cpython/Tools/idle/ParenMatch.py

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"""ParenMatch -- An IDLE extension for parenthesis matching.
When you hit a right paren, the cursor should move briefly to the left
paren. Paren here is used generically; the matching applies to
parentheses, square brackets, and curly braces.
WARNING: This extension will fight with the CallTips extension,
because they both are interested in the KeyRelease-parenright event.
We'll have to fix IDLE to do something reasonable when two or more
extensions what to capture the same event.
"""
import string
import PyParse
from AutoIndent import AutoIndent, index2line
from IdleConf import IdleConf
class ParenMatch:
"""Highlight matching parentheses
There are three supported style of paren matching, based loosely
on the Emacs options. The style is select based on the
HILITE_STYLE attribute; it can be changed used the set_style
method.
The supported styles are:
default -- When a right paren is typed, highlight the matching
left paren for 1/2 sec.
expression -- When a right paren is typed, highlight the entire
expression from the left paren to the right paren.
TODO:
- fix interaction with CallTips
- extend IDLE with configuration dialog to change options
- implement rest of Emacs highlight styles (see below)
- print mismatch warning in IDLE status window
Note: In Emacs, there are several styles of highlight where the
matching paren is highlighted whenever the cursor is immediately
to the right of a right paren. I don't know how to do that in Tk,
so I haven't bothered.
"""
menudefs = []
keydefs = {
'<<flash-open-paren>>' : ('<KeyRelease-parenright>',
'<KeyRelease-bracketright>',
'<KeyRelease-braceright>'),
'<<check-restore>>' : ('<KeyPress>',),
}
windows_keydefs = {}
unix_keydefs = {}
iconf = IdleConf.getsection('ParenMatch')
STYLE = iconf.get('style')
FLASH_DELAY = iconf.getint('flash-delay')
HILITE_CONFIG = iconf.getcolor('hilite')
BELL = iconf.getboolean('bell')
del iconf
def __init__(self, editwin):
self.editwin = editwin
self.text = editwin.text
self.finder = LastOpenBracketFinder(editwin)
self.counter = 0
self._restore = None
self.set_style(self.STYLE)
def set_style(self, style):
self.STYLE = style
if style == "default":
self.create_tag = self.create_tag_default
self.set_timeout = self.set_timeout_last
elif style == "expression":
self.create_tag = self.create_tag_expression
self.set_timeout = self.set_timeout_none
def flash_open_paren_event(self, event):
index = self.finder.find(keysym_type(event.keysym))
if index is None:
self.warn_mismatched()
return
self._restore = 1
self.create_tag(index)
self.set_timeout()
def check_restore_event(self, event=None):
if self._restore:
self.text.tag_delete("paren")
self._restore = None
def handle_restore_timer(self, timer_count):
if timer_count + 1 == self.counter:
self.check_restore_event()
def warn_mismatched(self):
if self.BELL:
self.text.bell()
# any one of the create_tag_XXX methods can be used depending on
# the style
def create_tag_default(self, index):
"""Highlight the single paren that matches"""
self.text.tag_add("paren", index)
self.text.tag_config("paren", self.HILITE_CONFIG)
def create_tag_expression(self, index):
"""Highlight the entire expression"""
self.text.tag_add("paren", index, "insert")
self.text.tag_config("paren", self.HILITE_CONFIG)
# any one of the set_timeout_XXX methods can be used depending on
# the style
def set_timeout_none(self):
"""Highlight will remain until user input turns it off"""
pass
def set_timeout_last(self):
"""The last highlight created will be removed after .5 sec"""
# associate a counter with an event; only disable the "paren"
# tag if the event is for the most recent timer.
self.editwin.text_frame.after(self.FLASH_DELAY,
lambda self=self, c=self.counter: \
self.handle_restore_timer(c))
self.counter = self.counter + 1
def keysym_type(ks):
# Not all possible chars or keysyms are checked because of the
# limited context in which the function is used.
if ks == "parenright" or ks == "(":
return "paren"
if ks == "bracketright" or ks == "[":
return "bracket"
if ks == "braceright" or ks == "{":
return "brace"
class LastOpenBracketFinder:
num_context_lines = AutoIndent.num_context_lines
indentwidth = AutoIndent.indentwidth
tabwidth = AutoIndent.tabwidth
context_use_ps1 = AutoIndent.context_use_ps1
def __init__(self, editwin):
self.editwin = editwin
self.text = editwin.text
def _find_offset_in_buf(self, lno):
y = PyParse.Parser(self.indentwidth, self.tabwidth)
for context in self.num_context_lines:
startat = max(lno - context, 1)
startatindex = `startat` + ".0"
# rawtext needs to contain everything up to the last
# character, which was the close paren. the parser also
# requires that the last line ends with "\n"
rawtext = self.text.get(startatindex, "insert")[:-1] + "\n"
y.set_str(rawtext)
bod = y.find_good_parse_start(
self.context_use_ps1,
self._build_char_in_string_func(startatindex))
if bod is not None or startat == 1:
break
y.set_lo(bod or 0)
i = y.get_last_open_bracket_pos()
return i, y.str
def find(self, right_keysym_type):
"""Return the location of the last open paren"""
lno = index2line(self.text.index("insert"))
i, buf = self._find_offset_in_buf(lno)
if i is None \
or keysym_type(buf[i]) != right_keysym_type:
return None
lines_back = string.count(buf[i:], "\n") - 1
# subtract one for the "\n" added to please the parser
upto_open = buf[:i]
j = string.rfind(upto_open, "\n") + 1 # offset of column 0 of line
offset = i - j
return "%d.%d" % (lno - lines_back, offset)
def _build_char_in_string_func(self, startindex):
def inner(offset, startindex=startindex,
icis=self.editwin.is_char_in_string):
return icis(startindex + "%dc" % offset)
return inner