<?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" />
<!-- hierarchy.qdoc -->
<title>Qt 4.8: Hierarchy Example (ActiveQt)</title>
<link rel="stylesheet" type="text/css" href="style/style.css" />
<script src="scripts/jquery.js" type="text/javascript"></script>
<script src="scripts/functions.js" type="text/javascript"></script>
<link rel="stylesheet" type="text/css" href="style/superfish.css" />
<link rel="stylesheet" type="text/css" href="style/narrow.css" />
<!--[if IE]>
<meta name="MSSmartTagsPreventParsing" content="true">
<meta http-equiv="imagetoolbar" content="no">
<![endif]-->
<!--[if lt IE 7]>
<link rel="stylesheet" type="text/css" href="style/style_ie6.css">
<![endif]-->
<!--[if IE 7]>
<link rel="stylesheet" type="text/css" href="style/style_ie7.css">
<![endif]-->
<!--[if IE 8]>
<link rel="stylesheet" type="text/css" href="style/style_ie8.css">
<![endif]-->
<script src="scripts/superfish.js" type="text/javascript"></script>
<script src="scripts/narrow.js" type="text/javascript"></script>
</head>
<body class="" onload="CheckEmptyAndLoadList();">
<div class="header" id="qtdocheader">
<div class="content">
<div id="nav-logo">
<a href="index.html">Home</a></div>
<a href="index.html" class="qtref"><span>Qt Reference Documentation</span></a>
<div id="narrowsearch"></div>
<div id="nav-topright">
<ul>
<li class="nav-topright-home"><a href="http://qt.digia.com/">Qt HOME</a></li>
<li class="nav-topright-dev"><a href="http://qt-project.org/">DEV</a></li>
<li class="nav-topright-doc nav-topright-doc-active"><a href="http://qt-project.org/doc/">
DOC</a></li>
<li class="nav-topright-blog"><a href="http://blog.qt.digia.com/">BLOG</a></li>
</ul>
</div>
<div id="shortCut">
<ul>
<li class="shortCut-topleft-inactive"><span><a href="index.html">Qt 4.8</a></span></li>
<li class="shortCut-topleft-active"><a href="http://qt-project.org/doc/">ALL VERSIONS </a></li>
</ul>
</div>
<ul class="sf-menu" id="narrowmenu">
<li><a href="#">API Lookup</a>
<ul>
<li><a href="classes.html">Class index</a></li>
<li><a href="functions.html">Function index</a></li>
<li><a href="modules.html">Modules</a></li>
<li><a href="namespaces.html">Namespaces</a></li>
<li><a href="qtglobal.html">Global Declarations</a></li>
<li><a href="qdeclarativeelements.html">QML elements</a></li>
</ul>
</li>
<li><a href="#">Qt Topics</a>
<ul>
<li><a href="qt-basic-concepts.html">Programming with Qt</a></li>
<li><a href="qtquick.html">Device UIs & Qt Quick</a></li>
<li><a href="qt-gui-concepts.html">UI Design with Qt</a></li>
<li><a href="supported-platforms.html">Supported Platforms</a></li>
<li><a href="technology-apis.html">Qt and Key Technologies</a></li>
<li><a href="best-practices.html">How-To's and Best Practices</a></li>
</ul>
</li>
<li><a href="#">Examples</a>
<ul>
<li><a href="all-examples.html">Examples</a></li>
<li><a href="tutorials.html">Tutorials</a></li>
<li><a href="demos.html">Demos</a></li>
<li><a href="qdeclarativeexamples.html">QML Examples</a></li>
</ul>
</li>
</ul>
</div>
</div>
<div class="wrapper">
<div class="hd">
<span></span>
</div>
<div class="bd group">
<div class="sidebar">
<div class="searchlabel">
Search index:</div>
<div class="search" id="sidebarsearch">
<form id="qtdocsearch" action="" onsubmit="return false;">
<fieldset>
<input type="text" name="searchstring" id="pageType" value="" />
<div id="resultdialog">
<a href="#" id="resultclose">Close</a>
<p id="resultlinks" class="all"><a href="#" id="showallresults">All</a> | <a href="#" id="showapiresults">API</a> | <a href="#" id="showarticleresults">Articles</a> | <a href="#" id="showexampleresults">Examples</a></p>
<p id="searchcount" class="all"><span id="resultcount"></span><span id="apicount"></span><span id="articlecount"></span><span id="examplecount"></span> results:</p>
<ul id="resultlist" class="all">
</ul>
</div>
</fieldset>
</form>
</div>
<div class="box first bottombar" id="lookup">
<h2 title="API Lookup"><span></span>
API Lookup</h2>
<div id="list001" class="list">
<ul id="ul001" >
<li class="defaultLink"><a href="classes.html">Class index</a></li>
<li class="defaultLink"><a href="functions.html">Function index</a></li>
<li class="defaultLink"><a href="modules.html">Modules</a></li>
<li class="defaultLink"><a href="namespaces.html">Namespaces</a></li>
<li class="defaultLink"><a href="qtglobal.html">Global Declarations</a></li>
<li class="defaultLink"><a href="qdeclarativeelements.html">QML elements</a></li>
</ul>
</div>
</div>
<div class="box bottombar" id="topics">
<h2 title="Qt Topics"><span></span>
Qt Topics</h2>
<div id="list002" class="list">
<ul id="ul002" >
<li class="defaultLink"><a href="qt-basic-concepts.html">Programming with Qt</a></li>
<li class="defaultLink"><a href="qtquick.html">Device UIs & Qt Quick</a></li>
<li class="defaultLink"><a href="qt-gui-concepts.html">UI Design with Qt</a></li>
<li class="defaultLink"><a href="supported-platforms.html">Supported Platforms</a></li>
<li class="defaultLink"><a href="technology-apis.html">Qt and Key Technologies</a></li>
<li class="defaultLink"><a href="best-practices.html">How-To's and Best Practices</a></li>
</ul>
</div>
</div>
<div class="box" id="examples">
<h2 title="Examples"><span></span>
Examples</h2>
<div id="list003" class="list">
<ul id="ul003">
<li class="defaultLink"><a href="all-examples.html">Examples</a></li>
<li class="defaultLink"><a href="tutorials.html">Tutorials</a></li>
<li class="defaultLink"><a href="demos.html">Demos</a></li>
<li class="defaultLink"><a href="qdeclarativeexamples.html">QML Examples</a></li>
</ul>
</div>
</div>
</div>
<div class="wrap">
<div class="toolbar">
<div class="breadcrumb toolblock">
<ul>
<li class="first"><a href="index.html">Home</a></li>
<!-- Breadcrumbs go here -->
<li><a href="all-examples.html">Examples</a></li>
<li>Hierarchy Example (ActiveQt)</li>
</ul>
</div>
<div class="toolbuttons toolblock">
<ul>
<li id="smallA" class="t_button">A</li>
<li id="medA" class="t_button active">A</li>
<li id="bigA" class="t_button">A</li>
<li id="print" class="t_button"><a href="javascript:this.print();">
<span>Print</span></a></li>
</ul>
</div>
</div>
<div class="content mainContent">
<h1 class="title">Hierarchy Example (ActiveQt)</h1>
<span class="subtitle"></span>
<!-- $$$activeqt/hierarchy-description -->
<div class="descr"> <a name="details"></a>
<p>Files:</p>
<ul>
<li><a href="activeqt-hierarchy-objects-cpp.html">activeqt/hierarchy/objects.cpp</a></li>
<li><a href="activeqt-hierarchy-objects-h.html">activeqt/hierarchy/objects.h</a></li>
<li><a href="activeqt-hierarchy-main-cpp.html">activeqt/hierarchy/main.cpp</a></li>
<li><a href="activeqt-hierarchy-hierarchy-pro.html">activeqt/hierarchy/hierarchy.pro</a></li>
</ul>
<p>The Hierarchy example is shows how to write an in-process ActiveX control. The control is a <a href="qwidget.html">QWidget</a> subclass with child widgets that are accessible as sub-types.<pre class="cpp"> <span class="keyword">class</span> <span class="type">QParentWidget</span> : <span class="keyword">public</span> <span class="type"><a href="qwidget.html">QWidget</a></span>
{
Q_OBJECT
Q_CLASSINFO(<span class="string">"ClassID"</span><span class="operator">,</span> <span class="string">"{d574a747-8016-46db-a07c-b2b4854ee75c}"</span>);
Q_CLASSINFO(<span class="string">"InterfaceID"</span><span class="operator">,</span> <span class="string">"{4a30719d-d9c2-4659-9d16-67378209f822}"</span>);
Q_CLASSINFO(<span class="string">"EventsID"</span><span class="operator">,</span> <span class="string">"{4a30719d-d9c2-4659-9d16-67378209f823}"</span>);
<span class="keyword">public</span>:
<span class="type">QParentWidget</span>(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>);
<span class="type"><a href="qsize.html">QSize</a></span> sizeHint() <span class="keyword">const</span>;
<span class="keyword">public</span> <span class="keyword">slots</span>:
<span class="type">void</span> createSubWidget( <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>name );
<span class="type">QSubWidget</span> <span class="operator">*</span>subWidget( <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>name );
<span class="keyword">private</span>:
<span class="type"><a href="qvboxlayout.html">QVBoxLayout</a></span> <span class="operator">*</span>vbox;
};</pre>
<p>The <tt>QParentWidget</tt> class provides slots to create a widget with a name, and to return a pointer to a named widget. The class declaration uses <tt>Q_CLASSINFO()</tt> to provide the COM identifiers for this class.</p>
<pre class="cpp"> <span class="type">QParentWidget</span><span class="operator">::</span><span class="type">QParentWidget</span>(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent)
: <span class="type"><a href="qwidget.html">QWidget</a></span>(parent)
{
vbox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qvboxlayout.html">QVBoxLayout</a></span>(<span class="keyword">this</span>);
}</pre>
<p>The constructor of QParentWidget creates a vertical box layout. New child widgets are automatically added to the layout.</p>
<pre class="cpp"> <span class="type">void</span> <span class="type">QParentWidget</span><span class="operator">::</span>createSubWidget(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>name)
{
<span class="type">QSubWidget</span> <span class="operator">*</span>sw <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QSubWidget</span>(<span class="keyword">this</span><span class="operator">,</span> name);
vbox<span class="operator">-</span><span class="operator">></span>addWidget(sw);
sw<span class="operator">-</span><span class="operator">></span>setLabel(name);
sw<span class="operator">-</span><span class="operator">></span>show();
}</pre>
<p>The <tt>createSubWidget</tt> slot creates a new <tt>QSubWidget</tt> with the name provided in the parameter, and sets the label to that name. The widget is also shown explicitly.</p>
<pre class="cpp"> <span class="type">QSubWidget</span> <span class="operator">*</span><span class="type">QParentWidget</span><span class="operator">::</span>subWidget(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>name)
{
<span class="keyword">return</span> findChild<span class="operator"><</span><span class="type">QSubWidget</span><span class="operator">*</span><span class="operator">></span>(name);
}</pre>
<p>The <tt>subWidget</tt> slot uses the <tt>QObject::child()</tt> function and returns the first child of type <tt>QSubWidget</tt> that has the requested name.</p>
<pre class="cpp"> <span class="keyword">class</span> <span class="type">QSubWidget</span> : <span class="keyword">public</span> <span class="type"><a href="qwidget.html">QWidget</a></span>
{
Q_OBJECT
Q_PROPERTY( <span class="type"><a href="qstring.html">QString</a></span> label READ label WRITE setLabel )
Q_CLASSINFO(<span class="string">"ClassID"</span><span class="operator">,</span> <span class="string">"{850652f4-8f71-4f69-b745-bce241ccdc30}"</span>);
Q_CLASSINFO(<span class="string">"InterfaceID"</span><span class="operator">,</span> <span class="string">"{2d76cc2f-3488-417a-83d6-debff88b3c3f}"</span>);
Q_CLASSINFO(<span class="string">"ToSuperClass"</span><span class="operator">,</span> <span class="string">"QSubWidget"</span>);
<span class="keyword">public</span>:
<span class="type">QSubWidget</span>(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span><span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>name <span class="operator">=</span> <span class="type"><a href="qstring.html">QString</a></span>());
<span class="type">void</span> setLabel( <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>text );
<span class="type"><a href="qstring.html">QString</a></span> label() <span class="keyword">const</span>;
<span class="type"><a href="qsize.html">QSize</a></span> sizeHint() <span class="keyword">const</span>;
<span class="keyword">protected</span>:
<span class="type">void</span> paintEvent( <span class="type"><a href="qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>e );
<span class="keyword">private</span>:
<span class="type"><a href="qstring.html">QString</a></span> lbl;
};</pre>
<p>The <tt>QSubWidget</tt> class has a single string-property <tt>label</tt>, and implements the paintEvent to draw the label. The class uses again <tt>Q_CLASSINFO</tt> to provide the COM identifiers, and also sets the <i>ToSuperClass</i> attribute to <i>QSubWidget</i>, to ensure that only no slots of any superclasses (i.e. <a href="qwidget.html">QWidget</a>) are exposed.</p>
<pre class="cpp"> <span class="type">QSubWidget</span><span class="operator">::</span><span class="type">QSubWidget</span>(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>name)
: <span class="type"><a href="qwidget.html">QWidget</a></span>(parent)
{
setObjectName(name);
}
<span class="type">void</span> <span class="type">QSubWidget</span><span class="operator">::</span>setLabel(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>text)
{
lbl <span class="operator">=</span> text;
setObjectName(text);
update();
}
<span class="type"><a href="qstring.html">QString</a></span> <span class="type">QSubWidget</span><span class="operator">::</span>label() <span class="keyword">const</span>
{
<span class="keyword">return</span> lbl;
}
<span class="type"><a href="qsize.html">QSize</a></span> <span class="type">QSubWidget</span><span class="operator">::</span>sizeHint() <span class="keyword">const</span>
{
<span class="type"><a href="qfontmetrics.html">QFontMetrics</a></span> fm(font());
<span class="keyword">return</span> <span class="type"><a href="qsize.html">QSize</a></span>(fm<span class="operator">.</span>width(lbl)<span class="operator">,</span> fm<span class="operator">.</span>height());
}
<span class="type">void</span> <span class="type">QSubWidget</span><span class="operator">::</span>paintEvent(<span class="type"><a href="qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>)
{
<span class="type"><a href="qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>);
painter<span class="operator">.</span>setPen(palette()<span class="operator">.</span>text()<span class="operator">.</span>color());
painter<span class="operator">.</span>drawText(rect()<span class="operator">,</span> <span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>AlignCenter<span class="operator">,</span> lbl);
}</pre>
<p>The implementation of the QSubWidget class is self-explanatory.</p>
<pre class="cpp"> <span class="preprocessor">#include "objects.h"</span>
<span class="preprocessor">#include <QAxFactory></span>
<a href="qaxfactory.html#QAXFACTORY_BEGIN">QAXFACTORY_BEGIN</a>(<span class="string">"{9e626211-be62-4d18-9483-9419358fbb03}"</span><span class="operator">,</span> <span class="string">"{75c276de-1df5-451f-a004-e4fa1a587df1}"</span>)
<a href="qaxfactory.html#QAXCLASS">QAXCLASS</a>(<span class="type">QParentWidget</span>)
<a href="qaxfactory.html#QAXTYPE">QAXTYPE</a>(<span class="type">QSubWidget</span>)
<a href="qaxfactory.html#QAXFACTORY_END">QAXFACTORY_END</a>()</pre>
<p>The classes are then exported using a <a href="qaxfactory.html">QAxFactory</a>. <tt>QParentWidget</tt> is exported as a full class (which can be created ), while <tt>QSubWidget</tt> is only exported as a type, which can only be created indirectly through APIs of <tt>QParentWidget</tt>.</p>
<p>To build the example you must first build the <a href="qaxserver.html">QAxServer</a> library. Then run qmake and your make tool in <tt>examples/activeqt/hierarchy</tt>.</p>
<p>The <a href="qaxserver-demo-hierarchy.html">demonstration</a> requires your WebBrowser to support ActiveX controls, and scripting to be enabled.</p>
<pre class="cpp"> <script language="javascript">
function createSubWidget( form )
{
ParentWidget.createSubWidget( form.nameEdit.value );
}
function renameSubWidget( form )
{
var SubWidget = ParentWidget.subWidget( form.nameEdit.value );
if ( !SubWidget ) {
alert( "No such widget " + form.nameEdit.value + "!" );
return;
}
SubWidget.label = form.labelEdit.value;
form.nameEdit.value = SubWidget.label;
}
function setFont( form )
{
ParentWidget.font = form.fontEdit.value;
}
</script>
<p>
This widget can have many children!
</p>
<object ID="ParentWidget" CLASSID="CLSID:d574a747-8016-46db-a07c-b2b4854ee75c"
CODEBASE="http://www.qt-project.org/demos/hierarchy.cab">
[Object not available! Did you forget to build and register the server?]
</object><br />
<form>
<input type="edit" ID="nameEdit" value="&lt;enter object name&gt;" />
<input type="button" value="Create" onClick="createSubWidget(this.form)" />
<input type="edit" ID="labelEdit" />
<input type="button" value="Rename" onClick="renameSubWidget(this.form)" />
<br />
<input type="edit" ID="fontEdit" value="MS Sans Serif" />
<input type="button" value = "Set Font" onClick="setFont(this.form)" />
</form></pre>
</div>
<!-- @@@activeqt/hierarchy -->
</div>
</div>
</div>
<div class="ft">
<span></span>
</div>
</div>
<div class="footer">
<p>
<acronym title="Copyright">©</acronym> 2015 The Qt Company Ltd.
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>
Qt and respective logos are trademarks of The Qt Company Ltd
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>
<script src="scripts/functions.js" type="text/javascript"></script>
</body>
</html>
