added ANSI color parsing and displaying colors in preview (closes #29)

fuzzyfinder.go

@@ -8,6 +8,7 @@ import (
 	"flag"
 	"fmt"
 	"reflect"
+	"regexp"
 	"sort"
 	"strings"
 	"sync"
@@ -23,8 +24,9 @@ import (
 
 var (
 	// ErrAbort is returned from Find* functions if there are no selections.
-	ErrAbort   = errors.New("abort")
-	errEntered = errors.New("entered")
+	ErrAbort    = errors.New("abort")
+	errEntered  = errors.New("entered")
+	colorsRegex = regexp.MustCompile(`\[[0-9;]*m`)
 )
 
 type state struct {
@@ -263,6 +265,53 @@ func (f *finder) _draw() {
 	}
 }
 
+func parseColor(rs *[]rune) (tcell.Color, bool) {
+	// only parses for 16 colors
+	// convert to string for easier parsing
+	str := string(*rs)
+	ansi := colorsRegex.FindStringSubmatch(str)
+	var bold bool
+
+	if len(ansi) == 0 {
+		// no color is being passed, return defaults
+		return tcell.ColorDefault, false
+	}
+
+	// ANSI color value is being passed
+	// find if bold is specified
+	if len(ansi[0]) > 4 && ansi[0][3:5] == ";1" {
+		bold = true
+	}
+
+	// find the color value
+	color := ansi[0][1:3]
+
+	// strip color codes (also strips trailing '[0m')
+	stripped := colorsRegex.ReplaceAllString(str, "")
+	*rs = []rune(stripped)
+
+	switch color {
+	case "30":
+		return tcell.ColorBlack, bold
+	case "31":
+		return tcell.ColorRed, bold
+	case "32":
+		return tcell.ColorGreen, bold
+	case "33":
+		return tcell.ColorYellow, bold
+	case "34":
+		return tcell.ColorBlue, bold
+	case "35":
+		return tcell.ColorDarkMagenta, bold
+	case "36":
+		return tcell.ColorDarkCyan, bold
+	case "37":
+		return tcell.ColorWhite, bold
+	default:
+		return tcell.ColorDefault, bold
+	}
+}
+
 func (f *finder) _drawPreview() {
 	if f.opt.previewFunc == nil {
 		return
@@ -354,6 +403,8 @@ func (f *finder) _drawPreview() {
 				}
 				j := i - width/2 - 2 // Two spaces.
 				l := prevLines[h-1]
+				// parse colors here and strip color codes from runes
+				col, isBold := parseColor(&l)
 				if j >= len(l) {
 					w++
 					continue
@@ -372,8 +423,9 @@ func (f *finder) _drawPreview() {
 				}
 
 				style := tcell.StyleDefault.
-					Foreground(tcell.ColorDefault).
-					Background(tcell.ColorDefault)
+					Foreground(col).
+					Background(tcell.ColorDefault).
+					Bold(isBold)
 				f.term.SetContent(w, h, l[j], nil, style)
 				w += rw
 			}