Improve contrast for base16 theme

fixes 54

autoload/airline/themes/base16.vim

@@ -1,31 +1,40 @@
+let s:improved_contrast = get(g:, 'airline_base16_improved_contrast', 0)
+
+" Color palette
+let s:gui_dark_gray = '#202020'
+let s:cterm_dark_gray = 234
+let s:gui_med_gray_hi = '#303030'
+let s:cterm_med_gray_hi = 236
+let s:gui_med_gray_lo = '#3a3a3a'
+let s:cterm_med_gray_lo = 237
+let s:gui_light_gray = '#505050'
+let s:cterm_light_gray = 239
+let s:gui_lightlight_gray = '#8A8A8A'
+let s:cterm_lightlight_gray = 245
+let s:gui_green = '#99cc99'
+let s:cterm_green = 151
+let s:gui_blue = '#6a9fb5'
+let s:cterm_blue = 67
+let s:gui_purple = '#aa759f'
+let s:cterm_purple = 139
+let s:gui_orange = '#d28445'
+let s:cterm_orange = 173
+let s:gui_red = '#ac4142'
+let s:cterm_red = 131
+let s:gui_pink = '#d7afd7'
+let s:cterm_pink = 182
+
 if get(g:, 'airline#themes#base16#constant', 0)
   let g:airline#themes#base16#palette = {}
 
-  " Color palette
-  let s:gui_dark_gray = '#202020'
-  let s:cterm_dark_gray = 234
-  let s:gui_med_gray_hi = '#303030'
-  let s:cterm_med_gray_hi = 236
-  let s:gui_med_gray_lo = '#3a3a3a'
-  let s:cterm_med_gray_lo = 237
-  let s:gui_light_gray = '#505050'
-  let s:cterm_light_gray = 239
-  let s:gui_green = '#99cc99'
-  let s:cterm_green = 151
-  let s:gui_blue = '#6a9fb5'
-  let s:cterm_blue = 67
-  let s:gui_purple = '#aa759f'
-  let s:cterm_purple = 139
-  let s:gui_orange = '#d28445'
-  let s:cterm_orange = 173
-  let s:gui_red = '#ac4142'
-  let s:cterm_red = 131
-  let s:gui_pink = '#d7afd7'
-  let s:cterm_pink = 182
-
   " Normal mode
   let s:N1 = [s:gui_dark_gray, s:gui_green, s:cterm_dark_gray, s:cterm_green]
-  let s:N2 = [s:gui_light_gray, s:gui_med_gray_lo, s:cterm_light_gray, s:cterm_med_gray_lo]
+  if s:improved_contrast
+    let s:N2 = [s:gui_lightlight_gray, s:gui_med_gray_lo, s:cterm_lightlight_gray, s:cterm_med_gray_lo]
+  else
+
+    let s:N2 = [s:gui_light_gray, s:gui_med_gray_lo, s:cterm_light_gray, s:cterm_med_gray_lo]
+  endif
   let s:N3 = [s:gui_green, s:gui_med_gray_hi, s:cterm_green, s:cterm_med_gray_hi]
   let g:airline#themes#base16#palette.normal = airline#themes#generate_color_map(s:N1, s:N2, s:N3)
   let g:airline#themes#base16#palette.normal_modified = {
@@ -55,7 +64,11 @@ if get(g:, 'airline#themes#base16#constant', 0)
   let g:airline#themes#base16#palette.visual_modified = copy(g:airline#themes#base16#palette.insert_modified)
 
   " Inactive window
-  let s:IA = [s:gui_dark_gray, s:gui_med_gray_hi, s:cterm_dark_gray, s:cterm_med_gray_hi, '']
+  if s:improved_contrast
+    let s:IA = [s:gui_dark_gray, s:gui_med_gray_hi, s:cterm_lightlight_gray, s:cterm_med_gray_hi, '']
+  else
+    let s:IA = [s:gui_dark_gray, s:gui_med_gray_hi, s:cterm_light_gray, s:cterm_med_gray_hi, '']
+  endif
   let g:airline#themes#base16#palette.inactive = airline#themes#generate_color_map(s:IA, s:IA, s:IA)
   let g:airline#themes#base16#palette.inactive_modified = {
         \ 'airline_c': [s:gui_orange, '', s:cterm_orange, '', ''],
@@ -98,10 +111,14 @@ else
 
     " Use VertSplit's bg and default fg (reversed) for inactive statusline.
     let s:VS = airline#themes#get_highlight('VertSplit')
-    let s:IA = [ s:VS[1], 'NONE', s:VS[2], 'NONE', 'reverse']
+    if s:improved_contrast
+      let s:IA = [ s:VS[1], 'NONE', s:VS[2], s:cterm_lightlight_gray, 'reverse']
+    else
+      let s:IA = [ s:VS[1], 'NONE', s:VS[2], 'NONE', 'reverse']
+    endif
     let g:airline#themes#base16#palette.inactive =
           \ airline#themes#generate_color_map(s:IA, s:IA, s:IA, s:IA, s:IA, s:IA)
-    let s:IM = [ s:VS[1], 'NONE', s:VS[2], 'NONE', 'reverse,italic']
+    let s:IM = [ s:VS[1], 'NONE', s:VS[2], 'NONE', 'reverse']
     let g:airline#themes#base16#palette.inactive_modified =
           \ airline#themes#generate_color_map(s:IM, s:IM, s:IM, s:IM, s:IM, s:IM)
 

doc/airline-themes.txt

@@ -26,7 +26,7 @@ FEATURES                                              *airline-themes-list*
 Currently this repository contains the following themes:
 
     * badwolf
-    * base16
+    * base16(|airline-theme-base16|)
     * base16_3024
     * base16_apathy
     * base16_ashes
@@ -109,7 +109,7 @@ g:airline_theme in your |.vimrc|  like this: >
 
     :let g:airline_theme='dark'
 <
-                                                  |airline-theme-solarized|
+                                                  *airline-theme-solarized*
 *g:solarized_base16*
 
 Base16 has a Solarized theme with the usual colors, but mapped in the
@@ -129,13 +129,34 @@ look more like classic powerline in normal mode. To enable it:
 >
     let g:airline_solarized_normal_green = 1
 
-g:airline_solarized_dark_inactive_border
+*g:airline_solarized_dark_inactive_border*
 
 Changes inactive window panes to have a dark bottom border instead
 of light by default. To enable it:
 >
     let g:airline_solarized_dark_inactive_border = 1
 
+                                                  *airline-theme-base16*
+Base16 is a popular theme from Chris Kempson
+(https://github.com/chriskempson/base16-vim)
+
+The default theme is base16, all other base16-themes have been generated and
+might not support all options.
+
+*g:airline_base16_improved_contrast*
+
+Improves the contrast for the inactive statusline. To enable it: >
+
+    let g:airline_base16_improved_contrast = 1
+<
+
+*airline#themes#base16#constant*
+
+Uses a predefined colorpalette for defining the colors, instead of guessing
+the values from other highlight groups. To enable it: >
+
+    let g:airline#themes#base16#constant = 1
+<
 ==============================================================================
 CONTRIBUTIONS                                *airline-themes-contributions*