276 lines
15 KiB
HTML
276 lines
15 KiB
HTML
<?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" />
|
|
<!-- extending-tutorial.qdoc -->
|
|
<title>Qt 4.8: Chapter 6: Writing an Extension Plugin</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>QML Examples & Demos</li>
|
|
<li>Chapter 6: Writing an Extension Plugin</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">Chapter 6: Writing an Extension Plugin</h1>
|
|
<span class="subtitle"></span>
|
|
<!-- $$$declarative/tutorials/extending/chapter6-plugins-description -->
|
|
<div class="descr"> <a name="details"></a>
|
|
<p>Files:</p>
|
|
<ul>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-app-qml.html">declarative/tutorials/extending/chapter6-plugins/app.qml</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-chartsplugin-cpp.html">declarative/tutorials/extending/chapter6-plugins/chartsplugin.cpp</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-chartsplugin-h.html">declarative/tutorials/extending/chapter6-plugins/chartsplugin.h</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-piechart-cpp.html">declarative/tutorials/extending/chapter6-plugins/piechart.cpp</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-piechart-h.html">declarative/tutorials/extending/chapter6-plugins/piechart.h</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-pieslice-cpp.html">declarative/tutorials/extending/chapter6-plugins/pieslice.cpp</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-pieslice-h.html">declarative/tutorials/extending/chapter6-plugins/pieslice.h</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-chapter6-plugins-pro.html">declarative/tutorials/extending/chapter6-plugins/chapter6-plugins.pro</a></li>
|
|
<li><a href="declarative-tutorials-extending-chapter6-plugins-qmldir.html">declarative/tutorials/extending/chapter6-plugins/qmldir</a></li>
|
|
</ul>
|
|
<p>Currently the <tt>PieChart</tt> and <tt>PieSlice</tt> types are used by <tt>app.qml</tt>, which is displayed using a <a href="qdeclarativeview.html">QDeclarativeView</a> in a C++ application. An alternative way to use our QML extension is to create a plugin library to make it available to the QML engine. This allows <tt>app.qml</tt> to be loaded with the <a href="qmlviewer.html">QML Viewer</a> (or some other QML <a href="qmlruntime.html">runtime</a> application) instead of writing a <tt>main.cpp</tt> file and loading our own C++ application.</p>
|
|
<p>To create a plugin library, we need:</p>
|
|
<ul>
|
|
<li>A plugin class that registers our QML types</li>
|
|
<li>A project file that describes the plugin</li>
|
|
<li>A <a href="qdeclarativemodules.html#writing-a-qmldir-file">qmldir</a> file that tells the QML engine to load the plugin</li>
|
|
</ul>
|
|
<p>First, we create a plugin class named <tt>ChartsPlugin</tt>. It subclasses <a href="qdeclarativeextensionplugin.html">QDeclarativeExtensionPlugin</a> and registers our QML types in the inherited <a href="qdeclarativeextensionplugin.html#registerTypes">registerTypes()</a> method. It also calls <a href="qtplugin.html#Q_EXPORT_PLUGIN2#q-export-plugin2">Q_EXPORT_PLUGIN2</a> for Qt's <a href="plugins-howto.html">plugin system</a>.</p>
|
|
<p>Here is the <tt>ChartsPlugin</tt> definition in <tt>chartsplugin.h</tt>:</p>
|
|
<pre class="cpp"> <span class="preprocessor">#include <QDeclarativeExtensionPlugin></span>
|
|
|
|
<span class="keyword">class</span> ChartsPlugin : <span class="keyword">public</span> <span class="type"><a href="qdeclarativeextensionplugin.html">QDeclarativeExtensionPlugin</a></span>
|
|
{
|
|
Q_OBJECT
|
|
<span class="keyword">public</span>:
|
|
<span class="type">void</span> registerTypes(<span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>uri);
|
|
};</pre>
|
|
<p>And its implementation in <tt>chartsplugin.cpp</tt>:</p>
|
|
<pre class="cpp"> <span class="preprocessor">#include "piechart.h"</span>
|
|
<span class="preprocessor">#include "pieslice.h"</span>
|
|
<span class="preprocessor">#include <qdeclarative.h></span>
|
|
|
|
<span class="type">void</span> ChartsPlugin<span class="operator">::</span>registerTypes(<span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>uri)
|
|
{
|
|
qmlRegisterType<span class="operator"><</span>PieChart<span class="operator">></span>(uri<span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="string">"PieChart"</span>);
|
|
qmlRegisterType<span class="operator"><</span>PieSlice<span class="operator">></span>(uri<span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="string">"PieSlice"</span>);
|
|
}
|
|
|
|
<a href="qtplugin.html#Q_EXPORT_PLUGIN2">Q_EXPORT_PLUGIN2</a>(chartsplugin<span class="operator">,</span> ChartsPlugin);</pre>
|
|
<p>Then, we write a <tt>.pro</tt> project file that defines the project as a plugin library and specifies with DESTDIR that library files should be built into a "lib" subdirectory:</p>
|
|
<pre class="cpp"> TEMPLATE = lib
|
|
CONFIG += qt plugin
|
|
QT += declarative
|
|
|
|
DESTDIR = lib
|
|
OBJECTS_DIR = tmp
|
|
MOC_DIR = tmp
|
|
|
|
HEADERS += piechart.h \
|
|
pieslice.h \
|
|
chartsplugin.h
|
|
|
|
SOURCES += piechart.cpp \
|
|
pieslice.cpp \
|
|
chartsplugin.cpp
|
|
|
|
symbian {
|
|
include($$QT_SOURCE_TREE/examples/symbianpkgrules.pri)
|
|
TARGET.EPOCALLOWDLLDATA = 1
|
|
}
|
|
maemo5: include($$QT_SOURCE_TREE/examples/maemo5pkgrules.pri)</pre>
|
|
<p>Finally, we add a <a href="qdeclarativemodules.html#writing-a-qmldir-file">qmldir</a> file that is automatically parsed by the QML engine. In this file, we specify that a plugin named "chapter6-plugin" (the name of the example project) can be found in the "lib" subdirectory:</p>
|
|
<pre class="cpp"> plugin chapter6<span class="operator">-</span>plugins lib</pre>
|
|
<p>Now we have a plugin, and instead of having a main.cpp and an executable, we can build the project and then load the QML file in the <a href="qmlviewer.html">QML Viewer</a>:</p>
|
|
<pre class="cpp"> qmlviewer app<span class="operator">.</span>qml</pre>
|
|
<p>(On Mac OS X, you can launch the "QMLViewer" application instead.)</p>
|
|
<p>Notice the "import Charts 1.0" statement has disappeared from <tt>app.qml</tt>. This is because the <tt>qmldir</tt> file is in the same directory as <tt>app.qml</tt>: this is equivalent to having PieChart.qml and PieSlice.qml files inside the project directory, which could both be used by <tt>app.qml</tt> without import statements.</p>
|
|
</div>
|
|
<!-- @@@declarative/tutorials/extending/chapter6-plugins -->
|
|
</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>
|