settings: make initial slave screen focus optional

doc/config

@@ -411,6 +411,8 @@
 ##
 #startup_slave_screen = ""
 #
+#startup_slave_screen_focus = no
+#
 ##
 ## Default width of locked screen (in %).
 ## Acceptable values are from 20 to 80.

doc/ncmpcpp.1

@@ -263,6 +263,9 @@ Screen that has to be displayed at start (playlist by default).
 .B startup_slave_screen = SCREEN_NAME
 Slave screen that has to be displayed at start (nothing by default).
 .TP
+.B startup_slave_screen_focus = yes/no
+If set to yes, slave screen will be the active one after startup. Otherwise master screen will be.
+.TP 
 .B locked_screen_width_part = 20-80
 If you want to lock a screen, ncmpcpp asks for % of locked screen's width to be reserved before that and provides a default value, which is the one you can set here.
 .TP

src/ncmpcpp.cpp

@@ -144,10 +144,16 @@ int main(int argc, char **argv)
 	// lock current screen and go to the slave one if applicable
 	if (Config.startup_slave_screen_type)
 	{
-		auto slave_screen = *Config.startup_slave_screen_type;
+		auto slave_screen_type = *Config.startup_slave_screen_type;
 		bool screen_locked = myScreen->lock();
-		if (screen_locked && slave_screen != myScreen->type())
-			toScreen(slave_screen)->switchTo();
+		if (screen_locked && slave_screen_type != myScreen->type())
+		{
+			auto slave_screen = toScreen(slave_screen_type);
+			assert(slave_screen != nullptr);
+			slave_screen->switchTo();
+			if (!Config.startup_slave_screen_focus)
+				Actions::get(Actions::Type::MasterScreen).execute();
+		}
 	}
 
 	// local variables

src/settings.cpp

@@ -546,6 +546,9 @@ bool Configuration::read(const std::vector<std::string> &config_paths, bool igno
 		}
 	}, defaults_to(startup_slave_screen_type, boost::none)
 	));
+	p.add("startup_slave_screen_focus", yes_no(
+		startup_slave_screen_focus, false
+	));
 	p.add("locked_screen_width_part", assign_default<double>(
 		locked_screen_width_part, 50.0, [](double v) {
 			return v / 100;

src/settings.h

@@ -165,6 +165,7 @@ struct Configuration
 	bool ask_for_locked_screen_width_part;
 	bool allow_for_physical_item_deletion;
 	bool progressbar_boldness;
+	bool startup_slave_screen_focus;
 
 	unsigned mpd_connection_timeout;
 	unsigned crossfade_time;