双方向テキストのソースを表示

[[Category:インプットメソッド]]
[[Wikipedia:ja:双方向テキスト|双方向テキスト(そうほうこうテキスト、英: bi-directional text)]]とは、右から左（RTL）と左から右（LTR）の2つの方向性を持つテキストです。

== コンセプト ==

; 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: {{bc|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. [https://imgur.com/a/lfQV88E 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.
; [[Wikipedia:Bidirectional_text#Unicode_bidi_support|Unicode support]]: there are three main Unicode control characters: [[Wikipedia:RLM]], [[Wikipedia:LRM]], [[Wikipedia:ALM]].

; [https://www.unicode.org/reports/tr9/ Bidirectional Algorithm]: is the set of rules applied to display text in the correct order.

{{AUR|fribidi-git}} is an open source implementations of Bidi Algorithm. {{AUR|python-bidi}} is a python library for related functions.

== サポート ==

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

; Letter rendering (RTL): able to correctly apply letter shaping and ligatures. See [[Wikipedia:Complex text layout|Complete Text Layout]]. This is often referred to shortly as RTL support.
; Switch text alignment (Bidi): E.g: Firefox {{ic|Ctrl+Shift+X}} shortcut.
; Logical navigation: in a RTL text, with RTL text alignment, arrow keys should not cause reversed navigation.

{| class="wikitable sortable"
! Tag 
! App 
! Date 
! RTL 
! Bidi 
! Nav 
! Notes
|-
| browser 
| [[chromium]] 
| 2022-08-28 
| {{Yes}} 
| {{No|1=https://bugs.chromium.org/p/chromium/issues/detail?id=1357401}} 
| {{Yes}} 
| Chromium is the engine of ElectronJS. Fixing this should resolve Electron Apps too.
|-
| browser 
| [[firefox]] 
| 2022-09-01 
| {{Yes}} 
| {{No|1=https://bugzilla.mozilla.org/show_bug.cgi?id=1787660}} 
| {{No|1=https://bugzilla.mozilla.org/show_bug.cgi?id=1788929}} 
| 
|-
| browser 
| [https://doc.qt.io/QtWebBrowser/ qtwebbrowser] 
| 2022-11-01 
| {{Yes}} 
| {{No|1=https://bugreports.qt.io/browse/QTWB-67}} 
|  
| 
|-
| browser 
| [https://webkit.org/ webkit] 
| 2022-11-01 
| {{Yes}} 
| {{No|1=https://bugs.webkit.org/show_bug.cgi?id=247334}} 
|  
| 
|-
| editor 
| [[AbiWord]] 
| 2007-12-06 
| {{Yes|1=https://bugzilla.abisource.com/show_bug.cgi?id=11307}} 
|  
|  
| 
|-
| editor 
| [[emacs]] 
| 2019-06-31 
| {{Yes}} 
| {{No|1=https://www.mail-archive.com/emacs-bidi@gnu.org/msg00582.html}} 
|  
| With [https://github.com/emacsmirror/bidi extension]
|-
| editor 
| {{Pkg|kate}} 
| 2016-06-20 
| {{Yes}} 
| {{No|1=https://bugs.kde.org/show_bug.cgi?id=280645}} 
|  
| 
|-
| editor 
| [[LibreOffice]] 
|  
| {{Yes}} 
| {{Yes}} 
| {{Yes}} 
| fully supported. Enabled using [https://help.libreoffice.org/Common/Languages_Using_Complex_Text_Layout Complex Text Layout] from settings.
|-
| editor 
| [[neovim]] 
| 2014-04-17 
| {{No}} 
| {{No|1=https://github.com/neovim/neovim/issues/553}} 
|  
| see [https://neovim.io/doc/user/arabic.html :set arabic]
|-
| editor 
| {{Pkg|texworks}} 
| 2009-03-01 
| {{Yes}} 
| {{No|1=https://tug.org/pipermail/texworks/2009q1/000547.html}} 
|  
| 
|-
| editor 
| [[vim]] 
| 2015-08-19 
| {{No}} 
| {{No|1=https://github.com/vim/vim/issues/204}} 
|  
| see [https://vim-jp.org/vimdoc-en/arabic.html :set arabic]
|-
| other 
| [[groff]] 
| 2005-12-02 
| {{No}} 
| {{No|1=https://web.archive.org/web/20220831201034/https://lists.arabeyes.org/archives/doc/2005/December/msg00004.html}} 
| {{-}} 
| 
|-
| other 
| [[Wikipedia:HTML]]
|  
| {{Yes}} 
| {{Yes}} 
| {{Yes}} 
| 
|-
| other 
| [[latex]] 
|  
| {{Yes}} 
| {{Yes}} 
| {{-}} 
| Using LuaTeX or XeLaTeX with polyglossia
|-
| other 
| [[wine]] 
| 2002-04-21 
| {{Yes}} 
| {{No|1=https://bugs.winehq.org/show_bug.cgi?id=609}} 
|  
| 
|-
| terminal 
| [[alacritty]] 
| 2017-07-15 
|  
| {{No|1=https://github.com/alacritty/alacritty/issues/663}} 
|  
| 
|-
| terminal 
| {{Pkg|dvtm}} 
| 2019-10-12 
|  
| {{No|1=https://github.com/martanne/dvtm/issues/99}} 
|  
| 
|-
| terminal 
| [[gedit]] 
|  
| {{Yes}} 
| {{No}} 
|  
| For Gedit <= 2.1, workaround by [https://github.com/behnam/gedit-bidiassist extension].
|-
| terminal 
| [[irssi]] 
| 2019-10-12 
|  
| {{No|1=https://github.com/irssi/irssi/issues/1133}} 
|  
| 
|-
| terminal 
| [[kitty]] 
| 2019-11-01 
|  
| {{No|1=https://github.com/kovidgoyal/kitty/issues/2109}} 
|  
| 
|-
| terminal 
| [[konsole]] 
|  
| {{Yes}} 
| {{No|1=https://bugs.kde.org/show_bug.cgi?id=461303}} 
|  
| 
|-
| terminal 
| libvte 
|  
| {{Yes|1=https://gitlab.gnome.org/GNOME/vte/-/issues/53}} 
| {{No}} 
|  
| including libvte-based like Gnome, sakura, xfce4...
|-
| terminal 
| {{AUR|mlterm}} 
|  
| {{Yes}} 
| {{No|1=https://github.com/arakiken/mlterm/issues/54}} 
|  
| 
|-
| terminal 
| {{AUR|neatvi-git}}
| 2019-07-04 
|  
| {{No|1=https://github.com/aligrudi/neatvi/issues/8}} 
|  
| 
|-
| terminal 
| pymux 
| 2019-10-12 
|  
| {{No|1=https://github.com/prompt-toolkit/pymux/issues/77}} 
|  
| 
|-
| terminal 
| {{Pkg|qterminal}} 
|  
| {{Yes}} 
| {{No|1=https://github.com/lxqt/qterminal/issues/1006}} 
|  
| 
|-
| terminal 
| {{Pkg|radare2}} 
| 2015-02-03 
|  
| {{No|1=https://github.com/radareorg/ideas/issues/19}} 
|  
| 
|-
| terminal 
| [[tmux]] 
| 2019-10-12 
|  
| {{No|1=https://github.com/tmux/tmux/issues/1936}} 
|  
| won't fix
|-
| terminal 
| [[wezterm]] 
| 2021-05-11 
|  
| {{No|1=https://github.com/wez/wezterm/issues/784#issuecomment-1025346930}} 
|  
| 
|-
| terminal 
| {{AUR|xst}}
| 2018-10-26 
|  
| {{No|1=https://github.com/gnotclub/xst/issues/55}} 
|  
| 
|}

== トラブルシューティング ==

Verify [[Locale#Troubleshooting|UTF-8 Encoding]] is properly configured first. Make sure you install the [[fonts]] corresponding to your language: [[Localization/Arabic#Fonts|Arabic]], [[Fonts#Persian|Persian]], [[Fonts#Hebrew|Hebrew]]. For some terminal, ({{AUR|bicon-git}}) is required to properly display Arabic and Hebrew text.

=== 一時的な回避策 ===
* [https://github.com/imdark/Sublime-Text-2-BIDI Sublime text].

== 参照 ==

=== 内部リンク ===

* [[ロケール]]
* [[ローカリゼーション]]

=== 外部リンク ===

* [https://www.freedesktop.org/wiki/Specifications/bidi-spec/ freedesktop specification for Bidi support]:  [https://terminal-wg.pages.freedesktop.org/bidi/ terminal].
* [https://rtlstyling.com/posts/rtl-styling Comprehensive guide of RTL styling in HTML]