""" help.py: Implement the Idle help menu. Contents are subject to revision at any time, without notice. Help => About IDLE: diplay About Idle dialog 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, Frame, Text, Menu from tkinter.ttk import Menubutton, Scrollbar from tkinter import font as tkfont from idlelib.config import idleConf ## 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 # 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 = '' # prefix such as '25.5' to strip from headings self.nested_dl = False # if we're in a nested

self.simplelist = False # simple list (no double spacing) self.toc = [] # pair headers with text indexes for toc self.header = '' # text 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.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* ' 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.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)) def handle_endtag(self, tag): "Handle endtags in help.html." if tag in ['h1', 'h2', 'h3']: self.indent(0) # clear tag, reset indent if self.show: indent = (' ' if tag == 'h3' else ' ' if tag == 'h2' else '') self.toc.append((indent+self.header, self.text.index('insert'))) 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(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': 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']) 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), background='#f6f6ff') 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) # keep references to widgets for test access. self.text = text = HelpText(self, filename) self['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) # text 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) 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. 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 proceedure 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): # try copy_strip, present message return HelpWindow(parent, filename, 'IDLE Help (%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)