support unicode characters

vendor/github.com/jesseduffield/gocui/view.go

@@ -10,6 +10,7 @@ import (
 	"io"
 	"strings"
 
+	"github.com/mattn/go-runewidth"
 	"github.com/nsf/termbox-go"
 )
 
@@ -312,24 +313,14 @@ func (v *View) draw() error {
 	if v.tainted {
 		v.viewLines = nil
 		for i, line := range v.lines {
+			wrap := 0
 			if v.Wrap {
-				if len(line) < maxX {
-					vline := viewLine{linesX: 0, linesY: i, line: line}
-					v.viewLines = append(v.viewLines, vline)
-					continue
-				} else {
-					for n := 0; n <= len(line); n += maxX {
-						if len(line[n:]) <= maxX {
-							vline := viewLine{linesX: n, linesY: i, line: line[n:]}
-							v.viewLines = append(v.viewLines, vline)
-						} else {
-							vline := viewLine{linesX: n, linesY: i, line: line[n : n+maxX]}
-							v.viewLines = append(v.viewLines, vline)
-						}
-					}
-				}
-			} else {
-				vline := viewLine{linesX: 0, linesY: i, line: line}
+				wrap = maxX
+			}
+
+			ls := lineWrap(line, wrap)
+			for j := range ls {
+				vline := viewLine{linesX: j, linesY: i, line: ls[j]}
 				v.viewLines = append(v.viewLines, vline)
 			}
 		}
@@ -368,7 +359,7 @@ func (v *View) draw() error {
 			if err := v.setRune(x, y, c.chr, fgColor, bgColor); err != nil {
 				return err
 			}
-			x++
+			x += runewidth.RuneWidth(c.chr)
 		}
 		y++
 	}
@@ -438,11 +429,7 @@ func (v *View) BufferLines() []string {
 // Buffer returns a string with the contents of the view's internal
 // buffer.
 func (v *View) Buffer() string {
-	str := ""
-	for _, l := range v.lines {
-		str += lineType(l).String() + "\n"
-	}
-	return strings.Replace(str, "\x00", " ", -1)
+	return linesToString(v.lines)
 }
 
 // ViewBufferLines returns the lines in the view's internal
@@ -460,11 +447,12 @@ func (v *View) ViewBufferLines() []string {
 // ViewBuffer returns a string with the contents of the view's buffer that is
 // shown to the user.
 func (v *View) ViewBuffer() string {
-	str := ""
-	for _, l := range v.viewLines {
-		str += lineType(l.line).String() + "\n"
+	lines := make([][]cell, len(v.viewLines))
+	for i := range v.viewLines {
+		lines[i] = v.viewLines[i].line
 	}
-	return strings.Replace(str, "\x00", " ", -1)
+
+	return linesToString(lines)
 }
 
 // Line returns a string with the line of the view's internal buffer
@@ -516,3 +504,49 @@ func (v *View) Word(x, y int) (string, error) {
 func indexFunc(r rune) bool {
 	return r == ' ' || r == 0
 }
+
+func lineWidth(line []cell) (n int) {
+	for i := range line {
+		n += runewidth.RuneWidth(line[i].chr)
+	}
+
+	return
+}
+
+func lineWrap(line []cell, columns int) [][]cell {
+	if columns == 0 {
+		return [][]cell{line}
+	}
+
+	var n int
+	var offset int
+	lines := make([][]cell, 0, 1)
+	for i := range line {
+		rw := runewidth.RuneWidth(line[i].chr)
+		n += rw
+		if n > columns {
+			n = rw
+			lines = append(lines, line[offset:i-1])
+			offset = i
+		}
+	}
+
+	lines = append(lines, line[offset:])
+	return lines
+}
+
+func linesToString(lines [][]cell) string {
+	str := make([]string, len(lines))
+	for i := range lines {
+		rns := make([]rune, 0, len(lines[i]))
+		line := lineType(lines[i]).String()
+		for _, c := range line {
+			if c != '\x00' {
+				rns = append(rns, c)
+			}
+		}
+		str[i] = string(rns)
+	}
+
+	return strings.Join(str, "\n")
+}