240 lines
9.9 KiB
Python
240 lines
9.9 KiB
Python
"""codecontext - display the block context above the edit window
|
|
|
|
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 maxlines
|
|
variable in the codecontext section of config-extensions.def. Lines which do
|
|
not open blocks are not shown in the context hints pane.
|
|
|
|
"""
|
|
import re
|
|
from sys import maxsize as INFINITY
|
|
|
|
import tkinter
|
|
from tkinter.constants import TOP, X, SUNKEN
|
|
|
|
from idlelib.config import idleConf
|
|
|
|
BLOCKOPENERS = {"class", "def", "elif", "else", "except", "finally", "for",
|
|
"if", "try", "while", "with", "async"}
|
|
|
|
|
|
def get_spaces_firstword(codeline, c=re.compile(r"^(\s*)(\w*)")):
|
|
"Extract the beginning whitespace and first word from codeline."
|
|
return c.match(codeline).groups()
|
|
|
|
|
|
def get_line_info(codeline):
|
|
"""Return tuple of (line indent value, codeline, block start keyword).
|
|
|
|
The indentation of empty lines (or comment lines) is INFINITY.
|
|
If the line does not start a block, the keyword value is False.
|
|
"""
|
|
spaces, firstword = get_spaces_firstword(codeline)
|
|
indent = len(spaces)
|
|
if len(codeline) == indent or codeline[indent] == '#':
|
|
indent = INFINITY
|
|
opener = firstword in BLOCKOPENERS and firstword
|
|
return indent, codeline, opener
|
|
|
|
|
|
class CodeContext:
|
|
"Display block context above the edit window."
|
|
UPDATEINTERVAL = 100 # millisec
|
|
|
|
def __init__(self, editwin):
|
|
"""Initialize settings for context block.
|
|
|
|
editwin is the Editor window for the context block.
|
|
self.text is the editor window text widget.
|
|
|
|
self.context displays the code context text above the editor text.
|
|
Initially None, it is toggled via <<toggle-code-context>>.
|
|
self.topvisible is the number of the top text line displayed.
|
|
self.info is a list of (line number, indent level, line text,
|
|
block keyword) tuples for the block structure above topvisible.
|
|
self.info[0] is initialized with a 'dummy' line which
|
|
starts the toplevel 'block' of the module.
|
|
|
|
self.t1 and self.t2 are two timer events on the editor text widget to
|
|
monitor for changes to the context text or editor font.
|
|
"""
|
|
self.editwin = editwin
|
|
self.text = editwin.text
|
|
self.context = None
|
|
self.topvisible = 1
|
|
self.info = [(0, -1, "", False)]
|
|
self.t1 = None
|
|
|
|
@classmethod
|
|
def reload(cls):
|
|
"Load class variables from config."
|
|
cls.context_depth = idleConf.GetOption("extensions", "CodeContext",
|
|
"maxlines", type="int",
|
|
default=15)
|
|
|
|
def __del__(self):
|
|
"Cancel scheduled events."
|
|
if self.t1 is not None:
|
|
try:
|
|
self.text.after_cancel(self.t1)
|
|
except tkinter.TclError:
|
|
pass
|
|
self.t1 = None
|
|
|
|
def toggle_code_context_event(self, event=None):
|
|
"""Toggle code context display.
|
|
|
|
If self.context doesn't exist, create it to match the size of the editor
|
|
window text (toggle on). If it does exist, destroy it (toggle off).
|
|
Return 'break' to complete the processing of the binding.
|
|
"""
|
|
if self.context is None:
|
|
# Calculate the border width and horizontal padding required to
|
|
# align the context with the text in the main Text widget.
|
|
#
|
|
# All values are passed through getint(), since some
|
|
# values may be pixel objects, which can't simply be added to ints.
|
|
widgets = self.editwin.text, self.editwin.text_frame
|
|
# Calculate the required horizontal padding and border width.
|
|
padx = 0
|
|
border = 0
|
|
for widget in widgets:
|
|
padx += widget.tk.getint(widget.pack_info()['padx'])
|
|
padx += widget.tk.getint(widget.cget('padx'))
|
|
border += widget.tk.getint(widget.cget('border'))
|
|
self.context = tkinter.Text(
|
|
self.editwin.top, font=self.text['font'],
|
|
height=1,
|
|
width=1, # Don't request more than we get.
|
|
padx=padx, border=border, relief=SUNKEN, state='disabled')
|
|
self.update_highlight_colors()
|
|
self.context.bind('<ButtonRelease-1>', self.jumptoline)
|
|
# Pack the context widget before and above the text_frame widget,
|
|
# thus ensuring that it will appear directly above text_frame.
|
|
self.context.pack(side=TOP, fill=X, expand=False,
|
|
before=self.editwin.text_frame)
|
|
menu_status = 'Hide'
|
|
self.t1 = self.text.after(self.UPDATEINTERVAL, self.timer_event)
|
|
else:
|
|
self.context.destroy()
|
|
self.context = None
|
|
self.text.after_cancel(self.t1)
|
|
self.t1 = None
|
|
menu_status = 'Show'
|
|
self.editwin.update_menu_label(menu='options', index='* Code Context',
|
|
label=f'{menu_status} Code Context')
|
|
return "break"
|
|
|
|
def get_context(self, new_topvisible, stopline=1, stopindent=0):
|
|
"""Return a list of block line tuples and the 'last' indent.
|
|
|
|
The tuple fields are (linenum, indent, text, opener).
|
|
The list represents header lines from new_topvisible back to
|
|
stopline with successively shorter indents > stopindent.
|
|
The list is returned ordered by line number.
|
|
Last indent returned is the smallest indent observed.
|
|
"""
|
|
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 linenum in range(new_topvisible, stopline-1, -1):
|
|
codeline = self.text.get(f'{linenum}.0', f'{linenum}.end')
|
|
indent, text, opener = get_line_info(codeline)
|
|
if indent < lastindent:
|
|
lastindent = indent
|
|
if opener in ("else", "elif"):
|
|
# Also show the if statement.
|
|
lastindent += 1
|
|
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_code_context(self):
|
|
"""Update context information and lines visible in the context pane.
|
|
|
|
No update is done if the text hasn't been scrolled. If the text
|
|
was scrolled, the lines that should be shown in the context will
|
|
be retrieved and the context area will be updated with the code,
|
|
up to the number of maxlines.
|
|
"""
|
|
new_topvisible = self.editwin.getlineno("@0,0")
|
|
if self.topvisible == new_topvisible: # Haven't scrolled.
|
|
return
|
|
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]
|
|
else: # self.topvisible > new_topvisible: # Scroll up.
|
|
stopindent = self.info[-1][1] + 1
|
|
# 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.get_context(new_topvisible,
|
|
self.info[-1][0]+1,
|
|
stopindent)
|
|
self.info.extend(lines)
|
|
self.topvisible = new_topvisible
|
|
# Last context_depth context lines.
|
|
context_strings = [x[2] for x in self.info[-self.context_depth:]]
|
|
showfirst = 0 if context_strings[0] else 1
|
|
# Update widget.
|
|
self.context['height'] = len(context_strings) - showfirst
|
|
self.context['state'] = 'normal'
|
|
self.context.delete('1.0', 'end')
|
|
self.context.insert('end', '\n'.join(context_strings[showfirst:]))
|
|
self.context['state'] = 'disabled'
|
|
|
|
def jumptoline(self, event=None):
|
|
"Show clicked context line at top of editor."
|
|
lines = len(self.info)
|
|
if lines == 1: # No context lines are showing.
|
|
newtop = 1
|
|
else:
|
|
# Line number clicked.
|
|
contextline = int(float(self.context.index('insert')))
|
|
# Lines not displayed due to maxlines.
|
|
offset = max(1, lines - self.context_depth) - 1
|
|
newtop = self.info[offset + contextline][0]
|
|
self.text.yview(f'{newtop}.0')
|
|
self.update_code_context()
|
|
|
|
def timer_event(self):
|
|
"Event on editor text widget triggered every UPDATEINTERVAL ms."
|
|
if self.context is not None:
|
|
self.update_code_context()
|
|
self.t1 = self.text.after(self.UPDATEINTERVAL, self.timer_event)
|
|
|
|
def update_font(self, font):
|
|
if self.context is not None:
|
|
self.context['font'] = font
|
|
|
|
def update_highlight_colors(self):
|
|
if self.context is not None:
|
|
colors = idleConf.GetHighlight(idleConf.CurrentTheme(), 'context')
|
|
self.context['background'] = colors['background']
|
|
self.context['foreground'] = colors['foreground']
|
|
|
|
|
|
CodeContext.reload()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
from unittest import main
|
|
main('idlelib.idle_test.test_codecontext', verbosity=2, exit=False)
|
|
|
|
# Add htest.
|