Replace RuneWidth to StringWidth to handle grapheme clusters

Fix #2482

2 files changed, 58 insertions, 55 deletions

diff --git a/src/tui/light.go b/src/tui/light.go
index 91b4c18e..d3e3faba 100644
--- a/src/tui/light.go
+++ b/src/tui/light.go
@@ -10,7 +10,8 @@ import (
 	"time"
 	"unicode/utf8"
 
-	"github.com/junegunn/fzf/src/util"
+	"github.com/mattn/go-runewidth"
+	"github.com/rivo/uniseg"
 
 	"golang.org/x/term"
 )
@@ -50,7 +51,7 @@ func (r *LightRenderer) stderrInternal(str string, allowNLCR bool) {
 		}
 		bytes = bytes[sz:]
 	}
-	r.queued += string(runes)
+	r.queued.WriteString(string(runes))
 }
 
 func (r *LightRenderer) csi(code string) {
@@ -58,9 +59,9 @@ func (r *LightRenderer) csi(code string) {
 }
 
 func (r *LightRenderer) flush() {
-	if len(r.queued) > 0 {
-		fmt.Fprint(os.Stderr, r.queued)
-		r.queued = ""
+	if r.queued.Len() > 0 {
+		fmt.Fprint(os.Stderr, r.queued.String())
+		r.queued.Reset()
 	}
 }
 
@@ -82,7 +83,7 @@ type LightRenderer struct {
 	escDelay      int
 	fullscreen    bool
 	upOneLine     bool
-	queued        string
+	queued        strings.Builder
 	y             int
 	x             int
 	maxHeightFunc func(int) int
@@ -889,20 +890,26 @@ func wrapLine(input string, prefixLength int, max int, tabstop int) []wrappedLin
 	lines := []wrappedLine{}
 	width := 0
 	line := ""
-	for _, r := range input {
-		w := util.RuneWidth(r, prefixLength+width, 8)
-		width += w
-		str := string(r)
-		if r == '\t' {
+	gr := uniseg.NewGraphemes(input)
+	for gr.Next() {
+		rs := gr.Runes()
+		str := string(rs)
+		var w int
+		if len(rs) == 1 && rs[0] == '\t' {
+			w = tabstop - (prefixLength+width)%tabstop
 			str = repeat(' ', w)
+		} else {
+			w = runewidth.StringWidth(str)
 		}
+		width += w
+
 		if prefixLength+width <= max {
 			line += str
 		} else {
 			lines = append(lines, wrappedLine{string(line), width - w})
 			line = str
 			prefixLength = 0
-			width = util.RuneWidth(r, prefixLength, 8)
+			width = w
 		}
 	}
 	lines = append(lines, wrappedLine{string(line), width})
diff --git a/src/tui/tcell.go b/src/tui/tcell.go
index 938c1ba0..859e6709 100644
--- a/src/tui/tcell.go
+++ b/src/tui/tcell.go
@@ -5,7 +5,6 @@ package tui
 import (
 	"os"
 	"time"
-	"unicode/utf8"
 
 	"runtime"
 
@@ -13,6 +12,7 @@ import (
 	"github.com/gdamore/tcell/encoding"
 
 	"github.com/mattn/go-runewidth"
+	"github.com/rivo/uniseg"
 )
 
 func HasFullscreenRenderer() bool {
@@ -482,7 +482,6 @@ func (w *TcellWindow) Print(text string) {
 }
 
 func (w *TcellWindow) printString(text string, pair ColorPair) {
-	t := text
 	lx := 0
 	a := pair.Attr()
 
@@ -496,33 +495,28 @@ func (w *TcellWindow) printString(text string, pair ColorPair) {
 			Dim(a&Attr(tcell.AttrDim) != 0)
 	}
 
-	for {
-		if len(t) == 0 {
-			break
-		}
-		r, size := utf8.DecodeRuneInString(t)
-		t = t[size:]
-
-		if r < rune(' ') { // ignore control characters
-			continue
-		}
-
-		if r == '\n' {
-			w.lastY++
-			lx = 0
-		} else {
+	gr := uniseg.NewGraphemes(text)
+	for gr.Next() {
+		rs := gr.Runes()
 
-			if r == '\u000D' { // skip carriage return
+		if len(rs) == 1 {
+			r := rs[0]
+			if r < rune(' ') { // ignore control characters
+				continue
+			} else if r == '\n' {
+				w.lastY++
+				lx = 0
+				continue
+			} else if r == '\u000D' { // skip carriage return
 				continue
 			}
-
-			var xPos = w.left + w.lastX + lx
-			var yPos = w.top + w.lastY
-			if xPos < (w.left+w.width) && yPos < (w.top+w.height) {
-				_screen.SetContent(xPos, yPos, r, nil, style)
-			}
-			lx += runewidth.RuneWidth(r)
 		}
+		var xPos = w.left + w.lastX + lx
+		var yPos = w.top + w.lastY
+		if xPos < (w.left+w.width) && yPos < (w.top+w.height) {
+			_screen.SetContent(xPos, yPos, rs[0], rs[1:], style)
+		}
+		lx += runewidth.StringWidth(string(rs))
 	}
 	w.lastX += lx
 }
@@ -549,30 +543,32 @@ func (w *TcellWindow) fillString(text string, pair ColorPair) FillReturn {
 		Underline(a&Attr(tcell.AttrUnderline) != 0).
 		Italic(a&Attr(tcell.AttrItalic) != 0)
 
-	for _, r := range text {
-		if r == '\n' {
+	gr := uniseg.NewGraphemes(text)
+	for gr.Next() {
+		rs := gr.Runes()
+		if len(rs) == 1 && rs[0] == '\n' {
 			w.lastY++
 			w.lastX = 0
 			lx = 0
-		} else {
-			var xPos = w.left + w.lastX + lx
-
-			// word wrap:
-			if xPos >= (w.left + w.width) {
-				w.lastY++
-				w.lastX = 0
-				lx = 0
-				xPos = w.left
-			}
-			var yPos = w.top + w.lastY
+			continue
+		}
 
-			if yPos >= (w.top + w.height) {
-				return FillSuspend
-			}
+		// word wrap:
+		xPos := w.left + w.lastX + lx
+		if xPos >= (w.left + w.width) {
+			w.lastY++
+			w.lastX = 0
+			lx = 0
+			xPos = w.left
+		}
 
-			_screen.SetContent(xPos, yPos, r, nil, style)
-			lx += runewidth.RuneWidth(r)
+		yPos := w.top + w.lastY
+		if yPos >= (w.top + w.height) {
+			return FillSuspend
 		}
+
+		_screen.SetContent(xPos, yPos, rs[0], rs[1:], style)
+		lx += runewidth.StringWidth(string(rs))
 	}
 	w.lastX += lx
 	if w.lastX == w.width {