Change 'previous' background color to 'current' and add some documentation

NEWS

@@ -15,6 +15,7 @@ ncmpcpp-0.8 (????-??-??)
 * Configuration variable 'visualizer_sample_multiplier' was deprecated and will be removed in 0.9.
 * Wide character version of ncurses is now required.
 * Added 'statusbar_time_color' and 'player_state_color' configuration variables for further customization of statusbar.
+* Setting foreground color only now preserves current background color.
 * Format information can now be attached to selected color variables in the configuration file. Because of that variable 'progressbar_boldness' is now deprecated in favor of extended 'progressbar_color' and 'progressbar_elapsed_color' (for more information see example configuration file).
 * Lyrics and last_fm can now be startup screens and are lockable.
 * Action 'update_environment' now also synchronizes status with MPD.

doc/config

@@ -495,6 +495,12 @@
 ## the bottom of the help screen for list of available colors
 ## and their numerical values.
 ##
+## What is more, there are two special values for the background
+## color: "transparent" and "current". The first one explicitly sets
+## the background to be transparent, while the second one allows you
+## to preserve current background color and change only the foreground
+## one. It's used implicitly when background color is not specified.
+##
 ## Moreover, it is possible to attach format information to
 ## selected color variables by appending to their end a
 ## colon followed by one or more format flags, e.g. black:b
@@ -506,7 +512,7 @@
 ## alternative_ui_separator_color.
 ##
 ## Note: due to technical limitations of older ncurses
-## versionw, if 256 colors are used there is a possibility
+## version, if 256 colors are used there is a possibility
 ## that you'll be able to use only colors with transparent
 ## background.
 #

src/curses/window.cpp

@@ -199,17 +199,17 @@ std::vector<int> color_pair_map;
 namespace NC {
 
 const short Color::transparent = -1;
-const short Color::previous = -2;
+const short Color::current = -2;
 
 Color Color::Default(0, 0, true, false);
-Color Color::Black(COLOR_BLACK, Color::previous);
+Color Color::Black(COLOR_BLACK, Color::current);
-Color Color::Red(COLOR_RED, Color::previous);
+Color Color::Red(COLOR_RED, Color::current);
-Color Color::Green(COLOR_GREEN, Color::previous);
+Color Color::Green(COLOR_GREEN, Color::current);
-Color Color::Yellow(COLOR_YELLOW, Color::previous);
+Color Color::Yellow(COLOR_YELLOW, Color::current);
-Color Color::Blue(COLOR_BLUE, Color::previous);
+Color Color::Blue(COLOR_BLUE, Color::current);
-Color Color::Magenta(COLOR_MAGENTA, Color::previous);
+Color Color::Magenta(COLOR_MAGENTA, Color::current);
-Color Color::Cyan(COLOR_CYAN, Color::previous);
+Color Color::Cyan(COLOR_CYAN, Color::current);
-Color Color::White(COLOR_WHITE, Color::previous);
+Color Color::White(COLOR_WHITE, Color::current);
 Color Color::End(0, 0, false, true);
 
 int Color::pairNumber() const
@@ -219,7 +219,7 @@ int Color::pairNumber() const
 		throw std::logic_error("'end' doesn't have a corresponding pair number");
 	else if (!isDefault())
 	{
-		if (!previousBackground())
+		if (!currentBackground())
 			result = (background() + 1) % COLORS;
 		result *= 256;
 		result += foreground() % COLORS;
@@ -270,8 +270,8 @@ std::istream &operator>>(std::istream &is, Color &c)
 			result = COLOR_WHITE;
 		else if (background && s == "transparent")
 			result = NC::Color::transparent;
-		else if (background && s == "previous")
+		else if (background && s == "current")
-			result = NC::Color::previous;
+			result = NC::Color::current;
 		else if (std::all_of(s.begin(), s.end(), isdigit))
 		{
 			result = atoi(s.c_str());
@@ -313,7 +313,7 @@ std::istream &operator>>(std::istream &is, Color &c)
 				c = Color(fg, bg);
 		}
 		else
-			c = Color(fg, NC::Color::previous);
+			c = Color(fg, NC::Color::current);
 	}
 	return is;
 }
@@ -571,7 +571,7 @@ void Window::setColor(Color c)
 		c = m_base_color;
 	if (c != Color::Default)
 	{
-		assert(!c.previousBackground());
+		assert(!c.currentBackground());
 		wcolor_set(m_window, c.pairNumber(), nullptr);
 	}
 	else
@@ -581,7 +581,7 @@ void Window::setColor(Color c)
 
 void Window::setBaseColor(const Color &color)
 {
-	if (color.previousBackground())
+	if (color.currentBackground())
 		m_base_color = Color(color.foreground(), Color::transparent);
 	else
 		m_base_color = color;
@@ -1316,7 +1316,7 @@ Window &Window::operator<<(const Color &c)
 	}
 	else
 	{
-		if (c.previousBackground())
+		if (c.currentBackground())
 		{
 			short background = m_color.isDefault()
 				? Color::transparent

src/curses/window.h

@@ -149,7 +149,7 @@ struct Color
 	friend struct Window;
 
 	static const short transparent;
-	static const short previous;
+	static const short current;
 
 	Color() : m_impl(0, 0, true, false) { }
 	Color(short foreground_value, short background_value,
@@ -183,7 +183,7 @@ struct Color
 private:
 	short foreground() const { return std::get<0>(m_impl); }
 	short background() const { return std::get<1>(m_impl); }
-	bool previousBackground() const { return background() == previous; }
+	bool currentBackground() const { return background() == current; }
 
 	std::tuple<short, short, bool, bool> m_impl;
 };