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GtkConstraintAttribute target_attribute,
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GtkConstraintRelation relation,
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double constant,
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int strength)
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{
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g_return_val_if_fail (target == NULL || GTK_IS_CONSTRAINT_TARGET (target), NULL);
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return g_object_new (GTK_TYPE_CONSTRAINT,
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"target", target,
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"target-attribute", target_attribute,
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"relation", relation,
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"source-attribute", GTK_CONSTRAINT_ATTRIBUTE_NONE,
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"constant", constant,
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"strength", strength,
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NULL);
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}
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/**
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* gtk_constraint_get_target:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the #GtkConstraintTarget used as the target for @constraint.
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*
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* If the #GtkConstraint:target property is set to %NULL, the @constraint
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* will use the #GtkConstraintLayout's widget.
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*
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* Returns: (transfer none) (nullable): a #GtkConstraintTarget
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*/
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GtkConstraintTarget *
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gtk_constraint_get_target (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), NULL);
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return constraint->target;
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}
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/**
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* gtk_constraint_get_target_attribute:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the attribute of the target to be set by the @constraint.
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*
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* Returns: the target's attribute
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*/
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GtkConstraintAttribute
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gtk_constraint_get_target_attribute (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_ATTRIBUTE_NONE);
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return constraint->target_attribute;
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}
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/**
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* gtk_constraint_get_source:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the #GtkConstraintTarget used as the source for @constraint.
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*
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* If the #GtkConstraint:source property is set to %NULL, the @constraint
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* will use the #GtkConstraintLayout's widget.
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*
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* Returns: (transfer none) (nullable): a #GtkConstraintTarget
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*/
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GtkConstraintTarget *
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gtk_constraint_get_source (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), NULL);
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return constraint->source;
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}
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/**
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* gtk_constraint_get_source_attribute:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the attribute of the source to be read by the @constraint.
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*
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* Returns: the target's attribute
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*/
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GtkConstraintAttribute
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gtk_constraint_get_source_attribute (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_ATTRIBUTE_NONE);
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return constraint->source_attribute;
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}
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/**
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* gtk_constraint_get_relation:
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* @constraint: a #GtkConstraint
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*
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* The order relation between the terms of the @constraint.
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*
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* Returns: a #GtkConstraintRelation value
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*/
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GtkConstraintRelation
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gtk_constraint_get_relation (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_RELATION_EQ);
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return constraint->relation;
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}
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/**
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* gtk_constraint_get_multiplier:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the multiplication factor applied to the source
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* attribute's value.
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*
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* Returns: a multiplication factor
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*/
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double
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gtk_constraint_get_multiplier (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), 1.0);
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return constraint->multiplier;
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}
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/**
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* gtk_constraint_get_constant:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the constant factor added to the source attributes' value.
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*
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* Returns: a constant factor
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*/
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double
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gtk_constraint_get_constant (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), 0.0);
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return constraint->constant;
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}
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/**
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* gtk_constraint_get_strength:
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* @constraint: a #GtkConstraint
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*
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* Retrieves the strength of the constraint.
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*
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* Returns: the strength of the constraint
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*/
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int
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gtk_constraint_get_strength (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), GTK_CONSTRAINT_STRENGTH_REQUIRED);
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return constraint->strength;
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}
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/**
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* gtk_constraint_is_required:
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* @constraint: a #GtkConstraint
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*
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* Checks whether the @constraint is a required relation for solving the
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* constraint layout.
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*
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* Returns: %TRUE if the constraint is required
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*/
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gboolean
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gtk_constraint_is_required (GtkConstraint *constraint)
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{
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g_return_val_if_fail (GTK_IS_CONSTRAINT (constraint), FALSE);
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return constraint->strength == GTK_CONSTRAINT_STRENGTH_REQUIRED;
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}
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/**
|
||
* 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)
|
||
{
|
||
}
|