Bidirectional text - ArchWiki

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From Wikipedia:Bidirectional text, is text that contains two text directionalities, right-to-left (RTL) and left-to-right (LTR).

## Concepts

Text direction
  in text editing, setting text direction changes how the program interacts with typed text including changes in text navigation, text selection, and text insertion.
Text alignment
  text alignment only changes how text is displayed and styled.
Fake Bidi
  a fake locale displaying completely reversed English sentences to mimic a RTL context. This helps developers who do not speak a RTL language to deal with RTL issues. For example:

      This English sentence contains SDROW CIBARA EMOS and ends with English words.

Poor man's bidi mode
  automatic visual text order right-to-left input in normal terminal.
Logical navigation
  words are traversed as they are read.
Visual navigation
  words are traversed as they are displayed. This GIF demonstrates the difference between the two.

Logical navigation is the correct way of navigation that programs should implement to fully support Bidi. Despite that, it would be preferable to have a switch between the two.

Unicode support
  In Unicode-supported text editors, text direction can be controlled by inserting special formatting characters in front of it: Wikipedia:RLM (U+200F), Wikipedia:LRM (U+200E), which is a workaround for text editors not supporting switching text direction.

Bidirectional Algorithm
  is the set of rules applied to display text in the correct order.

Some implementations:

- fribidi-gitAUR is an open source implementations of Bidi Algorithm.
- SheenBidi: Improved Unicode Implementation in C.
- python-bidiAUR is a python library for related functions.

## Support

In order for a program to fully support Bidi text, it must have:

Letter rendering (RTL)
  correctly apply letter shaping and ligatures. See W:harfbuzz and Complete Text Layout.
Force switch text alignment (Bidi)
  E.g: Firefox `Ctrl+Shift+X` shortcut.
Logical navigation
  in a RTL text, with RTL text alignment, arrow keys should not cause reversed navigation.

The factual accuracy of this article or section is disputed.

Reason: It's not clear if what the date refers to in the tables. Date of test by the editor? Date of implementation of the feature (since when the feature is supported)? (Discuss in Talk:Bidirectional text)

### Browsers

App | Date | RTL | Bidi | Nav | Notes
--- | --- | --- | --- | --- | ---
chromium | 2022-08-28 | Yes | No | Yes | Chromium is the engine of ElectronJS. Fixing this should resolve Electron Apps too.
firefox | 2022-09-01 | Yes | No | No |
qtwebbrowser | 2022-11-01 | Yes | No |  |
webkit | 2022-11-01 | Yes | No |  |
epiphany | 2023-08-27 | Yes | No |  |

### Editors

App | Date | RTL | Bidi | Nav | Notes
--- | --- | --- | --- | --- | ---
AbiWord | 2007-12-06 | Yes |  |  |
emacs | 2019-06-31 | Yes | No |  | With extension. See also: emacs bidi editing.
gedit |  | Yes | No |  | For Gedit <= 2.1, workaround by extension.
ghostwriter | 2023-08-27 | Yes | No |
kate | 2016-06-20 | Yes | No |  |
LibreOffice |  | Yes | Yes | Yes | Enabled from Complex Text Layout in settings.
marktextAUR | 2020-02-20 |  | No |  |
neovim | 2014-04-17 | No | No |  | see :set arabic
texworks | 2009-03-01 | Yes | No |  |
vim | 2015-08-19 | No | No |  | see :set arabic

### Terminal

App | Date | RTL | Bidi | Nav | Notes
--- | --- | --- | --- | --- | ---
alacritty | 2017-07-15 |  | No |  |
dvtm | 2019-10-12 |  | No |  |
kitty | 2019-11-01 | No | No |  | Tested with kitty version 0.31.0-1, the 2024-01-02. Does not support RLO (U+202E).
konsole |  | Yes | No |  | Tested with konsole version 23.08.4-2, the 2024-01-02.
libvte |  | Yes | No |  | including libvte-based like Gnome, sakura, xfce4, terminator…
mltermAUR |  | Yes | No |  |
neatvi-gitAUR | 2019-07-04 |  | No |  |
pymux | 2019-10-12 |  | No |  |
qterminal |  | No | No |  | Tested with qterminal version 1.4.0-1, the 2024-01-02. Does not support RLO (U+202E).
radare2 | 2015-02-03 |  | No |  |
Terminator |  | Yes | No |  | Tested with terminator version 2.1.3-3, the 2024-01-02.
tmux | 2019-10-12 |  | No |  | won't fix
wezterm | 2021-05-11 |  | No |  |
xstAUR | 2018-10-26 |  | No |  |

### Other

App | Date | RTL | Bidi | Nav | Notes
--- | --- | --- | --- | --- | ---
electronjs | 2023-08-26 |  | No |  |
groff | 2005-12-02 | No | No | – |
irssi | 2019-10-12 |  | No |  |
latex |  | Yes | Yes | – | Using LuaTeX or XeLaTeX with polyglossia
Wikipedia:HTML |  | Yes | Yes | Yes |
wine | 2002-04-21 | Yes | No |  |

## Troubleshooting

Verify UTF-8 Encoding is properly configured first. Make sure you install the fonts corresponding to your language: Arabic, Persian, Hebrew. For some terminals, (bicon-gitAUR) is required to properly display Arabic and Hebrew text.

### Temporary workarounds

- Sublime text.

## See also

### Internal links

- Locale
- Localization

### External links

- freedesktop specification for Bidi support: terminal.
- Comprehensive guide of RTL styling in HTML

Category:

- Input methods

Hidden category:

- Pages or sections flagged with Template:Accuracy