gtkmm: Gtk::ConstraintLayout Class Reference

A layout manager using constraints. More...

#include <gtkmm/constraintlayout.h>

Inheritance diagram for Gtk::ConstraintLayout:

[legend]

Public Types
using	VFLmap = std::map< Glib::ustring, Glib::RefPtr< ConstraintTarget > >
	A map type, used by add_constraints_from_description().

Public Member Functions
	ConstraintLayout (ConstraintLayout &&src) noexcept

ConstraintLayout &	operator= (ConstraintLayout &&src) noexcept

	~ConstraintLayout () noexcept override

GtkConstraintLayout *	gobj ()
	Provides access to the underlying C GObject.

const GtkConstraintLayout *	gobj () const
	Provides access to the underlying C GObject.

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

void	add_constraint (const Glib::RefPtr< Constraint > &constraint)
	Adds a constraint to the layout manager.

void	remove_constraint (const Glib::RefPtr< Constraint > &constraint)
	Removes `constraint` from the layout manager, so that it no longer influences the layout.

void	remove_all_constraints ()
	Removes all constraints from the layout manager.

void	add_guide (const Glib::RefPtr< ConstraintGuide > &guide)
	Adds a guide to `layout`.

void	remove_guide (const Glib::RefPtr< ConstraintGuide > &guide)
	Removes `guide` from the layout manager, so that it no longer influences the layout.

std::vector< Glib::RefPtr< Constraint > >	add_constraints_from_description (const std::vector< Glib::ustring > &lines, int hspacing, int vspacing, const VFLmap &views)
	Creates a list of constraints from a formal description using a compact description syntax called VFL, or "Visual Format Language".

Glib::RefPtr< Gio::ListModel >	observe_constraints ()
	Returns a `Gio::ListModel` to track the constraints that are part of the layout.

Glib::RefPtr< const Gio::ListModel >	observe_constraints () const
	Returns a `Gio::ListModel` to track the constraints that are part of the layout.

Glib::RefPtr< Gio::ListModel >	observe_guides ()
	Returns a `Gio::ListModel` to track the guides that are part of the layout.

Glib::RefPtr< const Gio::ListModel >	observe_guides () const
	Returns a `Gio::ListModel` to track the guides that are part of the layout.

Public Member Functions inherited from Gtk::LayoutManager
	LayoutManager (LayoutManager &&src) noexcept

LayoutManager &	operator= (LayoutManager &&src) noexcept

	~LayoutManager () noexcept override

GtkLayoutManager *	gobj ()
	Provides access to the underlying C GObject.

const GtkLayoutManager *	gobj () const
	Provides access to the underlying C GObject.

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

void	measure (Widget &widget, Orientation orientation, int for_size, int & minimum, int & natural, int &minimum_baseline, int &natural_baseline) const
	Measures the size of the widget using manager, for the given orientation and size.

void	allocate (Widget &widget, int width, int height, int baseline)
	Assigns the given width, height, and baseline to a widget, and computes the position and sizes of the children of the widget using the layout management policy of manager.

SizeRequestMode	get_request_mode () const
	Retrieves the request mode of manager.

Widget *	get_widget ()
	Retrieves the `Gtk::Widget` using the given `Gtk::LayoutManager`.

const Widget *	get_widget () const
	Retrieves the `Gtk::Widget` using the given `Gtk::LayoutManager`.

void	layout_changed ()
	Queues a resize on the `Gtk::Widget` using manager, if any.

Glib::RefPtr< LayoutChild >	get_layout_child (Widget &child)
	Retrieves a `Gtk::LayoutChild` instance for the `Gtk::LayoutManager`, creating one if necessary.

Glib::RefPtr< const LayoutChild >	get_layout_child (Widget &child) const
	Retrieves a `Gtk::LayoutChild` instance for the `Gtk::LayoutManager`, creating one if necessary.

Public Member Functions inherited from Gtk::Buildable
	Buildable (Buildable &&src) noexcept

Buildable &	operator= (Buildable &&src) noexcept

	~Buildable () noexcept override

GtkBuildable *	gobj ()
	Provides access to the underlying C GObject.

const GtkBuildable *	gobj () const
	Provides access to the underlying C GObject.

Glib::ustring	get_buildable_id () const
	Gets the ID of the buildable object.

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

static Glib::RefPtr< ConstraintLayout >	create ()

Static Public Member Functions inherited from Gtk::LayoutManager
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Static Public Member Functions inherited from Gtk::Buildable
static void	add_interface (GType gtype_implementer)

static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Member Functions
	ConstraintLayout ()

Protected Member Functions inherited from Gtk::LayoutManager
	LayoutManager ()
	There is no create() method that corresponds to this constructor, because only derived classes shall be created.

virtual SizeRequestMode	get_request_mode_vfunc (const Widget &widget) const

virtual void	measure_vfunc (const Widget &widget, Orientation orientation, int for_size, int & minimum, int & natural, int &minimum_baseline, int &natural_baseline) const

virtual void	allocate_vfunc (const Widget &widget, int width, int height, int baseline)

virtual Glib::RefPtr< LayoutChild >	create_layout_child_vfunc (const Widget &widget, const Widget &for_child)

virtual void	root_vfunc ()

virtual void	unroot_vfunc ()

Protected Member Functions inherited from Gtk::Buildable
	Buildable ()
	You should derive from this class to use it.

Related Symbols
(Note that these are not member symbols.)
Glib::RefPtr< Gtk::ConstraintLayout >	wrap (GtkConstraintLayout *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Related Symbols inherited from Gtk::LayoutManager
Glib::RefPtr< Gtk::LayoutManager >	wrap (GtkLayoutManager *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Related Symbols inherited from Gtk::Buildable
Glib::RefPtr< Gtk::Buildable >	wrap (GtkBuildable *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

A layout manager using constraints.

ConstraintLayout is a layout manager that uses relations between widget attributes, expressed via Gtk::Constraint instances, to measure and allocate widgets.

See the description of GtkConstraintLayout in GTK for a detailed description of how constraints work.

Since gtkmm 3.96:

Member Typedef Documentation

◆ VFLmap

using Gtk::ConstraintLayout::VFLmap = std::map<Glib::ustring, Glib::RefPtr<ConstraintTarget> >

A map type, used by add_constraints_from_description().

Constructor & Destructor Documentation

◆ ConstraintLayout() [1/2]

Gtk::ConstraintLayout::ConstraintLayout ( ConstraintLayout && src )

noexcept

◆ ~ConstraintLayout()

Gtk::ConstraintLayout::~ConstraintLayout ( )

overridenoexcept

◆ ConstraintLayout() [2/2]

Gtk::ConstraintLayout::ConstraintLayout ( )

protected

Member Function Documentation

◆ add_constraint()

void Gtk::ConstraintLayout::add_constraint ( const Glib::RefPtr< Constraint > & constraint )

Adds a constraint to the layout manager.

The Gtk::Constraint::property_source() and Gtk::Constraint::property_target() properties of constraint can be:

set to nullptr to indicate that the constraint refers to the widget using layout
set to the Gtk::Widget using layout
set to a child of the Gtk::Widget using layout
set to a Gtk::ConstraintGuide that is part of layout

The layout acquires the ownership of constraint after calling this function.

Parameters

constraint A Gtk::Constraint.

◆ add_constraints_from_description()

std::vector< Glib::RefPtr< Constraint > > Gtk::ConstraintLayout::add_constraints_from_description	(	const std::vector< Glib::ustring > &	lines,
		int	hspacing,
		int	vspacing,
		const VFLmap &	views
	)

Creates a list of constraints from a formal description using a compact description syntax called VFL, or "Visual Format Language".

The Visual Format Language is based on Apple's AutoLayout VFL. See also the description of gtk_constraint_layout_add_constraints_from_descriptionv() in GTK.

The views dictionary is used to match Gtk::ConstraintTargets to the symbolic view name inside the VFL.

Note: The VFL grammar used by GTK is slightly different than the one defined by Apple, as it can use symbolic values for the constraint's strength instead of numeric values; additionally, GTK allows adding simple arithmetic operations inside predicates.

Parameters

lines	A vector of Visual Format Language lines defining a set of constraints.
hspacing	Default horizontal spacing value, or -1 for the fallback value.
vspacing	Default vertical spacing value, or -1 for the fallback value.
views	A dictionary of [ name, target ] pairs; the `name` keys map to the view names in the VFL lines, while the `target` values map to children of the widget using a Gtk::ConstraintLayout, or guides.

Returns: The vector of Gtk::Constraints that were added to the layout.

Exceptions

Gtk::ConstraintVflParserError

◆ add_guide()

void Gtk::ConstraintLayout::add_guide ( const Glib::RefPtr< ConstraintGuide > & guide )

Adds a guide to layout.

A guide can be used as the source or target of constraints, like a widget, but it is not visible.

The layout acquires the ownership of guide after calling this function.

Parameters

guide A Gtk::ConstraintGuide object.

◆ create()

static Glib::RefPtr< ConstraintLayout > Gtk::ConstraintLayout::create ( )

static

◆ get_type()

static GType Gtk::ConstraintLayout::get_type ( )

static

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

◆ gobj() [1/2]

GtkConstraintLayout * Gtk::ConstraintLayout::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GtkConstraintLayout * Gtk::ConstraintLayout::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GtkConstraintLayout * Gtk::ConstraintLayout::gobj_copy ( )

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

◆ observe_constraints() [1/2]

Glib::RefPtr< Gio::ListModel > Gtk::ConstraintLayout::observe_constraints ( )

Returns a Gio::ListModel to track the constraints that are part of the layout.

Calling this function will enable extra internal bookkeeping to track constraints and emit signals on the returned listmodel. It may slow down operations a lot.

Applications should try hard to avoid calling this function because of the slowdowns.

Returns: A Gio::ListModel tracking the layout's constraints.

◆ observe_constraints() [2/2]

Glib::RefPtr< const Gio::ListModel > Gtk::ConstraintLayout::observe_constraints ( ) const

Returns a Gio::ListModel to track the constraints that are part of the layout.

Calling this function will enable extra internal bookkeeping to track constraints and emit signals on the returned listmodel. It may slow down operations a lot.

Applications should try hard to avoid calling this function because of the slowdowns.

Returns: A Gio::ListModel tracking the layout's constraints.

◆ observe_guides() [1/2]

Glib::RefPtr< Gio::ListModel > Gtk::ConstraintLayout::observe_guides ( )

Returns a Gio::ListModel to track the guides that are part of the layout.

Calling this function will enable extra internal bookkeeping to track guides and emit signals on the returned listmodel. It may slow down operations a lot.

Applications should try hard to avoid calling this function because of the slowdowns.

Returns: A Gio::ListModel tracking the layout's guides.

◆ observe_guides() [2/2]

Glib::RefPtr< const Gio::ListModel > Gtk::ConstraintLayout::observe_guides ( ) const

Returns a Gio::ListModel to track the guides that are part of the layout.

Calling this function will enable extra internal bookkeeping to track guides and emit signals on the returned listmodel. It may slow down operations a lot.

Applications should try hard to avoid calling this function because of the slowdowns.

Returns: A Gio::ListModel tracking the layout's guides.

◆ operator=()

ConstraintLayout & Gtk::ConstraintLayout::operator= ( ConstraintLayout && src )

noexcept

◆ remove_all_constraints()

void Gtk::ConstraintLayout::remove_all_constraints ( )

Removes all constraints from the layout manager.

◆ remove_constraint()

void Gtk::ConstraintLayout::remove_constraint ( const Glib::RefPtr< Constraint > & constraint )

Removes constraint from the layout manager, so that it no longer influences the layout.

Parameters

constraint A Gtk::Constraint.

◆ remove_guide()

void Gtk::ConstraintLayout::remove_guide ( const Glib::RefPtr< ConstraintGuide > & guide )

Removes guide from the layout manager, so that it no longer influences the layout.

Parameters

guide A Gtk::ConstraintGuide object.

Friends And Related Symbol Documentation

◆ wrap()

Glib::RefPtr< Gtk::ConstraintLayout > wrap	(	GtkConstraintLayout *	object,
		bool	take_copy = `false`
	)

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

Parameters

object	The C instance.
take_copy	False 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.

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Related Symbols

Detailed Description

Member Typedef Documentation

◆ VFLmap

Constructor & Destructor Documentation

◆ ConstraintLayout() [1/2]

◆ ~ConstraintLayout()

◆ ConstraintLayout() [2/2]

Member Function Documentation

◆ add_constraint()

◆ add_constraints_from_description()

◆ add_guide()

◆ create()

◆ get_type()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ observe_constraints() [1/2]

◆ observe_constraints() [2/2]

◆ observe_guides() [1/2]

◆ observe_guides() [2/2]

◆ operator=()

◆ remove_all_constraints()

◆ remove_constraint()

◆ remove_guide()

Friends And Related Symbol Documentation

◆ wrap()