tcell/tscreen_darwin.go

143 lines
3.7 KiB
Go

// +build darwin
// Copyright 2019 The TCell Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use file except in compliance with the License.
// You may obtain a copy of the license at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tcell
// The Darwin system is *almost* a real BSD system, but it suffers from
// a brain damaged TTY driver. This TTY driver does not actually
// wake up in poll() or similar calls, which means that we cannot reliably
// shut down the terminal without resorting to obscene custom C code
// and a dedicated poller thread.
//
// So instead, we do a best effort, and simply try to do the close in the
// background. Probably this will cause a leak of two goroutines and
// maybe also the file descriptor, meaning that applications on Darwin
// can't reinitialize the screen, but that's probably a very rare behavior,
// and accepting that is the best of some very poor alternative options.
//
// Maybe someday Apple will fix there tty driver, but its been broken for
// a long time (probably forever) so holding one's breath is contraindicated.
import (
"os"
"os/signal"
"syscall"
"unsafe"
)
type termiosPrivate syscall.Termios
func (t *tScreen) termioInit() error {
var e error
var newtios termiosPrivate
var fd uintptr
var tios uintptr
var ioc uintptr
t.tiosp = &termiosPrivate{}
if t.in, e = os.OpenFile("/dev/tty", os.O_RDONLY, 0); e != nil {
goto failed
}
if t.out, e = os.OpenFile("/dev/tty", os.O_WRONLY, 0); e != nil {
goto failed
}
tios = uintptr(unsafe.Pointer(t.tiosp))
ioc = uintptr(syscall.TIOCGETA)
fd = uintptr(t.out.Fd())
if _, _, e1 := syscall.Syscall6(syscall.SYS_IOCTL, fd, ioc, tios, 0, 0, 0); e1 != 0 {
e = e1
goto failed
}
newtios = *t.tiosp
newtios.Iflag &^= syscall.IGNBRK | syscall.BRKINT | syscall.PARMRK |
syscall.ISTRIP | syscall.INLCR | syscall.IGNCR |
syscall.ICRNL | syscall.IXON
newtios.Oflag &^= syscall.OPOST
newtios.Lflag &^= syscall.ECHO | syscall.ECHONL | syscall.ICANON |
syscall.ISIG | syscall.IEXTEN
newtios.Cflag &^= syscall.CSIZE | syscall.PARENB
newtios.Cflag |= syscall.CS8
tios = uintptr(unsafe.Pointer(&newtios))
ioc = uintptr(syscall.TIOCSETA)
if _, _, e1 := syscall.Syscall6(syscall.SYS_IOCTL, fd, ioc, tios, 0, 0, 0); e1 != 0 {
e = e1
goto failed
}
signal.Notify(t.sigwinch, syscall.SIGWINCH)
if w, h, e := t.getWinSize(); e == nil && w != 0 && h != 0 {
t.cells.Resize(w, h)
}
return nil
failed:
if t.in != nil {
t.in.Close()
}
if t.out != nil {
t.out.Close()
}
return e
}
func (t *tScreen) termioFini() {
signal.Stop(t.sigwinch)
<-t.indoneq
if t.out != nil {
fd := uintptr(t.out.Fd())
ioc := uintptr(syscall.TIOCSETAF)
tios := uintptr(unsafe.Pointer(t.tiosp))
syscall.Syscall6(syscall.SYS_IOCTL, fd, ioc, tios, 0, 0, 0)
t.out.Close()
}
// See above -- we background this call which might help, but
// really the tty is probably open.
go func() {
if t.in != nil {
t.in.Close()
}
}()
}
func (t *tScreen) getWinSize() (int, int, error) {
fd := uintptr(t.out.Fd())
dim := [4]uint16{}
dimp := uintptr(unsafe.Pointer(&dim))
ioc := uintptr(syscall.TIOCGWINSZ)
if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL,
fd, ioc, dimp, 0, 0, 0); err != 0 {
return -1, -1, err
}
return int(dim[1]), int(dim[0]), nil
}
func (t *tScreen) Beep() error {
t.writeString(string(byte(7)))
return nil
}