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| -rw-r--r-- | Tools/idle/ParenMatch.py | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/Tools/idle/ParenMatch.py b/Tools/idle/ParenMatch.py new file mode 100644 index 0000000..7500603 --- /dev/null +++ b/Tools/idle/ParenMatch.py @@ -0,0 +1,193 @@ +"""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 + +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 = {} + + STYLE = "default" # or "expression" + FLASH_DELAY = 500 + HILITE_CONFIG = {"foreground": "black", + "background": "#43cd80", # SeaGreen3 + } + BELL = 1 # set to false for no bell + + 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. also need to + # append "\n" to please the parser, which seems to expect + # a complete line + 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: + return i + if keysym_type(buf[i]) != right_keysym_type: + return None + lines_back = buf[i:].count("\n") - 1 + # subtract one for the "\n" added to please the parser + upto_open = buf[:i] + j = upto_open.rfind("\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 + |