Python IDLE清屏

 1 """
 2 
 3 Clear Window Extension
 4 Version: 0.2
 5 
 6 Author: Roger D. Serwy
 7         roger.serwy@gmail.com
 8 
 9 Date: 2009-06-14
10 
11 It provides "Clear Shell Window" under "Options"
12 with ability to undo.
13 
14 Add these lines to config-extensions.def
15 
16 [ClearWindow]
17 enable=1
18 enable_editor=0
19 enable_shell=1
20 [ClearWindow_cfgBindings]
21 clear-window=<Control-Key-l>
22 
23 
24 """
25 
26 class ClearWindow:
27 
28     menudefs = [
29         (‘options‘, [None,
30                (‘Clear Shell Window‘, ‘<<clear-window>>‘),
31        ]),]
32 
33     def __init__(self, editwin):
34         self.editwin = editwin
35         self.text = self.editwin.text
36         self.text.bind("<<clear-window>>", self.clear_window2)
37 
38         self.text.bind("<<undo>>", self.undo_event)  # add="+" doesn‘t work
39 
40     def undo_event(self, event):
41         text = self.text
42         
43         text.mark_set("iomark2", "iomark")
44         text.mark_set("insert2", "insert")
45         self.editwin.undo.undo_event(event)
46 
47         # fix iomark and insert
48         text.mark_set("iomark", "iomark2")
49         text.mark_set("insert", "insert2")
50         text.mark_unset("iomark2")
51         text.mark_unset("insert2")
52         
53 
54     def clear_window2(self, event): # Alternative method
55         # work around the ModifiedUndoDelegator
56         text = self.text
57         text.undo_block_start()
58         text.mark_set("iomark2", "iomark")
59         text.mark_set("iomark", 1.0)
60         text.delete(1.0, "iomark2 linestart")
61         text.mark_set("iomark", "iomark2")
62         text.mark_unset("iomark2")
63         text.undo_block_stop()
64         if self.text.compare(‘insert‘, ‘<‘, ‘iomark‘):
65             self.text.mark_set(‘insert‘, ‘end-1c‘)
66         self.editwin.set_line_and_column()
67 
68     def clear_window(self, event):
69         # remove undo delegator
70         undo = self.editwin.undo
71         self.editwin.per.removefilter(undo)
72 
73         # clear the window, but preserve current command
74         self.text.delete(1.0, "iomark linestart")
75         if self.text.compare(‘insert‘, ‘<‘, ‘iomark‘):
76             self.text.mark_set(‘insert‘, ‘end-1c‘)
77         self.editwin.set_line_and_column()
78 
79         # restore undo delegator
80         self.editwin.per.insertfilter(undo)