gtkmm  4.8.0
Classes | Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | Related Functions | List of all members
Gtk::Constraint Class Reference

The description of a constraint. More...

#include <gtkmm/constraint.h>

Inherits Glib::Object.

Classes

class  Strength_Wrapper
 Wrapper for enum Strength. More...
 

Public Types

enum class  Attribute {
  NONE ,
  LEFT ,
  RIGHT ,
  TOP ,
  BOTTOM ,
  START ,
  END ,
  WIDTH ,
  HEIGHT ,
  CENTER_X ,
  CENTER_Y ,
  BASELINE
}
 The widget attributes that can be used when creating a Gtk::Constraint. More...
 
enum class  Relation {
  LE = -1 ,
  EQ ,
  GE
}
 The relation between two terms of a constraint. More...
 
using Strength = Strength_Wrapper::Strength
 Strength enumerators are scoped by the wrapper class and can be implicitly converted to int. More...
 

Public Member Functions

 Constraint (Constraint && src) noexcept
 
Constraintoperator= (Constraint && src) noexcept
 
 ~Constraint () noexcept override
 
GtkConstraint * gobj ()
 Provides access to the underlying C GObject. More...
 
const GtkConstraint * gobj () const
 Provides access to the underlying C GObject. More...
 
GtkConstraint * gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
 
Glib::RefPtr< ConstraintTargetget_target ()
 Retrieves the Gtk::ConstraintTarget used as the target for the constraint. More...
 
Glib::RefPtr< const ConstraintTargetget_target () const
 Retrieves the Gtk::ConstraintTarget used as the target for the constraint. More...
 
Attribute get_target_attribute () const
 Retrieves the attribute of the target to be set by the constraint. More...
 
Glib::RefPtr< ConstraintTargetget_source ()
 Retrieves the Gtk::ConstraintTarget used as the source for the constraint. More...
 
Glib::RefPtr< const ConstraintTargetget_source () const
 Retrieves the Gtk::ConstraintTarget used as the source for the constraint. More...
 
Attribute get_source_attribute () const
 Retrieves the attribute of the source to be read by the constraint. More...
 
Relation get_relation () const
 The order relation between the terms of the constraint. More...
 
double get_multiplier () const
 Retrieves the multiplication factor applied to the source attribute's value. More...
 
double get_constant () const
 Retrieves the constant factor added to the source attributes' value. More...
 
int get_strength () const
 Retrieves the strength of the constraint. More...
 
bool is_required () const
 Checks whether the constraint is a required relation for solving the constraint layout. More...
 
bool is_attached () const
 Checks whether the constraint is attached to a Gtk::ConstraintLayout, and it is contributing to the layout. More...
 
bool is_constant () const
 Checks whether the constraint describes a relation between an attribute on the property_target() and a constant value. More...
 
Glib::PropertyProxy_ReadOnly< Glib::RefPtr< ConstraintTarget > > property_target () const
 The target of the constraint. More...
 
Glib::PropertyProxy_ReadOnly< Attributeproperty_target_attribute () const
 The attribute of the property_target() set by the constraint. More...
 
Glib::PropertyProxy_ReadOnly< Relationproperty_relation () const
 The order relation between the terms of the constraint. More...
 
Glib::PropertyProxy_ReadOnly< Glib::RefPtr< ConstraintTarget > > property_source () const
 The source of the constraint. More...
 
Glib::PropertyProxy_ReadOnly< Attributeproperty_source_attribute () const
 The attribute of the property_source() read by the constraint. More...
 
Glib::PropertyProxy_ReadOnly< double > property_multiplier () const
 The multiplication factor to be applied to the property_source_attribute(). More...
 
Glib::PropertyProxy_ReadOnly< double > property_constant () const
 The constant value to be added to the property_source_attribute(). More...
 
Glib::PropertyProxy_ReadOnly< int > property_strength () const
 The strength of the constraint. More...
 

Static Public Member Functions

static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...
 
static Glib::RefPtr< Constraintcreate (const Glib::RefPtr< ConstraintTarget > & target, Attribute target_attribute, Relation relation, const Glib::RefPtr< ConstraintTarget > & source, Attribute source_attribute, double multiplier, double constant, int strength)
 Creates a new Gtk::Constraint representing a relation between a layout attribute on a source and a layout attribute on a target. More...
 
static Glib::RefPtr< Constraintcreate (const Glib::RefPtr< ConstraintTarget > & target, Attribute target_attribute, Relation relation, double constant, int strength)
 Creates a new Gtk::Constraint representing a relation between a layout attribute on a target and a constant value. More...
 

Protected Member Functions

 Constraint (const Glib::RefPtr< ConstraintTarget > & target, Attribute target_attribute, Relation relation, const Glib::RefPtr< ConstraintTarget > & source, Attribute source_attribute, double multiplier, double constant, int strength)
 
 Constraint (const Glib::RefPtr< ConstraintTarget > & target, Attribute target_attribute, Relation relation, double constant, int strength)
 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gtk::Constraintwrap (GtkConstraint * object, bool take_copy=false)
 A Glib::wrap() method for this object. More...
 

Detailed Description

The description of a constraint.

Gtk::Constraint 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 Constraint is part of a system that will be solved by a Gtk::ConstraintLayout in order to allocate and position each child widget.

A Constraint is immutable once it's created.

Since gtkmm 3.96:

Constructor & Destructor Documentation

◆ Constraint() [1/3]

Gtk::Constraint::Constraint ( Constraint &&  src)
noexcept

◆ ~Constraint()

Gtk::Constraint::~Constraint ( )
overridenoexcept

◆ Constraint() [2/3]

Gtk::Constraint::Constraint ( const Glib::RefPtr< ConstraintTarget > &  target,
Attribute  target_attribute,
Relation  relation,
const Glib::RefPtr< ConstraintTarget > &  source,
Attribute  source_attribute,
double  multiplier,
double  constant,
int  strength 
)
explicitprotected

◆ Constraint() [3/3]

Gtk::Constraint::Constraint ( const Glib::RefPtr< ConstraintTarget > &  target,
Attribute  target_attribute,
Relation  relation,
double  constant,
int  strength 
)
explicitprotected

Member Function Documentation

◆ create() [1/2]

static Glib::RefPtr<Constraint> Gtk::Constraint::create ( const Glib::RefPtr< ConstraintTarget > &  target,
Attribute  target_attribute,
Relation  relation,
const Glib::RefPtr< ConstraintTarget > &  source,
Attribute  source_attribute,
double  multiplier,
double  constant,
int  strength 
)
static

Creates a new Gtk::Constraint representing a relation between a layout attribute on a source and a layout attribute on a target.

Parameters
targetA Gtk::ConstraintTarget or an empty Glib::RefPtr.
target_attributeThe attribute of target to be set.
relationThe relation equivalence between target_attribute and source_attribute.
sourceA Gtk::ConstraintTarget or an empty Glib::RefPtr.
source_attributeThe attribute of source to be read.
multiplierA multiplication factor to be applied to source_attribute.
constantA constant to be added to source_attribute.
strengthThe strength of the constraint.
Returns
The newly created Gtk::Constraint.

◆ create() [2/2]

static Glib::RefPtr<Constraint> Gtk::Constraint::create ( const Glib::RefPtr< ConstraintTarget > &  target,
Attribute  target_attribute,
Relation  relation,
double  constant,
int  strength 
)
static

Creates a new Gtk::Constraint representing a relation between a layout attribute on a target and a constant value.

Parameters
targetA Gtk::ConstraintTarget or an empty Glib::RefPtr.
target_attributeThe attribute of target to be set.
relationThe relation equivalence between target_attribute and constant.
constantA constant to be set on target_attribute.
strengthThe strength of the constraint.
Returns
The newly created Gtk::Constraint.

◆ get_constant()

double Gtk::Constraint::get_constant ( ) const

Retrieves the constant factor added to the source attributes' value.

Returns
A constant factor.

◆ get_multiplier()

double Gtk::Constraint::get_multiplier ( ) const

Retrieves the multiplication factor applied to the source attribute's value.

Returns
A multiplication factor.

◆ get_relation()

Relation Gtk::Constraint::get_relation ( ) const

The order relation between the terms of the constraint.

Returns
A relation type.

◆ get_source() [1/2]

Glib::RefPtr<ConstraintTarget> Gtk::Constraint::get_source ( )

Retrieves the Gtk::ConstraintTarget used as the source for the constraint.

If the source is set to nullptr at creation, the constraint will use the widget using the Gtk::ConstraintLayout as the source.

Returns
The source of the constraint.

◆ get_source() [2/2]

Glib::RefPtr<const ConstraintTarget> Gtk::Constraint::get_source ( ) const

Retrieves the Gtk::ConstraintTarget used as the source for the constraint.

If the source is set to nullptr at creation, the constraint will use the widget using the Gtk::ConstraintLayout as the source.

Returns
The source of the constraint.

◆ get_source_attribute()

Attribute Gtk::Constraint::get_source_attribute ( ) const

Retrieves the attribute of the source to be read by the constraint.

Returns
The source's attribute.

◆ get_strength()

int Gtk::Constraint::get_strength ( ) const

Retrieves the strength of the constraint.

Returns
The strength value.

◆ get_target() [1/2]

Glib::RefPtr<ConstraintTarget> Gtk::Constraint::get_target ( )

Retrieves the Gtk::ConstraintTarget used as the target for the constraint.

If the targe is set to nullptr at creation, the constraint will use the widget using the Gtk::ConstraintLayout as the target.

Returns
A Gtk::ConstraintTarget.

◆ get_target() [2/2]

Glib::RefPtr<const ConstraintTarget> Gtk::Constraint::get_target ( ) const

Retrieves the Gtk::ConstraintTarget used as the target for the constraint.

If the targe is set to nullptr at creation, the constraint will use the widget using the Gtk::ConstraintLayout as the target.

Returns
A Gtk::ConstraintTarget.

◆ get_target_attribute()

Attribute Gtk::Constraint::get_target_attribute ( ) const

Retrieves the attribute of the target to be set by the constraint.

Returns
The target's attribute.

◆ get_type()

static GType Gtk::Constraint::get_type ( )
static

Get the GType for this class, for use with the underlying GObject type system.

◆ gobj() [1/2]

GtkConstraint* Gtk::Constraint::gobj ( )
inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GtkConstraint* Gtk::Constraint::gobj ( ) const
inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GtkConstraint* Gtk::Constraint::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

◆ is_attached()

bool Gtk::Constraint::is_attached ( ) const

Checks whether the constraint is attached to a Gtk::ConstraintLayout, and it is contributing to the layout.

Returns
true if the constraint is attached.

◆ is_constant()

bool Gtk::Constraint::is_constant ( ) const

Checks whether the constraint describes a relation between an attribute on the property_target() and a constant value.

Returns
true if the constraint is a constant relation.

◆ is_required()

bool Gtk::Constraint::is_required ( ) const

Checks whether the constraint is a required relation for solving the constraint layout.

Returns
true if the constraint is required.

◆ operator=()

Constraint& Gtk::Constraint::operator= ( Constraint &&  src)
noexcept

◆ property_constant()

Glib::PropertyProxy_ReadOnly< double > Gtk::Constraint::property_constant ( ) const

The constant value to be added to the property_source_attribute().

Default value: 0

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_multiplier()

Glib::PropertyProxy_ReadOnly< double > Gtk::Constraint::property_multiplier ( ) const

The multiplication factor to be applied to the property_source_attribute().

Default value: 1

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_relation()

Glib::PropertyProxy_ReadOnly< Relation > Gtk::Constraint::property_relation ( ) const

The order relation between the terms of the constraint.

Default value: Gtk::Constraint::Relation::EQ

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_source()

Glib::PropertyProxy_ReadOnly< Glib::RefPtr<ConstraintTarget> > Gtk::Constraint::property_source ( ) const

The source of the constraint.

The constraint will set the property_target_attribute() property of the target using the property_source_attribute() property of the source.

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_source_attribute()

Glib::PropertyProxy_ReadOnly< Attribute > Gtk::Constraint::property_source_attribute ( ) const

The attribute of the property_source() read by the constraint.

Default value: Gtk::Constraint::Attribute::NONE

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_strength()

Glib::PropertyProxy_ReadOnly< int > Gtk::Constraint::property_strength ( ) const

The strength of the constraint.

The strength can be expressed either using one of the symbolic values of the Gtk::ConstraintStrength enumeration, or any positive integer value.

Default value: 1001001000

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_target()

Glib::PropertyProxy_ReadOnly< Glib::RefPtr<ConstraintTarget> > Gtk::Constraint::property_target ( ) const

The target of the constraint.

The constraint will set the property_target_attribute() property of the target using the property_source_attribute() property of the source widget.

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_target_attribute()

Glib::PropertyProxy_ReadOnly< Attribute > Gtk::Constraint::property_target_attribute ( ) const

The attribute of the property_target() set by the constraint.

Default value: Gtk::Constraint::Attribute::NONE

Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gtk::Constraint > wrap ( GtkConstraint *  object,
bool  take_copy = false 
)
related

A Glib::wrap() method for this object.

Parameters
objectThe C instance.
take_copyFalse if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns
A C++ instance that wraps this C instance.