Initial right_prompt work

reader.cpp

@@ -246,7 +246,10 @@ class reader_data_t
 	wcstring prompt;
 
 	/** The output of the last evaluation of the prompt command */
-	wcstring prompt_buff;
+	wcstring left_prompt_buff;
+    
+	/** The output of the last evaluation of the right prompt command */
+	wcstring right_prompt_buff;
 	
 	/**
 	   Color is the syntax highlighting for buff.  The format is that
@@ -455,7 +458,8 @@ static void reader_repaint()
     indents.resize(len);
 
 	s_write( &data->screen,
-		 data->prompt_buff.c_str(),
+		 data->left_prompt_buff.c_str(),
+         data->right_prompt_buff.c_str(),
 		 full_line.c_str(),
          data->command_line.size(),
 		 &colors[0],
@@ -660,13 +664,15 @@ static void exec_prompt()
 	
 	reader_write_title();
 	
-    data->prompt_buff.clear();
+    data->left_prompt_buff.clear();
 	
 	for( size_t i = 0; i < prompt_list.size(); i++ )
 	{
-        if (i > 0) data->prompt_buff += L'\n';
-        data->prompt_buff += prompt_list.at(i);
+        if (i > 0) data->left_prompt_buff += L'\n';
+        data->left_prompt_buff += prompt_list.at(i);
 	}
+    
+    data->right_prompt_buff = L"This is my right prompt";
 }
 
 void reader_init()
@@ -2120,7 +2126,7 @@ int reader_shell_test( const wchar_t *b )
 		int tmp[1];
 		int tmp2[1];
 		
-		s_write( &data->screen, L"", L"", 0, tmp, tmp2, 0 );
+		s_write( &data->screen, L"", L"", L"", 0, tmp, tmp2, 0 );
 		
 		parser_t::principal_parser().test( b, 0, &sb, L"fish" );
 		fwprintf( stderr, L"%ls", sb.c_str() );

screen.cpp

@@ -715,9 +715,11 @@ static void invalidate_soft_wrap(screen_t *scr)
 /**
    Update the screen to match the desired output.
 */
-static void s_update( screen_t *scr, const wchar_t *prompt )
+static void s_update( screen_t *scr, const wchar_t *left_prompt, const wchar_t *right_prompt )
 {
-	size_t prompt_width = calc_prompt_width( prompt );
+	const size_t left_prompt_width = calc_prompt_width( left_prompt );
+    const size_t right_prompt_width = calc_prompt_width( right_prompt );
+    
 	int screen_width = common_get_width();
 	bool need_clear = scr->need_clear;
     
@@ -737,19 +739,19 @@ static void s_update( screen_t *scr, const wchar_t *prompt )
 		s_reset( scr, false );
 	}
 	
-	if( wcscmp( prompt, scr->actual_prompt.c_str() ) )
+	if( wcscmp( left_prompt, scr->actual_left_prompt.c_str() ) )
 	{
 		s_move( scr, &output, 0, 0 );
-		s_write_str( &output, prompt );
-        scr->actual_prompt = prompt;
-		scr->actual.cursor.x = (int)prompt_width;
+		s_write_str( &output, left_prompt );
+        scr->actual_left_prompt = left_prompt;
+		scr->actual.cursor.x = (int)left_prompt_width;
 	}
 	
     for (size_t i=0; i < scr->desired.line_count(); i++)
 	{
 		const line_t &o_line = scr->desired.line(i);
 		line_t &s_line = scr->actual.create_line(i);
-		size_t start_pos = (i==0 ? prompt_width : 0);
+		size_t start_pos = (i==0 ? left_prompt_width : 0);
         int current_width = 0;
                 
         /* Note that skip_remaining is a width, not a character count */
@@ -817,6 +819,15 @@ static void s_update( screen_t *scr, const wchar_t *prompt )
 			s_move( scr, &output, current_width, (int)i );
 			s_write_mbs( &output, clr_eol);
 		}
+        
+        /* Output any rprompt if this is the first line. We do this at the end under the assumption that we will have to issue fewer commands this way. */
+        if (i == 0 && right_prompt_width > 0)
+        {
+            s_move( scr, &output, (int)(screen_width - right_prompt_width - 1), (int)i );
+            s_set_color( scr, &output, 0xffffffff);
+            s_write_str( &output, right_prompt );
+            scr->actual.cursor.x += right_prompt_width;
+        }
 	}
     
     /* Determine how many lines have stuff on them; we need to clear lines with stuff that we don't want */
@@ -853,7 +864,8 @@ static int is_dumb()
 
 
 void s_write( screen_t *s,
-	      const wchar_t *prompt,
+	      const wchar_t *left_prompt,
+          const wchar_t *right_prompt,
 	      const wchar_t *commandline, 
 	      size_t explicit_len,
 	      const int *c, 
@@ -869,18 +881,18 @@ void s_write( screen_t *s,
     size_t max_line_width = 0;
 	
 	CHECK( s, );
-	CHECK( prompt, );
+	CHECK( left_prompt, );
 	CHECK( commandline, );
 	CHECK( c, );
 	CHECK( indent, );
 
 	/*
 	  If we are using a dumb terminal, don't try any fancy stuff,
-	  just print out the text.
+	  just print out the text. right_prompt not supported.
 	 */
 	if( is_dumb() )
 	{
-		char *prompt_narrow = wcs2str( prompt );
+		char *prompt_narrow = wcs2str( left_prompt );
 		char *buffer_narrow = wcs2str( commandline );
 		
 		write_loop( 1, "\r", 1 );
@@ -893,7 +905,7 @@ void s_write( screen_t *s,
 		return;
 	}
 	
-	prompt_width = calc_prompt_width( prompt );
+	prompt_width = calc_prompt_width( left_prompt );
 	screen_width = common_get_width();
 
 	s_check_status( s );
@@ -907,7 +919,7 @@ void s_write( screen_t *s,
 	*/
 	if( prompt_width >= screen_width )
 	{
-		prompt = L"> ";
+		left_prompt = L"> ";
 		prompt_width = 2;
 	}
 	
@@ -997,7 +1009,7 @@ void s_write( screen_t *s,
 	}
 	
     s->desired.cursor = cursor_arr;
-	s_update( s, prompt );
+	s_update( s, left_prompt, right_prompt ? right_prompt : L"" );
 	s_save_status( s );
 }
 
@@ -1012,14 +1024,14 @@ void s_reset( screen_t *s, bool reset_cursor )
 	int prev_line = s->actual.cursor.y;
     
     /* If the prompt is multi-line, we need to move up to the prompt's initial line. We do this by lying to ourselves and claiming that we're really below what we consider "line 0" (which is the last line of the prompt). This will cause is to move up to try to get back to line 0, but really we're getting back to the initial line of the prompt. */
-    const size_t prompt_line_count = calc_prompt_lines(s->actual_prompt.c_str());
+    const size_t prompt_line_count = calc_prompt_lines(s->actual_left_prompt.c_str());
     assert(prompt_line_count >= 1);
     prev_line += (prompt_line_count - 1);
     
     s->actual.resize(0);
     s->actual.cursor.x = 0;
     s->actual.cursor.y = 0;
-    s->actual_prompt.clear();
+    s->actual_left_prompt.clear();
 	s->need_clear=true;
     
 	if( !reset_cursor )
@@ -1038,7 +1050,7 @@ void s_reset( screen_t *s, bool reset_cursor )
 screen_t::screen_t() :
     desired(),
     actual(),
-    actual_prompt(),
+    actual_left_prompt(),
     actual_width(0),
     soft_wrap_location(INVALID_LOCATION),
     need_clear(false),

screen.h

@@ -120,7 +120,7 @@ class screen_t
        A string containing the prompt which was last printed to
        the screen.
     */
-    wcstring actual_prompt;
+    wcstring actual_left_prompt;
 
     /**
       The actual width of the screen at the time of the last screen
@@ -157,7 +157,8 @@ class screen_t
    as possible.
    
     \param s the screen on which to write
-    \param prompt the prompt to prepend to the command line
+    \param left_prompt the prompt to prepend to the command line
+    \param right_prompt the right prompt, or NULL if none
     \param commandline the command line
     \param explicit_len the number of characters of the "explicit" (non-autosuggestion) portion of the command line
     \param colors the colors to use for the comand line
@@ -165,7 +166,8 @@ class screen_t
     \param cursor_pos where the cursor is
 */
 void s_write( screen_t *s, 
-			  const wchar_t *prompt, 
+			  const wchar_t *left_prompt,
+			  const wchar_t *right_prompt,
 			  const wchar_t *commandline,
 			  size_t explicit_len,
 			  const int *colors,