path: root/docs/tmpl/text-attributes.sgml

<!-- ##### SECTION Title ##### -->
Text Attributes

<!-- ##### SECTION Short_Description ##### -->
Font and other attributes for annotating text

<!-- ##### SECTION Long_Description ##### -->
<para>
Attributed text is used in a number of places in Pango. It
is used as the input to the itemization process and also when
creating a #PangoLayout. The data types and functions in
this section are used to represent and manipulate sets
of attributes applied to a portion of text.
</para>

<!-- ##### SECTION See_Also ##### -->
<para>

</para>

<!-- ##### SECTION Stability_Level ##### -->


<!-- ##### ENUM PangoAttrType ##### -->
<para>
The #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_type_register(). The predefined
values are given below. The type of structure used to store the
attribute is listed in parentheses after the description.
</para>

@PANGO_ATTR_INVALID: does not happen
@PANGO_ATTR_LANGUAGE: language (#PangoAttrLanguage)
@PANGO_ATTR_FAMILY: font family name list (#PangoAttrString)
@PANGO_ATTR_STYLE: font slant style (#PangoAttrInt)
@PANGO_ATTR_WEIGHT: font weight (#PangoAttrInt)
@PANGO_ATTR_VARIANT: font variant (normal or small caps) (#PangoAttrInt)
@PANGO_ATTR_STRETCH: font stretch (#PangoAttrInt)
@PANGO_ATTR_SIZE: font size in points scaled by %PANGO_SCALE (#PangoAttrInt)
@PANGO_ATTR_FONT_DESC: font description (#PangoAttrFontDesc)
@PANGO_ATTR_FOREGROUND: foreground color (#PangoAttrColor)
@PANGO_ATTR_BACKGROUND: background color (#PangoAttrColor)
@PANGO_ATTR_UNDERLINE: whether the text has an underline (#PangoAttrInt)
@PANGO_ATTR_STRIKETHROUGH: whether the text is struck-through (#PangoAttrInt)
@PANGO_ATTR_RISE: baseline displacement (#PangoAttrInt)
@PANGO_ATTR_SHAPE: shape (#PangoAttrShape)
@PANGO_ATTR_SCALE: font size scale factor (#PangoAttrFloat)
@PANGO_ATTR_FALLBACK: whether fallback is enabled (#PangoAttrInt)
@PANGO_ATTR_LETTER_SPACING: letter spacing (#PangoAttrInt)
@PANGO_ATTR_UNDERLINE_COLOR: underline color (#PangoAttrColor)
@PANGO_ATTR_STRIKETHROUGH_COLOR: strikethrough color (#PangoAttrColor)
@PANGO_ATTR_ABSOLUTE_SIZE: font size in pixels scaled by %PANGO_SCALE (#PangoAttrInt)
@PANGO_ATTR_GRAVITY: base text gravity (#PangoAttrInt)
@PANGO_ATTR_GRAVITY_HINT: gravity hint (#PangoAttrInt)

<!-- ##### MACRO PANGO_TYPE_ATTR_TYPE ##### -->
<para>
The #GObject type for #PangoAttrType.
</para>



<!-- ##### STRUCT PangoAttrClass ##### -->
<para>
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.
</para>

@type: the type ID for this attribute
@copy: function to duplicate an attribute of this type (see pango_attribute_copy())
@destroy: function to free an attribute of this type (see pango_attribute_destroy())
@equal: function to check two attributes of this type for equality (see pango_attribute_equal())

<!-- ##### STRUCT PangoAttribute ##### -->
<para>
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 and should be initialized using pango_attribute_init().
By default an attribute will have an all-inclusive range of [0,%G_MAXUINT].
</para>

@klass: the class structure holding information about the type of the attribute
@start_index: the start index of the range (in bytes).
@end_index: end index of the range (in bytes). The character at this index
	is not included in the range.

<!-- ##### STRUCT PangoAttrString ##### -->
<para>
The #PangoAttrString structure is used to represent attributes with
a string value.
</para>

@attr: the common portion of the attribute
@value: the string which is the value of the attribute

<!-- ##### STRUCT PangoAttrLanguage ##### -->
<para>
The #PangoAttrLanguage structure is used to represent attributes that
are languages.
</para>

@attr: the common portion of the attribute
@value: the #PangoLanguage which is the value of the attribute

<!-- ##### STRUCT PangoAttrColor ##### -->
<para>
The #PangoAttrColor structure is used to represent attributes that
are colors.
</para>

@attr: the common portion of the attribute
@color: the #PangoColor which is the value of the attribute

<!-- ##### STRUCT PangoAttrInt ##### -->
<para>
The #PangoAttrInt structure is used to represent attributes with
an integer or enumeration value.
</para>

@attr: the common portion of the attribute
@value: the value of the attribute

<!-- ##### STRUCT PangoAttrFloat ##### -->
<para>
The #PangoAttrFloat structure is used to represent attributes with
a float or double value.
</para>

@attr: the common portion of the attribute
@value: the value of the attribute

<!-- ##### STRUCT PangoAttrFontDesc ##### -->
<para>
The #PangoAttrFontDesc structure is used to store an attribute that
sets all aspects of the font description at once.
</para>

@attr: the common portion of the attribute
@desc: the font description which is the value of this attribute

<!-- ##### STRUCT PangoAttrShape ##### -->
<para>
The #PangoAttrShape structure is used to represent attributes which 
impose shape restrictions.
</para>

@attr: the common portion of the attribute
@ink_rect: the ink rectangle to restrict to
@logical_rect: the logical rectangle to restrict to
@data: user data set (see pango_attr_shape_new_with_data())
@copy_func: copy function for the user data
@destroy_func: destroy function for the user data

<!-- ##### STRUCT PangoAttrSize ##### -->
<para>
The #PangoAttrShape structure is used to represent attributes which
set font size.
</para>

@attr: the common portion of the attribute
@size: size of font, in units of 1/%PANGO_SCALE of a point (for
  %PANGO_ATTR_SIZE) or of a device uni (for %PANGO_ATTR_ABSOLUTE_SIZE)
@absolute: whether the font size is in device units or points.
   This field is only present for compatibility with Pango-1.8.0
   (%PANGO_ATTR_ABSOLUTE_SIZE was added in 1.8.1); and always will
   be %FALSE for %PANGO_ATTR_SIZE and %TRUE for %PANGO_ATTR_ABSOLUTE_SIZE.

<!-- ##### FUNCTION pango_parse_markup ##### -->
<para>

</para>

@markup_text: 
@length: 
@accel_marker: 
@attr_list: 
@text: 
@accel_char: 
@error: 
@Returns: 


<!-- ##### FUNCTION pango_attr_type_register ##### -->
<para>

</para>

@name: 
@Returns: 


<!-- ##### FUNCTION pango_attr_type_get_name ##### -->
<para>

</para>

@type: 
@Returns: 


<!-- ##### FUNCTION pango_attribute_init ##### -->
<para>

</para>

@attr: 
@klass: 


<!-- ##### FUNCTION pango_attribute_copy ##### -->
<para>

</para>

@attr: 
@Returns: 


<!-- ##### FUNCTION pango_attribute_equal ##### -->
<para>

</para>

@attr1: 
@attr2: 
@Returns: 


<!-- ##### FUNCTION pango_attribute_destroy ##### -->
<para>

</para>

@attr: 


<!-- ##### FUNCTION pango_attr_language_new ##### -->
<para>

</para>

@language: 
@Returns: 


<!-- ##### FUNCTION pango_attr_family_new ##### -->
<para>

</para>

@family: 
@Returns: 


<!-- ##### FUNCTION pango_attr_style_new ##### -->
<para>

</para>

@style: 
@Returns: 


<!-- ##### FUNCTION pango_attr_variant_new ##### -->
<para>

</para>

@variant: 
@Returns: 


<!-- ##### FUNCTION pango_attr_stretch_new ##### -->
<para>

</para>

@stretch: 
@Returns: 


<!-- ##### FUNCTION pango_attr_weight_new ##### -->
<para>

</para>

@weight: 
@Returns: 


<!-- ##### FUNCTION pango_attr_size_new ##### -->
<para>

</para>

@size: 
@Returns: 


<!-- ##### FUNCTION pango_attr_size_new_absolute ##### -->
<para>

</para>

@size: 
@Returns: 


<!-- ##### FUNCTION pango_attr_font_desc_new ##### -->
<para>

</para>

@desc: 
@Returns: 


<!-- ##### FUNCTION pango_attr_foreground_new ##### -->
<para>

</para>

@red: 
@green: 
@blue: 
@Returns: 


<!-- ##### FUNCTION pango_attr_background_new ##### -->
<para>

</para>

@red: 
@green: 
@blue: 
@Returns: 


<!-- ##### FUNCTION pango_attr_strikethrough_new ##### -->
<para>

</para>

@strikethrough: 
@Returns: 


<!-- ##### FUNCTION pango_attr_strikethrough_color_new ##### -->
<para>

</para>

@red: 
@green: 
@blue: 
@Returns: 


<!-- ##### FUNCTION pango_attr_underline_new ##### -->
<para>

</para>

@underline: 
@Returns: 


<!-- ##### FUNCTION pango_attr_underline_color_new ##### -->
<para>

</para>

@red: 
@green: 
@blue: 
@Returns: 


<!-- ##### ENUM PangoUnderline ##### -->
<para>
the #PangoUnderline enumeration is used to specify
whether text should be underlined, and if so, the type
of underlining.
</para>

@PANGO_UNDERLINE_NONE: no underline should be drawn
@PANGO_UNDERLINE_SINGLE: a single underline should be drawn
@PANGO_UNDERLINE_DOUBLE: a double underline should be drawn
@PANGO_UNDERLINE_LOW: a single underline should be drawn at a position
                      beneath the ink extents of the text being
                      underlined. This should be used only for underlining
                      single characters, such as for keyboard
                      accelerators. %PANGO_UNDERLINE_SINGLE should
                      be used for extended portions of text.
@PANGO_UNDERLINE_ERROR: a wavy underline should be drawn below.
                      This underline is typically used to indicate
                      an error such as a possilble mispelling; in some
                      cases a contrasting color may automatically
                      be used. This type of underlining is available
                      since Pango 1.4.

<!-- ##### MACRO PANGO_TYPE_UNDERLINE ##### -->
<para>
The #GObject type for #PangoUnderline.
</para>



<!-- ##### FUNCTION pango_attr_shape_new ##### -->
<para>

</para>

@ink_rect: 
@logical_rect: 
@Returns: 


<!-- ##### FUNCTION pango_attr_shape_new_with_data ##### -->
<para>

</para>

@ink_rect: 
@logical_rect: 
@data: 
@copy_func: 
@destroy_func: 
@Returns: 


<!-- ##### USER_FUNCTION PangoAttrDataCopyFunc ##### -->
<para>
A copy function passed to attribute new functions that take
user data.
</para>

@data: the user data
@Returns: a new copy of @data.


<!-- ##### FUNCTION pango_attr_scale_new ##### -->
<para>

</para>

@scale_factor: 
@Returns: 


<!-- ##### MACRO PANGO_SCALE_XX_SMALL ##### -->
<para>
The scale factor for three shrinking steps (1 / (1.2 * 1.2 * 1.2)).
</para>



<!-- ##### MACRO PANGO_SCALE_X_SMALL ##### -->
<para>
The scale factor for two shrinking steps (1 / (1.2 * 1.2)).
</para>



<!-- ##### MACRO PANGO_SCALE_SMALL ##### -->
<para>
The scale factor for one shrinking step (1 / 1.2).
</para>



<!-- ##### MACRO PANGO_SCALE_MEDIUM ##### -->
<para>
The scale factor for normal size (1.0).
</para>



<!-- ##### MACRO PANGO_SCALE_LARGE ##### -->
<para>
The scale factor for one magnification step (1.2).
</para>



<!-- ##### MACRO PANGO_SCALE_X_LARGE ##### -->
<para>
The scale factor for two magnification steps (1.2 * 1.2).
</para>



<!-- ##### MACRO PANGO_SCALE_XX_LARGE ##### -->
<para>
The scale factor for three magnification steps (1.2 * 1.2 * 1.2).
</para>



<!-- ##### FUNCTION pango_attr_rise_new ##### -->
<para>

</para>

@rise: 
@Returns: 


<!-- ##### FUNCTION pango_attr_letter_spacing_new ##### -->
<para>

</para>

@letter_spacing: 
@Returns: 


<!-- ##### FUNCTION pango_attr_fallback_new ##### -->
<para>

</para>

@enable_fallback: 
@Returns: 


<!-- ##### FUNCTION pango_attr_gravity_new ##### -->
<para>

</para>

@gravity: 
@Returns: 


<!-- ##### FUNCTION pango_attr_gravity_hint_new ##### -->
<para>

</para>

@hint: 
@Returns: 


<!-- ##### STRUCT PangoColor ##### -->
<para>
The #PangoColor structure is used to
represent a color in an uncalibrated RGB color-space.
</para>

@red: The red component of the color. This is a value between 0 and 65535, 
      with 65535 indicating full intensity.
@green: The green component of the color. This is a value between 0 and 65535, 
      with 65535 indicating full intensity.
@blue: The blue component of the color. This is a value between 0 and 65535, 
      with 65535 indicating full intensity.

<!-- ##### MACRO PANGO_TYPE_COLOR ##### -->
<para>
The #GObject type for #PangoColor.
</para>



<!-- ##### FUNCTION pango_color_parse ##### -->
<para>

</para>

@color: 
@spec: 
@Returns: 


<!-- ##### FUNCTION pango_color_copy ##### -->
<para>

</para>

@src: 
@Returns: 


<!-- ##### FUNCTION pango_color_free ##### -->
<para>

</para>

@color: 


<!-- ##### FUNCTION pango_color_to_string ##### -->
<para>

</para>

@color: 
@Returns: 


<!-- ##### STRUCT PangoLanguage ##### -->
<para>
The #PangoLanguage structure is used to
represent a language.
</para>
<para>
#PangoLanguage pointers can be efficiently 
copied and compared with each other.
</para>


<!-- ##### MACRO PANGO_TYPE_LANGUAGE ##### -->
<para>
The #GObject type for #PangoLanguage. 
</para>



<!-- ##### FUNCTION pango_language_from_string ##### -->
<para>

</para>

@language: 
@Returns: 


<!-- ##### FUNCTION pango_language_to_string ##### -->
<para>

</para>

@language:
@Returns:


<!-- ##### FUNCTION pango_language_matches ##### -->
<para>

</para>

@language: 
@range_list: 
@Returns: 


<!-- ##### STRUCT PangoAttrList ##### -->
<para>
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.
</para>
<para>
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.
</para>


<!-- ##### MACRO PANGO_TYPE_ATTR_LIST ##### -->
<para>
The #GObject type for #PangoAttrList.
</para>



<!-- ##### FUNCTION pango_attr_list_new ##### -->
<para>

</para>

@Returns: 


<!-- ##### FUNCTION pango_attr_list_ref ##### -->
<para>

</para>

@list: 
@Returns: 


<!-- ##### FUNCTION pango_attr_list_unref ##### -->
<para>

</para>

@list: 


<!-- ##### FUNCTION pango_attr_list_copy ##### -->
<para>

</para>

@list: 
@Returns: 


<!-- ##### FUNCTION pango_attr_list_insert ##### -->
<para>

</para>

@list: 
@attr: 


<!-- ##### FUNCTION pango_attr_list_insert_before ##### -->
<para>

</para>

@list: 
@attr: 


<!-- ##### FUNCTION pango_attr_list_change ##### -->
<para>

</para>

@list: 
@attr: 


<!-- ##### FUNCTION pango_attr_list_splice ##### -->
<para>

</para>

@list: 
@other: 
@pos: 
@len: 


<!-- ##### FUNCTION pango_attr_list_filter ##### -->
<para>

</para>

@list: 
@func: 
@data: 
@Returns: 


<!-- ##### USER_FUNCTION PangoAttrFilterFunc ##### -->
<para>
A predicate function used by pango_attr_list_filter()
to filter out a subset of attributes for a list.
</para>

@attribute: a #PangoAttribute
@data: callback data passed to pango_attr_list_filter()
@Returns: %TRUE if the attribute should be filtered out


<!-- ##### FUNCTION pango_attr_list_get_iterator ##### -->
<para>

</para>

@list: 
@Returns: 


<!-- ##### STRUCT PangoAttrIterator ##### -->
<para>
The #PangoAttrIterator structure is used to represent an
iterator through a #PangoAttrList. 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.
</para>


<!-- ##### FUNCTION pango_attr_iterator_copy ##### -->
<para>

</para>

@iterator: 
@Returns: 


<!-- ##### FUNCTION pango_attr_iterator_next ##### -->
<para>

</para>

@iterator: 
@Returns: 


<!-- ##### FUNCTION pango_attr_iterator_range ##### -->
<para>

</para>

@iterator: 
@start: 
@end: 


<!-- ##### FUNCTION pango_attr_iterator_get ##### -->
<para>

</para>

@iterator: 
@type: 
@Returns: 


<!-- ##### FUNCTION pango_attr_iterator_get_font ##### -->
<para>

</para>

@iterator: 
@desc: 
@language: 
@extra_attrs: 


<!-- ##### FUNCTION pango_attr_iterator_get_attrs ##### -->
<para>

</para>

@iterator: 
@Returns: 


<!-- ##### FUNCTION pango_attr_iterator_destroy ##### -->
<para>

</para>

@iterator: