fitz/bidi.h

Index

typedef

• fz_bidi_fragment_fn

enum

• fz_bidi_direction
• fz_bidi_flags

function

• fz_bidi_fragment_text

Bidi

Bidirectional text processing.

Derived from the SmartOffice code, which is itself derived from the example unicode standard code. Original copyright messages follow:

Copyright (C) Picsel, 2004-2008. All Rights Reserved.

Processes Unicode text by arranging the characters into an order suitable for display. E.g. Hebrew text will be arranged from right-to-left and any English within the text will remain in the left-to-right order.

This is an implementation of the Unicode Bidirectional Algorithm which can be found here: http://www.unicode.org/reports/tr9/ and is based on the reference implementation found on Unicode.org.

enum fz_bidi_direction

enum fz_bidi_direction
{
        FZ_BIDI_LTR = 0,
        FZ_BIDI_RTL = 1,
        FZ_BIDI_NEUTRAL = 2,
        FZ_BIDI_UNSET = 3
}

enum fz_bidi_flags

enum fz_bidi_flags
{
        FZ_BIDI_CLASSIFY_WHITE_SPACE = 1,
        FZ_BIDI_REPLACE_TAB = 2
}

typedef fz_bidi_fragment_fn

typedef void (fz_bidi_fragment_fn)(
        const uint32_t *fragment,
        size_t fragmentLen,
        int bidiLevel,
        int script,
        void *arg
)

Prototype for callback function supplied to fz_bidi_fragment_text.

fragment:

first character in fragment

fragmentLen:

number of characters in fragment

bidiLevel:

The bidirectional level for this text. The bottom bit will be set iff block should concatenate with other blocks as right-to-left.

script:

The script in use for this fragment (other than common or inherited)

arg:

Data from caller of Bidi_fragmentText

function fz_bidi_fragment_text

void
fz_bidi_fragment_text (
        fz_context *ctx,
        const uint32_t *text,
        size_t textlen,
        fz_bidi_direction *baseDir,
        fz_bidi_fragment_fn *callback,
        void *arg,
        int flags
)

Partitions the given Unicode sequence into one or more unidirectional fragments and invokes the given callback function for each fragment.

For example, if directionality of text is:

0123456789
rrlllrrrrr,

we’ll invoke callback with:

&text[0], length == 2
&text[2], length == 3
&text[5], length == 5

text:

start of Unicode sequence

textlen:

number of Unicodes to analyse

baseDir:

direction of paragraph (specify FZ_BIDI_NEUTRAL to force auto-detection)

callback:

function to be called for each fragment

arg:

data to be passed to the callback function

flags:

flags to control operation (see fz_bidi_flags above)