""" 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 the text part of idle.html to help.html while rstripping each line.

show_idlehelp - Create HelpWindow. Called in EditorWindow.help_dialog.

_get_dochome() - Return path to docs on user's system if present,

otherwise return link to docs.python.org.

"""

import os

import sys

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.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 == '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

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']:

self.header = ''

self.text.insert('end', '\n\n')

self.tags = tag

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

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 not self.hdrlink:

d = data if self.pre else data.replace('\n', ' ')

if self.tags == 'h1':

try:

self.hprefix = d[:d.index(' ')]

if not self.hprefix.isdigit():

self.hprefix = ''

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 the text part of idle.html to idlelib/help.html while 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 change

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, 'r', encoding="utf-8") as inn, open(dst, 'w', encoding="utf-8") as out:

copy = False

for line in inn:

if '<section id="idle">' in line: copy = True

if '<div class="clearer">' in line: break

if copy: out.write(line.strip() + '\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())

def _get_dochome():

"Return path to local docs if present, otherwise link to docs.python.org."

dochome = os.path.join(sys.base_prefix, 'Doc', 'index.html')

if sys.platform.count('linux'):

# look for html docs in a couple of standard places

pyver = 'python-docs-' + '%s.%s.%s' % sys.version_info[:3]

if os.path.isdir('/var/www/html/python/'): # rpm package manager

dochome = '/var/www/html/python/index.html'

else:

basepath = '/usr/share/doc/' # dnf/apt package managers

dochome = os.path.join(basepath, pyver, 'Doc', 'index.html')

elif sys.platform[:3] == 'win':

import winreg # Windows only, block only executed once.

docfile = ''

KEY = (rf"Software\Python\PythonCore\{sys.winver}"

r"\Help\Main Python Documentation")

try:

docfile = winreg.QueryValue(winreg.HKEY_CURRENT_USER, KEY)

except FileNotFoundError:

try:

docfile = winreg.QueryValue(winreg.HKEY_LOCAL_MACHINE, KEY)

except FileNotFoundError:

pass

if os.path.isfile(docfile):

dochome = docfile

elif sys.platform == 'darwin':

# documentation may be stored inside a python framework

dochome = os.path.join(sys.base_prefix,

'Resources/English.lproj/Documentation/index.html')

dochome = os.path.normpath(dochome)

if os.path.isfile(dochome):

if sys.platform == 'darwin':

# Safari requires real file:-URLs

return 'file://' + dochome

return dochome

else:

return "https://docs.python.org/%d.%d/" % sys.version_info[:2]

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)