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

A layout manager using constraints. More...

#include <gtkmm/constraintlayout.h>

Inheritance diagram for Gtk::ConstraintLayout:
Inheritance graph
[legend]

Public Types

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

Public Member Functions

 ConstraintLayout (ConstraintLayout && src) noexcept
 
ConstraintLayoutoperator= (ConstraintLayout && src) noexcept
 
 ~ConstraintLayout () noexcept override
 
GtkConstraintLayout * gobj ()
 Provides access to the underlying C GObject. More...
 
const GtkConstraintLayout * gobj () const
 Provides access to the underlying C GObject. More...
 
GtkConstraintLayout * gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
 
void add_constraint (const Glib::RefPtr< Constraint > & constraint)
 Adds a constraint to the layout manager. More...
 
void remove_constraint (const Glib::RefPtr< Constraint > & constraint)
 Removes constraint from the layout manager, so that it no longer influences the layout. More...
 
void remove_all_constraints ()
 Removes all constraints from the layout manager. More...
 
void add_guide (const Glib::RefPtr< ConstraintGuide > & guide)
 Adds a guide to layout. More...
 
void remove_guide (const Glib::RefPtr< ConstraintGuide > & guide)
 Removes guide from the layout manager, so that it no longer influences the layout. More...
 
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". More...
 
Glib::RefPtr< Gio::ListModel > observe_constraints ()
 Returns a Gio::ListModel to track the constraints that are part of the layout. More...
 
Glib::RefPtr< const Gio::ListModel > observe_constraints () const
 Returns a Gio::ListModel to track the constraints that are part of the layout. More...
 
Glib::RefPtr< Gio::ListModel > observe_guides ()
 Returns a Gio::ListModel to track the guides that are part of the layout. More...
 
Glib::RefPtr< const Gio::ListModel > observe_guides () const
 Returns a Gio::ListModel to track the guides that are part of the layout. More...
 
- Public Member Functions inherited from Gtk::LayoutManager
 LayoutManager (LayoutManager && src) noexcept
 
LayoutManageroperator= (LayoutManager && src) noexcept
 
 ~LayoutManager () noexcept override
 
GtkLayoutManager * gobj ()
 Provides access to the underlying C GObject. More...
 
const GtkLayoutManager * gobj () const
 Provides access to the underlying C GObject. More...
 
GtkLayoutManager * gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
 
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. More...
 
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. More...
 
SizeRequestMode get_request_mode () const
 Retrieves the request mode of manager. More...
 
Widgetget_widget ()
 Retrieves the Gtk::Widget using the given Gtk::LayoutManager. More...
 
const Widgetget_widget () const
 Retrieves the Gtk::Widget using the given Gtk::LayoutManager. More...
 
void layout_changed ()
 Queues a resize on the Gtk::Widget using manager, if any. More...
 
Glib::RefPtr< LayoutChildget_layout_child (Widget & child)
 Retrieves a Gtk::LayoutChild instance for the Gtk::LayoutManager, creating one if necessary. More...
 
Glib::RefPtr< const LayoutChildget_layout_child (Widget & child) const
 Retrieves a Gtk::LayoutChild instance for the Gtk::LayoutManager, creating one if necessary. More...
 
- Public Member Functions inherited from Gtk::Buildable
 Buildable (Buildable && src) noexcept
 
Buildableoperator= (Buildable && src) noexcept
 
 ~Buildable () noexcept override
 
GtkBuildable * gobj ()
 Provides access to the underlying C GObject. More...
 
const GtkBuildable * gobj () const
 Provides access to the underlying C GObject. More...
 
Glib::ustring get_buildable_id () const
 Gets the ID of the buildable object. 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< ConstraintLayoutcreate ()
 
- 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. More...
 
- 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. More...
 

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. More...
 
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< LayoutChildcreate_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. More...
 

Related Functions

(Note that these are not member functions.)

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

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
constraintA 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
linesA vector of Visual Format Language lines defining a set of constraints.
hspacingDefault horizontal spacing value, or -1 for the fallback value.
vspacingDefault vertical spacing value, or -1 for the fallback value.
viewsA 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
guideA 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
constraintA 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
guideA Gtk::ConstraintGuide object.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gtk::ConstraintLayout > wrap ( GtkConstraintLayout *  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.