gtkmm: Gdk::Cursor Class Reference

Gdk::Cursor is used to create and destroy cursors. More...

#include <gdkmm/cursor.h>

Inheritance diagram for Gdk::Cursor:

Public Types
using	SlotGetTexture = sigc::slot< Glib::RefPtr< Texture >(int, double, int &, int &, int &, int &)>
	Callback used by a dynamic Gdk::Cursor to generate a texture for the cursor image at the given cursor_size and scale. More...

Public Member Functions
	Cursor (Cursor && src) noexcept

Cursor &	operator= (Cursor && src) noexcept

	~Cursor () noexcept override

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

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

GdkCursor *	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< Cursor >	get_fallback ()
	Returns the fallback for this cursor. More...

Glib::RefPtr< const Cursor >	get_fallback () const
	Returns the fallback for this cursor. More...

Glib::ustring	get_name () const
	Returns the name of the cursor. More...

Glib::RefPtr< Texture >	get_texture ()
	Returns the texture for the cursor. More...

Glib::RefPtr< const Texture >	get_texture () const
	Returns the texture for the cursor. More...

int	get_hotspot_x () const
	Returns the horizontal offset of the hotspot. More...

int	get_hotspot_y () const
	Returns the vertical offset of the hotspot. More...

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Cursor > >	property_fallback () const
	Cursor to fall back to if this cursor cannot be displayed. More...

Glib::PropertyProxy_ReadOnly< int >	property_hotspot_x () const
	X position of the cursor hotspot in the cursor image. More...

Glib::PropertyProxy_ReadOnly< int >	property_hotspot_y () const
	Y position of the cursor hotspot in the cursor image. More...

Glib::PropertyProxy_ReadOnly< Glib::ustring >	property_name () const
	Name of this this cursor. More...

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Texture > >	property_texture () const
	The texture displayed by this cursor. 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< Cursor >	create (const Glib::RefPtr< const Texture > & texture, int hotspot_x, int hotspot_y, const Glib::RefPtr< Cursor > & fallback={})
	Creates a new cursor from a `Gdk::Texture`. More...

static Glib::RefPtr< Cursor >	create (const Glib::ustring & name, const Glib::RefPtr< Cursor > & fallback={})
	Creates a new cursor by looking up name in the current cursor theme. More...

static Glib::RefPtr< Cursor >	create (const SlotGetTexture & slot, const Glib::RefPtr< Cursor > & fallback={})
	Creates a new callback-based cursor object. More...

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gdk::Cursor >	wrap (GdkCursor * object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Detailed Description

Gdk::Cursor is used to create and destroy cursors.

Cursors are immutable objects, so once you created them, there is no way to modify them later. You should create a new cursor when you want to change something about it.

Cursors by themselves are not very interesting: they must be bound to a window for users to see them. This is done with Gdk::Surface::set_cursor() or Gdk::Surface::set_device_cursor(). Applications will typically use higher-level GTK functions such as Gtk::Widget::set_cursor() instead.

Cursors are not bound to a given Gdk::Display, so they can be shared. However, the appearance of cursors may vary when used on different platforms.

Named and texture cursors

There are multiple ways to create cursors. The platform's own cursors can be created with create(const Glib::ustring& name, const Glib::RefPtr<Cursor>& fallback). That function lists the commonly available names that are shared with the CSS specification. Other names may be available, depending on the platform in use. On some platforms, what images are used for named cursors may be influenced by the cursor theme.

Another option to create a cursor is to use create(const Glib::RefPtr<const Texture>& texture, int hotspot_x, int hotspot_y, const Glib::RefPtr<Cursor>& fallback) and provide an image to use for the cursor.

To ease work with unsupported cursors, a fallback cursor can be provided. If a Gdk::Surface cannot use a cursor, it will try the fallback cursor. Fallback cursors can themselves have fallback cursors again, so it is possible to provide a chain of progressively easier to support cursors. If none of the provided cursors can be supported, the default cursor will be the ultimate fallback.

Member Typedef Documentation

◆ SlotGetTexture

using Gdk::Cursor::SlotGetTexture = sigc::slot<Glib::RefPtr<Texture>(int, double, int&, int&, int&, int&)>

Callback used by a dynamic Gdk::Cursor to generate a texture for the cursor image at the given cursor_size and scale.

The actual cursor size in application pixels may be different from cursor_size x cursor_size, and will be returned in width, height. The returned texture should have a size that corresponds to the actual cursor size, in device pixels (i.e. application pixels, multiplied by scale).

This function may fail and return an empty RefPtr, in which case the fallback cursor will be used.

Parameters

	cursor_size	The nominal cursor size, in application pixels.
	scale	The device scale.
[out]	width	Return location for the actual cursor width, in application pixels.
[out]	height	Return location for the actual cursor height, in application pixels.
[out]	hotspot_x	Return location for the hotspot X position, in application pixels.
[out]	hotspot_y	Return location for the hotspot Y position, in application pixels.

Returns: The cursor image, or an empty RefPtr if none could be produced..

Since gtkmm 4.16:

Constructor & Destructor Documentation

◆ Cursor()

Gdk::Cursor::Cursor ( Cursor && src )

noexcept

◆ ~Cursor()

Gdk::Cursor::~Cursor ( )

overridenoexcept

Member Function Documentation

◆ create() [1/3]

static Glib::RefPtr< Cursor > Gdk::Cursor::create	(	const Glib::RefPtr< const Texture > &	texture,
		int	hotspot_x,
		int	hotspot_y,
		const Glib::RefPtr< Cursor > &	fallback = `{}`
	)

static

Creates a new cursor from a Gdk::Texture.

Parameters

texture	The texture providing the pixel data.
hotspot_x	The horizontal offset of the “hotspot” of the cursor.
hotspot_y	The vertical offset of the “hotspot” of the cursor.
fallback	The `Gdk::Cursor` to fall back to when this one cannot be supported.

Returns: A new Gdk::Cursor.

◆ create() [2/3]

static Glib::RefPtr< Cursor > Gdk::Cursor::create	(	const Glib::ustring &	name,
		const Glib::RefPtr< Cursor > &	fallback = `{}`
	)

static

Creates a new cursor by looking up name in the current cursor theme.

A recommended set of cursor names that will work across different platforms can be found in the CSS specification:


"none"	"default"	"help"	"pointer"
"context-menu"	"progress"	"wait"	"cell"
"crosshair"	"text"	"vertical-text"	"alias"
"copy"	"no-drop"	"move"	"not-allowed"
"grab"	"grabbing"	"all-scroll"	"col-resize"
"row-resize"	"n-resize"	"e-resize"	"s-resize"
"w-resize"	"ne-resize"	"nw-resize"	"sw-resize"
"se-resize"	"ew-resize"	"ns-resize"	"nesw-resize"
"nwse-resize"	"zoom-in"	"zoom-out"

Parameters

name	The name of the cursor.
fallback	`nullptr` or the `Gdk::Cursor` to fall back to when this one cannot be supported.

Returns: A new Gdk::Cursor, or nullptr if there is no cursor with the given name.

◆ create() [3/3]

static Glib::RefPtr< Cursor > Gdk::Cursor::create	(	const SlotGetTexture &	slot,
		const Glib::RefPtr< Cursor > &	fallback = `{}`
	)

static

Creates a new callback-based cursor object.

Cursors of this kind produce textures for the cursor image on demand, when the slot is called.

Since gtkmm 4.16:

Parameters

slot	Callback that lets you create a suitable texture.
fallback	The Gdk::Cursor to fall back to when this one cannot be supported.

Returns: A new Gdk::Cursor.

◆ get_fallback() [1/2]

Glib::RefPtr< Cursor > Gdk::Cursor::get_fallback ( )

Returns the fallback for this cursor.

The fallback will be used if this cursor is not available on a given Gdk::Display. For named cursors, this can happen when using nonstandard names or when using an incomplete cursor theme. For textured cursors, this can happen when the texture is too large or when the Gdk::Display it is used on does not support textured cursors.

Returns: The fallback of the cursor or nullptr to use the default cursor as fallback.

◆ get_fallback() [2/2]

Glib::RefPtr< const Cursor > Gdk::Cursor::get_fallback ( ) const

Returns the fallback for this cursor.

Returns: The fallback of the cursor or nullptr to use the default cursor as fallback.

◆ get_hotspot_x()

int Gdk::Cursor::get_hotspot_x ( ) const

Returns the horizontal offset of the hotspot.

The hotspot indicates the pixel that will be directly above the cursor.

Note that named cursors may have a nonzero hotspot, but this function will only return the hotspot position for cursors created with new_from_texture().

Returns: The horizontal offset of the hotspot or 0 for named cursors.

◆ get_hotspot_y()

int Gdk::Cursor::get_hotspot_y ( ) const

Returns the vertical offset of the hotspot.

The hotspot indicates the pixel that will be directly above the cursor.

Note that named cursors may have a nonzero hotspot, but this function will only return the hotspot position for cursors created with new_from_texture().

Returns: The vertical offset of the hotspot or 0 for named cursors.

◆ get_name()

Glib::ustring Gdk::Cursor::get_name ( ) const

Returns the name of the cursor.

If the cursor is not a named cursor, nullptr will be returned.

Returns: The name of the cursor or nullptr if it is not a named cursor.

◆ get_texture() [1/2]

Glib::RefPtr< Texture > Gdk::Cursor::get_texture ( )

Returns the texture for the cursor.

If the cursor is a named cursor, nullptr will be returned.

Returns: The texture for cursor or nullptr if it is a named cursor.

◆ get_texture() [2/2]

Glib::RefPtr< const Texture > Gdk::Cursor::get_texture ( ) const

Returns the texture for the cursor.

If the cursor is a named cursor, nullptr will be returned.

Returns: The texture for cursor or nullptr if it is a named cursor.

◆ get_type()

static GType Gdk::Cursor::get_type ( )

static

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

◆ gobj() [1/2]

GdkCursor * Gdk::Cursor::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GdkCursor * Gdk::Cursor::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GdkCursor * Gdk::Cursor::gobj_copy ( )

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

◆ operator=()

Cursor & Gdk::Cursor::operator= ( Cursor && src )

noexcept

◆ property_fallback()

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Cursor > > Gdk::Cursor::property_fallback ( ) const

Cursor to fall back to if this cursor cannot be displayed.

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_hotspot_x()

Glib::PropertyProxy_ReadOnly< int > Gdk::Cursor::property_hotspot_x ( ) const

X position of the cursor hotspot in the cursor image.

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_hotspot_y()

Glib::PropertyProxy_ReadOnly< int > Gdk::Cursor::property_hotspot_y ( ) const

Y position of the cursor hotspot in the cursor image.

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_name()

Glib::PropertyProxy_ReadOnly< Glib::ustring > Gdk::Cursor::property_name ( ) const

Name of this this cursor.

The name will be nullptr if the cursor was created from a texture.

Default value: ""

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_texture()

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Texture > > Gdk::Cursor::property_texture ( ) const

The texture displayed by this cursor.

The texture will be nullptr if the cursor was created from a name.

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< Gdk::Cursor > wrap	(	GdkCursor *	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

Related Functions

Detailed Description

Named and texture cursors

Member Typedef Documentation

◆ SlotGetTexture

Constructor & Destructor Documentation

◆ Cursor()

◆ ~Cursor()

Member Function Documentation

◆ create() [1/3]

◆ create() [2/3]

◆ create() [3/3]

◆ get_fallback() [1/2]

◆ get_fallback() [2/2]

◆ get_hotspot_x()

◆ get_hotspot_y()

◆ get_name()

◆ get_texture() [1/2]

◆ get_texture() [2/2]

◆ get_type()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ operator=()

◆ property_fallback()

◆ property_hotspot_x()

◆ property_hotspot_y()

◆ property_name()

◆ property_texture()

Friends And Related Function Documentation

◆ wrap()