1 """
2 CSSRuleList implements DOM Level 2 CSS CSSRuleList.
3
4 Partly also
5 * http://dev.w3.org/csswg/cssom/#the-cssrulelist
6 """
7 __all__ = ['CSSRuleList']
8 __docformat__ = 'restructuredtext'
9 __version__ = '$Id: cssrulelist.py 1116 2008-03-05 13:52:23Z cthedot $'
10
12 """
13 The CSSRuleList object represents an (ordered) list of statements.
14
15 The items in the CSSRuleList are accessible via an integral index,
16 starting from 0.
17
18 Subclasses a standard Python list so theoretically all standard list
19 methods are available. Setting methods like ``__init__``, ``append``,
20 ``extend`` or ``__setslice__`` are added later on instances of this
21 class if so desired.
22 E.g. CSSStyleSheet adds ``append`` which is not available in a simple
23 instance of this class!
24
25 Properties
26 ==========
27 length: of type unsigned long, readonly
28 The number of CSSRules in the list. The range of valid child rule
29 indices is 0 to length-1 inclusive.
30 """
32 "nothing is set as this must also be defined later"
33 pass
34
36 "no direct setting possible"
37 raise NotImplementedError(
38 'Must be implemented by class using an instance of this class.')
39
40 append = extend = __setitem__ = __setslice__ = __notimplemented
41
42 - def item(self, index):
43 """
44 (DOM)
45 Used to retrieve a CSS rule by ordinal index. The order in this
46 collection represents the order of the rules in the CSS style
47 sheet. If index is greater than or equal to the number of rules in
48 the list, this returns None.
49
50 Returns CSSRule, the style rule at the index position in the
51 CSSRuleList, or None if that is not a valid index.
52 """
53 try:
54 return self[index]
55 except IndexError:
56 return None
57
58 length = property(lambda self: len(self),
59 doc="(DOM) The number of CSSRules in the list.")
60