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
|
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en_US" lang="en_US">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- basictypes.qdoc -->
<title>Qt 4.8: QML Basic Type: list</title>
<link rel="stylesheet" type="text/css" href="style/offline.css" />
</head>
<body>
<div class="header" id="qtdocheader">
<div class="content">
<a href="index.html" class="qtref"><span>Qt Reference Documentation</span></a>
</div>
<div class="breadcrumb toolblock">
<ul>
<li class="first"><a href="index.html">Home</a></li>
<!-- Breadcrumbs go here -->
</ul>
</div>
</div>
<div class="content mainContent">
<h1 class="title">QML Basic Type: list</h1>
<span class="subtitle"></span>
<!-- $$$list-description -->
<div class="descr"> <a name="details"></a>
<p>A list type contains a list of objects. While not technically a basic type, QML supports lists of object types. When used from QML, the engine automatically appends each value to the list. Items in the list can be accessed by index using the usual <tt>listName[index]</tt> syntax.</p>
<p>For example, the <a href="qml-item.html">Item</a> class contains a list property named children that can be used like this:</p>
<pre class="qml"> <span class="type"><a href="qml-item.html">Item</a></span> {
<span class="name">children</span>: [
<span class="type"><a href="qml-item.html">Item</a></span> { <span class="name">id</span>: <span class="name">child1</span> },
<span class="type"><a href="qml-rectangle.html">Rectangle</a></span> { <span class="name">id</span>: <span class="name">child2</span>; <span class="name">width</span>: <span class="number">200</span> },
<span class="type"><a href="qml-text.html">Text</a></span> { <span class="name">id</span>: <span class="name">child3</span> }
]
<span class="name">Component</span>.onCompleted: {
<span class="name">console</span>.<span class="name">log</span>(<span class="string">"Width of child rectangle:"</span>, <span class="name">children</span>[<span class="number">1</span>].<span class="name">width</span>)
}
}</pre>
<p><tt>child1</tt>, <tt>child2</tt> and <tt>child3</tt> will be added to the children list in the order in which they appear.</p>
<p>List <a href="propertybinding.html">properties</a> can be created as a <tt>variant</tt> type, or as a <tt>list<Type></tt> type, where <tt>Type</tt> is the type of the object in the list:</p>
<pre class="qml"> <span class="type"><a href="qml-item.html">Item</a></span> {
property list<<span class="type"><a href="qml-rectangle.html">Rectangle</a></span>> <span class="name">rects</span>: [
<span class="type"><a href="qml-rectangle.html">Rectangle</a></span> { <span class="name">width</span>: <span class="number">100</span>; <span class="name">height</span>: <span class="number">100</span>},
<span class="type"><a href="qml-rectangle.html">Rectangle</a></span> { <span class="name">width</span>: <span class="number">200</span>; <span class="name">height</span>: <span class="number">200</span>}
]
}</pre>
<p>A list property can only contain values that match (or are derived from) the specified <tt>Type</tt>.</p>
<p>While the <tt>rects</tt> property can be reassigned to a different list value (including an empty list), its individual values cannot be modified. See the <a href="qml-variant.html">variant</a> type documentation for details.</p>
</div>
<p><b>See also </b><a href="qdeclarativebasictypes.html">QML Basic Types</a>.</p>
<!-- @@@list -->
<div class="ft">
<span></span>
</div>
</div>
<div class="footer">
<p>
<acronym title="Copyright">©</acronym> 2012 Nokia Corporation and/or its
subsidiaries. Documentation contributions included herein are the copyrights of
their respective owners.</p>
<br />
<p>
The documentation provided herein is licensed under the terms of the
<a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation
License version 1.3</a> as published by the Free Software Foundation.</p>
<p>
Documentation sources may be obtained from <a href="http://www.qt-project.org">
www.qt-project.org</a>.</p>
<br />
<p>
Nokia, Qt and their respective logos are trademarks of Nokia Corporation
in Finland and/or other countries worldwide. All other trademarks are property
of their respective owners. <a title="Privacy Policy"
href="http://en.gitorious.org/privacy_policy/">Privacy Policy</a></p>
</div>
</body>
</html>
|
