diff --git a/Lib/idlelib/CodeContext.py b/Lib/idlelib/CodeContext.py new file mode 100644 index 00000000000..32dec82a126 --- /dev/null +++ b/Lib/idlelib/CodeContext.py @@ -0,0 +1,127 @@ +"""CodeContext - Display the block context of code at top of edit window + +Once code has scolled off the top of the screen, it can be difficult +to determine which block you are in. This extension implements a pane +at the top of each IDLE edit window which provides block structure +hints. These hints are the lines which contain the block opening +keywords, e.g. 'if', for the enclosing block. The number of hint lines +is determined by the numlines variable in the CodeContext section of +config-extensions.def. Lines which do not open blocks are not shown in +the context hints pane. + +""" +import Tkinter +from configHandler import idleConf +from PyShell import PyShell +from string import whitespace +import re + +BLOCKOPENERS = dict([(x, None) for x in ("class", "def", "elif", "else", + "except", "finally", "for", "if", + "try", "while")]) +INFINITY = 1 << 30 +UPDATEINTERVAL = 100 #ms +FONTUPDATEINTERVAL = 1000 #ms + +getspacesfirstword = lambda s, c=re.compile(r"^(\s*)(\w*)"): c.match(s).groups() + +class CodeContext: + menudefs = [] + numlines = idleConf.GetOption("extensions", "CodeContext", + "numlines", type="int", default=3) + bgcolor = idleConf.GetOption("extensions", "CodeContext", + "bgcolor", type="str", default="LightGray") + fgcolor = idleConf.GetOption("extensions", "CodeContext", + "fgcolor", type="str", default="Black") + def __init__(self, editwin): + if isinstance(editwin, PyShell): + return + self.editwin = editwin + self.text = editwin.text + self.textfont = self.text["font"] + self.label = Tkinter.Label(self.editwin.top, + text="\n" * (self.numlines - 1), + anchor="w", justify="left", + font=self.textfont, + bg=self.bgcolor, fg=self.fgcolor, + relief="sunken", + width=1, # Don't request more than we get + ) + self.label.pack(side="top", fill="x", expand=0, + after=self.editwin.status_bar) + # Dummy line, which starts the "block" of the whole document: + self.info = list(self.interesting_lines(1)) + self.lastfirstline = 1 + # Start two update cycles, one for context lines, one for font changes. + self.text.after(UPDATEINTERVAL, self.timer_event) + self.text.after(FONTUPDATEINTERVAL, self.font_timer_event) + + def get_line_info(self, linenum): + """Get the line indent value, text, and any block start keyword + + If the line does not start a block, the keyword value is False. + The indentation of empty lines (or comment lines) is INFINITY. + There is a dummy block start, with indentation -1 and text "". + + Return the indent level, text (including leading whitespace), + and the block opening keyword. + + """ + if linenum == 0: + return -1, "", True + text = self.text.get("%d.0" % linenum, "%d.end" % linenum) + spaces, firstword = getspacesfirstword(text) + opener = firstword in BLOCKOPENERS and firstword + if len(text) == len(spaces) or text[len(spaces)] == '#': + indent = INFINITY + else: + indent = len(spaces) + return indent, text, opener + + def interesting_lines(self, firstline): + """Generator which yields context lines, starting at firstline.""" + # The indentation level we are currently in: + lastindent = INFINITY + # For a line to be interesting, it must begin with a block opening + # keyword, and have less indentation than lastindent. + for line_index in xrange(firstline, -1, -1): + indent, text, opener = self.get_line_info(line_index) + if indent < lastindent: + lastindent = indent + if opener == "else" or "elif": + # We also show the if statement + lastindent += 1 + if opener and line_index < firstline: + yield line_index, text + + def update_label(self): + firstline = int(self.text.index("@0,0").split('.')[0]) + if self.lastfirstline == firstline: + return + self.lastfirstline = firstline + tmpstack = [] + for line_index, text in self.interesting_lines(firstline): + # Remove irrelevant self.info items, and when we reach a relevant + # item (which must happen because of the dummy element), break. + while self.info[-1][0] > line_index: + del self.info[-1] + if self.info[-1][0] == line_index: + break + # Add the block starting line info to tmpstack + tmpstack.append((line_index, text)) + while tmpstack: + self.info.append(tmpstack.pop()) + lines = [""] * max(0, self.numlines - len(self.info)) + \ + [x[1] for x in self.info[-self.numlines:]] + self.label["text"] = '\n'.join(lines) + + def timer_event(self): + self.update_label() + self.text.after(UPDATEINTERVAL, self.timer_event) + + def font_timer_event(self): + newtextfont = self.text["font"] + if newtextfont != self.textfont: + self.textfont = newtextfont + self.label["font"] = self.textfont + self.text.after(FONTUPDATEINTERVAL, self.font_timer_event) diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt index 800e44b4de2..ba66bf6c2f6 100644 --- a/Lib/idlelib/NEWS.txt +++ b/Lib/idlelib/NEWS.txt @@ -3,6 +3,9 @@ What's New in IDLE 1.1a0? *Release date: XX-XXX-2004* +- New Extension: CodeContext. Provides block structuring hints for code + which has scrolled above an edit window. Patch 936169 Noam Raphael. + - If nulls somehow got into the strings in recent-files.lst EditorWindow.update_recent_files_list() was failing. Python Bug 931336. diff --git a/Lib/idlelib/config-extensions.def b/Lib/idlelib/config-extensions.def index 1a02805bb34..00162a0539f 100644 --- a/Lib/idlelib/config-extensions.def +++ b/Lib/idlelib/config-extensions.def @@ -3,7 +3,7 @@ # # Each extension must have at least one section, named after the extension # module. This section must contain an 'enable' item (=1 to enable the -# extension, =0 to disable it) and also contains any other general +# extension, =0 to disable it) and also contain any other general # configuration items for the extension. Each extension may also define up to # two optional sections named ExtensionName_bindings and # ExtensionName_cfgBindings. If present, ExtensionName_bindings defines virtual @@ -12,10 +12,15 @@ # extension that may be sensibly re-configured. # Currently it is necessary to manually modify this file to change extension -# key bindings. Note: If a keybinding is already in use when the extension is +# key bindings and default values. To customize, create +# ~/.idlerc/config-extensions.cfg and append the appropriate customized +# section(s). Those sections will override the defaults in this file. + +# Note: If a keybinding is already in use when the extension is # loaded, the extension's virtual event's keybinding will be set to ''. -# See config-keys.def for notes on specifying keys. +# See config-keys.def for notes on specifying keys and extend.txt for +# information on creating IDLE extensions. [FormatParagraph] enable=1 @@ -56,3 +61,9 @@ hilite-background= #43cd80 [ParenMatch_bindings] flash-open-paren= check-restore= + +[CodeContext] +enable=1 +numlines=3 +bgcolor=LightGray +fgcolor=Black