Step coloring for fish_pager introduces new variable

fish_pager_color_secondary to set background of every second completion
line. It simplifies finding the options corresponding to given
description. Default color is 151515.

doc_src/index.hdr.in

@@ -1004,6 +1004,7 @@ highlighting in the completion pager:
 - \c fish_pager_color_completion, the color of the completion itself
 - \c fish_pager_color_description, the color of the completion description
 - \c fish_pager_color_progress, the color of the progress bar at the bottom left corner
+- \c fish_pager_color_secondary, the background color of the every second completion
 
 Example:
 
@@ -1227,8 +1228,8 @@ fish_color_substitution, \c fish_color_redirection, \c fish_color_end,
 \c fish_color_error, \c fish_color_param, \c fish_color_comment, \c
 fish_color_match, \c fish_color_search_match, \c fish_color_cwd, \c
 fish_pager_color_prefix, \c fish_pager_color_completion, \c
-fish_pager_color_description and \c
+fish_pager_color_description, \c fish_pager_color_progress
-fish_pager_color_progress. Usually, the value of these variables will
+and \c fish_pager_color_secondary. Usually, the value of these variables will
 be one of \c black, \c red, \c green, \c brown, \c yellow, \c blue, \c
 magenta, \c purple, \c cyan, \c white or \c normal, but they can be an
 array containing any color options for the set_color command.

fish_pager.cpp

@@ -77,7 +77,8 @@ enum
 	HIGHLIGHT_PAGER_PREFIX,
 	HIGHLIGHT_PAGER_COMPLETION,
 	HIGHLIGHT_PAGER_DESCRIPTION,
-	HIGHLIGHT_PAGER_PROGRESS
+	HIGHLIGHT_PAGER_PROGRESS,
+	HIGHLIGHT_PAGER_SECONDARY
 }
 	;
 
@@ -152,7 +153,8 @@ static const wchar_t *hightlight_var[] =
 	L"fish_pager_color_prefix",
 	L"fish_pager_color_completion",
 	L"fish_pager_color_description",
-	L"fish_pager_color_progress"
+	L"fish_pager_color_progress",
+	L"fish_pager_color_secondary"
 }
 	;
 
@@ -206,7 +208,7 @@ static rgb_color_t get_color( int highlight )
 
 	if( highlight < 0 )
 		return rgb_color_t::normal();
-	if( highlight >= (4) )
+	if( highlight >= (5) )
 		return rgb_color_t::normal();
 	
 	val = wgetenv( hightlight_var[highlight]);
@@ -389,7 +391,7 @@ static int print_max( const wchar_t *str, int max, int has_more )
 /**
    Print the specified item using at the specified amount of space
 */
-static void completion_print_item( const wchar_t *prefix, comp_t *c, int width )
+static void completion_print_item( const wchar_t *prefix, comp_t *c, int width, bool primary )
 {
 	int comp_width=0, desc_width=0;
 	int written=0;
@@ -422,14 +424,15 @@ static void completion_print_item( const wchar_t *prefix, comp_t *c, int width )
 		
 	}
 	
+    rgb_color_t bg = primary ? rgb_color_t::normal() : get_color(HIGHLIGHT_PAGER_SECONDARY);
 	for( size_t i=0; i<c->comp.size(); i++ )
 	{
         const wcstring &comp = c->comp.at(i);
 		if( i != 0 )
 			written += print_max( L"  ", comp_width - written, 2 );
-		set_color( get_color(HIGHLIGHT_PAGER_PREFIX),rgb_color_t::normal() );
+		set_color( get_color(HIGHLIGHT_PAGER_PREFIX), bg );
 		written += print_max( prefix, comp_width - written, comp.empty()?0:1 );
-		set_color( get_color(HIGHLIGHT_PAGER_COMPLETION),rgb_color_t::ignore() );
+		set_color( get_color(HIGHLIGHT_PAGER_COMPLETION), bg);
 		written += print_max( comp.c_str(), comp_width - written, i!=(c->comp.size()-1) );
 	}
 
@@ -442,7 +445,7 @@ static void completion_print_item( const wchar_t *prefix, comp_t *c, int width )
 			writech( L' ');
 		}
 		written += print_max( L"(", 1, 0 );
-		set_color( get_color( HIGHLIGHT_PAGER_DESCRIPTION ), rgb_color_t::ignore() );
+		set_color( get_color( HIGHLIGHT_PAGER_DESCRIPTION ), bg);
 		written += print_max( c->desc.c_str(), desc_width, 0 );
 		written += print_max( L")", 1, 0 );
 	}
@@ -454,7 +457,8 @@ static void completion_print_item( const wchar_t *prefix, comp_t *c, int width )
 			writech( L' ');
 		}
 	}
-	
+	if ( !primary )
+		set_color( rgb_color_t::normal(), rgb_color_t::normal() );
 }
 
 /**
@@ -495,7 +499,7 @@ static void completion_print( int cols,
 
 			el = lst.at(j*rows + i );
 			
-			completion_print_item( prefix, el, width[j] - (is_last?0:2) );
+			completion_print_item( prefix, el, width[j] - (is_last?0:2), i%2 );
 			
 			if( !is_last)
 				writestr( L"  " );

share/functions/__fish_config_interactive.fish

@@ -122,6 +122,7 @@ function __fish_config_interactive -d "Initializations that should be performed
 		set_default fish_pager_color_completion normal
 		set_default fish_pager_color_description normal
 		set_default fish_pager_color_progress cyan
+        set_default fish_pater_color_secondary 151515
 
 		#
 		# Directory history colors