piframe-go/vendor/github.com/eiannone/keyboard/keyboard.go

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2020-08-29 23:11:30 +00:00
// +build !windows
package keyboard
import (
"errors"
"golang.org/x/sys/unix"
"os"
"os/signal"
"runtime"
"strings"
"syscall"
"unicode/utf8"
)
type (
input_event struct {
data []byte
err error
}
)
var (
out *os.File
in int
// term specific keys
keys []string
// termbox inner state
orig_tios unix.Termios
sigio = make(chan os.Signal, 1)
quitEvProd = make(chan bool)
quitConsole = make(chan bool)
inbuf = make([]byte, 0, 128)
input_buf = make(chan input_event)
)
func parse_escape_sequence(buf []byte) (size int, event KeyEvent) {
bufstr := string(buf)
for i, key := range keys {
if strings.HasPrefix(bufstr, key) {
event.Rune = 0
event.Key = Key(0xFFFF - i)
size = len(key)
return
}
}
return 0, event
}
func extract_event(inbuf []byte) (int, KeyEvent) {
if len(inbuf) == 0 {
return 0, KeyEvent{}
}
if inbuf[0] == '\033' {
if len(inbuf) == 1 {
return 1, KeyEvent{Key: KeyEsc}
}
// possible escape sequence
if size, event := parse_escape_sequence(inbuf); size != 0 {
return size, event
} else {
// it's not a recognized escape sequence, return error
i := 1 // check for multiple sequences in the buffer
for ; i < len(inbuf) && inbuf[i] != '\033'; i++ {
}
return i, KeyEvent{Key: KeyEsc, Err: errors.New("Unrecognized escape sequence")}
}
}
// if we're here, this is not an escape sequence and not an alt sequence
// so, it's a FUNCTIONAL KEY or a UNICODE character
// first of all check if it's a functional key
if Key(inbuf[0]) <= KeySpace || Key(inbuf[0]) == KeyBackspace2 {
return 1, KeyEvent{Key: Key(inbuf[0])}
}
// the only possible option is utf8 rune
if r, n := utf8.DecodeRune(inbuf); r != utf8.RuneError {
return n, KeyEvent{Rune: r}
}
return 0, KeyEvent{}
}
// Wait for an event and return it. This is a blocking function call.
func inputEventsProducer() {
for {
select {
case <-quitEvProd:
return
case ev := <-input_buf:
if ev.err != nil {
select {
case <-quitEvProd:
return
case inputComm <- KeyEvent{Err: ev.err}:
}
break
}
inbuf = append(inbuf, ev.data...)
for {
size, event := extract_event(inbuf)
if size > 0 {
select {
case <-quitEvProd:
return
case inputComm <- event:
}
copy(inbuf, inbuf[size:])
inbuf = inbuf[:len(inbuf)-size]
}
if size == 0 || len(inbuf) == 0 {
break
}
}
}
}
}
func initConsole() (err error) {
out, err = os.OpenFile("/dev/tty", unix.O_WRONLY, 0)
if err != nil {
return
}
in, err = syscall.Open("/dev/tty", unix.O_RDONLY, 0)
if err != nil {
return
}
err = setup_term()
if err != nil {
return errors.New("Error while reading terminfo data:" + err.Error())
}
signal.Notify(sigio, unix.SIGIO)
if _, err = unix.FcntlInt(uintptr(in), unix.F_SETFL, unix.O_ASYNC|unix.O_NONBLOCK); err != nil {
return
}
_, err = unix.FcntlInt(uintptr(in), unix.F_SETOWN, unix.Getpid())
if runtime.GOOS != "darwin" && err != nil {
return
}
if err = unix.IoctlSetTermios(int(out.Fd()), ioctl_GETATTR, &orig_tios); err != nil {
return
}
tios := orig_tios
tios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK |
unix.ISTRIP | unix.INLCR | unix.IGNCR |
unix.ICRNL | unix.IXON
tios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON |
unix.ISIG | unix.IEXTEN
tios.Cflag &^= unix.CSIZE | unix.PARENB
tios.Cflag |= unix.CS8
tios.Cc[unix.VMIN] = 1
tios.Cc[unix.VTIME] = 0
if err = unix.IoctlSetTermios(int(out.Fd()), ioctl_SETATTR, &tios); err != nil {
return
}
go func() {
buf := make([]byte, 128)
for {
select {
case <-quitConsole:
return
case <-sigio:
for {
bytesRead, err := syscall.Read(in, buf)
if err == unix.EAGAIN || err == unix.EWOULDBLOCK {
break
}
if err != nil {
bytesRead = 0
}
data := make([]byte, bytesRead)
copy(data, buf)
select {
case <-quitConsole:
return
case input_buf <- input_event{data, err}:
continue
}
}
}
}
}()
go inputEventsProducer()
return
}
func releaseConsole() {
quitConsole <- true
quitEvProd <- true
unix.IoctlSetTermios(int(out.Fd()), ioctl_SETATTR, &orig_tios)
out.Close()
unix.Close(in)
}