- New Extension: CodeContext. Provides block structuring hints for code
which has scrolled above an edit window. Patch 936169 Noam Raphael.
A CodeContext.py
M NEWS.txt
M config-extensions.def
diff --git a/Lib/idlelib/CodeContext.py b/Lib/idlelib/CodeContext.py
new file mode 100644
index 0000000..32dec82
--- /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 800e44b..ba66bf6 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -3,6 +3,9 @@
*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 1a02805..00162a0 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 @@
[ParenMatch_bindings]
flash-open-paren=<KeyRelease-parenright> <KeyRelease-bracketright> <KeyRelease-braceright>
check-restore=<KeyPress>
+
+[CodeContext]
+enable=1
+numlines=3
+bgcolor=LightGray
+fgcolor=Black