cpython/Lib/idlelib/help.py

251 lines
9.4 KiB
Python

""" help.py: Implement the Idle help menu.
Contents are subject to revision at any time, without notice.
Help => About IDLE: diplay About Idle dialog
<to be moved here from aboutDialog.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 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, isdir, isfile, join
from tkinter import Tk, Toplevel, Frame, Text, Scrollbar, Menu, Menubutton
from tkinter import font as tkfont
use_ttk = False # until available to import
if use_ttk:
from tkinter.ttk import Menubutton
## 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.
"""
def __init__(self, text):
HTMLParser.__init__(self, convert_charrefs=True)
self.text = text # text widget we're rendering into
self.tags = '' # current text tags to apply
self.show = False # used so we exclude page navigation
self.hdrlink = False # used so we don't show header links
self.level = 0 # indentation level
self.pre = False # displaying preformatted text
self.hprefix = '' # strip e.g. '25.5' from headings
self.nested_dl = False # if we're in a nested <dl>
self.simplelist = False # simple list (no double spacing)
self.tocid = 1 # id for table of contents entries
self.contents = [] # map toc ids to section titles
self.data = '' # to record data within header tags for toc
def indent(self, amt=1):
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 == 'div' and class_ == 'section':
self.show = True # start of main content
elif tag == 'div' and class_ == 'sphinxsidebar':
self.show = False # end of main content
elif tag == 'p' and class_ != 'first':
s = '\n\n'
elif tag == 'span' and class_ == 'pre':
self.tags = 'pre'
elif tag == 'span' and class_ == 'versionmodified':
self.tags = 'em'
elif tag == 'em':
self.tags = '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* ' if self.simplelist else '\n\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.text.mark_set('toc'+str(self.tocid),
self.text.index('end-1line'))
self.tags = tag
elif tag in ['h2', 'h3']:
if self.show:
self.data = ''
self.text.mark_set('toc'+str(self.tocid),
self.text.index('end-1line'))
self.text.insert('end', '\n\n')
self.tags = tag
if self.show:
self.text.insert('end', s, self.tags)
def handle_endtag(self, tag):
"Handle endtags in help.html."
if tag in ['h1', 'h2', 'h3', 'span', 'em']:
self.indent(0) # clear tag, reset indent
if self.show and tag in ['h1', 'h2', 'h3']:
title = self.data
self.contents.append(('toc'+str(self.tocid), title))
self.tocid += 1
elif tag == 'a':
self.hdrlink = False
elif tag == 'pre':
self.pre = False
self.tags = ''
elif tag in ['ul', 'dd', 'ol']:
self.indent(amt=-1)
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':
self.hprefix = d[0:d.index(' ')]
if self.tags in ['h1', 'h2', 'h3'] and self.hprefix != '':
if d[0:len(self.hprefix)] == self.hprefix:
d = d[len(self.hprefix):].strip()
self.data += d
self.text.insert('end', d, self.tags)
class HelpText(Text):
"Display help.html."
def __init__(self, parent, filename):
"Configure tags and feed file to parser."
Text.__init__(self, parent, wrap='word', highlightthickness=0,
padx=5, borderwidth=0)
normalfont = self.findfont(['TkDefaultFont', 'arial', 'helvetica'])
fixedfont = self.findfont(['TkFixedFont', 'monaco', 'courier'])
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))
self.tag_configure('preblock', font=(fixedfont, 10), lmargin1=25,
borderwidth=1, relief='solid', background='#eeffcc')
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)
text = HelpText(self, filename)
self['background'] = text['background']
scroll = Scrollbar(self, command=text.yview)
text['yscrollcommand'] = scroll.set
text.grid(column=1, row=0, sticky='nsew')
scroll.grid(column=2, row=0, sticky='ns')
self.grid_columnconfigure(1, weight=1)
self.grid_rowconfigure(0, weight=1)
toc = self.contents_widget(text)
toc.grid(column=0, row=0, sticky='nw')
def contents_widget(self, text):
"Create table of contents."
toc = Menubutton(self, text='TOC')
drop = Menu(toc, tearoff=False)
for tag, lbl in text.parser.contents:
drop.add_command(label=lbl, command=lambda mark=tag:text.see(mark))
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)
HelpFrame(self, filename).grid(column=0, row=0, sticky='nsew')
self.grid_columnconfigure(0, weight=1)
self.grid_rowconfigure(0, weight=1)
def copy_strip():
"Copy idle.html to idlelib/help.html, stripping trailing whitespace."
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('idle.html copied to help.html')
def show_idlehelp(parent):
"Create HelpWindow; called from Idle Help event handler."
filename = join(abspath(dirname(__file__)), 'help.html')
if not isfile(filename):
# try copy_strip, present message
return
HelpWindow(parent, filename, 'IDLE Help')
if __name__ == '__main__':
from idlelib.idle_test.htest import run
run(show_idlehelp)