Simply check for a new size every 'Clear' and 'Present' call.

Instead of relying on sigwinch. Two syscalls per one screen update won't hurt.

api.go

@@ -38,8 +38,7 @@ func Init() error {
 
 	// we set two signal handlers, because input/output are not really
 	// connected, but they both need to be aware of window size changes
-	signal.Notify(sigwinch_input, syscall.SIGWINCH)
-	signal.Notify(sigwinch_draw, syscall.SIGWINCH)
+	signal.Notify(sigwinch, syscall.SIGWINCH)
 
 	err = tcgetattr(out.Fd(), &orig_tios)
 	if err != nil {
@@ -106,11 +105,7 @@ func Present() {
 	lastx = coord_invalid
 	lasty = coord_invalid
 
-	select {
-	case <-sigwinch_draw:
-		update_size()
-	default:
-	}
+	update_size_maybe()
 
 	for y := 0; y < front_buffer.height; y++ {
 		line_offset := y * front_buffer.width
@@ -200,7 +195,7 @@ func PollEvent() Event {
 			if extract_event(&event) {
 				return event
 			}
-		case <-sigwinch_input:
+		case <-sigwinch:
 			event.Type = EventResize
 			event.Width, event.Height = get_term_size(out.Fd())
 			return event
@@ -217,11 +212,7 @@ func Size() (int, int) {
 
 // Clears the internal back buffer.
 func Clear() {
-	select {
-	case <-sigwinch_draw:
-		update_size()
-	default:
-	}
+	update_size_maybe()
 	back_buffer.clear()
 }
 

termbox.go

@@ -57,8 +57,7 @@ var (
 	background     = ColorDefault
 	inbuf          = make([]byte, 0, 64)
 	outbuf         bytes.Buffer
-	sigwinch_input = make(chan os.Signal, 1)
-	sigwinch_draw  = make(chan os.Signal, 1)
+	sigwinch       = make(chan os.Signal, 1)
 	input_comm     = make(chan []byte)
 	intbuf         = make([]byte, 0, 16)
 )
@@ -166,12 +165,15 @@ func send_clear() {
 	lasty = coord_invalid
 }
 
-func update_size() {
-	termw, termh = get_term_size(out.Fd())
-	back_buffer.resize(termw, termh)
-	front_buffer.resize(termw, termh)
-	front_buffer.clear()
-	send_clear()
+func update_size_maybe() {
+	w, h := get_term_size(out.Fd())
+	if w != termw || h != termh {
+		termw, termh = w, h
+		back_buffer.resize(termw, termh)
+		front_buffer.resize(termw, termh)
+		front_buffer.clear()
+		send_clear()
+	}
 }
 
 func tcsetattr(fd uintptr, termios *syscall_Termios) error {