readline/runebuf.go

236 lines
3.8 KiB
Go

package readline
import (
"bytes"
"io"
)
type RuneBuffer struct {
buf []rune
idx int
prompt []byte
w io.Writer
}
func NewRuneBuffer(w io.Writer, prompt string) *RuneBuffer {
rb := &RuneBuffer{
prompt: []byte(prompt),
w: w,
}
return rb
}
func (r *RuneBuffer) Runes() []rune {
return r.buf
}
func (r *RuneBuffer) Pos() int {
return r.idx
}
func (r *RuneBuffer) Len() int {
return len(r.buf)
}
func (r *RuneBuffer) MoveToLineStart() {
if r.idx == 0 {
return
}
r.idx = 0
r.Refresh()
}
func (r *RuneBuffer) MoveBackward() {
if r.idx == 0 {
return
}
r.idx--
r.Refresh()
}
func (rb *RuneBuffer) WriteString(s string) {
rb.WriteRunes([]rune(s))
}
func (rb *RuneBuffer) WriteRune(r rune) {
rb.WriteRunes([]rune{r})
}
func (rb *RuneBuffer) WriteRunes(r []rune) {
tail := append(r, rb.buf[rb.idx:]...)
rb.buf = append(rb.buf[:rb.idx], tail...)
rb.idx++
rb.Refresh()
}
func (r *RuneBuffer) MoveForward() {
if r.idx == len(r.buf) {
return
}
r.idx++
r.Refresh()
}
func (r *RuneBuffer) Delete() {
if r.idx == len(r.buf) {
return
}
r.buf = append(r.buf[:r.idx], r.buf[r.idx+1:]...)
r.Refresh()
}
func (r *RuneBuffer) DeleteWord() {
if r.idx == len(r.buf) {
return
}
init := r.idx
for init < len(r.buf) && r.buf[init] == ' ' {
init++
}
for i := init + 1; i < len(r.buf); i++ {
if r.buf[i] != ' ' && r.buf[i-1] == ' ' {
r.buf = append(r.buf[:r.idx], r.buf[i-1:]...)
r.Refresh()
return
}
}
r.Kill()
}
func (r *RuneBuffer) MoveToPrevWord() {
if r.idx == 0 {
return
}
for i := r.idx - 1; i > 0; i-- {
if r.buf[i] != ' ' && r.buf[i-1] == ' ' {
r.idx = i
r.Refresh()
return
}
}
r.idx = 0
r.Refresh()
}
func (r *RuneBuffer) SetIdx(idx int) (change int) {
i := r.idx
r.idx = idx
return r.idx - i
}
func (r *RuneBuffer) Kill() {
r.buf = r.buf[:r.idx]
r.Refresh()
}
func (r *RuneBuffer) MoveToNextWord() {
for i := r.idx + 1; i < len(r.buf); i++ {
if r.buf[i] != ' ' && r.buf[i-1] == ' ' {
r.idx = i
r.Refresh()
return
}
}
r.idx = len(r.buf)
r.Refresh()
}
func (r *RuneBuffer) BackEscapeWord() {
if r.idx == 0 {
return
}
for i := r.idx - 1; i > 0; i-- {
if r.buf[i] != ' ' && r.buf[i-1] == ' ' {
r.buf = append(r.buf[:i], r.buf[r.idx:]...)
r.idx = i
r.Refresh()
return
}
}
r.buf = r.buf[:0]
r.idx = 0
r.Refresh()
}
func (r *RuneBuffer) Backspace() {
if r.idx == 0 {
return
}
r.idx--
r.buf = append(r.buf[:r.idx], r.buf[r.idx+1:]...)
r.Refresh()
}
func (r *RuneBuffer) MoveToLineEnd() {
if r.idx == len(r.buf) {
return
}
r.idx = len(r.buf)
r.Refresh()
}
func (r *RuneBuffer) LineCount() int {
return LineCount(RunesWidth(r.buf) + len(r.prompt))
}
func (r *RuneBuffer) IdxLine() int {
totalWidth := RunesWidth(r.buf[:r.idx]) + len(r.prompt)
w := getWidth()
line := 0
for totalWidth >= w {
totalWidth -= w
line++
}
return line
}
func (r *RuneBuffer) CursorLineCount() int {
return r.LineCount() - r.IdxLine()
}
func (r *RuneBuffer) Refresh() {
r.w.Write(r.Output())
}
func (r *RuneBuffer) Output() []byte {
buf := bytes.NewBuffer(nil)
buf.Write(r.CleanOutput())
buf.Write(r.prompt)
buf.Write([]byte(string(r.buf)))
buf.Write(bytes.Repeat([]byte{'\b'}, len(r.buf)-r.idx))
return buf.Bytes()
}
func (r *RuneBuffer) CleanOutput() []byte {
buf := bytes.NewBuffer(nil)
buf.Write([]byte("\033[J")) // just like ^k :)
// TODO: calculate how many line before cursor.
for i := 0; i <= 100; i++ {
buf.WriteString("\033[2K\r\b")
}
return buf.Bytes()
}
func (r *RuneBuffer) Clean() {
r.w.Write(r.CleanOutput())
}
func (r *RuneBuffer) Reset() []rune {
ret := r.buf
r.buf = r.buf[:0]
r.idx = 0
return ret
}
func (r *RuneBuffer) SetWithIdx(idx int, buf []rune) {
r.buf = buf
r.idx = idx
r.Refresh()
}
func (r *RuneBuffer) Set(buf []rune) {
r.SetWithIdx(len(buf), buf)
}