autoload themes to match colorscheme. resolves #145.

autoload/airline.vim

@@ -20,6 +20,23 @@ function! airline#switch_theme(name)
   call airline#check_mode()
 endfunction
 
+function! airline#switch_matching_theme()
+  let v:errmsg = ''
+  silent! let palette = g:airline#themes#{g:colors_name}#palette
+  if empty(v:errmsg)
+    call airline#switch_theme(g:colors_name)
+    return 1
+  else
+    for map in items(g:airline_theme_map)
+      if match(g:colors_name, map[0]) > -1
+        call airline#switch_theme(map[1])
+        return 1
+      endif
+    endfor
+  endif
+  return 0
+endfunction
+
 function! s:get_section(winnr, key, ...)
   let text = airline#util#getwinvar(a:winnr, 'airline_section_'.a:key, g:airline_section_{a:key})
   let [prefix, suffix] = [get(a:000, 0, '%( '), get(a:000, 1, ' %)')]

doc/airline.txt

@@ -61,8 +61,9 @@ values):
   only the filename of that buffer.  >
   let g:airline_inactive_collapse=1
 <
-* change the default theme >
+* themes are automatically selected based on the matching colorscheme. this
-  let g:airline_theme='dark'
+  can be overridden by defining a value. >
+  let g:airline_theme=
 <
 * enable/disable usage of patched powerline font symbols >
   let g:airline_powerline_fonts=0

plugin/airline.vim

@@ -31,7 +31,6 @@ call s:check_defined('g:airline_branch_prefix', exists('g:airline_powerline_font
 call s:check_defined('g:airline_readonly_symbol', exists('g:airline_powerline_fonts')?'':'RO')
 call s:check_defined('g:airline_linecolumn_prefix', exists('g:airline_powerline_fonts')?' ':':')
 call s:check_defined('g:airline_paste_symbol', (exists('g:airline_powerline_fonts') ? ' ' : '').'PASTE')
-call s:check_defined('g:airline_theme', 'dark')
 call s:check_defined('g:airline_inactive_collapse', 1)
 call s:check_defined('g:airline_exclude_filenames', ['DebuggerWatch','DebuggerStack','DebuggerStatus'])
 call s:check_defined('g:airline_exclude_filetypes', [])
@@ -53,6 +52,12 @@ call s:check_defined('g:airline_mode_map', {
       \ '' : 'S-BLOCK',
       \ })
 
+call s:check_defined('g:airline_theme_map', {
+      \ 'Tomorrow.*': 'tomorrow',
+      \ 'mo[l|n]okai': 'molokai',
+      \ 'wombat.*': 'wombat',
+      \ })
+
 call s:check_defined('g:airline_section_a', '%{get(w:, "airline_current_mode", "")}')
 call s:check_defined('g:airline_section_b', '%{get(w:, "airline_current_branch", "")}')
 call s:check_defined('g:airline_section_c', '%f%m')
@@ -63,15 +68,31 @@ call s:check_defined('g:airline_section_z', '%3p%% '.g:airline_linecolumn_prefix
 call s:check_defined('g:airline_section_warning', '')
 
 let s:airline_initialized = 0
+let s:airline_theme_defined = 0
 function! s:on_window_changed()
   if !s:airline_initialized
     call airline#extensions#load()
-    call airline#switch_theme(g:airline_theme)
+
+    let s:airline_theme_defined = exists('g:airline_theme')
+    let g:airline_theme = get(g:, 'airline_theme', 'dark')
+    call <sid>on_colorscheme_changed()
+
     let s:airline_initialized = 1
   endif
   call airline#update_statusline()
 endfunction
 
+function! s:on_colorscheme_changed()
+  if !s:airline_theme_defined
+    if airline#switch_matching_theme()
+      return
+    endif
+  endif
+
+  " couldn't find a match, or theme was defined, just refresh
+  call airline#load_theme()
+endfunction
+
 function airline#cmdwinenter()
   call airline#extensions#apply_left_override('Command Line', '')
 endfunction
@@ -95,7 +116,7 @@ function! s:airline_toggle()
             \ | call <sid>on_window_changed()
       autocmd CmdwinLeave * call remove(g:airline_statusline_funcrefs, -1)
 
-      autocmd ColorScheme * call airline#load_theme()
+      autocmd ColorScheme * call <sid>on_colorscheme_changed()
       autocmd WinEnter,BufWinEnter,FileType,BufUnload,ShellCmdPost *
             \ call <sid>on_window_changed()
     augroup END