Cursors

Cursors — Named and texture cursors

Properties

GdkCursor * fallback Read / Write / Construct Only
gint hotspot-x Read / Write / Construct Only
gint hotspot-y Read / Write / Construct Only
gchar * name Read / Write / Construct Only
GdkTexture * texture Read / Write / Construct Only

Types and Values

Object Hierarchy

    GObject
    ╰── GdkCursor

Includes

#include <gdk/gdk.h>

Description

These functions are used to create and destroy cursors. Cursors are immutable objects, so once you created them, there is no way to modify them later. 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 GdkDisplay, so they can be shared. However, the appearance of cursors may vary when used on different platforms.

There are multiple ways to create cursors. The platform's own cursors can be created with gdk_cursor_new_from_name(). 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. Another option to create a cursor is to use gdk_cursor_new_from_texture() and provide an image to use for the cursor. Depending on the GdkDisplay in use, the type of supported images may be limited. See gdk_display_supports_cursor_alpha(), gdk_display_supports_cursor_color(), gdk_display_get_default_cursor_size() and gdk_display_get_maximal_cursor_size() for the limitations that might apply.

To ease work with unsupported cursors, a fallback cursor can be provided. If a GdkSurface cannot use a cursor because of the reasons mentioned above, it will try the fallback cursor. Of course, 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.

Functions

gdk_cursor_new_from_texture ()

GdkCursor *
gdk_cursor_new_from_texture (GdkTexture *texture,
                             int hotspot_x,
                             int hotspot_y,
                             GdkCursor *fallback);

Creates a new cursor from a GdkTexture.

Not all GDK backends support RGBA cursors. If they are not supported, a monochrome approximation will be displayed. The functions gdk_display_supports_cursor_alpha() and gdk_display_supports_cursor_color() can be used to determine whether RGBA cursors are supported; gdk_display_get_default_cursor_size() and gdk_display_get_maximal_cursor_size() give information about cursor sizes.

On the X backend, support for RGBA cursors requires a sufficently new version of the X Render extension.

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

NULL or the GdkCursor to fall back to when this one cannot be supported.

[allow-none]

Returns

a new GdkCursor.


gdk_cursor_new_from_name ()

GdkCursor *
gdk_cursor_new_from_name (const gchar *name,
                          GdkCursor *fallback);

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

fallback

NULL or the GdkCursor to fall back to when this one cannot be supported.

[allow-none]

name

the name of the cursor

 

Returns

a new GdkCursor, or NULL if there is no cursor with the given name.

[nullable]


gdk_cursor_get_fallback ()

GdkCursor *
gdk_cursor_get_fallback (GdkCursor *cursor);

Returns the fallback for this cursor . The fallback will be used if this cursor is not available on a given GdkDisplay.

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 GdkDisplay it is used on does not support textured cursors.

Parameters

cursor

a GdkCursor.

 

Returns

the fallback of the cursor or NULL to use the default cursor as fallback.

[transfer none][nullable]


gdk_cursor_get_name ()

const char *
gdk_cursor_get_name (GdkCursor *cursor);

Returns the name of the cursor. If the cursor is not a named cursor, NULL will be returned and the GdkCursor::texture property will be set.

Parameters

cursor

a GdkCursor.

 

Returns

the name of the cursor or NULL if it is not a named cursor.

[transfer none][nullable]


gdk_cursor_get_texture ()

GdkTexture *
gdk_cursor_get_texture (GdkCursor *cursor);

Returns the texture for the cursor. If the cursor is a named cursor, NULL will be returned and the GdkCursor::name property will be set.

Parameters

cursor

a GdkCursor.

 

Returns

the texture for cursor or NULL if it is a named cursor.

[transfer none][nullable]


gdk_cursor_get_hotspot_x ()

int
gdk_cursor_get_hotspot_x (GdkCursor *cursor);

Returns the horizontal offset of the hotspot. The hotspot indicates the pixel that will be directly above the cursor.

Parameters

cursor

a GdkCursor.

 

Returns

the horizontal offset of the hotspot or 0 for named cursors


gdk_cursor_get_hotspot_y ()

int
gdk_cursor_get_hotspot_y (GdkCursor *cursor);

Returns the vertical offset of the hotspot. The hotspot indicates the pixel that will be directly above the cursor.

Parameters

cursor

a GdkCursor.

 

Returns

the vertical offset of the hotspot or 0 for named cursors

Types and Values

GdkCursor

typedef struct _GdkCursor GdkCursor;

A GdkCursor represents a cursor. Its contents are private.

Cursors are immutable objects, so they can not change after they have been constructed.

Property Details

The “fallback” property

  “fallback”                 GdkCursor *

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

Flags: Read / Write / Construct Only


The “hotspot-x” property

  “hotspot-x”                gint

Horizontal offset of the cursor hotspot.

Flags: Read / Write / Construct Only

Allowed values: >= 0

Default value: 0


The “hotspot-y” property

  “hotspot-y”                gint

Vertical offset of the cursor hotspot.

Flags: Read / Write / Construct Only

Allowed values: >= 0

Default value: 0


The “name” property

  “name”                     gchar *

Name of this cursor.

Flags: Read / Write / Construct Only

Default value: NULL


The “texture” property

  “texture”                  GdkTexture *

The texture displayed by this cursor.

Flags: Read / Write / Construct Only