gg/wrap.go
2016-02-24 17:22:21 -05:00

62 lines
1.2 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") {
fields := splitOnSpace(line)
widths := make([]float64, len(fields))
for i, field := range fields {
widths[i], _ = m.MeasureString(field)
}
start := 0
total := 0.0
for i := 0; i < len(fields); i += 2 {
if total+widths[i] > width {
if i == start {
end := i + 2
result = append(result, strings.Join(fields[start:end], ""))
start, total = end, 0
continue
} else {
end := i
result = append(result, strings.Join(fields[start:end], ""))
start, total = end, 0
}
}
total += widths[i] + widths[i+1]
}
if start < len(fields) {
result = append(result, strings.Join(fields[start:], ""))
}
}
for i, line := range result {
result[i] = strings.TrimSpace(line)
}
return result
}