"""ParenMatch -- 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.config import idleConf _openers = {')':'(',']':'[','}':'{'} CHECK_DELAY = 100 # milliseconds class ParenMatch: """Highlight matching openers and closers, (), [], and {}. There are three supported styles of paren matching. When a right paren (opener) is typed: opener -- highlight the matching left paren (closer); parens -- highlight the left and right parens (opener and closer); expression -- highlight the entire expression from opener to closer. (For back compatibility, 'default' is a synonym for 'opener'). Flash-delay is the maximum milliseconds the highlighting remains. Any cursor movement (key press or click) before that removes the highlight. If flash-delay is 0, there is no maximum. TODO: - Augment bell() with mismatch warning in status window. - Highlight when cursor is moved to the right of a closer. This might be too expensive to check. """ 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 @classmethod def reload(cls): cls.STYLE = idleConf.GetOption( 'extensions','ParenMatch','style', default='opener') cls.FLASH_DELAY = idleConf.GetOption( 'extensions','ParenMatch','flash-delay', type='int',default=500) cls.BELL = idleConf.GetOption( 'extensions','ParenMatch','bell', type='bool', default=1) cls.HILITE_CONFIG = idleConf.GetHighlight(idleConf.CurrentTheme(), 'hilite') def activate_restore(self): "Activate mechanism to restore text from highlighting." 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): "Remove restore event bindings." 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 flash_paren_event(self, event): "Handle editor 'show surrounding parens' event (menu or shortcut)." indices = (HyperParser(self.editwin, "insert") .get_surrounding_brackets()) self.finish_paren_event(indices) return "break" def paren_closed_event(self, event): "Handle user input of closer." # If user bound non-closer to <<paren-closed>>, 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) self.finish_paren_event(indices) return # Allow calltips to see ')' def finish_paren_event(self, indices): if indices is None and self.BELL: self.text.bell() return self.activate_restore() # self.create_tag(indices) self.tagfuncs.get(self.STYLE, self.create_tag_expression)(self, indices) # self.set_timeout() (self.set_timeout_last if self.FLASH_DELAY else self.set_timeout_none)() def restore_event(self, event=None): "Remove effect of doing match." 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() # any one of the create_tag_XXX methods can be used depending on # the style def create_tag_opener(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_parens(self, indices): """Highlight the left and right parens""" if self.text.get(indices[1]) in (')', ']', '}'): rightindex = indices[1]+"+1c" else: rightindex = indices[1] self.text.tag_add("paren", indices[0], indices[0]+"+1c", rightindex+"-1c", rightindex) 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) tagfuncs = { 'opener': create_tag_opener, 'default': create_tag_opener, 'parens': create_tag_parens, 'expression': create_tag_expression, } # 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 FLASH_DELAY millisecs""" # 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)) ParenMatch.reload() if __name__ == '__main__': from unittest import main main('idlelib.idle_test.test_parenmatch', verbosity=2)