1 """ParenMatch -- for parenthesis matching.
2
3 When you hit a right paren, the cursor should move briefly to the left
4 paren. Paren here is used generically; the matching applies to
5 parentheses, square brackets, and curly braces.
6 """
7 from idlelib.hyperparser import HyperParser
8 from idlelib.config import idleConf
9
10 _openers = {')':'(',']':'[','}':'{'}
11 CHECK_DELAY = 100 # milliseconds
12
13 class ESC[4;38;5;81mParenMatch:
14 """Highlight matching openers and closers, (), [], and {}.
15
16 There are three supported styles of paren matching. When a right
17 paren (opener) is typed:
18
19 opener -- highlight the matching left paren (closer);
20 parens -- highlight the left and right parens (opener and closer);
21 expression -- highlight the entire expression from opener to closer.
22 (For back compatibility, 'default' is a synonym for 'opener').
23
24 Flash-delay is the maximum milliseconds the highlighting remains.
25 Any cursor movement (key press or click) before that removes the
26 highlight. If flash-delay is 0, there is no maximum.
27
28 TODO:
29 - Augment bell() with mismatch warning in status window.
30 - Highlight when cursor is moved to the right of a closer.
31 This might be too expensive to check.
32 """
33
34 RESTORE_VIRTUAL_EVENT_NAME = "<<parenmatch-check-restore>>"
35 # We want the restore event be called before the usual return and
36 # backspace events.
37 RESTORE_SEQUENCES = ("<KeyPress>", "<ButtonPress>",
38 "<Key-Return>", "<Key-BackSpace>")
39
40 def __init__(self, editwin):
41 self.editwin = editwin
42 self.text = editwin.text
43 # Bind the check-restore event to the function restore_event,
44 # so that we can then use activate_restore (which calls event_add)
45 # and deactivate_restore (which calls event_delete).
46 editwin.text.bind(self.RESTORE_VIRTUAL_EVENT_NAME,
47 self.restore_event)
48 self.counter = 0
49 self.is_restore_active = 0
50
51 @classmethod
52 def reload(cls):
53 cls.STYLE = idleConf.GetOption(
54 'extensions','ParenMatch','style', default='opener')
55 cls.FLASH_DELAY = idleConf.GetOption(
56 'extensions','ParenMatch','flash-delay', type='int',default=500)
57 cls.BELL = idleConf.GetOption(
58 'extensions','ParenMatch','bell', type='bool', default=1)
59 cls.HILITE_CONFIG = idleConf.GetHighlight(idleConf.CurrentTheme(),
60 'hilite')
61
62 def activate_restore(self):
63 "Activate mechanism to restore text from highlighting."
64 if not self.is_restore_active:
65 for seq in self.RESTORE_SEQUENCES:
66 self.text.event_add(self.RESTORE_VIRTUAL_EVENT_NAME, seq)
67 self.is_restore_active = True
68
69 def deactivate_restore(self):
70 "Remove restore event bindings."
71 if self.is_restore_active:
72 for seq in self.RESTORE_SEQUENCES:
73 self.text.event_delete(self.RESTORE_VIRTUAL_EVENT_NAME, seq)
74 self.is_restore_active = False
75
76 def flash_paren_event(self, event):
77 "Handle editor 'show surrounding parens' event (menu or shortcut)."
78 indices = (HyperParser(self.editwin, "insert")
79 .get_surrounding_brackets())
80 self.finish_paren_event(indices)
81 return "break"
82
83 def paren_closed_event(self, event):
84 "Handle user input of closer."
85 # If user bound non-closer to <<paren-closed>>, quit.
86 closer = self.text.get("insert-1c")
87 if closer not in _openers:
88 return
89 hp = HyperParser(self.editwin, "insert-1c")
90 if not hp.is_in_code():
91 return
92 indices = hp.get_surrounding_brackets(_openers[closer], True)
93 self.finish_paren_event(indices)
94 return # Allow calltips to see ')'
95
96 def finish_paren_event(self, indices):
97 if indices is None and self.BELL:
98 self.text.bell()
99 return
100 self.activate_restore()
101 # self.create_tag(indices)
102 self.tagfuncs.get(self.STYLE, self.create_tag_expression)(self, indices)
103 # self.set_timeout()
104 (self.set_timeout_last if self.FLASH_DELAY else
105 self.set_timeout_none)()
106
107 def restore_event(self, event=None):
108 "Remove effect of doing match."
109 self.text.tag_delete("paren")
110 self.deactivate_restore()
111 self.counter += 1 # disable the last timer, if there is one.
112
113 def handle_restore_timer(self, timer_count):
114 if timer_count == self.counter:
115 self.restore_event()
116
117 # any one of the create_tag_XXX methods can be used depending on
118 # the style
119
120 def create_tag_opener(self, indices):
121 """Highlight the single paren that matches"""
122 self.text.tag_add("paren", indices[0])
123 self.text.tag_config("paren", self.HILITE_CONFIG)
124
125 def create_tag_parens(self, indices):
126 """Highlight the left and right parens"""
127 if self.text.get(indices[1]) in (')', ']', '}'):
128 rightindex = indices[1]+"+1c"
129 else:
130 rightindex = indices[1]
131 self.text.tag_add("paren", indices[0], indices[0]+"+1c", rightindex+"-1c", rightindex)
132 self.text.tag_config("paren", self.HILITE_CONFIG)
133
134 def create_tag_expression(self, indices):
135 """Highlight the entire expression"""
136 if self.text.get(indices[1]) in (')', ']', '}'):
137 rightindex = indices[1]+"+1c"
138 else:
139 rightindex = indices[1]
140 self.text.tag_add("paren", indices[0], rightindex)
141 self.text.tag_config("paren", self.HILITE_CONFIG)
142
143 tagfuncs = {
144 'opener': create_tag_opener,
145 'default': create_tag_opener,
146 'parens': create_tag_parens,
147 'expression': create_tag_expression,
148 }
149
150 # any one of the set_timeout_XXX methods can be used depending on
151 # the style
152
153 def set_timeout_none(self):
154 """Highlight will remain until user input turns it off
155 or the insert has moved"""
156 # After CHECK_DELAY, call a function which disables the "paren" tag
157 # if the event is for the most recent timer and the insert has changed,
158 # or schedules another call for itself.
159 self.counter += 1
160 def callme(callme, self=self, c=self.counter,
161 index=self.text.index("insert")):
162 if index != self.text.index("insert"):
163 self.handle_restore_timer(c)
164 else:
165 self.editwin.text_frame.after(CHECK_DELAY, callme, callme)
166 self.editwin.text_frame.after(CHECK_DELAY, callme, callme)
167
168 def set_timeout_last(self):
169 """The last highlight created will be removed after FLASH_DELAY millisecs"""
170 # associate a counter with an event; only disable the "paren"
171 # tag if the event is for the most recent timer.
172 self.counter += 1
173 self.editwin.text_frame.after(
174 self.FLASH_DELAY,
175 lambda self=self, c=self.counter: self.handle_restore_timer(c))
176
177
178 ParenMatch.reload()
179
180
181 if __name__ == '__main__':
182 from unittest import main
183 main('idlelib.idle_test.test_parenmatch', verbosity=2)