gtkmm: Gtk::LayoutManager Class Reference

Base class for layout manager. More...

#include <gtkmm/layoutmanager.h>

Inheritance diagram for Gtk::LayoutManager:

[legend]

Public Member Functions
	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.

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

Protected Member Functions
	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 ()

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

Detailed Description

Base class for layout manager.

Layout managers are delegate classes that handle the preferred size and the allocation of a container widget.

You typically subclass Gtk::LayoutManager if you want to implement a layout policy for the children of a widget, or if you want to determine the size of a widget depending on its contents.

Each Gtk::Widget can only have one Gtk::LayoutManager instance associated to it at any given time; it is possible, though, to replace the layout manager instance using Gtk::Widget::set_layout_manager().

Layout properties

A layout manager can expose properties for controlling the layout of each child, by creating an object type derived from Gtk::LayoutChild and installing the properties on it as normal GObject properties.

Each Gtk::LayoutChild instance storing the layout properties for a specific child is created through the get_layout_child() method; a Gtk::LayoutManager controls the creation of its Gtk::LayoutChild instances by overriding the create_layout_child_vfunc() virtual function.

Gtk::LayoutChild::property_layout_manager() and Gtk::LayoutChild::property_child_widget() on the newly created Gtk::LayoutChild instance are mandatory. The Gtk::LayoutManager will cache the newly created Gtk::LayoutChild instance until the widget is removed from its parent, or the parent removes the layout manager.

Each Gtk::LayoutManager instance creating a Gtk::LayoutChild should use get_layout_child() every time it needs to query the layout properties; each Gtk::LayoutChild instance should call layout_changed() every time a property is updated, in order to queue a new size measuring and allocation.

Since gtkmm 3.96:

Constructor & Destructor Documentation

◆ LayoutManager() [1/2]

Gtk::LayoutManager::LayoutManager ( LayoutManager && src )

noexcept

◆ ~LayoutManager()

Gtk::LayoutManager::~LayoutManager ( )

overridenoexcept

◆ LayoutManager() [2/2]

Gtk::LayoutManager::LayoutManager ( )

protected

There is no create() method that corresponds to this constructor, because only derived classes shall be created.

Member Function Documentation

◆ allocate()

void Gtk::LayoutManager::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.

Parameters

widget	The `Gtk::Widget` using manager.
width	The new width of the widget.
height	The new height of the widget.
baseline	The baseline position of the widget, or -1.

◆ allocate_vfunc()

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

protectedvirtual

◆ create_layout_child_vfunc()

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

protectedvirtual

◆ get_layout_child() [1/2]

Glib::RefPtr< LayoutChild > Gtk::LayoutManager::get_layout_child ( Widget & child )

Retrieves a Gtk::LayoutChild instance for the Gtk::LayoutManager, creating one if necessary.

The child widget must be a child of the widget using manager.

The Gtk::LayoutChild instance is owned by the Gtk::LayoutManager, and is guaranteed to exist as long as child is a child of the Gtk::Widget using the given Gtk::LayoutManager.

Parameters

child A Gtk::Widget.

Returns: A Gtk::LayoutChild.

◆ get_layout_child() [2/2]

Glib::RefPtr< const LayoutChild > Gtk::LayoutManager::get_layout_child ( Widget & child ) const

Retrieves a Gtk::LayoutChild instance for the Gtk::LayoutManager, creating one if necessary.

The child widget must be a child of the widget using manager.

The Gtk::LayoutChild instance is owned by the Gtk::LayoutManager, and is guaranteed to exist as long as child is a child of the Gtk::Widget using the given Gtk::LayoutManager.

Parameters

child A Gtk::Widget.

Returns: A Gtk::LayoutChild.

◆ get_request_mode()

SizeRequestMode Gtk::LayoutManager::get_request_mode ( ) const

Retrieves the request mode of manager.

Returns: A Gtk::SizeRequestMode.

◆ get_request_mode_vfunc()

virtual SizeRequestMode Gtk::LayoutManager::get_request_mode_vfunc ( const Widget & widget ) const

protectedvirtual

◆ get_type()

static GType Gtk::LayoutManager::get_type ( )

static

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

◆ get_widget() [1/2]

Widget * Gtk::LayoutManager::get_widget ( )

Retrieves the Gtk::Widget using the given Gtk::LayoutManager.

Returns: A Gtk::Widget.

◆ get_widget() [2/2]

const Widget * Gtk::LayoutManager::get_widget ( ) const

Retrieves the Gtk::Widget using the given Gtk::LayoutManager.

Returns: A Gtk::Widget.

◆ gobj() [1/2]

GtkLayoutManager * Gtk::LayoutManager::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GtkLayoutManager * Gtk::LayoutManager::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GtkLayoutManager * Gtk::LayoutManager::gobj_copy ( )

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

◆ layout_changed()

void Gtk::LayoutManager::layout_changed ( )

Queues a resize on the Gtk::Widget using manager, if any.

This function should be called by subclasses of Gtk::LayoutManager in response to changes to their layout management policies.

◆ measure()

void Gtk::LayoutManager::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.

See the Gtk::Widget documentation on layout management for more details.

Parameters

widget	The `Gtk::Widget` using manager.
orientation	The orientation to measure.
for_size	Size for the opposite of orientation; for instance, if the orientation is Gtk::Orientation::HORIZONTAL, this is the height of the widget; if the orientation is Gtk::Orientation::VERTICAL, this is the width of the widget. This allows to measure the height for the given width, and the width for the given height. Use -1 if the size is not known.
minimum	The minimum size for the given size and orientation.
natural	The natural, or preferred size for the given size and orientation.
minimum_baseline	The baseline position for the minimum size.
natural_baseline	The baseline position for the natural size.

◆ measure_vfunc()

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

protectedvirtual

◆ operator=()

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

noexcept

◆ root_vfunc()

virtual void Gtk::LayoutManager::root_vfunc ( )

protectedvirtual

◆ unroot_vfunc()

virtual void Gtk::LayoutManager::unroot_vfunc ( )

protectedvirtual

Friends And Related Symbol Documentation

◆ wrap()

Glib::RefPtr< Gtk::LayoutManager > wrap	(	GtkLayoutManager *	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 Member Functions

Static Public Member Functions

Protected Member Functions

Related Symbols

Detailed Description

Layout properties

Constructor & Destructor Documentation

◆ LayoutManager() [1/2]

◆ ~LayoutManager()

◆ LayoutManager() [2/2]

Member Function Documentation

◆ allocate()

◆ allocate_vfunc()

◆ create_layout_child_vfunc()

◆ get_layout_child() [1/2]

◆ get_layout_child() [2/2]

◆ get_request_mode()

◆ get_request_mode_vfunc()

◆ get_type()

◆ get_widget() [1/2]

◆ get_widget() [2/2]

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ layout_changed()

◆ measure()

◆ measure_vfunc()

◆ operator=()

◆ root_vfunc()

◆ unroot_vfunc()

Friends And Related Symbol Documentation

◆ wrap()