cairo_font_face_t

cairo_font_face_t — Base class for font faces

Synopsis

typedef             cairo_font_face_t;
cairo_font_face_t * cairo_font_face_reference           (cairo_font_face_t *font_face);
void                cairo_font_face_destroy             (cairo_font_face_t *font_face);
cairo_status_t      cairo_font_face_status              (cairo_font_face_t *font_face);
enum                cairo_font_type_t;
cairo_font_type_t   cairo_font_face_get_type            (cairo_font_face_t *font_face);
unsigned int        cairo_font_face_get_reference_count (cairo_font_face_t *font_face);
cairo_status_t      cairo_font_face_set_user_data       (cairo_font_face_t *font_face,
                                                         const cairo_user_data_key_t *key,
                                                         void *user_data,
                                                         cairo_destroy_func_t destroy);
void *              cairo_font_face_get_user_data       (cairo_font_face_t *font_face,
                                                         const cairo_user_data_key_t *key);

Description

cairo_font_face_t represents a particular font at a particular weight, slant, and other characteristic but no size, transformation, or size.

Font faces are created using font-backend-specific constructors, typically of the form cairo_backend_font_face_create(), or implicitly using the toy text API by way of cairo_select_font_face(). The resulting face can be accessed using cairo_get_font_face().

Details

cairo_font_face_t

typedef struct _cairo_font_face cairo_font_face_t;

A cairo_font_face_t specifies all aspects of a font other than the size or font matrix (a font matrix is used to distort a font by sheering it or scaling it unequally in the two directions) . A font face can be set on a cairo_t by using cairo_set_font_face(); the size and font matrix are set with cairo_set_font_size() and cairo_set_font_matrix().

There are various types of font faces, depending on the font backend they use. The type of a font face can be queried using cairo_font_face_get_type().

Memory management of cairo_font_face_t is done with cairo_font_face_reference() and cairo_font_face_destroy().


cairo_font_face_reference ()

cairo_font_face_t * cairo_font_face_reference           (cairo_font_face_t *font_face);

Increases the reference count on font_face by one. This prevents font_face from being destroyed until a matching call to cairo_font_face_destroy() is made.

The number of references to a cairo_font_face_t can be get using cairo_font_face_get_reference_count().

font_face :

a cairo_font_face_t, (may be NULL in which case this function does nothing).

Returns :

the referenced cairo_font_face_t.

cairo_font_face_destroy ()

void                cairo_font_face_destroy             (cairo_font_face_t *font_face);

Decreases the reference count on font_face by one. If the result is zero, then font_face and all associated resources are freed. See cairo_font_face_reference().

font_face :

a cairo_font_face_t

cairo_font_face_status ()

cairo_status_t      cairo_font_face_status              (cairo_font_face_t *font_face);

Checks whether an error has previously occurred for this font face

font_face :

a cairo_font_face_t

Returns :

CAIRO_STATUS_SUCCESS or another error such as CAIRO_STATUS_NO_MEMORY.

enum cairo_font_type_t

typedef enum _cairo_font_type {
    CAIRO_FONT_TYPE_TOY,
    CAIRO_FONT_TYPE_FT,
    CAIRO_FONT_TYPE_WIN32,
    CAIRO_FONT_TYPE_QUARTZ,
    CAIRO_FONT_TYPE_USER
} cairo_font_type_t;

cairo_font_type_t is used to describe the type of a given font face or scaled font. The font types are also known as "font backends" within cairo.

The type of a font face is determined by the function used to create it, which will generally be of the form cairo_type_font_face_create(). The font face type can be queried with cairo_font_face_get_type()

The various cairo_font_face_t functions can be used with a font face of any type.

The type of a scaled font is determined by the type of the font face passed to cairo_scaled_font_create(). The scaled font type can be queried with cairo_scaled_font_get_type()

The various cairo_scaled_font_t functions can be used with scaled fonts of any type, but some font backends also provide type-specific functions that must only be called with a scaled font of the appropriate type. These functions have names that begin with cairo_type_scaled_font() such as cairo_ft_scaled_font_lock_face().

The behavior of calling a type-specific function with a scaled font of the wrong type is undefined.

New entries may be added in future versions.

CAIRO_FONT_TYPE_TOY

The font was created using cairo's toy font api

CAIRO_FONT_TYPE_FT

The font is of type FreeType

CAIRO_FONT_TYPE_WIN32

The font is of type Win32

CAIRO_FONT_TYPE_QUARTZ

The font is of type Quartz (Since: 1.6)

CAIRO_FONT_TYPE_USER

The font was create using cairo's user font api (Since: 1.8)

Since 1.2


cairo_font_face_get_type ()

cairo_font_type_t   cairo_font_face_get_type            (cairo_font_face_t *font_face);

This function returns the type of the backend used to create a font face. See cairo_font_type_t for available types.

font_face :

a font face

Returns :

The type of font_face.

Since 1.2


cairo_font_face_get_reference_count ()

unsigned int        cairo_font_face_get_reference_count (cairo_font_face_t *font_face);

Returns the current reference count of font_face.

font_face :

a cairo_font_face_t

Returns :

the current reference count of font_face. If the object is a nil object, 0 will be returned.

Since 1.4


cairo_font_face_set_user_data ()

cairo_status_t      cairo_font_face_set_user_data       (cairo_font_face_t *font_face,
                                                         const cairo_user_data_key_t *key,
                                                         void *user_data,
                                                         cairo_destroy_func_t destroy);

Attach user data to font_face. To remove user data from a font face, call this function with the key that was used to set it and NULL for data.

font_face :

a cairo_font_face_t

key :

the address of a cairo_user_data_key_t to attach the user data to

user_data :

the user data to attach to the font face

destroy :

a cairo_destroy_func_t which will be called when the font face is destroyed or when new user data is attached using the same key.

Returns :

CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY if a slot could not be allocated for the user data.

cairo_font_face_get_user_data ()

void *              cairo_font_face_get_user_data       (cairo_font_face_t *font_face,
                                                         const cairo_user_data_key_t *key);

Return user data previously attached to font_face using the specified key. If no user data has been attached with the given key this function returns NULL.

font_face :

a cairo_font_face_t

key :

the address of the cairo_user_data_key_t the user data was attached to

Returns :

the user data previously attached or NULL.

See Also

cairo_scaled_font_t