neuims: An Input Method Switcher for (Neo)Vim

2020-02-21 14:50

1 Background
2 Requirement
3 Installation
4 Usage
5 Configuration

1 Background

People who use CJK or other non-Latin input methods can relate how pain it is to toggle input methods between insert and normal mode in (Neo)Vim. The first time I came across this problem several years ago, VimIM was the tool I found. But I always had problems with getting expected candidates or setting up on a new machine. I read the manual but it didn't change anything. (Yea, I must be dumb.) Also, the switching performance of VimIM was poor, and I'm not sure about the reason - my potato laptop, or the plugin itself. For a while, I use other editors instead of Vim to do my "CJK" job.

But finally I have had enough of it, because I always accidentally typed in "h", "j", "k", "l". A new search was started again. Tools like vim-barbaric and vim-xkbswitch, they don't have support for Windows OS or require the user to read the manual for an hour and to configure for another.

I'm probably wrong about them, and actually, I just want to write some code. So here is "neuims", neur1n's input method switcher.

2 Requirement

Windows 7/10

Currently this plugin is only tested on Windows 7 and 10. And since commit fe2abf1, Python dependencies were removed and a binary written in C++ is used instead. The binary is static-linked, so it should work even there are no VC++ redistributables installed in your system.

Linux/Unix

Currently this plugin is only test on Ubuntu 16.04, and it is limited to IBus. The ibus engine [ENGINE_NAME] command is called to switched the input method.

3 Installation

vim-plug

Put

    Plug 'neur1n/neuims'

into your configuration file. But using the on-demand loading feature of vim-plug is recommended:

    Plug 'neur1n/neuims', {'on': 'IMSToggle'}

4 Usage

4.1 Enable

This plugin needs to be manually enabled before being used to switch input methods. There are two ways to enable:

Using the command :IMSToggle
Calling the function neuims#Toggle(), or using a key mapping, e.g.:

    nnoremap <silent> <leader>it :call neuims#Toggle()<CR>

4.2 Disable

While in enabled status (can be checked with :echo g:neuims.status), use :IMSToggle or press <leader>it again.

4.3 Switch

Usually, the switching is automatically controlled by the InsertEnter and InsertLeave event. However, one may call the function neuims#Switch(0) to switch manually, or using a key mapping, e.g.:

      nnoremap <silent> <leader>is :call neuims#Switch()<CR>

5 Configuration

There are default configurations in the source code:

    let s:win = {
          \ 'im': 'US Keyboard',
          \ 'status': 0,
          \ 'keyboards': {
          \   'US Keyboard': 0x0409,
          \   'Microsoft Pinyin': 0x0804,
          \ },
          \ }

    let s:ibus = {
          \ 'im': 'English (US)',
          \ 'status': 0,
          \ 'keyboards': {
          \   'English (US)': 'xkb:us::eng',
          \   'Pinyin': 'pinyin',
          \ },
          \ }

This should work well with Windows's (7/10) and Ubuntu's (16.04) built-in input methods. Let's break it down:

im: The input method specified here should be the "default" one, which is the one in normal mode.
status: 0 means neuims is not enabled, 1 means neuims is enabled. It is controlled by the plugin itself, the user shall not care about it.
keyboards: The two input methods one wants to use in normal/insert mode should be specified here, one of which must have the same name of that in "im". For example, if im is specified as "English (US)", then there has to be "English (US)" in "keyboards".

For example, if one uses RIME (IBus based) in Ubuntu, the configuration may be:

    let g:neuims = {
          \ 'im': 'English (US)',
          \ 'status': 0,
          \ 'keyboards': {
          \   'English (US)': 'xkb:us::eng',
          \   'Rime': 'rime',
          \ },
          \ }

Jihang Li