Use plain style color for unclassified text

I believe this fixes #159.

m/ansiTokenizer.go

@@ -41,11 +41,11 @@ func NewLine(raw string) Line {
 
 // Returns a representation of the string split into styled tokens. Any regexp
 // matches are highlighted. A nil regexp means no highlighting.
-func (line *Line) HighlightedTokens(search *regexp.Regexp) cellsWithTrailer {
+func (line *Line) HighlightedTokens(linePrefix string, search *regexp.Regexp) cellsWithTrailer {
 	plain := line.Plain()
 	matchRanges := getMatchRanges(&plain, search)
 
-	fromString := cellsFromString(line.raw)
+	fromString := cellsFromString(linePrefix + line.raw)
 	returnCells := make([]twin.Cell, 0, len(fromString.Cells))
 	for _, token := range fromString.Cells {
 		style := token.Style

m/linewrapper_test.go

@@ -9,7 +9,7 @@ import (
 
 func tokenize(input string) []twin.Cell {
 	line := NewLine(input)
-	return line.HighlightedTokens(nil).Cells
+	return line.HighlightedTokens("", nil).Cells
 }
 
 func rowsToString(cellLines [][]twin.Cell) string {

m/pager.go

@@ -4,8 +4,10 @@ import (
 	"fmt"
 	"math"
 	"regexp"
+	"strings"
 	"time"
 
+	"github.com/alecthomas/chroma/v2"
 	log "github.com/sirupsen/logrus"
 	"github.com/walles/moar/twin"
 )
@@ -93,6 +95,16 @@ type Pager struct {
 	// If true, pager will clear the screen on return. If false, pager will
 	// clear the last line, and show the cursor.
 	DeInit bool
+
+	// Render the UI using this style
+	ChromaStyle *chroma.Style
+
+	// Render the UI using this formatter
+	ChromaFormatter *chroma.Formatter
+
+	// Optional ANSI to prefix each text line with. Initialised using
+	// ChromaStyle and ChromaFormatter.
+	linePrefix string
 }
 
 type _PreHelpState struct {
@@ -428,6 +440,32 @@ func (p *Pager) onRune(char rune) {
 	}
 }
 
+func (p *Pager) initStyle() {
+	if p.ChromaStyle == nil && p.ChromaFormatter == nil {
+		return
+	}
+	if p.ChromaStyle == nil || p.ChromaFormatter == nil {
+		panic("Both ChromaStyle and ChromaFormatter should be set or neither")
+	}
+
+	stringBuilder := strings.Builder{}
+	err := (*p.ChromaFormatter).Format(&stringBuilder, p.ChromaStyle, chroma.Literator(chroma.Token{
+		Type:  chroma.Other,
+		Value: "XXX",
+	}))
+	if err != nil {
+		panic(err)
+	}
+
+	string := stringBuilder.String()
+	cutoff := strings.Index(string, "XXX")
+	if cutoff < 0 {
+		panic("XXX not found in " + string)
+	}
+
+	p.linePrefix = string[:cutoff]
+}
+
 // StartPaging brings up the pager on screen
 func (p *Pager) StartPaging(screen twin.Screen) {
 	log.Trace("Pager starting")
@@ -443,6 +481,7 @@ func (p *Pager) StartPaging(screen twin.Screen) {
 	ConsumeLessTermcapEnvs()
 
 	p.screen = screen
+	p.initStyle()
 
 	go func() {
 		for range p.reader.moreLinesAdded {

m/pager_test.go

@@ -583,6 +583,15 @@ func TestClearToEndOfLine_ClearFromStartScrolledRight(t *testing.T) {
 	assert.DeepEqual(t, actual, expected, cmp.AllowUnexported(twin.Style{}))
 }
 
+func TestInitStyle(t *testing.T) {
+	testMe := Pager{
+		ChromaStyle:     styles.Registry["gruvbox"],
+		ChromaFormatter: &formatters.TTY16m,
+	}
+	testMe.initStyle()
+	assert.Equal(t, testMe.linePrefix, "\x1b[38;2;235;219;178m")
+}
+
 func benchmarkSearch(b *testing.B, highlighted bool) {
 	// Pick a go file so we get something with highlighting
 	_, sourceFilename, _, ok := runtime.Caller(0)

m/screenLines.go

@@ -204,7 +204,7 @@ func (p *Pager) renderLines() ([]renderedLine, string, overflowState) {
 // lineNumber and numberPrefixLength are required for knowing how much to
 // indent, and to (optionally) render the line number.
 func (p *Pager) renderLine(line *Line, lineNumber int) ([]renderedLine, overflowState) {
-	highlighted := line.HighlightedTokens(p.searchPattern)
+	highlighted := line.HighlightedTokens(p.linePrefix, p.searchPattern)
 	var wrapped [][]twin.Cell
 	overflow := didFit
 	if p.WrapLongLines {

moar.go

@@ -199,8 +199,8 @@ func parseUnprintableStyle(styleOption string) (m.UnprintableStyle, error) {
 
 func parseScrollHint(scrollHint string) (twin.Cell, error) {
 	scrollHint = strings.ReplaceAll(scrollHint, "ESC", "\x1b")
-	hintParser := m.NewLine(scrollHint)
-	parsedTokens := hintParser.HighlightedTokens(nil).Cells
+	hintAsLine := m.NewLine(scrollHint)
+	parsedTokens := hintAsLine.HighlightedTokens("", nil).Cells
 	if len(parsedTokens) == 1 {
 		return parsedTokens[0], nil
 	}
@@ -492,6 +492,8 @@ func main() {
 	pager.ScrollLeftHint = *scrollLeftHint
 	pager.ScrollRightHint = *scrollRightHint
 	pager.SideScrollAmount = int(*shift)
+	pager.ChromaStyle = style
+	pager.ChromaFormatter = formatter
 
 	pager.TargetLineNumberOneBased = targetLineNumberOneBased
 	if *follow && pager.TargetLineNumberOneBased == 0 {