Added more examples and documentation

Author: kmvanbrunt

docs/unfreefeatures.rst

@@ -191,11 +191,11 @@ what exit code is sent to the shell when your application exits from
 ``cmdloop()``.
 
 
-Asynchronous printing
+Asynchronous Feedback
 =====================
 ``cmd2`` provides two functions to provide asynchronous feedback to the user without interfering with
 the command line. This means the feedback is provided to the user when they are still entering text at
-the prompt. To use this functionality, the application must be running in any terminal that supports
+the prompt. To use this functionality, the application must be running in a terminal that supports
 VT100 control characters and readline. Linux, Mac, and Windows 10 and greater all support these.
 
 async_alert()
@@ -208,6 +208,13 @@ async_update_prompt()
     changes dynamically in between commands. For instance you could alter the color of the prompt to indicate
     a system status or increase a counter to report an event.
 
+``cmd2`` also provides a function to change the title of the terminal window. This feature requires the
+application be running in a terminal that support VT100 control characters. Linux, Mac, and Windows 10 and
+greater all support these.
+
+set_window_title()
+    Sets the terminal window title
+
 
 The easiest way to understand these function is to see the AsyncPrinting_ example for a demonstration.
 

examples/async_printing.py

@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 # coding=utf-8
-"""A simple example demonstrating an application that asynchronously prints alerts and updates the prompt"""
+"""
+A simple example demonstrating an application that asynchronously prints alerts, updates the prompt
+and changes the window title
+"""
 
 import random
 import threading
@@ -18,6 +21,7 @@
           "Keep typing...",
           "Move that cursor...",
           "Pretty seamless, eh?",
+          "Feedback can also be given in the window title. Notice the arg count up there?",
           "You can stop and start the alerts by typing stop_alerts and start_alerts",
           "This demo will now continue to print alerts at random intervals"
           ]
@@ -105,8 +109,8 @@ def _get_alerts(self) -> List[str]:
                 return []
 
             for i in range(0, rand_num):
-                alerts.append("Alert {}".format(self._alert_count))
                 self._alert_count += 1
+                alerts.append("Alert {}".format(self._alert_count))
 
             self._next_alert_time = 0
 
@@ -180,6 +184,8 @@ def _alerter_thread_func(self) -> None:
                 if alert_str:
                     # new_prompt is an optional parameter to async_alert()
                     self.async_alert(alert_str, new_prompt)
+                    new_title = "Alerts Printed: {}".format(self._alert_count)
+                    self.set_window_title(new_title)
 
                 # No alerts needed to be printed, check if the prompt changed
                 elif new_prompt != self.prompt: