/ 
CSS-Flip-0.04_03
/ CSS::Yamaantaka

NAME

CSS::Yamaantaka - Converts direction of Cascading Style Sheet (CSS)

SYNOPSIS

use CSS::Yamaantaka;

$ya = CSS::Yamaantaka->new('lr_tb' => 'tb_rl');
$css_source_vertical_rl = $ya->transform($css_source);

DESCRIPTION

As Yamāntaka has many legs, texts can run in various directions: left to right and right to left horizontally; vertically with lines extending right to left and left to right.

CSS::Yamaantaka replaces things directed to "left" or "horizontal-tb" in a Cascading Style Sheet (CSS) file such as float, padding, margin with values directed to "right" or "vertical-rl", and so on.

Constructor

new ( SRC => DEST, [ options... ] )
new ( 'adaptor' => ADAPTOR, [ options... ] )

Creates new CSS::Yamaantaka object.

In first form, SRC and DEST are the original and resulting directions. Available directions are 'lr_tb', 'rl_tb', 'tb_lr' and 'tb_rl'. Their synonyms are 'ltr', 'rtl', 'vertical-lr' and 'vertical-rl', respectively.

Following options are available.

flip_bg => 0|1

Fixes background positions properties. Default is 1, will fix.

flip_cursor => 0|1

Fixes positions "n"/"e"/"s"/"w" and so on within cursor properties. Default is 1, will fix.

flip_url => 0|1

Fixes "top"/"right"/"bottom"/"left" string within URLs. Default is 0, won't fix.

ignore_bad_bgp => 0|1

Ignores unmirrorable background-position values. Default is 1, WILL ignore and won't croak it.

swap_ltr_rtl_in_url => 0|1

Fixes "ltr"/"rtl" string within URLs, if needed. Default is 0, won't fix.

In second form, ADAPTOR is a name of package or an object. package will be automatically loaded. See "Adaptors" about standard adaptors.

Methods

body_direction

Get direction property or dir attribute of body element thought to be appropriate. Returns 'ltr', 'rtl' or undef (unknown).

text_orientation

Get text-orientation property of texts assumed. Returns 'sideways-left' or undef (upright or sideways-right is assumed).

transform ( $lines, [ options... ] )

Runs the fixing functions against CSS source.

$lines is a string. Following options are available.

flip_bg => 0|1
flip_cursor => 0|1
flip_url => 0|1
swap_ltr_rtl_in_url => 0|1

Overrides these flags if params are set.

Returns same lines directions are changed.

writing_mode

Get writing-mode property of texts thought to be appropriate. Returns 'horizontal-tb', 'vertical-lr', 'vertical-rl' or undef (unknown).

Adaptors

This module supports four directions of documents:

lr-tb

The direction specified by { direction: ltr; writing-mode: horizontal-tb; }. For example, most Western writing systems employ it.

rl-tb

The direction specified by { direction: rtl; writing-mode: horizontal-tb; }. For example, some Middle Eastern writing systems employ it.

tb-lr

The direction specified by { writing-mode: vertical-lr; }. For example, several North Asian writing systems employ it.

lr-tb

The direction specified by { writing-mode: vertical-rl; }. East Asian writing systems with vertical layout employ it.

This module chooses adaptors by source & resulting directions:

table 1. Choosing adaptors
+-----------+-------------+-------------+-------------+--------------+
| from \ to | lr-tb       : rl-tb       : tb-lr       : tb-rl        |
+-----------+-------------+-------------+-------------+--------------+
| lr-tb     |      -      : MirrorH     : MirrorTL_BR : RotateR      |
| rl-tb     | MirrorH     :      -      : RotateL*    : MirrorTR_BL* |
| tb-lr     | MirrorTL_BR : RotateR     :      -      : MirrorV      |
| tb-rl     | RotateL     : MirrorTR_BL : MirrorV     :       -      |
+-----------+-------------+-------------+-------------+--------------+
 * Assumed text-orientation: sideways-left.

 n.b.: Prefixing "CSS::Yamaantaka::" are omitted.

Each adaptor will or won't change following "directions" of CSS properties.

line-relative box directions

"right" / "left" of text-align, float and clear. "top" / "bottom" of vertical-align.

physical box directions

"top" / "right" / "bottom" / "left".

global directions

Directions specified by body element, "ltr" / "rtl".

direction swapping

Horizontal and vertical orientation.

table 2. Feature of adaptors
+-------------+-----------+-------------------------+---------+------+
|             | line-rel. | box directions          : global  : h/v  |
+-------------+-----------+-------------------------+---------+------+
| MirrorH     | reverse h.: reverse horizontally    : reverse :   -  |
| MirrorV     |     -     : reverse horizontally    : reverse :   -  |
| RotateR     |     -     : rotate clockwise        : reverse : swap |
| RotateL     |     -     : rotate counter-clockwise: reverse : swap |
| MirrorTL_BR |     -     : reverse with tl-br axis :    -    : swap |
| MirrorTR_BL |     -     : reverse with tr-bl axis :    -    : swap |
+-------------+-----------+-------------------------+---------+------+

Any adaptors listed above won't fix line-relative text directions ("rtl" / "ltr").

VERSION

Consult $VERSION variable.

SEE ALSO

CSS::Janus

Extended CSSJanus supporting vertical-rl writing-mode: http://www.epubcafe.jp/download

cssflip(1)

AUTHOR

Hatuka*nezumi - IKEDA Soji <hatuka(at)nezumi.nu>.

COPYRIGHT

Copyright (C) 2013 Hatuka*nezumi - IKEDA Soji.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.