Text Attributes

enum PangoAttrType

typedef enum
{
  PANGO_ATTR_INVALID,           /* 0 is an invalid attribute type */
  PANGO_ATTR_LANGUAGE,		/* PangoAttrLanguage */
  PANGO_ATTR_FAMILY,		/* PangoAttrString */
  PANGO_ATTR_STYLE,		/* PangoAttrInt */
  PANGO_ATTR_WEIGHT,		/* PangoAttrInt */
  PANGO_ATTR_VARIANT,		/* PangoAttrInt */
  PANGO_ATTR_STRETCH,		/* PangoAttrInt */
  PANGO_ATTR_SIZE,		/* PangoAttrSize */
  PANGO_ATTR_FONT_DESC,		/* PangoAttrFontDesc */
  PANGO_ATTR_FOREGROUND,	/* PangoAttrColor */
  PANGO_ATTR_BACKGROUND,	/* PangoAttrColor */
  PANGO_ATTR_UNDERLINE,		/* PangoAttrInt */
  PANGO_ATTR_STRIKETHROUGH,	/* PangoAttrInt */
  PANGO_ATTR_RISE,		/* PangoAttrInt */
  PANGO_ATTR_SHAPE,		/* PangoAttrShape */
  PANGO_ATTR_SCALE              /* PangoAttrFloat */
} PangoAttrType;

distinguishes between different types of attributes. Along with the predefined values, it is possible to allocate additional values for custom attributes using pango_attr_register_type(). The predefined values are given below. The type of structure used to store the attribute is listed in parentheses after the description.

PANGO_TYPE_ATTR_TYPE

#define PANGO_TYPE_ATTR_TYPE (pango_attr_type_get_type())

The GObject type for PangoAttrType.

struct PangoAttrClass

struct PangoAttrClass
{
  PangoAttrType type;
  PangoAttribute * (*copy) (const PangoAttribute *attr);
  void             (*destroy) (PangoAttribute *attr);
  gboolean         (*equal) (const PangoAttribute *attr1, const PangoAttribute *attr2);
};

The PangoAttrClass structure stores the type and operations for a particular type of attribute. The functions in this structure should not be called directly. Instead, one should use the wrapper functions provided for PangoAttribute.

struct PangoAttribute

struct PangoAttribute
{
  const PangoAttrClass *klass;
  guint start_index;
  guint end_index;
};

The PangoAttribute structure represents the common portions of all attributes. Particular types of attributes include this structure as their initial portion. The common portion of the attribute holds the range to which the value in the type-specific part of the attribute applies.

struct PangoAttrString

struct PangoAttrString
{
  PangoAttribute attr;
  char *value;
};

The PangoAttrString structure is used to represent attributes with a string value.

struct PangoAttrLanguage

struct PangoAttrLanguage
{
  PangoAttribute attr;
  PangoLanguage *value;
};

The PangoAttrColor structure is used to represent attributes that are languages.

struct PangoAttrColor

struct PangoAttrColor
{
  PangoAttribute attr;
  PangoColor color;
};

The PangoAttrColor structure is used to represent attributes that are colors.

struct PangoAttrInt

struct PangoAttrInt
{
  PangoAttribute attr;
  int value;
};

The PangoAttrInt structure is used to represent attributes with a integer or enumeration value.

struct PangoAttrFloat

struct PangoAttrFloat
{
  PangoAttribute attr;
  double value;
};

The PangoAttrFloat structure is used to represent attributes with a float or double value.

struct PangoAttrFontDesc

struct PangoAttrFontDesc
{
  PangoAttribute attr;
  PangoFontDescription *desc;
};

The PangoAttrFontDesc structure is used to store an attribute that sets all aspects of the font description at once.

struct PangoAttrShape

struct PangoAttrShape
{
  PangoAttribute attr;
  PangoRectangle ink_rect;
  PangoRectangle logical_rect;
};

The PangoAttrShape structure is used to represent attributes which impose shape restrictions.

pango_parse_markup ()

gboolean    pango_parse_markup              (const char *markup_text,
                                             int length,
                                             gunichar accel_marker,
                                             PangoAttrList **attr_list,
                                             char **text,
                                             gunichar *accel_char,
                                             GError **error);

Parses marked-up text (see markup format) to create a plaintext string and an attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, the accel marker might be an ampersand or underscore. All characters marked as an accelerator will receive a PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char. Two accel_marker characters following each other produce a single literal accel_marker character.

pango_attr_type_register ()

PangoAttrType pango_attr_type_register      (const gchar *name);

Allocate a new attribute type ID.

pango_attribute_copy ()

PangoAttribute* pango_attribute_copy        (const PangoAttribute *attr);

Make a copy of an attribute.

pango_attribute_equal ()

gboolean    pango_attribute_equal           (const PangoAttribute *attr1,
                                             const PangoAttribute *attr2);

Compare two attributes for equality. This compares only the actual value of the two attributes and not the ranges that the attributes apply to.

pango_attribute_destroy ()

void        pango_attribute_destroy         (PangoAttribute *attr);

Destroy a PangoAttribute and free all associated memory.

pango_attr_language_new ()

PangoAttribute* pango_attr_language_new     (PangoLanguage *language);

Create a new language tag attribute.

pango_attr_family_new ()

PangoAttribute* pango_attr_family_new       (const char *family);

Create a new font family attribute.

pango_attr_style_new ()

PangoAttribute* pango_attr_style_new        (PangoStyle style);

Create a new font slant style attribute.

pango_attr_variant_new ()

PangoAttribute* pango_attr_variant_new      (PangoVariant variant);

Create a new font variant attribute (normal or small caps)

pango_attr_stretch_new ()

PangoAttribute* pango_attr_stretch_new      (PangoStretch stretch);

Create a new font stretch attribute

pango_attr_weight_new ()

PangoAttribute* pango_attr_weight_new       (PangoWeight weight);

Create a new font weight attribute.

pango_attr_size_new ()

PangoAttribute* pango_attr_size_new         (int size);

Create a new font-size attribute.

pango_attr_font_desc_new ()

PangoAttribute* pango_attr_font_desc_new    (const PangoFontDescription *desc);

Create a new font description attribute. (This attribute allows setting family, style, weight, variant, stretch, and size simultaneously.)

pango_attr_foreground_new ()

PangoAttribute* pango_attr_foreground_new   (guint16 red,
                                             guint16 green,
                                             guint16 blue);

Create a new foreground color attribute.

pango_attr_background_new ()

PangoAttribute* pango_attr_background_new   (guint16 red,
                                             guint16 green,
                                             guint16 blue);

Create a new background color attribute.

pango_attr_strikethrough_new ()

PangoAttribute* pango_attr_strikethrough_new
                                            (gboolean strikethrough);

Create a new font strike-through attribute.

pango_attr_underline_new ()

PangoAttribute* pango_attr_underline_new    (PangoUnderline underline);

Create a new underline-style object.

enum PangoUnderline

typedef enum {
  PANGO_UNDERLINE_NONE,
  PANGO_UNDERLINE_SINGLE,
  PANGO_UNDERLINE_DOUBLE,
  PANGO_UNDERLINE_LOW
} PangoUnderline;

the PangoUnderline enumeration is used to specify whether text should be underlined, and if so, the type of underlining.

PANGO_TYPE_UNDERLINE

#define PANGO_TYPE_UNDERLINE (pango_underline_get_type())

The GObject type for PangoUnderline.

pango_attr_shape_new ()

PangoAttribute* pango_attr_shape_new        (const PangoRectangle *ink_rect,
                                             const PangoRectangle *logical_rect);

Create a new shape attribute. A shape is used to impose a particular ink and logical rect on the result of shaping a particular glyph. This might be used, for instance, for embedding a picture or a widget inside a PangoLayout.

pango_attr_scale_new ()

PangoAttribute* pango_attr_scale_new        (double scale_factor);

Create a new font size scale attribute. The base font for the affected text will have its size multiplied by scale_factor.

PANGO_SCALE_XX_SMALL

#define PANGO_SCALE_XX_SMALL ((double)0.5787037037037)

The scale factor for three shrinking steps (1 / (1.2 * 1.2 * 1.2)).

PANGO_SCALE_X_SMALL

#define PANGO_SCALE_X_SMALL  ((double)0.6444444444444)

The scale factor for two shrinking steps (1 / (1.2 * 1.2)).

PANGO_SCALE_SMALL

#define PANGO_SCALE_SMALL    ((double)0.8333333333333)

The scale factor for one shrinking step (1 / 1.2).

PANGO_SCALE_MEDIUM

#define PANGO_SCALE_MEDIUM   ((double)1.0)

The scale factor for normal size (1.0).

PANGO_SCALE_LARGE

#define PANGO_SCALE_LARGE    ((double)1.2)

The scale factor for one magnification step (1.2).

PANGO_SCALE_X_LARGE

#define PANGO_SCALE_X_LARGE  ((double)1.4399999999999)

The scale factor for two magnification steps (1.2 * 1.2).

PANGO_SCALE_XX_LARGE

#define PANGO_SCALE_XX_LARGE ((double)1.728)

The scale factor for three magnification steps (1.2 * 1.2 * 1.2).

pango_attr_rise_new ()

PangoAttribute* pango_attr_rise_new         (int rise);

Create a new baseline displacement attribute.

struct PangoColor

struct PangoColor
{
  guint16 red;
  guint16 green;
  guint16 blue;
};

The PangoColor structure is used to represent a color in an uncalibrated RGB colorspace.

PANGO_TYPE_COLOR

#define PANGO_TYPE_COLOR pango_color_get_type ()

The GObject type for PangoColor.

pango_color_free ()

void        pango_color_free                (PangoColor *color);

Frees a color allocated by pango_color_copy().

pango_color_parse ()

gboolean    pango_color_parse               (PangoColor *color,
                                             const char *spec);

Fill in the fields of a color from a string specification. The string can either one of a large set of standard names. (Taken from the X11 rgb.txt file), or it can be a hex value in the form '#rgb' '#rrggbb' '#rrrgggbbb' or '#rrrrggggbbbb' where 'r', 'g' and 'b' are hex digits of the red, green, and blue components of the color, respectively. (White in the four forms is '#fff' '#ffffff' '#fffffffff' and '#ffffffffffff')

pango_color_copy ()

PangoColor* pango_color_copy                (const PangoColor *src);

Creates a copy of src, which should be freed with pango_color_free(). Primarily used by language bindings, not that useful otherwise (since colors can just be copied by assignment in C).

struct PangoLanguage

struct PangoLanguage;

The PangoLanguage structure is used to represent a language.

PangoLanguage pointers can be efficiently copied and compared with each other.

PANGO_TYPE_LANGUAGE

#define PANGO_TYPE_LANGUAGE (pango_language_get_type ())

The GObject type for PangoLanguage.

pango_language_from_string ()

PangoLanguage* pango_language_from_string   (const char *language);

Take a RFC-3066 format language tag as a string and convert it to a PangoLanguage pointer that can be efficiently copied (copy the pointer) and compared with other language tags (compare the pointer.)

This function first canonicalizes the string by converting it to lowercase, mapping '_' to '-', and stripping all characters other than letters and '-'.

pango_language_to_string()

#define pango_language_to_string(language) ((const char *)language)

Returns a RFC-3066 format string representing the given language tag.

pango_language_matches ()

gboolean    pango_language_matches          (PangoLanguage *language,
                                             const char *range_list);

Checks if a language tag matches one of the elements in a list of language ranges. A language tag is considered to match a range in the list if the range is '*', the range is exactly the tag, or the range is a prefix of the tag, and the character after the tag is '-'.

struct PangoAttrList

struct PangoAttrList;

The PangoAttrList structure represents a list of attributes that apply to a section of text. The attributes are, in general, allowed to overlap in an arbitrary fashion, however, if the attributes are manipulated only through pango_attr_list_change(), the overlap between properties will meet stricter criteria.

Since the PangoAttrList structure is stored as a linear list, it is not suitable for storing attributes for large amounts of text. In general, you should not use a single PangoAttrList for more than one paragraph of text.

PANGO_TYPE_ATTR_LIST

#define PANGO_TYPE_ATTR_LIST pango_attr_list_get_type ()

The GObject type for PangoAttrList.

pango_attr_list_new ()

PangoAttrList* pango_attr_list_new          (void);

Create a new empty attribute list with a reference count of 1.

pango_attr_list_ref ()

void        pango_attr_list_ref             (PangoAttrList *list);

Increase the reference count of the given attribute list by one.

pango_attr_list_unref ()

void        pango_attr_list_unref           (PangoAttrList *list);

Decrease the reference count of the given attribute list by one. If the result is zero, free the attribute list and the attributes it contains.

pango_attr_list_copy ()

PangoAttrList* pango_attr_list_copy         (PangoAttrList *list);

Copy list and return an identical, new list.

pango_attr_list_insert ()

void        pango_attr_list_insert          (PangoAttrList *list,
                                             PangoAttribute *attr);

Insert the given attribute into the PangoAttrList. It will be inserted after all other attributes with a matching start_index.

pango_attr_list_insert_before ()

void        pango_attr_list_insert_before   (PangoAttrList *list,
                                             PangoAttribute *attr);

Insert the given attribute into the PangoAttrList. It will be inserted before all other attributes with a matching start_index.

pango_attr_list_change ()

void        pango_attr_list_change          (PangoAttrList *list,
                                             PangoAttribute *attr);

Insert the given attribute into the PangoAttrList. It will replace any attributes of the same type on that segment and be merged with any adjoining attributes that are identical.

This function is slower than pango_attr_list_insert() for creating a attribute list in order (potentially much slower for large lists). However, pango_attr_list_insert() is not suitable for continually changing a set of attributes since it never removes or combines existing attributes.

pango_attr_list_splice ()

void        pango_attr_list_splice          (PangoAttrList *list,
                                             PangoAttrList *other,
                                             gint pos,
                                             gint len);

This function splices attribute list other into list. This operation is equivalent to stretching every attribute applies at position pos in list by an amount len, and then calling pango_attr_list_change() with a copy of each attributes in other in sequence (offset in position by pos).

This operation proves useful for, for instance, inserting a preedit string in the middle of an edit buffer.

pango_attr_list_get_iterator ()

PangoAttrIterator* pango_attr_list_get_iterator
                                            (PangoAttrList *list);

Create a iterator initialized to the beginning of the list.

struct PangoAttrIterator

struct PangoAttrIterator;

The PangoAttrIterator structure is used to represent an iterator through a PangoList. A new iterator is created with pango_attr_list_get_iterator(). Once the iterator is created, it can be advanced through the style changes in the text using pango_attr_iterator_next(). At each style change, the range of the current style segment and the attributes currently in effect can be queried.

pango_attr_iterator_copy ()

PangoAttrIterator* pango_attr_iterator_copy (PangoAttrIterator *iterator);

Copy a PangoAttrIterator

pango_attr_iterator_next ()

gboolean    pango_attr_iterator_next        (PangoAttrIterator *iterator);

Advance the iterator until the next change of style.

pango_attr_iterator_range ()

void        pango_attr_iterator_range       (PangoAttrIterator *iterator,
                                             gint *start,
                                             gint *end);

Get the range of the current segment.

pango_attr_iterator_get ()

PangoAttribute* pango_attr_iterator_get     (PangoAttrIterator *iterator,
                                             PangoAttrType type);

Find the current attribute of a particular type at the iterator location. When multiple attributes of the same type overlap, the attribute whose range starts closest to the current location is used.

pango_attr_iterator_get_font ()

void        pango_attr_iterator_get_font    (PangoAttrIterator *iterator,
                                             PangoFontDescription *desc,
                                             PangoLanguage **language,
                                             GSList **extra_attrs);

Get the font and other attributes at the current iterator position.

pango_attr_iterator_destroy ()

void        pango_attr_iterator_destroy     (PangoAttrIterator *iterator);

Destroy a PangoAttrIterator and free all associated memory.