summaryrefslogtreecommitdiffstats
path: root/Lib/idlelib/help.py
blob: 562551b685256093e610f3263149f0b948111248 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
""" 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() + '\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)