1QLayoutIterator(3qt)                                      QLayoutIterator(3qt)
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3
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NAME

6       QLayoutIterator - Iterators over QLayoutItem
7

SYNOPSIS

9       #include <qlayout.h>
10
11   Public Members
12       QLayoutIterator ( QGLayoutIterator * gi )
13       QLayoutIterator ( const QLayoutIterator & i )
14       ~QLayoutIterator ()
15       QLayoutIterator & operator= ( const QLayoutIterator & i )
16       QLayoutItem * operator++ ()
17       QLayoutItem * current ()
18       QLayoutItem * takeCurrent ()
19       void deleteCurrent ()
20

DESCRIPTION

22       The QLayoutIterator class provides iterators over QLayoutItem.
23
24       Use QLayoutItem::iterator() to create an iterator over a layout.
25
26       QLayoutIterator uses explicit sharing with a reference count. If an
27       iterator is copied and one of the copies is modified, both iterators
28       will be modified.
29
30       A QLayoutIterator is not protected against changes in its layout. If
31       the layout is modified or deleted the iterator will become invalid. It
32       is not possible to test for validity. It is safe to delete an invalid
33       layout; any other access may lead to an illegal memory reference and
34       the abnormal termination of the program.
35
36       Calling takeCurrent() or deleteCurrent() leaves the iterator in a valid
37       state, but may invalidate any other iterators that access the same
38       layout.
39
40       The following code will draw a rectangle for each layout item in the
41       layout structure of the widget.
42
43           static void paintLayout( QPainter *p, QLayoutItem *lay )
44           {
45               QLayoutIterator it = lay->iterator();
46               QLayoutItem *child;
47               while ( (child = it.current()) != 0 ) {
48                   paintLayout( p, child );
49                   ++it;
50               }
51               p->drawRect( lay->geometry() );
52           }
53           void ExampleWidget::paintEvent( QPaintEvent * )
54           {
55               QPainter p( this );
56               if ( layout() )
57                   paintLayout( &p, layout() );
58           }
59
60       All the functionality of QLayoutIterator is implemented by subclasses
61       of QGLayoutIterator. QLayoutIterator itself is not designed to be
62       subclassed.
63
64       See also Widget Appearance and Style and Layout Management.
65

MEMBER FUNCTION DOCUMENTATION

QLayoutIterator::QLayoutIterator ( QGLayoutIterator * gi )
68       Constructs an iterator based on gi. The constructed iterator takes
69       ownership of gi and will delete it.
70
71       This constructor is provided for layout implementors. Application
72       programmers should use QLayoutItem::iterator() to create an iterator
73       over a layout.
74

QLayoutIterator::QLayoutIterator ( const QLayoutIterator & i )
76       Creates a shallow copy of i, i.e. if the copy is modified, then the
77       original will also be modified.
78

QLayoutIterator::~QLayoutIterator ()
80       Destroys the iterator.
81

QLayoutItem * QLayoutIterator::current ()
83       Returns the current item, or 0 if there is no current item.
84

void QLayoutIterator::deleteCurrent ()
86       Removes and deletes the current child item from the layout and moves
87       the iterator to the next item. This iterator will still be valid, but
88       any other iterator over the same layout may become invalid.
89

QLayoutItem * QLayoutIterator::operator++ ()
91       Moves the iterator to the next child item and returns that item, or 0
92       if there is no such item.
93

QLayoutIterator & QLayoutIterator::operator= ( const QLayoutIterator & i )
95       Assigns i to this iterator and returns a reference to this iterator.
96

QLayoutItem * QLayoutIterator::takeCurrent ()
98       Removes the current child item from the layout without deleting it, and
99       moves the iterator to the next item. Returns the removed item, or 0 if
100       there was no item to be removed. This iterator will still be valid, but
101       any other iterator over the same layout may become invalid.
102
103

SEE ALSO
105       http://doc.trolltech.com/qlayoutiterator.html
106       http://www.trolltech.com/faq/tech.html
107

109       Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com.  See the
110       license file included in the distribution for a complete license
111       statement.
112

AUTHOR
114       Generated automatically from the source code.
115

BUGS
117       If you find a bug in Qt, please report it as described in
118       http://doc.trolltech.com/bughowto.html.  Good bug reports help us to
119       help you. Thank you.
120
121       The definitive Qt documentation is provided in HTML format; it is
122       located at $QTDIR/doc/html and can be read using Qt Assistant or with a
123       web browser. This man page is provided as a convenience for those users
124       who prefer man pages, although this format is not officially supported
125       by Trolltech.
126
127       If you find errors in this manual page, please report them to qt-
128       bugs@trolltech.com.  Please include the name of the manual page
129       (qlayoutiterator.3qt) and the Qt version (3.3.8).
130
131
132
133Trolltech AS                    2 February 2007           QLayoutIterator(3qt)



        

    


            
        

        

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