Allow unsetting the listener. With multiple tabs there's only one

terminal view that is attached to the window and can receive messages at
all.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25964 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/terminal/TerminalBuffer.cpp

@@ -17,7 +17,8 @@
 TerminalBuffer::TerminalBuffer()
 	:
 	BLocker("terminal buffer"),
-	fEncoding(M_UTF8)
+	fEncoding(M_UTF8),
+	fListenerValid(false)
 {
 }
 
@@ -41,6 +42,14 @@ void
 TerminalBuffer::SetListener(BMessenger listener)
 {
 	fListener = listener;
+	fListenerValid = true;
+}
+
+
+void
+TerminalBuffer::UnsetListener()
+{
+	fListenerValid = false;
 }
 
 
@@ -61,23 +70,28 @@ TerminalBuffer::SetEncoding(int encoding)
 void
 TerminalBuffer::SetTitle(const char* title)
 {
+	if (fListenerValid) {
 		BMessage message(MSG_SET_TERMNAL_TITLE);
 		message.AddString("title", title);
 		fListener.SendMessage(&message);
+	}
 }
 
 
 void
 TerminalBuffer::NotifyQuit(int32 reason)
 {
+	if (fListenerValid) {
 		BMessage message(MSG_QUIT_TERMNAL);
 		message.AddInt32("reason", reason);
 		fListener.SendMessage(&message);
+	}
 }
 
 
 void
 TerminalBuffer::NotifyListener()
 {
+	if (fListenerValid)
 		fListener.SendMessage(MSG_TERMINAL_BUFFER_CHANGED);
 }

src/apps/terminal/TerminalBuffer.h

@@ -20,6 +20,7 @@ public:
 									int32 historySize);
 
 			void				SetListener(BMessenger listener);
+			void				UnsetListener();
 
 			int					Encoding() const;
 			void				SetEncoding(int encoding);
@@ -35,6 +36,7 @@ private:
 
 			// listener/dirty region management
 			BMessenger			fListener;
+			bool				fListenerValid;
 };