-"""CodeContext - Display the block context of code at top of edit window
+"""CodeContext - Extension to display the block context above the edit window
-Once code has scrolled 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.
+Once code has scrolled off the top of a window, 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
UPDATEINTERVAL = 100 # millisec
FONTUPDATEINTERVAL = 1000 # millisec
-getspacesfirstword = lambda s, c=re.compile(r"^(\s*)(\w*)"): c.match(s).groups()
+getspacesfirstword =\
+ lambda s, c=re.compile(r"^(\s*)(\w*)"): c.match(s).groups()
class CodeContext:
menudefs = [('options', [('!Code Conte_xt', '<<toggle-code-context>>')])]
- numlines = idleConf.GetOption("extensions", "CodeContext",
- "numlines", type="int", default=3)
+ context_depth = idleConf.GetOption("extensions", "CodeContext",
+ "numlines", type="int", default=3)
bgcolor = idleConf.GetOption("extensions", "CodeContext",
"bgcolor", type="str", default="LightGray")
fgcolor = idleConf.GetOption("extensions", "CodeContext",
self.text = editwin.text
self.textfont = self.text["font"]
self.label = None
- # self.info holds information about the context lines of line number
- # self.lastfirstline. The information is a tuple of the line's
- # indentation, the line's text and the keyword at the beginning of the
- # line, as returned by get_line_info. At the beginning of the list
- # there's a dummy line, which starts the "block" of the whole document.
+ # self.info is a list of (line number, indent level, line text, block
+ # keyword) tuples providing the block structure associated with
+ # self.topvisible (the linenumber of the line displayed at the top of
+ # the edit window). self.info[0] is initialized as a 'dummy' line which
+ # starts the toplevel 'block' of the module.
self.info = [(0, -1, "", False)]
- self.lastfirstline = 1
+ self.topvisible = 1
visible = idleConf.GetOption("extensions", "CodeContext",
"visible", type="bool", default=False)
if visible:
def toggle_code_context_event(self, event=None):
if not self.label:
self.label = Tkinter.Label(self.editwin.top,
- text="\n" * (self.numlines - 1),
+ text="\n" * (self.context_depth - 1),
anchor="w", justify="left",
font=self.textfont,
bg=self.bgcolor, fg=self.fgcolor,
If the line does not start a block, the keyword value is False.
The indentation of empty lines (or comment lines) is INFINITY.
+
"""
text = self.text.get("%d.0" % linenum, "%d.end" % linenum)
spaces, firstword = getspacesfirstword(text)
indent = len(spaces)
return indent, text, opener
- def interesting_lines(self, firstline, stopline=1, stopindent=0):
- """
- Find the context lines, starting at firstline.
- Will not return lines whose index is smaller than stopline or whose
- indentation is smaller than stopindent.
- stopline should always be >= 1, so the dummy block start will never
- be returned (This function doesn't know what to do about it.)
- Returns a list with the context lines, starting from the first (top),
- and a number which all context lines above the inspected region should
- have a smaller indentation than it.
+ def get_context(self, new_topvisible, stopline=1, stopindent=0):
+ """Get context lines, starting at new_topvisible and working backwards.
+
+ Stop when stopline or stopindent is reached. Return a tuple of context
+ data and the indent level at the top of the region inspected.
+
"""
+ assert stopline > 0
lines = []
# 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, stopline-1, -1):
- indent, text, opener = self.get_line_info(line_index)
+ for linenum in xrange(new_topvisible, stopline-1, -1):
+ indent, text, opener = self.get_line_info(linenum)
if indent < lastindent:
lastindent = indent
if opener in ("else", "elif"):
# We also show the if statement
lastindent += 1
- if opener and line_index < firstline and indent >= stopindent:
- lines.append((line_index, indent, text, opener))
+ if opener and linenum < new_topvisible and indent >= stopindent:
+ lines.append((linenum, indent, text, opener))
if lastindent <= stopindent:
break
lines.reverse()
return lines, lastindent
- def update_label(self):
- """Update the CodeContext label, if needed.
+ def update_code_context(self):
+ """Update context information and lines visible in the context pane.
+
"""
- firstline = int(self.text.index("@0,0").split('.')[0])
- if self.lastfirstline == firstline:
+ new_topvisible = int(self.text.index("@0,0").split('.')[0])
+ if self.topvisible == new_topvisible: # haven't scrolled
return
- if self.lastfirstline < firstline:
- lines, lastindent = self.interesting_lines(firstline,
- self.lastfirstline)
+ if self.topvisible < new_topvisible: # scroll down
+ lines, lastindent = self.get_context(new_topvisible,
+ self.topvisible)
+ # retain only context info applicable to the region
+ # between topvisible and new_topvisible:
while self.info[-1][1] >= lastindent:
del self.info[-1]
- self.info.extend(lines)
- else:
+ elif self.topvisible > new_topvisible: # scroll up
stopindent = self.info[-1][1] + 1
- while self.info[-1][0] >= firstline:
+ # retain only context info associated
+ # with lines above new_topvisible:
+ while self.info[-1][0] >= new_topvisible:
stopindent = self.info[-1][1]
del self.info[-1]
- lines, lastindent = self.interesting_lines(
- firstline, self.info[-1][0]+1, stopindent)
- self.info.extend(lines)
- self.lastfirstline = firstline
- lines = [""] * max(0, self.numlines - len(self.info)) + \
- [x[2] for x in self.info[-self.numlines:]]
- self.label["text"] = '\n'.join(lines)
+ lines, lastindent = self.get_context(new_topvisible,
+ self.info[-1][0]+1,
+ stopindent)
+ self.info.extend(lines)
+ self.topvisible = new_topvisible
+
+ # empty lines in context pane:
+ context_strings = [""] * max(0, self.context_depth - len(self.info))
+ # followed by the context hint lines:
+ context_strings += [x[2] for x in self.info[-self.context_depth:]]
+ self.label["text"] = '\n'.join(context_strings)
def timer_event(self):
if self.label:
- self.update_label()
+ self.update_code_context()
self.text.after(UPDATEINTERVAL, self.timer_event)
def font_timer_event(self):
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