gg/wrap.go
2021-08-04 20:00:51 +02:00

63 lines
1.1 KiB
Go

package gg
import (
"strings"
"unicode"
)
type measureStringer interface {
MeasureString(s string) (w, h float64)
}
func splitOnSpace(x string) []string {
var result []string
pi := 0
ps := false
for i, c := range x {
s := unicode.IsSpace(c)
if s != ps && i > 0 {
result = append(result, x[pi:i])
pi = i
}
ps = s
}
result = append(result, x[pi:])
return result
}
func wordWrap(m measureStringer, s string, width float64) []string {
var result []string
for _, line := range strings.Split(s, "\n") {
if strings.TrimSpace(line) == "" {
result = append(result, line)
continue
}
fields := splitOnSpace(line)
if len(fields)%2 == 1 {
fields = append(fields, "")
}
x := ""
for i := 0; i < len(fields); i += 2 {
w, _ := m.MeasureString(x + fields[i])
if w > width {
if x == "" {
result = append(result, fields[i])
x = ""
continue
} else {
result = append(result, x)
x = ""
}
}
x += fields[i] + fields[i+1]
}
if x != "" {
result = append(result, x)
}
}
for i, line := range result {
result[i] = strings.TrimSpace(line)
}
return result
}