""" help.py: Implement the Idle help menu.
Contents are subject to revision at any time, without notice.
Help => About IDLE: display About Idle dialog
<to be moved here from help_about.py>
Help => IDLE Help: Display help.html with proper formatting.
Doc/library/idle.rst (Sphinx)=> Doc/build/html/library/idle.html
(help.copy_strip)=> Lib/idlelib/help.html
HelpParser - Parse help.html and render to tk Text.
HelpText - Display formatted help.html.
HelpFrame - Contain text, scrollbar, and table-of-contents.
(This will be needed for display in a future tabbed window.)
HelpWindow - Display HelpFrame in a standalone window.
copy_strip - Copy idle.html to help.html, rstripping each line.
show_idlehelp - Create HelpWindow. Called in EditorWindow.help_dialog.
"""
from html.parser import HTMLParser
from os.path import abspath, dirname, isfile, join
from platform import python_version
from tkinter import Toplevel, Text, Menu
from tkinter.ttk import Frame, Menubutton, Scrollbar, Style
from tkinter import font as tkfont
from idlelib.config import idleConf
from idlelib.colorizer import color_config
## About IDLE ##
## IDLE Help ##
class HelpParser(HTMLParser):
"""Render help.html into a text widget.
The overridden handle_xyz methods handle a subset of html tags.
The supplied text should have the needed tag configurations.
The behavior for unsupported tags, such as table, is undefined.
If the tags generated by Sphinx change, this class, especially
the handle_starttag and handle_endtags methods, might have to also.
"""
def __init__(self, text):
HTMLParser.__init__(self, convert_charrefs=True)
self.text = text # Text widget we're rendering into.
self.tags = '' # Current block level text tags to apply.
self.chartags = '' # Current character level text tags.
self.show = False # Exclude html page navigation.
self.hdrlink = False # Exclude html header links.
self.level = 0 # Track indentation level.
self.pre = False # Displaying preformatted text?
self.hprefix = '' # Heading prefix (like '25.5'?) to remove.
self.nested_dl = False # In a nested <dl>?
self.simplelist = False # In a simple list (no double spacing)?
self.toc = [] # Pair headers with text indexes for toc.
self.header = '' # Text within header tags for toc.
self.prevtag = None # Previous tag info (opener?, tag).
def indent(self, amt=1):
"Change indent (+1, 0, -1) and tags."
self.level += amt
self.tags = '' if self.level == 0 else 'l'+str(self.level)
def handle_starttag(self, tag, attrs):
"Handle starttags in help.html."
class_ = ''
for a, v in attrs:
if a == 'class':
class_ = v
s = ''
if tag == 'section' and attrs == [('id', 'idle')]:
self.show = True # Start main content.
elif tag == 'div' and class_ == 'clearer':
self.show = False # End main content.
elif tag == 'p' and self.prevtag and not self.prevtag[0]:
# Begin a new block for <p> tags after a closed tag.
# Avoid extra lines, e.g. after <pre> tags.
lastline = self.text.get('end-1c linestart', 'end-1c')
s = '\n\n' if lastline and not lastline.isspace() else '\n'
elif tag == 'span' and class_ == 'pre':
self.chartags = 'pre'
elif tag == 'span' and class_ == 'versionmodified':
self.chartags = 'em'
elif tag == 'em':
self.chartags = 'em'
elif tag in ['ul', 'ol']:
if class_.find('simple') != -1:
s = '\n'
self.simplelist = True
else:
self.simplelist = False
self.indent()
elif tag == 'dl':
if self.level > 0:
self.nested_dl = True
elif tag == 'li':
s = '\n* '
elif tag == 'dt':
s = '\n\n' if not self.nested_dl else '\n' # Avoid extra line.
self.nested_dl = False
elif tag == 'dd':
self.indent()
s = '\n'
elif tag == 'pre':
self.pre = True
if self.show:
self.text.insert('end', '\n\n')
self.tags = 'preblock'
elif tag == 'a' and class_ == 'headerlink':
self.hdrlink = True
elif tag == 'h1':
self.tags = tag
elif tag in ['h2', 'h3']:
if self.show:
self.header = ''
self.text.insert('end', '\n\n')
self.tags = tag
if self.show:
self.text.insert('end', s, (self.tags, self.chartags))
self.prevtag = (True, tag)
def handle_endtag(self, tag):
"Handle endtags in help.html."
if tag in ['h1', 'h2', 'h3']:
assert self.level == 0
if self.show:
indent = (' ' if tag == 'h3' else
' ' if tag == 'h2' else
'')
self.toc.append((indent+self.header, self.text.index('insert')))
self.tags = ''
elif tag in ['span', 'em']:
self.chartags = ''
elif tag == 'a':
self.hdrlink = False
elif tag == 'pre':
self.pre = False
self.tags = ''
elif tag in ['ul', 'dd', 'ol']:
self.indent(-1)
self.prevtag = (False, tag)
def handle_data(self, data):
"Handle date segments in help.html."
if self.show and not self.hdrlink:
d = data if self.pre else data.replace('\n', ' ')
if self.tags == 'h1':
try:
self.hprefix = d[0:d.index(' ')]
except ValueError:
self.hprefix = ''
if self.tags in ['h1', 'h2', 'h3']:
if (self.hprefix != '' and
d[0:len(self.hprefix)] == self.hprefix):
d = d[len(self.hprefix):]
self.header += d.strip()
self.text.insert('end', d, (self.tags, self.chartags))
class HelpText(Text):
"Display help.html."
def __init__(self, parent, filename):
"Configure tags and feed file to parser."
uwide = idleConf.GetOption('main', 'EditorWindow', 'width', type='int')
uhigh = idleConf.GetOption('main', 'EditorWindow', 'height', type='int')
uhigh = 3 * uhigh // 4 # Lines average 4/3 of editor line height.
Text.__init__(self, parent, wrap='word', highlightthickness=0,
padx=5, borderwidth=0, width=uwide, height=uhigh)
normalfont = self.findfont(['TkDefaultFont', 'arial', 'helvetica'])
fixedfont = self.findfont(['TkFixedFont', 'monaco', 'courier'])
color_config(self)
self['font'] = (normalfont, 12)
self.tag_configure('em', font=(normalfont, 12, 'italic'))
self.tag_configure('h1', font=(normalfont, 20, 'bold'))
self.tag_configure('h2', font=(normalfont, 18, 'bold'))
self.tag_configure('h3', font=(normalfont, 15, 'bold'))
self.tag_configure('pre', font=(fixedfont, 12))
preback = self['selectbackground']
self.tag_configure('preblock', font=(fixedfont, 10), lmargin1=25,
background=preback)
self.tag_configure('l1', lmargin1=25, lmargin2=25)
self.tag_configure('l2', lmargin1=50, lmargin2=50)
self.tag_configure('l3', lmargin1=75, lmargin2=75)
self.tag_configure('l4', lmargin1=100, lmargin2=100)
self.parser = HelpParser(self)
with open(filename, encoding='utf-8') as f:
contents = f.read()
self.parser.feed(contents)
self['state'] = 'disabled'
def findfont(self, names):
"Return name of first font family derived from names."
for name in names:
if name.lower() in (x.lower() for x in tkfont.names(root=self)):
font = tkfont.Font(name=name, exists=True, root=self)
return font.actual()['family']
elif name.lower() in (x.lower()
for x in tkfont.families(root=self)):
return name
class HelpFrame(Frame):
"Display html text, scrollbar, and toc."
def __init__(self, parent, filename):
Frame.__init__(self, parent)
self.text = text = HelpText(self, filename)
self.style = Style(parent)
self['style'] = 'helpframe.TFrame'
self.style.configure('helpframe.TFrame', background=text['background'])
self.toc = toc = self.toc_menu(text)
self.scroll = scroll = Scrollbar(self, command=text.yview)
text['yscrollcommand'] = scroll.set
self.rowconfigure(0, weight=1)
self.columnconfigure(1, weight=1) # Only expand the text widget.
toc.grid(row=0, column=0, sticky='nw')
text.grid(row=0, column=1, sticky='nsew')
scroll.grid(row=0, column=2, sticky='ns')
def toc_menu(self, text):
"Create table of contents as drop-down menu."
toc = Menubutton(self, text='TOC')
drop = Menu(toc, tearoff=False)
for lbl, dex in text.parser.toc:
drop.add_command(label=lbl, command=lambda dex=dex:text.yview(dex))
toc['menu'] = drop
return toc
class HelpWindow(Toplevel):
"Display frame with rendered html."
def __init__(self, parent, filename, title):
Toplevel.__init__(self, parent)
self.wm_title(title)
self.protocol("WM_DELETE_WINDOW", self.destroy)
self.frame = HelpFrame(self, filename)
self.frame.grid(column=0, row=0, sticky='nsew')
self.grid_columnconfigure(0, weight=1)
self.grid_rowconfigure(0, weight=1)
def copy_strip(): # pragma: no cover
"""Copy idle.html to idlelib/help.html, stripping trailing whitespace.
Files with trailing whitespace cannot be pushed to the git cpython
repository. For 3.x (on Windows), help.html is generated, after
editing idle.rst on the master branch, with
sphinx-build -bhtml . build/html
python_d.exe -c "from idlelib.help import copy_strip; copy_strip()"
Check build/html/library/idle.html, the help.html diff, and the text
displayed by Help => IDLE Help. Add a blurb and create a PR.
It can be worthwhile to occasionally generate help.html without
touching idle.rst. Changes to the master version and to the doc
build system may result in changes that should not changed
the displayed text, but might break HelpParser.
As long as master and maintenance versions of idle.rst remain the
same, help.html can be backported. The internal Python version
number is not displayed. If maintenance idle.rst diverges from
the master version, then instead of backporting help.html from
master, repeat the procedure above to generate a maintenance
version.
"""
src = join(abspath(dirname(dirname(dirname(__file__)))),
'Doc', 'build', 'html', 'library', 'idle.html')
dst = join(abspath(dirname(__file__)), 'help.html')
with open(src, 'rb') as inn,\
open(dst, 'wb') as out:
for line in inn:
out.write(line.rstrip() + b'\n')
print(f'{src} copied to {dst}')
def show_idlehelp(parent):
"Create HelpWindow; called from Idle Help event handler."
filename = join(abspath(dirname(__file__)), 'help.html')
if not isfile(filename): # pragma: no cover
# Try copy_strip, present message.
return
return HelpWindow(parent, filename, 'IDLE Doc (%s)' % python_version())
if __name__ == '__main__':
from unittest import main
main('idlelib.idle_test.test_help', verbosity=2, exit=False)
from idlelib.idle_test.htest import run
run(show_idlehelp)
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