diff options
Diffstat (limited to 'Lib/idlelib/parenmatch.py')
| -rw-r--r-- | Lib/idlelib/parenmatch.py | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/Lib/idlelib/parenmatch.py b/Lib/idlelib/parenmatch.py new file mode 100644 index 0000000000..ccec708f31 --- /dev/null +++ b/Lib/idlelib/parenmatch.py @@ -0,0 +1,174 @@ +"""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.config 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.bell = self.text.bell if self.BELL else lambda: None + 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.bell() + 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.bell() + 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() + + # 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) |