Source Code for Module tipy.clbk

 1  #!/usr/bin/env python3 
 2  # -*- coding: utf-8 -*- 
 3   
 4  """Callback class holds the buffers and allow the outer world to access them.""" 
 5   
 6   
 7 -class Callback(object): 
 8      """Allow access to the current buffers from anywhere. 
 9   
10      This class is used as a callback to retrieve and modify the input buffers. 
11      There is two input buffers the left buffer and the right buffer: 
12          - Left buffer contains every characters preceding the cursor. 
13          - Right buffer contains every characters following the cursor. 
14   
15      It is possible to subclass this class and override its methods in order to 
16      use the program in other GUIs or command line interfaces. 
17   
18      G{classtree Callback} 
19      """ 
20   
21 -    def __init__(self): 
22          """Initialize the left and right buffer to empty string.""" 
23          self.left = '' 
24          self.right = '' 
25   
26 -    def update(self, character, offset=0): 
27          """Update the left and right buffers. 
28   
29          This method should be called after each character addition or deletion 
30          or after each cursor move. 
31          In the default GUI this method is called when a signal indicating that 
32          the input text have changed or that the cursor position have changed. 
33   
34          @param character: 
35              The character which has been inputted. It could be any character 
36              associated to keyboard keys including backspace, arrow keys... 
37          @type character: str 
38          @param offset: 
39              Indicate the cursor position offset against the previous cursor 
40              position. 0 means no move, a positive value means move to the right 
41              and a negative value means move to the left. 
42          @type offset: int 
43          """ 
44          if character == '\b' and len(self.left) >= offset: 
45              self.left = self.left[:-offset] 
46          elif character == '\x1B[D' and len(self.left) >= offset: 
47              self.right = self.left[offset:] + self.right 
48              self.left = self.left[:offset] 
49          elif character == '\x1B[C' and len(self.right) >= offset: 
50              self.left += self.right[:offset] 
51              self.right = self.right[offset:] 
52          else: 
53              self.left += character 
54