new feature: display remaining time of song instead of elapsed time

doc/config

@@ -209,6 +209,8 @@
 #
 #display_bitrate = "no"
 #
+#display_remaining_time = "no"
+#
 #regular_expressions = "basic" (basic/extended)
 #
 ##

doc/ncmpcpp.1

@@ -198,6 +198,9 @@ If enabled, clock will display time in format hh:mm:ss, otherwise hh:mm.
 .B display_bitrate = yes/no
 If enabled, bitrate of currently playing song will be displayed in statusbar.
 .TP 
+.B display_remaining_time = yes/no
+If enabled, remaining time of currently playing song will be be displayed in statusbar instead of elapsed time.
+.TP 
 .B ignore_leading_the = yes/no
 If enabled, word "the" at the beginning of tags/filenames will be ignored while sorting items.
 .TP 

src/ncmpcpp.cpp

@@ -1115,6 +1115,12 @@ int main(int argc, char *argv[])
 				*wFooter << fmtBold;
 				if (Config.new_design)
 				{
+					if (Config.display_remaining_time)
+					{
+						tracklength = "-";
+						tracklength += Song::ShowTime(s->GetTotalLength()-songpos);
+					}
+					else
 						tracklength = Song::ShowTime(songpos);
 					tracklength += "/";
 					tracklength += s->GetLength();
@@ -1123,7 +1129,17 @@ int main(int argc, char *argv[])
 				}
 				else
 				{
-					tracklength = "[" + Song::ShowTime(songpos) + "/" + s->GetLength() + "]";
+					tracklength = "[";
+					if (Config.display_remaining_time)
+					{
+						tracklength += "-";
+						tracklength += Song::ShowTime(s->GetTotalLength()-songpos);
+					}
+					else
+						tracklength = Song::ShowTime(songpos);
+					tracklength += "/";
+					tracklength += s->GetLength();
+					tracklength += "]";
 					*wFooter << XY(wFooter->GetWidth()-tracklength.length(), 1) << tracklength;
 				}
 				double progressbar_size = songpos/double(s->GetTotalLength());

src/settings.cpp

@@ -292,6 +292,7 @@ void DefaultConfiguration(ncmpcpp_config &conf)
 	conf.jump_to_now_playing_song_at_start = true;
 	conf.clock_display_seconds = false;
 	conf.display_bitrate = false;
+	conf.display_remaining_time = false;
 	conf.ignore_leading_the = false;
 	conf.block_search_constraints_change = true;
 	conf.use_console_editor = false;
@@ -743,6 +744,10 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			{
 				conf.display_bitrate = v == "yes";
 			}
+			else if (cl.find("display_remaining_time") != std::string::npos)
+			{
+				conf.display_remaining_time = v == "yes";
+			}
 			else if (cl.find("ignore_leading_the") != std::string::npos)
 			{
 				conf.ignore_leading_the = v == "yes";

src/settings.h

@@ -190,6 +190,7 @@ struct ncmpcpp_config
 	bool jump_to_now_playing_song_at_start;
 	bool clock_display_seconds;
 	bool display_bitrate;
+	bool display_remaining_time;
 	bool ignore_leading_the;
 	bool block_search_constraints_change;
 	bool use_console_editor;

src/status.cpp

@@ -415,6 +415,12 @@ void NcmpcppStatusChanged(Connection *, StatusChanges changed, void *)
 			std::string tracklength;
 			if (Config.new_design)
 			{
+				if (Config.display_remaining_time)
+				{
+					tracklength = "-";
+					tracklength += Song::ShowTime(np.GetTotalLength()-elapsed);
+				}
+				else
 					tracklength = Song::ShowTime(elapsed);
 				if (np.GetTotalLength())
 				{
@@ -466,6 +472,12 @@ void NcmpcppStatusChanged(Connection *, StatusChanges changed, void *)
 				tracklength += " [";
 				if (np.GetTotalLength())
 				{
+					if (Config.display_remaining_time)
+					{
+						tracklength += "-";
+						tracklength += Song::ShowTime(np.GetTotalLength()-elapsed);
+					}
+					else
 						tracklength += Song::ShowTime(elapsed);
 					tracklength += "/";
 					tracklength += np.GetLength();