Add `--color=[dark|light|16|bw]` option

- dark:  the current default for 256-color terminal
- light: color scheme for 256-color terminal with light background
- 16:    the default color scheme for 16-color terminal (`+2`)
- bw:    no colors (`+c`)

4 files changed, 103 insertions, 40 deletions

diff --git a/src/core.go b/src/core.go
index 7230cffd..d7a6a0bb 100644
--- a/src/core.go
+++ b/src/core.go
@@ -68,7 +68,7 @@ func Run(options *Options) {
 		return data, nil
 	}
 	if opts.Ansi {
-		if opts.Color {
+		if opts.Theme != nil {
 			ansiProcessor = func(data *string) (*string, []ansiOffset) {
 				return extractColor(data)
 			}
diff --git a/src/curses/curses.go b/src/curses/curses.go
index 3340a5c3..f3263615 100644
--- a/src/curses/curses.go
+++ b/src/curses/curses.go
@@ -95,6 +95,18 @@ const (
 	doubleClickDuration = 500 * time.Millisecond
 )
 
+type ColorTheme struct {
+	darkBg       C.short
+	prompt       C.short
+	match        C.short
+	current      C.short
+	currentMatch C.short
+	spinner      C.short
+	info         C.short
+	cursor       C.short
+	selected     C.short
+}
+
 type Event struct {
 	Type       int
 	Char       rune
@@ -117,6 +129,9 @@ var (
 	_colorMap     map[int]int
 	_prevDownTime time.Time
 	_clickY       []int
+	Default16     *ColorTheme
+	Dark256       *ColorTheme
+	Light256      *ColorTheme
 	DarkBG        C.short
 )
 
@@ -124,6 +139,36 @@ func init() {
 	_prevDownTime = time.Unix(0, 0)
 	_clickY = []int{}
 	_colorMap = make(map[int]int)
+	Default16 = &ColorTheme{
+		darkBg:       C.COLOR_BLACK,
+		prompt:       C.COLOR_BLUE,
+		match:        C.COLOR_GREEN,
+		current:      C.COLOR_YELLOW,
+		currentMatch: C.COLOR_GREEN,
+		spinner:      C.COLOR_GREEN,
+		info:         C.COLOR_WHITE,
+		cursor:       C.COLOR_RED,
+		selected:     C.COLOR_MAGENTA}
+	Dark256 = &ColorTheme{
+		darkBg:       236,
+		prompt:       110,
+		match:        108,
+		current:      254,
+		currentMatch: 151,
+		spinner:      148,
+		info:         144,
+		cursor:       161,
+		selected:     168}
+	Light256 = &ColorTheme{
+		darkBg:       251,
+		prompt:       25,
+		match:        66,
+		current:      237,
+		currentMatch: 23,
+		spinner:      65,
+		info:         101,
+		cursor:       161,
+		selected:     168}
 }
 
 func attrColored(pair int, bold bool) C.int {
@@ -173,7 +218,7 @@ func getch(nonblock bool) int {
 	return int(b[0])
 }
 
-func Init(color bool, color256 bool, black bool, mouse bool) {
+func Init(theme *ColorTheme, black bool, mouse bool) {
 	{
 		in, err := os.OpenFile("/dev/tty", syscall.O_RDONLY, 0)
 		if err != nil {
@@ -203,42 +248,35 @@ func Init(color bool, color256 bool, black bool, mouse bool) {
 		os.Exit(1)
 	}()
 
-	if color {
+	if theme != nil {
 		C.start_color()
-		var bg C.short
-		if black {
-			bg = C.COLOR_BLACK
-		} else {
-			C.use_default_colors()
-			bg = -1
-		}
-		if color256 {
-			DarkBG = 236
-			C.init_pair(ColPrompt, 110, bg)
-			C.init_pair(ColMatch, 108, bg)
-			C.init_pair(ColCurrent, 254, DarkBG)
-			C.init_pair(ColCurrentMatch, 151, DarkBG)
-			C.init_pair(ColSpinner, 148, bg)
-			C.init_pair(ColInfo, 144, bg)
-			C.init_pair(ColCursor, 161, DarkBG)
-			C.init_pair(ColSelected, 168, DarkBG)
-		} else {
-			DarkBG = C.COLOR_BLACK
-			C.init_pair(ColPrompt, C.COLOR_BLUE, bg)
-			C.init_pair(ColMatch, C.COLOR_GREEN, bg)
-			C.init_pair(ColCurrent, C.COLOR_YELLOW, DarkBG)
-			C.init_pair(ColCurrentMatch, C.COLOR_GREEN, DarkBG)
-			C.init_pair(ColSpinner, C.COLOR_GREEN, bg)
-			C.init_pair(ColInfo, C.COLOR_WHITE, bg)
-			C.init_pair(ColCursor, C.COLOR_RED, DarkBG)
-			C.init_pair(ColSelected, C.COLOR_MAGENTA, DarkBG)
-		}
+		initPairs(theme, black)
 		_color = attrColored
 	} else {
 		_color = attrMono
 	}
 }
 
+func initPairs(theme *ColorTheme, black bool) {
+	var bg C.short
+	if black {
+		bg = C.COLOR_BLACK
+	} else {
+		C.use_default_colors()
+		bg = -1
+	}
+
+	DarkBG = theme.darkBg
+	C.init_pair(ColPrompt, theme.prompt, bg)
+	C.init_pair(ColMatch, theme.match, bg)
+	C.init_pair(ColCurrent, theme.current, DarkBG)
+	C.init_pair(ColCurrentMatch, theme.currentMatch, DarkBG)
+	C.init_pair(ColSpinner, theme.spinner, bg)
+	C.init_pair(ColInfo, theme.info, bg)
+	C.init_pair(ColCursor, theme.cursor, DarkBG)
+	C.init_pair(ColSelected, theme.selected, DarkBG)
+}
+
 func Close() {
 	C.endwin()
 	C.swapOutput()
diff --git a/src/options.go b/src/options.go
index d13a53b8..173dee91 100644
--- a/src/options.go
+++ b/src/options.go
@@ -35,8 +35,8 @@ const usage = `usage: fzf [options]
     -m, --multi           Enable multi-select with tab/shift-tab
         --ansi            Enable processing of ANSI color codes
         --no-mouse        Disable mouse
-    +c, --no-color        Disable colors
-    +2, --no-256          Disable 256-color
+        --color=COL       Color scheme [dark|light|16|bw]
+                          (default: dark on 256-color terminal, otherwise 16)
         --black           Use black background
         --reverse         Reverse orientation
         --no-hscroll      Disable horizontal scroll
@@ -101,8 +101,7 @@ type Options struct {
 	Multi      bool
 	Ansi       bool
 	Mouse      bool
-	Color      bool
-	Color256   bool
+	Theme      *curses.ColorTheme
 	Black      bool
 	Reverse    bool
 	Hscroll    bool
@@ -119,6 +118,13 @@ type Options struct {
 }
 
 func defaultOptions() *Options {
+	var defaultTheme *curses.ColorTheme
+	if strings.Contains(os.Getenv("TERM"), "256") {
+		defaultTheme = curses.Dark256
+	} else {
+		defaultTheme = curses.Default16
+	}
+
 	return &Options{
 		Mode:       ModeFuzzy,
 		Case:       CaseSmart,
@@ -131,8 +137,7 @@ func defaultOptions() *Options {
 		Multi:      false,
 		Ansi:       false,
 		Mouse:      true,
-		Color:      true,
-		Color256:   strings.Contains(os.Getenv("TERM"), "256"),
+		Theme:      defaultTheme,
 		Black:      false,
 		Reverse:    false,
 		Hscroll:    true,
@@ -266,6 +271,22 @@ func parseTiebreak(str string) tiebreak {
 	return byLength
 }
 
+func parseTheme(str string) *curses.ColorTheme {
+	switch strings.ToLower(str) {
+	case "dark":
+		return curses.Dark256
+	case "light":
+		return curses.Light256
+	case "16":
+		return curses.Default16
+	case "bw", "off", "no", "none":
+		return nil
+	default:
+		errorExit("invalid color scheme: " + str)
+	}
+	return nil
+}
+
 func checkToggleSort(str string) int {
 	keys := parseKeyChords(str, "key name required")
 	if len(keys) != 1 {
@@ -295,6 +316,8 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.Expect = parseKeyChords(nextString(allArgs, &i, "key names required"), "key names required")
 		case "--tiebreak":
 			opts.Tiebreak = parseTiebreak(nextString(allArgs, &i, "sort criterion required"))
+		case "--color":
+			opts.Theme = parseTheme(nextString(allArgs, &i, "color scheme name required"))
 		case "--toggle-sort":
 			opts.ToggleSort = checkToggleSort(nextString(allArgs, &i, "key name required"))
 		case "-d", "--delimiter":
@@ -326,9 +349,9 @@ func parseOptions(opts *Options, allArgs []string) {
 		case "--no-mouse":
 			opts.Mouse = false
 		case "+c", "--no-color":
-			opts.Color = false
+			opts.Theme = nil
 		case "+2", "--no-256":
-			opts.Color256 = false
+			opts.Theme = curses.Default16
 		case "--black":
 			opts.Black = true
 		case "--no-black":
@@ -384,6 +407,8 @@ func parseOptions(opts *Options, allArgs []string) {
 				opts.Expect = parseKeyChords(value, "key names required")
 			} else if match, value := optString(arg, "--tiebreak="); match {
 				opts.Tiebreak = parseTiebreak(value)
+			} else if match, value := optString(arg, "--color="); match {
+				opts.Theme = parseTheme(value)
 			} else {
 				errorExit("unknown option: " + arg)
 			}
diff --git a/src/terminal.go b/src/terminal.go
index eaec9a3f..959c84d9 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -105,7 +105,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		suppress:   true,
 		startChan:  make(chan bool, 1),
 		initFunc: func() {
-			C.Init(opts.Color, opts.Color256, opts.Black, opts.Mouse)
+			C.Init(opts.Theme, opts.Black, opts.Mouse)
 		}}
 }