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46 // This file is not part of the Qt API. It exists purely as an
47 // implementation detail. This header file may change from version to
48 // version without notice, or even be removed.
52 #ifndef Patternist_Focus_H
53 #define Patternist_Focus_H
55 #include <private/qdelegatingdynamiccontext_p.h>
64 * @short A DynamicContext that maintains the focus, a sequence
67 * Focus implements both the outer and inner focus. The focus is one of
68 * the things that characterizes the XPath language. The focus is what's
69 * iterated over in a predicate, whose current item can be received
70 * via the context item expression, <tt>.</tt>(the dot),
71 * and whose size is retrievable via the function <tt>fn:last()</tt>.
73 * @author Frans Englich <frans.englich@nokia.com>
75 class Focus : public DelegatingDynamicContext
78 Focus(const DynamicContext::Ptr &prevContext);
80 virtual xsInteger contextPosition() const;
81 virtual Item contextItem() const;
82 virtual xsInteger contextSize();
84 virtual void setFocusIterator(const Item::Iterator::Ptr &it);
85 virtual Item::Iterator::Ptr focusIterator() const;
88 * If there is no top level expression that sets the current item,
89 * the focus should be used. This implementation ensures that.
91 virtual Item currentItem() const;
94 Item::Iterator::Ptr m_focusIterator;
95 xsInteger m_contextSizeCached;