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Xfc::Pango Namespace Reference
[The Xfc Namespace]

The C++ framework for the Pango text handling library. More...

Classes

Typedefs

Enumerations

Functions

Rendering Methods
Item methods
Script Methods
Direction Methods

Detailed Description

The C++ framework for the Pango text handling library.

Pango is a library for internationalized text handling. It centers around the Pango::Layout object, representing a paragraph of text. Pango provides the engine for Gtk::TextView, Gtk::Label, Gtk::Entry and other widgets that display text.


Typedef Documentation

typedef PangoGlyph Xfc::Pango::Glyph

Glyph is a convenient typedef for PangoGlyph.

Glyph structure represents a single glyph in the output form of a glyph string.

typedef PangoGlyphUnit Xfc::Pango::GlyphUnit

GlyphUnit is a convenient typedef for PangoGlyphUnit.

The GlyphUnit type is used to store dimensions within Pango. Dimensions are stored in 1/PANGO_SCALE of a device unit. (A device unit might be a pixel for screen display, or a point on a printer.) PANGO_SCALE is currently 1024, and is unlikely to change, but you should not depend on its exact value. The PANGO_PIXELS() macro can be used to convert from glyph units into device units with correct rounding.


Enumeration Type Documentation

enum Xfc::Pango::Alignment

Describes how to align the lines of a Layout within the available space.

If the PangoLayout is set to justify using Pango::Layout::set_justify(), then this only has an effect for partial lines.

Enumerator:
ALIGN_LEFT  Put all available space on the right.
ALIGN_CENTER  Center the line within the available space.
ALIGN_RIGHT  Put all available space on the left.

enum Xfc::Pango::AttrType

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 class used to store the attribute is listed in parentheses after the description.

Enumerator:
ATTR_INVALID  Invalid.
ATTR_LANGUAGE  Language (AttrLanguage).
ATTR_FAMILY  Font family name list (AttrString).
ATTR_STYLE  Font slant style (AttrInt).
ATTR_WEIGHT  Font weight (AttrInt).
ATTR_VARIANT  Font variant (normal or small caps) (AttrInt).
ATTR_STRETCH  Font stretch (AttrInt).
ATTR_SIZE  Font size in points divided by PANGO_SCALE (AttrInt).
ATTR_FONT_DESC  Font description (AttrFontDesc).
ATTR_FOREGROUND  Foreground color (AttrColor).
ATTR_BACKGROUND  Background color (AttrColor).
ATTR_UNDERLINE  Whether the text has an underline (AttrInt).
ATTR_STRIKETHROUGH  Whether the text is struck-through (AttrInt).
ATTR_RISE  Baseline displacement (AttrInt).
ATTR_SHAPE  Shape (AttrShape).
ATTR_SCALE  Font size scale factor (AttrScale).
ATTR_FALLBACK  Whether fallback is enabled (AttrInt).
ATTR_LETTER_SPACING  The amount of extra space to add between graphemes.
ATTR_UNDERLINE_COLOR  The color of underlines.
ATTR_STRIKETHROUGH_COLOR  The color of strikethrough lines.

enum Xfc::Pango::CoverageLevel

Used to indicate how well a font can represent a particular ISO 10646 character point for a particular script.

Enumerator:
COVERAGE_NONE  The character is not representable with the font.
COVERAGE_FALLBACK  The character is represented in a way that may be comprehensible but is not the correct graphical form; for instance, a Hangul character represented as a a sequence of Jamos, or a Latin transliteration of a Cyrillic word.
COVERAGE_APPROXIMATE  The character is represented as basically the correct graphical form, but with a stylistic variant inappropriate for the current script.
COVERAGE_EXACT  The character is represented as the correct graphical form.

enum Xfc::Pango::Direction

The Direction type represents the direction of writing for unicode bidirectional text.

Note: Not every value in this enumeration makes sense for every usage of Pango::Direction.

Enumerator:
DIRECTION_LTR  The text is written left-to-right.
DIRECTION_RTL  The text is written right-to-left.
DIRECTION_TTB_LTR  The text is written vertically top-to-bottom, with the rows ordered from left to right.
DIRECTION_TTB_RTL  The text is written vertically top-to-bottom, with the rows ordered from right to left.
DIRECTION_WEAK_LTR  A weak left-to-right direction.
DIRECTION_WEAK_RTL  A weak right-to-left direction .
DIRECTION_NEUTRAL  No direction specified.

enum Xfc::Pango::EllipsizeMode

Describes what sort of (if any) ellipsization should be applied to a line of text.

Enumerator:
ELLIPSIZE_NONE  No ellipsization.
ELLIPSIZE_START  Omit characters at the start of the text.
ELLIPSIZE_MIDDLE  Omit characters in the middle of the text.
ELLIPSIZE_END  Omit characters at the end of the text.

enum Xfc::Pango::FontMask

The bit flags in a FontMask correspond to fields in a FontDescription that have been set.

Enumerator:
FONT_MASK_FAMILY  The font family is specified.
FONT_MASK_STYLE  The font style is specified.
FONT_MASK_VARIANT  T font variant is specified.
FONT_MASK_WEIGHT  The font weight is specified.
FONT_MASK_STRETCH  The font stretch is specified.
FONT_MASK_SIZE  The font size is specified.

enum Xfc::Pango::RenderPart

Defines different items to render for such purposes as setting colors.

Enumerator:
RENDER_PART_FOREGROUND  The text itself.
RENDER_PART_BACKGROUND  The area behind the text.
RENDER_PART_UNDERLINE  Underlines.
RENDER_PART_STRIKETHROUGH  Strikethrough lines.

enum Xfc::Pango::Script

Identifies different writing systems.

The values correspond to the names defined in the Unicode standard (see Unicode Standard Annex 24: Script names).

Enumerator:
SCRIPT_INVALID_CODE  A value never used for any unicode character.
SCRIPT_COMMON  Zyyy; a character used by multiple different scripts.
SCRIPT_INHERITED  Qaai; a mark glyph that takes its script from the base glyph to which it is attached.
SCRIPT_ARABIC  Arab.
SCRIPT_ARMENIAN  Armn.
SCRIPT_BENGALI  Beng.
SCRIPT_BOPOMOFO  Bopo.
SCRIPT_CHEROKEE  Cher.
SCRIPT_COPTIC  Qaac.
SCRIPT_CYRILLIC  Cyrl (Cyrs).
SCRIPT_DESERET  Dsrt.
SCRIPT_DEVANAGARI  Deva.
SCRIPT_ETHIOPIC  Ethi.
SCRIPT_GEORGIAN  Geor (Geon, Geoa).
SCRIPT_GOTHIC  Goth.
SCRIPT_GREEK  Grek.
SCRIPT_GUJARATI  Gujr.
SCRIPT_GURMUKHI  Guru.
SCRIPT_HAN  Hani.
SCRIPT_HANGUL  Hang.
SCRIPT_HEBREW  Hebr.
SCRIPT_HIRAGANAPANGO_SCRIPT_HIRAGANA  Hira.
SCRIPT_KANNADA  Knda.
SCRIPT_KATAKANA  Kana.
SCRIPT_KHMER  Khmr.
SCRIPT_LAO  Laoo.
SCRIPT_LATIN  Latn (Latf, Latg).
SCRIPT_MALAYALAM  Mlym.
SCRIPT_MONGOLIAN  Mong.
SCRIPT_MYANMAR  Mymr.
SCRIPT_OGHAM  Ogam.
SCRIPT_OLD_ITALIC  Ital.
SCRIPT_ORIYA  Orya.
SCRIPT_RUNIC  Runr.
SCRIPT_SINHALA  Sinh.
SCRIPT_SYRIAC  Syrc (Syrj, Syrn, Syre).
SCRIPT_TAMIL  Taml.
SCRIPT_TELUGU  Telu.
SCRIPT_THAANA  Thaa.
SCRIPT_THAI  Thai.
SCRIPT_TIBETAN  Tibt.
SCRIPT_CANADIAN_ABORIGINAL  Cans.
SCRIPT_YI  Yiii.
SCRIPT_TAGALOG  Tglg.
SCRIPT_HANUNOO  Hano.
SCRIPT_BUHID  Buhd.
SCRIPT_TAGBANWA  Tagb.
SCRIPT_BRAILLE  Brai.
SCRIPT_CYPRIOTPANGO_SCRIPT_CYPRIOT  Cprt.
SCRIPT_LIMBUPANGO_SCRIPT_LIMBU  Limb.
SCRIPT_OSMANYA  Osma.
SCRIPT_SHAVIAN  Shaw.
SCRIPT_LINEAR_B  Linb.
SCRIPT_TAI_LE  Tale.
SCRIPT_UGARITIC  Ugar.

enum Xfc::Pango::Stretch

Specifies the width of the font relative to other designs within a family.

Enumerator:
STRETCH_UTLRA_CONDENSED  Ultra condensed width.
STRETCH_EXTRA_CONDENSED  Extra condensed width.
STRETCH_CONDENSED  Condensed width.
STRETCH_SEMI_CONDENSED  Semi condensed width.
STRETCH_NORMAL  Normal width.
STRETCH_SEMI_EXPANDED  Semi expanded width.
STRETCH_EXPANDED  Expanded width.
STRETCH_EXTRA_EXPANDED  Extra expanded width.
STRETCH_ULTRA_EXPANDED  Ultra expanded width.

enum Xfc::Pango::Style

Specifies the various slant styles possible for a font.

Enumerator:
STYLE_NORMAL  The font is upright.
STYLE_OBLIQUE  The font is slanted, but in a roman style.
STYLE_ITALIC  The font is slanted in an italic style.

enum Xfc::Pango::TabAlign

Specifies where a tab stop appears relative to the text.

Currently there is only TAB_LEFT, but TAB_RIGHT, TAB_CENTER and TAB_NUMERIC may be supported in the future.

Enumerator:
TAB_LEFT  The tab stop appears to the left of the text.

enum Xfc::Pango::Underline

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

Enumerator:
UNDERLINE_NONE  No underline should be drawn.
UNDERLINE_SINGLE  A single underline should be drawn.
UNDERLINE_DOUBLE  A double underline should be drawn.
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; UNDERLINE_SINGLE should be used for extended portions of text.
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 an contrasting color may automatically be used.

enum Xfc::Pango::Variant

Specifies the capitalization variant of the font.

Enumerator:
VARIANT_NORMAL  A normal font.
VARIANT_SMALL_CAPS  A font with the lower case characters replaced by smaller variants of the capital characters.

enum Xfc::Pango::Weight

Specifies the weight (boldness) of a font.

This is a numerical value ranging from 100 to 900, but there are some predefined values:

Enumerator:
WEIGHT_ULTALIGHT  The ultralight weight (= 200).
WEIGHT_LIGHT  The light weight (=300).
WEIGHT_NORMAL  The default weight (= 400).
WEIGHT_SEMIBOLD  The semi bold weight (= 600).
WEIGHT_BOLD  The bold weight (= 700).
WEIGHT_ULTRABOLD  The ultrabold weight (= 800).
WEIGHT_HEAVY  The heavy weight (= 900).

enum Xfc::Pango::WrapMode

Enumerator:
WRAP_WORD  Wrap lines at word boundaries.
WRAP_CHAR  Wrap lines at character boundaries.
WRAP_WORD_CHAR  Wrap lines at word boundaries, but fall back to character boundaries if there is not enought space for a full word.


Function Documentation

void Xfc::Pango::break_text ( const String &  text,
const Analysis &  analysis,
std::vector< LogAttr > &  attrs 
)

Determines possible line, word, and character breaks for a string of Unicode text.

Parameters:
text The text to process.
analysis An Analysis structure from Pango::Context::itemize().
attrs A vector of LogAttr to store the character information in.

Direction Xfc::Pango::find_base_dir ( const char *  text,
int  length = -1 
)

Searches a string for the first character that has a strong direction, according to the Unicode bidirectional algorithm.

Parameters:
text The text to process.
length The length of text in bytes, or -1 if text is null-terminated.
Returns:
The direction corresponding to the first strong character.
If no such character is found, then Pango::DIRECTION_NEUTRAL is returned.

void Xfc::Pango::find_paragraph_boundary ( const String &  text,
int *  paragraph_delimiter_index,
int *  next_paragraph_start 
)

Locates a paragraph boundary in text.

Parameters:
text The UTF-8 text.
paragraph_delimiter_index The return location for index of delimiter.
next_paragraph_start The return location for start of next paragraph.
A boundary is caused by delimiter characters, such as a newline, carriage return, carriage return-newline pair, or Unicode paragraph separator character. The index of the run of delimiters is returned in paragraph_delimiter_index. The index of the start of the paragraph (index after all delimiters) is stored in next_paragraph_start. If no delimiters are found, both paragraph_delimiter_index and next_paragraph_start are filled with the length of text (an index one off the end).

void Xfc::Pango::get_log_attrs ( const String &  text,
PangoLanguage *  language,
std::vector< LogAttr > &  attrs,
int  level = -1 
)

Computes a LogAttr for each character in text.

Parameters:
text The text to process.
language The language tag.
attrs A vector of LogAttr with one LogAttr per character in text, plus one extra, to be filled in.
level The embedding level, or -1 if unknown.
The log_attrs vector must have one LogAttr for each position in text; if text contains N characters, it has N+1 positions, including the last position at the end of the text. text should be an entire paragraph; logical attributes can't be computed without context (for example you need to see spaces on either side of a word to know the word is a word).

bool Xfc::Pango::language_includes_script ( PangoLanguage *  language,
Script  script 
)

Determines if script is one of the scripts used to write language.

Parameters:
language A PangoLanguage.
script A Pango::Script
Returns:
true if script is one of the scripts used to write language, or if nothing is known about language.
The returned value is conservative; if nothing is known about the language tag language, true will be returned, since, as far as Pango knows, script might be used to write language.

This routine is used in Pango's itemization process when determining if a supplied language tag is relevant to a particular section of text. It probably is not useful for applications in most circumstances.

std::vector<Pointer<Item> > Xfc::Pango::reorder_items ( const std::vector< Pointer< Item > > &  logical_items  ) 

From a list of items in logical order and the associated directional levels, produce a list in visual order (the original list is unmodified).

Parameters:
logical_items A vector of Pointer<Item> in logical order.
Returns:
A vector of Pointer<Item> in visual order.
Please mail otaylor@redhat.com if you use this method. It is not a particularly convenient interface, and the code is duplicated elsewhere in Pango for that reason.

Script Xfc::Pango::script_for_unichar ( G::Unichar  ch  ) 

Looks up the Pango::Script for a particular character (as defined by Unicode Technical report 24).

Parameters:
ch A unicode character
Returns:
The PangoScript for the character.
No check is made for ch being valid unicode character; if you pass in an invalid character, the result is undefined.

PangoLanguage* Xfc::Pango::script_get_sample_language ( Script  script  ) 

Given a script, finds a language tag that is reasonably representative of that script.

Parameters:
script A Pango::Script
Returns:
A PangoLanguage that is representative of the script, or null if no such language exists.
This will usually be the most widely spoken or used language written in that script: for instance, the sample language for Pango::SCRIPT_CYRILLIC is ru (Russian), the sample lanugage for Pango::SCRIPT_ARABIC is ar. For some scripts, no sample language will be returned because there is no language that is sufficiently representative. The best example of this is Pango::SCRIPT_HAN, where various different variants of written Chinese, Japanese, and Korean all use significantly different sets of Han characters and forms of shared characters. No sample language can be provided for many historical scripts as well.

Direction Xfc::Pango::unichar_direction ( G::Unichar  ch  ) 

Determines the direction of a character; either Pango::DIRECTION_LTR, Pango::DIRECTION_LTR, or Pango::DIRECTION_NEUTRAL.

Parameters:
ch The character to examine.
Returns:
The direction of a the character, as used in the Unicode bidirectional algorithm.

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