added deck.chat modules

deck/chat.py

@@ -10,11 +10,10 @@ except:
   pass
 
 def _echo(msg, state):
-  print(msg)
-  return state
+  return msg, state
 
 class DeckChat:
-  def __init__(self, start_state={}, chat_prefix='> ', command_prefix='/'):
+  def __init__(self, start_state={}, chat_prefix='> ', command_prefix='/', paginate=0):
     """Init the chat class"""
     self.command_prefix = command_prefix # prefix that commands start with
     self.chat_prefix = chat_prefix       # prefix to write before input
@@ -22,6 +21,7 @@ class DeckChat:
       'default': _echo                   # echo handler by default
     }
     self.state = start_state             # internal state object (impl-specific)
+    self.paginate_n = paginate           # paginate the responses exceeding N>0 lines
 
   def command(self, command, handler):
     """
@@ -46,13 +46,26 @@ class DeckChat:
         res = (cmd, arg)
     return res
 
+  def _paginate_output(self, text):
+    """Splits output for small terminals."""
+    lines = text.split('\n')
+    for i in range(0, len(lines), self.paginate_n):
+      chunk = lines[i:i + self.paginate_n]
+      for line in chunk: print(line)
+      if i + self.paginate_n < len(lines):
+        input("-- Press Enter --")
+
   def start(self):
     """Start the chat loop"""
     while True:
       try:
         input_msg = input('\n' + self.chat_prefix).strip()
         cmd, msg = self._detect_command(input_msg)
-        self.state = self.command_handlers[cmd](msg, self.state)
+        output, self.state = self.command_handlers[cmd](msg, self.state)
+        if self.paginate_n > 0:
+          self._paginate_output(output.strip())
+        else:
+          print(output)  
         if self.state is None:
           break
       except KeyboardInterrupt: break