pango-Text-Attributes: Text Attributes
Description
Font and other attributes for annotating textMethods and Functions
pangoParseMarkup(markup.text, accel.marker, .errwarn = TRUE)
pangoAttrTypeRegister(name)
pangoAttrTypeGetName(type)
pangoAttributeInit(attr, klass)
pangoAttributeCopy(object)
pangoAttributeEqual(object, attr2)
pangoAttrLanguageNew(language)
pangoAttrFamilyNew(family)
pangoAttrStyleNew(style)
pangoAttrVariantNew(variant)
pangoAttrStretchNew(stretch)
pangoAttrWeightNew(weight)
pangoAttrSizeNew(size)
pangoAttrSizeNewAbsolute(size)
pangoAttrFontDescNew(desc)
pangoAttrForegroundNew(red, green, blue)
pangoAttrBackgroundNew(red, green, blue)
pangoAttrStrikethroughNew(strikethrough)
pangoAttrStrikethroughColorNew(red, green, blue)
pangoAttrUnderlineNew(underline)
pangoAttrUnderlineColorNew(red, green, blue)
pangoAttrShapeNew(ink.rect, logical.rect)
pangoAttrShapeNewWithData(ink.rect, logical.rect, data)
pangoAttrScaleNew(scale.factor)
pangoAttrRiseNew(rise)
pangoAttrLetterSpacingNew(letter.spacing)
pangoAttrFallbackNew(fallback)
pangoAttrGravityNew(gravity)
pangoAttrGravityHintNew(hint)
pangoColorParse(spec)
pangoColorCopy(object)
pangoColorFree(object)
pangoColorToString(object)
pangoAttrListNew()
pangoAttrListCopy(object)
pangoAttrListInsert(object, attr)
pangoAttrListInsertBefore(object, attr)
pangoAttrListChange(object, attr)
pangoAttrListSplice(object, other, pos, len)
pangoAttrListFilter(object, func, data)
pangoAttrListGetIterator(object)
pangoAttrIteratorCopy(object)
pangoAttrIteratorNext(object)
pangoAttrIteratorRange(object)
pangoAttrIteratorGet(object, type)
pangoAttrIteratorGetFont(object)
pangoAttrIteratorGetAttrs(object)Detailed Description
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.Structures
PangoAttrClass-
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.
PangoAttribute-
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 pangoAttributeInit.
By default an attribute will have an all-inclusive range of [0,G_MAXUINT].
klass- [
PangoAttrClass] the class structure holding information about the type of the attribute startIndex- [numeric] the start index of the range (in bytes).
endIndex- [numeric] end index of the range (in bytes). The character at this index
is not included in the range.
PangoAttrString-
The
PangoAttrString structure is used to represent attributes with
a string value.
PangoAttrLanguage-
The
PangoAttrLanguage structure is used to represent attributes that
are languages.
PangoAttrColor-
The
PangoAttrColor structure is used to represent attributes that
are colors.
PangoAttrInt-
The
PangoAttrInt structure is used to represent attributes with
an integer or enumeration value.
PangoAttrFloat-
The
PangoAttrFloat structure is used to represent attributes with
a float or double value.
PangoAttrFontDesc-
The
PangoAttrFontDesc structure is used to store an attribute that
sets all aspects of the font description at once.
PangoAttrShape-
The
PangoAttrShape structure is used to represent attributes which
impose shape restrictions.
inkRect- [
PangoRectangle] the common portion of the attribute logicalRect- [
PangoRectangle] the ink rectangle to restrict to
PangoAttrSize-
The
PangoAttrShape structure is used to represent attributes which
set font size.
size- [integer] the common portion of the attribute
absolute- [numeric] 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)
PangoColor-
The
PangoColor structure is used to
represent a color in an uncalibrated RGB color-space.
red- [integer] The red component of the color. This is a value between 0 and 65535,
with 65535 indicating full intensity.
green- [integer] The green component of the color. This is a value between 0 and 65535,
with 65535 indicating full intensity.
blue- [integer] The blue component of the color. This is a value between 0 and 65535,
with 65535 indicating full intensity.
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 pangoAttrListChange,
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. PangoAttrIterator-
The
PangoAttrIterator structure is used to represent an
iterator through a PangoAttrList. A new iterator is created
with pangoAttrListGetIterator. Once the iterator
is created, it can be advanced through the style changes
in the text using pangoAttrIteratorNext. At each
style change, the range of the current style segment and the
attributes currently in effect can be queried.
Enums and Flags
PangoAttrType-
The
PangoAttrType
distinguishes between different types of attributes. Along with the
predefined values, it is possible to allocate additional values
for custom attributes using pangoAttrTypeRegister. The predefined
values are given below. The type of structure used to store the
attribute is listed in parentheses after the description.
invalid- does not happen
language- language (
PangoAttrLanguage) family- font family name list (
PangoAttrString) style- font slant style (
PangoAttrInt) weight- font weight (
PangoAttrInt) variant- font variant (normal or small caps) (
PangoAttrInt) stretch- font stretch (
PangoAttrInt) size- font size in points scaled by
PANGO_SCALE (PangoAttrInt) font-desc- font description (
PangoAttrFontDesc) foreground- foreground color (
PangoAttrColor) background- background color (
PangoAttrColor) underline- whether the text has an underline (
PangoAttrInt) strikethrough- whether the text is struck-through (
PangoAttrInt) rise- baseline displacement (
PangoAttrInt) shape- shape (
PangoAttrShape) scale- font size scale factor (
PangoAttrFloat) fallback- whether fallback is enabled (
PangoAttrInt) letter-spacing- letter spacing (
PangoAttrInt) underline-color- underline color (
PangoAttrColor) strikethrough-color- strikethrough color (
PangoAttrColor) absolute-size- font size in pixels scaled by
PANGO_SCALE (PangoAttrInt) gravity- base text gravity (
PangoAttrInt) gravity-hint- gravity hint (
PangoAttrInt)
PangoUnderline-
the
PangoUnderline enumeration is used to specify
whether text should be underlined, and if so, the type
of underlining.
none- no underline should be drawn
single- a single underline should be drawn
double- a double underline should be drawn
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.
User Functions
PangoAttrDataCopyFunc(data)-
A copy function passed to attribute new functions that take
user data.
Returns: [R object] a new copy of data. PangoAttrFilterFunc(attribute, data)-
A predicate function used by
pangoAttrListFilter
to filter out a subset of attributes for a list.
attribute- [
PangoAttribute] a PangoAttribute data- [R object] callback data passed to
pangoAttrListFilter
Returns: [logical] TRUE if the attribute should be filtered out