settings: add option to disable data fetching delay in media library and playlist editor

doc/config

@@ -332,6 +332,8 @@
 ##
 #user_interface = classic
 #
+data_fetching_delay = yes
+#
 ## Available values: artist, album_artist, date, genre, composer, performer.
 ##
 #media_library_primary_tag = artist

doc/ncmpcpp.1

@@ -309,6 +309,9 @@ Type of currently used regular expressions.
 .B user_interface = classic/alternative
 Default user interface used by ncmpcpp at start.
 .TP 
+.B data_fetching_delay = yes/no
+If enabled, there will be a 250ms delay between refreshing position in media library or playlist editor and fetching appropriate data from MPD. This limits data fetched from the server and is particularly useful if ncmpcpp is connected to a remote host.
+.TP
 .B media_library_primary_tag = artist/date/genre/composer/performer
 Default tag type for leftmost column in media library.
 .TP 

src/media_library.cpp

@@ -48,9 +48,6 @@ MediaLibrary *myLibrary;
 
 namespace {
 
-const auto ml_wtimeout = 250;
-const auto fetch_delay = boost::posix_time::milliseconds(ml_wtimeout);
-
 bool hasTwoColumns;
 size_t itsLeftColStartX;
 size_t itsLeftColWidth;
@@ -149,6 +146,8 @@ public:
 
 MediaLibrary::MediaLibrary()
 : m_timer(boost::posix_time::from_time_t(0))
+, m_window_timeout(Config.data_fetching_delay ? 250 : 500)
+, m_fetching_delay(boost::posix_time::milliseconds(Config.data_fetching_delay ? 250 : -1))
 {
 	hasTwoColumns = 0;
 	itsLeftColWidth = COLS/3-1;
@@ -342,7 +341,7 @@ void MediaLibrary::update()
 		}
 		
 		if (!Tags.empty()
-		&& ((Albums.reallyEmpty() && Global::Timer - m_timer > fetch_delay) || m_albums_update_request)
+		&& ((Albums.reallyEmpty() && Global::Timer - m_timer > m_fetching_delay) || m_albums_update_request)
 		)
 		{
 			Albums.clearSearchResults();
@@ -390,7 +389,7 @@ void MediaLibrary::update()
 	}
 	
 	if (!Albums.empty()
-	&& ((Songs.reallyEmpty() && Global::Timer - m_timer > fetch_delay) || m_songs_update_request)
+	&& ((Songs.reallyEmpty() && Global::Timer - m_timer > m_fetching_delay) || m_songs_update_request)
 	)
 	{
 		Songs.clearSearchResults();
@@ -427,7 +426,7 @@ void MediaLibrary::update()
 int MediaLibrary::windowTimeout()
 {
 	if (Albums.reallyEmpty() || Songs.reallyEmpty())
-		return ml_wtimeout;
+		return m_window_timeout;
 	else
 		return Screen<WindowType>::windowTimeout();
 }

src/media_library.h

@@ -150,6 +150,9 @@ private:
 	bool m_songs_update_request;
 
 	boost::posix_time::ptime m_timer;
+
+	const int m_window_timeout;
+	const boost::posix_time::time_duration m_fetching_delay;
 };
 
 extern MediaLibrary *myLibrary;

src/playlist_editor.cpp

@@ -45,9 +45,6 @@ PlaylistEditor *myPlaylistEditor;
 
 namespace {
 
-const int pe_timeout = 250;
-const auto fetch_delay = boost::posix_time::milliseconds(pe_timeout);
-
 size_t LeftColumnStartX;
 size_t LeftColumnWidth;
 size_t RightColumnStartX;
@@ -61,6 +58,8 @@ bool SongEntryMatcher(const boost::regex &rx, const MPD::Song &s);
 
 PlaylistEditor::PlaylistEditor()
 : m_timer(boost::posix_time::from_time_t(0))
+, m_window_timeout(Config.data_fetching_delay ? 250 : 500)
+, m_fetching_delay(boost::posix_time::milliseconds(Config.data_fetching_delay ? 250 : -1))
 {
 	LeftColumnWidth = COLS/3-1;
 	RightColumnStartX = LeftColumnWidth+1;
@@ -158,7 +157,7 @@ void PlaylistEditor::update()
 	}
 	
 	if (!Playlists.empty()
-	&& ((Content.reallyEmpty() && Global::Timer - m_timer > fetch_delay) || m_content_update_requested)
+	&& ((Content.reallyEmpty() && Global::Timer - m_timer > m_fetching_delay) || m_content_update_requested)
 	)
 	{
 		m_content_update_requested = false;
@@ -212,7 +211,7 @@ void PlaylistEditor::update()
 int PlaylistEditor::windowTimeout()
 {
 	if (Content.reallyEmpty())
-		return pe_timeout;
+		return m_window_timeout;
 	else
 		return Screen<WindowType>::windowTimeout();
 }

src/playlist_editor.h

@@ -95,6 +95,9 @@ private:
 	bool m_content_update_requested;
 
 	boost::posix_time::ptime m_timer;
+
+	const int m_window_timeout;
+	const boost::posix_time::time_duration m_fetching_delay;
 };
 
 extern PlaylistEditor *myPlaylistEditor;

src/settings.cpp

@@ -400,6 +400,9 @@ bool Configuration::read(const std::string &config_path)
 	p.add("user_interface", assign_default(
 		design, Design::Classic
 	));
+	p.add("data_fetching_delay", yes_no(
+		data_fetching_delay, true
+	));
 	p.add("media_library_primary_tag", option_parser::worker([this](std::string &&v) {
 		if (v == "artist")
 			media_lib_primary_tag = MPD_TAG_ARTIST;

src/settings.h

@@ -153,6 +153,7 @@ struct Configuration
 	bool mouse_list_scroll_whole_page;
 	bool visualizer_use_wave;
 	bool visualizer_in_stereo;
+	bool data_fetching_delay;
 	bool media_library_sort_by_mtime;
 	bool tag_editor_extended_numeration;
 	bool discard_colors_if_item_is_selected;