From 0609a1f94562c75c5b24bef7b435dec566b927e7 Mon Sep 17 00:00:00 2001
From: Lars Michelsen <lm@larsmichelsen.com>
Date: Sun, 14 Oct 2018 20:14:56 +0200
Subject: [PATCH] Visualize that ale is currently checking the current buffer

At the moment you can never be sure whether you look at the results
that ale just produced after your last changes or you are looking at
outdated information.

Instead of showing the last results while ale executes checks on the
current buffer it can now show a specific indicator.

This commit introduces the new config variable
`g:airline#extensions#ale#checking_symbol` which defaults to "...". In
case you don't want to see this, you may set it to an empty string.
---
 autoload/airline/extensions/ale.vim | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/autoload/airline/extensions/ale.vim b/autoload/airline/extensions/ale.vim
index ec85076..71f6317 100644
--- a/autoload/airline/extensions/ale.vim
+++ b/autoload/airline/extensions/ale.vim
@@ -3,10 +3,6 @@
 
 scriptencoding utf-8
 
-let s:error_symbol = get(g:, 'airline#extensions#ale#error_symbol', 'E:')
-let s:warning_symbol = get(g:, 'airline#extensions#ale#warning_symbol', 'W:')
-let s:show_line_numbers = get(g:, 'airline#extensions#ale#show_line_numbers', 1)
-
 function! s:airline_ale_count(cnt, symbol)
   return a:cnt ? a:symbol. a:cnt : ''
 endfunction
@@ -37,13 +33,20 @@ function! airline#extensions#ale#get(type)
     return ''
   endif
 
-  let is_err = a:type ==# 'error'
-  let symbol = is_err ? s:error_symbol : s:warning_symbol
+  let error_symbol = get(g:, 'airline#extensions#ale#error_symbol', 'E:')
+  let warning_symbol = get(g:, 'airline#extensions#ale#warning_symbol', 'W:')
+  let checking_symbol = get(g:, 'airline#extensions#ale#checking_symbol', '...')
+  let show_line_numbers = get(g:, 'airline#extensions#ale#show_line_numbers', 1)
 
   let is_err = a:type ==# 'error'
+
+  if ale#engine#IsCheckingBuffer(bufnr('')) == 1
+    return is_err ? '' : checking_symbol
+  endif
+
+  let symbol = is_err ? error_symbol : warning_symbol
+
   let counts = ale#statusline#Count(bufnr(''))
-  let symbol = is_err ? s:error_symbol : s:warning_symbol
-
   if type(counts) == type({}) && has_key(counts, 'error')
     " Use the current Dictionary format.
     let errors = counts.error + counts.style_error
@@ -53,7 +56,7 @@ function! airline#extensions#ale#get(type)
     let num = is_err ? counts[0] : counts[1]
   endif
 
-  if s:show_line_numbers == 1
+  if show_line_numbers == 1
     return s:airline_ale_count(num, symbol) . <sid>airline_ale_get_line_number(num, a:type)
   else
     return s:airline_ale_count(num, symbol)