Add gen_tags.vim plugin support

Display a "Gen. gen_tags" text in section x when gen_tags
is generating tags, similar to gutentags support.

CHANGELOG.md

@@ -17,6 +17,7 @@ This is the Changelog for the vim-airline project.
     - [Vim-CMake](https://github.com/cdelledonne/vim-cmake) support
     - [battery.vim](https://github.com/lambdalisue/battery.vim) support
     - [nvim-lspconfig](https://github.com/neovim/nvim-lspconfig) support
+    - [gen_tags.vim](https://github.com/jsfaint/gen_tags.vim) support
 - Improvements
   - git branch can also be displayed using [gina.vim](https://github.com/lambdalisue/gina.vim)
   - coc extensions can also show additional status messages

autoload/airline/extensions.vim

@@ -408,6 +408,11 @@ function! airline#extensions#load()
     call add(s:loaded_ext, 'gutentags')
   endif
 
+  if get(g:, 'airline#extensions#gen_tags#enabled', 1) && (get(g:, 'loaded_gentags#gtags', 0) || get(g:, 'loaded_gentags#ctags', 0))
+    call airline#extensions#gen_tags#init(s:ext)
+    call add(s:loaded_ext, 'gen_tags')
+  endif
+
   if (get(g:, 'airline#extensions#grepper#enabled', 1) && get(g:, 'loaded_grepper', 0))
     call airline#extensions#grepper#init(s:ext)
     call add(s:loaded_ext, 'grepper')

autoload/airline/extensions/gen_tags.vim

@@ -0,0 +1,19 @@
+" MIT License. Copyright (c) 2014-2020 Mathias Andersson et al.
+" Written by Kamil Cukrowski 2020
+" Plugin: https://github.com/jsfaint/gen_tags.vim
+" vim: et ts=2 sts=2 sw=2
+
+scriptencoding utf-8
+
+if !(get(g:, 'loaded_gentags#gtags', 0) || !get(g:, 'loaded_gentags#ctags', 0))
+  finish
+endif
+
+function! airline#extensions#gen_tags#status(...) abort
+  return gen_tags#job#is_running() != 0 ? 'Gen. gen_tags' : ''
+endfunction
+
+function! airline#extensions#gen_tags#init(ext) abort
+  call airline#parts#define_function('gen_tags', 'airline#extensions#gen_tags#status')
+endfunction
+

autoload/airline/init.vim

@@ -176,6 +176,7 @@ function! airline#init#bootstrap()
   call airline#parts#define_text('bookmark', '')
   call airline#parts#define_text('capslock', '')
   call airline#parts#define_text('gutentags', '')
+  call airline#parts#define_text('gen_tags', '')
   call airline#parts#define_text('grepper', '')
   call airline#parts#define_text('xkblayout', '')
   call airline#parts#define_text('keymap', '')
@@ -211,7 +212,7 @@ function! airline#init#sections()
     let g:airline_section_gutter = airline#section#create(['%='])
   endif
   if !exists('g:airline_section_x')
-    let g:airline_section_x = airline#section#create_right(['bookmark', 'tagbar', 'vista', 'gutentags', 'omnisharp', 'grepper', 'filetype'])
+    let g:airline_section_x = airline#section#create_right(['bookmark', 'tagbar', 'vista', 'gutentags', 'gen_tags', 'omnisharp', 'grepper', 'filetype'])
   endif
   if !exists('g:airline_section_y')
     let g:airline_section_y = airline#section#create_right(['ffenc'])

doc/airline.txt

@@ -787,6 +787,12 @@ vim-gutentags <https://github.com/ludovicchabant/vim-gutentags>
 * enable/disable vim-gutentags integration >
   let g:airline#extensions#gutentags#enabled = 1
 
+-------------------------------------                     *gen_tags.vim*
+gen_tags.vim <https://github.com/jsfaint/gen_tags.vim>
+
+* enable/disable gen_tags.vim integration >
+  let g:airline#extensions#gen_tags#enabled = 1
+
 -------------------------------------                        *airline-hunks*
 vim-gitgutter <https://github.com/airblade/vim-gitgutter>
 vim-signify <https://github.com/mhinz/vim-signify>

t/init.vim

@@ -34,7 +34,7 @@ describe 'init sections'
   end
 
   it 'section x should be filetype'
-    Expect g:airline_section_x == '%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#wrap(airline#parts#filetype(),0)}'
+    Expect g:airline_section_x == '%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#prepend("",0)}%{airline#util#wrap(airline#parts#filetype(),0)}'
   end
 
   it 'section y should be fenc and ff'