Add support for OSC 777 (notify)

This considers OSC 777 is supported (or at least correctly dropped)
when the terminal supports Ms (usually OSC 52).

See: gdamore#499

console_win.go

@@ -1100,6 +1100,10 @@ func (s *cScreen) Size() (int, int) {
 	return w, h
 }
 
+func (s *cScreen) Notify(title string, body string) bool {
+	return false
+}
+
 func (s *cScreen) SetSize(w, h int) {
 	xy, _, _ := procGetLargestConsoleWindowSize.Call(uintptr(s.out))
 

screen.go

@@ -241,6 +241,13 @@ type Screen interface {
 	// when unsuccessful.
 	Beep() error
 
+	// Notify attempts to send a desktop notification with the given notification
+	// title and body.
+	//
+	// Many terminals cannot support this. Most terminals also drop the notification
+	// if the terminal window is currently focused.
+	Notify(title string, body string) bool
+
 	// SetSize attempts to resize the window.  It also invalidates the cells and
 	// calls the resize function.  Note that if the window size is changed, it will
 	// not be restored upon application exit.

simulation.go

@@ -463,6 +463,10 @@ func (s *simscreen) CharacterSet() string {
 	return s.charset
 }
 
+func (s *simscreen) Notify(title string, body string) bool {
+	return false
+}
+
 func (s *simscreen) SetSize(w, h int) {
 	s.Lock()
 	newc := make([]SimCell, w*h)

tscreen.go

@@ -154,6 +154,7 @@ type tScreen struct {
 	disablePaste string
 	enterUrl     string
 	exitUrl      string
+	notification string
 	setWinSize   string
 	cursorStyles map[CursorStyle]string
 	cursorStyle  CursorStyle
@@ -348,8 +349,8 @@ func (t *tScreen) prepareBracketedPaste() {
 func (t *tScreen) prepareExtendedOSC() {
 	// Linux is a special beast - because it has a mouse entry, but does
 	// not swallow these OSC commands properly.
-	if (strings.Contains(t.ti.Name, "linux")) {
-		return;
+	if strings.Contains(t.ti.Name, "linux") {
+		return
 	}
 	// More stuff for limits in terminfo.  This time we are applying
 	// the most common OSC (operating system commands).  Generally
@@ -368,6 +369,10 @@ func (t *tScreen) prepareExtendedOSC() {
 	} else if t.ti.Mouse != "" {
 		t.setWinSize = "\x1b[8;%p1%p2%d;%dt"
 	}
+
+	if t.ti.Mouse != "" {
+		t.notification = "\x1b]777;notify;%p1%s;%p2%s\a"
+	}
 }
 
 func (t *tScreen) prepareCursorStyles() {
@@ -1758,6 +1763,15 @@ func (t *tScreen) HasKey(k Key) bool {
 	return t.keyexist[k]
 }
 
+func (t *tScreen) Notify(title string, body string) bool {
+	if t.notification == "" {
+		return false
+	}
+	ti := t.ti
+	t.TPuts(ti.TParm(t.notification, title, body))
+	return true
+}
+
 func (t *tScreen) SetSize(w, h int) {
 	if t.setWinSize != "" {
 		t.TPuts(t.ti.TParm(t.setWinSize, w, h))