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Edit File: ParenMatch.py

"""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. """ from idlelib.HyperParser import HyperParser from idlelib.configHandler import idleConf _openers = {')':'(',']':'[','}':'{'} CHECK_DELAY = 100 # milliseconds 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: - 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 = [ ('edit', [ ("Show surrounding parens", "<<flash-paren>>"), ]) ] STYLE = idleConf.GetOption('extensions','ParenMatch','style', default='expression') FLASH_DELAY = idleConf.GetOption('extensions','ParenMatch','flash-delay', type='int',default=500) HILITE_CONFIG = idleConf.GetHighlight(idleConf.CurrentTheme(),'hilite') BELL = idleConf.GetOption('extensions','ParenMatch','bell', type='bool',default=1) RESTORE_VIRTUAL_EVENT_NAME = "<<parenmatch-check-restore>>" # We want the restore event be called before the usual return and # backspace events. RESTORE_SEQUENCES = ("<KeyPress>", "<ButtonPress>", "<Key-Return>", "<Key-BackSpace>") def __init__(self, editwin): self.editwin = editwin self.text = editwin.text # Bind the check-restore event to the function restore_event, # so that we can then use activate_restore (which calls event_add) # and deactivate_restore (which calls event_delete). editwin.text.bind(self.RESTORE_VIRTUAL_EVENT_NAME, self.restore_event) self.counter = 0 self.is_restore_active = 0 self.set_style(self.STYLE) def activate_restore(self): if not self.is_restore_active: for seq in self.RESTORE_SEQUENCES: self.text.event_add(self.RESTORE_VIRTUAL_EVENT_NAME, seq) self.is_restore_active = True def deactivate_restore(self): if self.is_restore_active: for seq in self.RESTORE_SEQUENCES: self.text.event_delete(self.RESTORE_VIRTUAL_EVENT_NAME, seq) self.is_restore_active = False 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_paren_event(self, event): indices = (HyperParser(self.editwin, "insert") .get_surrounding_brackets()) if indices is None: self.warn_mismatched() return self.activate_restore() self.create_tag(indices) self.set_timeout_last() def paren_closed_event(self, event): # If it was a shortcut and not really a closing paren, quit. closer = self.text.get("insert-1c") if closer not in _openers: return hp = HyperParser(self.editwin, "insert-1c") if not hp.is_in_code(): return indices = hp.get_surrounding_brackets(_openers[closer], True) if indices is None: self.warn_mismatched() return self.activate_restore() self.create_tag(indices) self.set_timeout() def restore_event(self, event=None): self.text.tag_delete("paren") self.deactivate_restore() self.counter += 1 # disable the last timer, if there is one. def handle_restore_timer(self, timer_count): if timer_count == self.counter: self.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, indices): """Highlight the single paren that matches""" self.text.tag_add("paren", indices[0]) self.text.tag_config("paren", self.HILITE_CONFIG) def create_tag_expression(self, indices): """Highlight the entire expression""" if self.text.get(indices[1]) in (')', ']', '}'): rightindex = indices[1]+"+1c" else: rightindex = indices[1] self.text.tag_add("paren", indices[0], rightindex) 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 or the insert has moved""" # After CHECK_DELAY, call a function which disables the "paren" tag # if the event is for the most recent timer and the insert has changed, # or schedules another call for itself. self.counter += 1 def callme(callme, self=self, c=self.counter, index=self.text.index("insert")): if index != self.text.index("insert"): self.handle_restore_timer(c) else: self.editwin.text_frame.after(CHECK_DELAY, callme, callme) self.editwin.text_frame.after(CHECK_DELAY, callme, callme) 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.counter += 1 self.editwin.text_frame.after( self.FLASH_DELAY, lambda self=self, c=self.counter: self.handle_restore_timer(c)) if __name__ == '__main__': import unittest unittest.main('idlelib.idle_test.test_parenmatch', verbosity=2)