mirror of https://github.com/docker/cli.git
62 lines
1.5 KiB
Go
62 lines
1.5 KiB
Go
package formatter
|
|
|
|
import (
|
|
"unicode/utf8"
|
|
|
|
"golang.org/x/text/width"
|
|
)
|
|
|
|
// charWidth returns the number of horizontal positions a character occupies,
|
|
// and is used to account for wide characters when displaying strings.
|
|
//
|
|
// In a broad sense, wide characters include East Asian Wide, East Asian Full-width,
|
|
// (when not in East Asian context) see http://unicode.org/reports/tr11/.
|
|
func charWidth(r rune) int {
|
|
switch width.LookupRune(r).Kind() {
|
|
case width.EastAsianWide, width.EastAsianFullwidth:
|
|
return 2
|
|
default:
|
|
return 1
|
|
}
|
|
}
|
|
|
|
// Ellipsis truncates a string to fit within maxDisplayWidth, and appends ellipsis (…).
|
|
// For maxDisplayWidth of 1 and lower, no ellipsis is appended.
|
|
// For maxDisplayWidth of 1, first char of string will return even if its width > 1.
|
|
func Ellipsis(s string, maxDisplayWidth int) string {
|
|
if maxDisplayWidth <= 0 {
|
|
return ""
|
|
}
|
|
rs := []rune(s)
|
|
if maxDisplayWidth == 1 {
|
|
return string(rs[0])
|
|
}
|
|
|
|
byteLen := len(s)
|
|
if byteLen == utf8.RuneCountInString(s) {
|
|
if byteLen <= maxDisplayWidth {
|
|
return s
|
|
}
|
|
return string(rs[:maxDisplayWidth-1]) + "…"
|
|
}
|
|
|
|
var (
|
|
display = make([]int, 0, len(rs))
|
|
displayWidth int
|
|
)
|
|
for _, r := range rs {
|
|
cw := charWidth(r)
|
|
displayWidth += cw
|
|
display = append(display, displayWidth)
|
|
}
|
|
if displayWidth <= maxDisplayWidth {
|
|
return s
|
|
}
|
|
for i := range display {
|
|
if display[i] <= maxDisplayWidth-1 && display[i+1] > maxDisplayWidth-1 {
|
|
return string(rs[:i+1]) + "…"
|
|
}
|
|
}
|
|
return s
|
|
}
|