<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- sensor_explorer.qdoc -->
<title>Qt Sensors - Explorer QML Example | Qt Sensors 5.9</title>
<link rel="stylesheet" type="text/css" href="style/offline-simple.css" />
<script type="text/javascript">
document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css");
// loading style sheet breaks anchors that were jumped to before
// so force jumping to anchor again
setTimeout(function() {
var anchor = location.hash;
// need to jump to different anchor first (e.g. none)
location.hash = "#";
setTimeout(function() {
location.hash = anchor;
}, 0);
}, 0);
</script>
</head>
<body>
<div class="header" id="qtdocheader">
<div class="main">
<div class="main-rounded">
<div class="navigationbar">
<table><tr>
<td >Qt 5.9</td><td ><a href="qtsensors-index.html">Qt Sensors</a></td><td ><a href="qtsensors-examples.html">Qt Sensors Examples</a></td><td >Qt Sensors - Explorer QML Example</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td>
</tr></table>
</div>
</div>
<div class="content">
<div class="line">
<div class="content mainContent">
<div class="sidebar">
<div class="toc">
<h3><a name="toc">Contents</a></h3>
<ul>
<li class="level1"><a href="#sensor-explorer-qml-import">Sensor Explorer QML Import</a></li>
<li class="level1"><a href="#sensor-explorer-qml-application">Sensor Explorer QML Application</a></li>
</ul>
</div>
<div class="sidebar-content" id="sidebar-content"></div></div>
<h1 class="title">Qt Sensors - Explorer QML Example</h1>
<span class="subtitle"></span>
<!-- $$$sensor_explorer-description -->
<div class="descr"> <a name="details"></a>
<p class="centerAlign"><img src="images/qtsensors-examples-explorer.png" alt="" /></p><p>This example is divided into two parts:</p>
<ul>
<li>A <a href="qtsensors-sensor-explorer-example.html#sensor-explorer-qml-import">C++ plugin</a> that provides QML alternatives for <code>QSensorExplorer</code>, <code>QPropertyInfo</code> and <code>QSensorItem</code> C++ classes.</li>
<li>A <a href="qtsensors-sensor-explorer-example.html#sensor-explorer-qml-application">QML Application</a> that uses the QML types to read the sensor meta-data and present it.</li>
</ul>
<p>This example is built as an executable with C++ code that runs the QML, but it can also be launched directly using the <code>qmlscene</code> tool. You should build the top-level <i>sensor_explorer</i> project before trying to run this example or it will not be able to find its dependencies.</p>
<pre class="cpp">
qmlscene <span class="operator">-</span>I <span class="operator">.</span> sensor_explorer<span class="operator">.</span>qml
</pre>
<p>Above, the -I . parameter adds the current directory as a module import path to locate the Explorer QML module.</p>
<a name="sensor-explorer-qml-import"></a>
<h2 id="sensor-explorer-qml-import">Sensor Explorer QML Import</h2>
<p>The Sensor Explorer QML import defines the <i>Explorer</i> QML module, exporting <code>QSensorExplorer</code>, <code>QPropertyInfo</code> and <code>QSensorItem</code> C++ classes as QML types. The source code is available in the <code>sensor_explorer/import</code> subdirectory.</p>
<a name="sensor-explorer-qml-application"></a>
<h2 id="sensor-explorer-qml-application">Sensor Explorer QML Application</h2>
<p>To write a QML application that will use the QML types exposed by the Explorer module, following steps are needed:</p>
<p>Import the Explorer 1.0 declarative plugin:</p>
<pre class="qml">
import Explorer 1.0
</pre>
<p>Create a SensorExplorer QML item:</p>
<pre class="qml">
<span class="type">SensorExplorer</span> {
<span class="name">id</span>: <span class="name">explorer</span>
}
</pre>
<p>You can retrieve a list of all available sensors using <code>SensorExplorer.availableSensors</code>:</p>
<pre class="qml">
<span class="name">model</span>: <span class="name">explorer</span>.<span class="name">availableSensors</span>
</pre>
<p>The example uses the returned list as a model to populate a view of available sensors.</p>
<p>To retrieve the properties of a sensor, use <code>SensorItem.properties</code>:</p>
<pre class="qml">
<span class="name">propertyList</span>.<span class="name">model</span> <span class="operator">=</span> <span class="name">explorer</span>.<span class="name">selectedSensorItem</span>.<span class="name">properties</span>
</pre>
<p>The property list is used as a model for another view that displays the property names and values.</p>
<p>It is possible to edit the values of certain sensor properties. Selecting a writable property value will open an editor. <code>SensorExplorer</code> QML type allows you to pass a new value for a sensor property value as follows:</p>
<pre class="qml">
<span class="name">explorer</span>.<span class="name">selectedSensorItem</span>.<span class="name">changePropertyValue</span>(<span class="name">propertyList</span>.<span class="name">selectedItem</span>, <span class="name">loaderEditor</span>.<span class="name">item</span>.<span class="name">text</span>);
</pre>
<p>Starting and stopping a sensor can be done by setting the <code>SensorItem.start</code> property:</p>
<pre class="qml">
<span class="keyword">if</span> (<span class="name">text</span> <span class="operator">===</span> <span class="string">"Start"</span>) {
<span class="name">explorer</span>.<span class="name">selectedSensorItem</span>.<span class="name">start</span> <span class="operator">=</span> <span class="number">true</span>;
<span class="name">text</span> <span class="operator">=</span> <span class="string">"Stop"</span>;
}
<span class="keyword">else</span> {
<span class="name">explorer</span>.<span class="name">selectedSensorItem</span>.<span class="name">start</span> <span class="operator">=</span> <span class="number">false</span>;
<span class="name">text</span> <span class="operator">=</span> <span class="string">"Start"</span>;
}
</pre>
<p>Files:</p>
<ul>
<li><a href="qtsensors-sensor-explorer-makefile-qml.html">sensor_explorer/Makefile.qml</a></li>
<li><a href="qtsensors-sensor-explorer-sensor-explorer-qml.html">sensor_explorer/sensor_explorer.qml</a></li>
<li><a href="qtsensors-sensor-explorer-import-explorer-cpp.html">sensor_explorer/import/explorer.cpp</a></li>
<li><a href="qtsensors-sensor-explorer-import-explorer-h.html">sensor_explorer/import/explorer.h</a></li>
<li><a href="qtsensors-sensor-explorer-import-propertyinfo-cpp.html">sensor_explorer/import/propertyinfo.cpp</a></li>
<li><a href="qtsensors-sensor-explorer-import-propertyinfo-h.html">sensor_explorer/import/propertyinfo.h</a></li>
<li><a href="qtsensors-sensor-explorer-import-sensoritem-cpp.html">sensor_explorer/import/sensoritem.cpp</a></li>
<li><a href="qtsensors-sensor-explorer-import-sensoritem-h.html">sensor_explorer/import/sensoritem.h</a></li>
<li><a href="qtsensors-sensor-explorer-main-cpp.html">sensor_explorer/main.cpp</a></li>
<li><a href="qtsensors-sensor-explorer-qml-pro.html">sensor_explorer/qml.pro</a></li>
<li><a href="qtsensors-sensor-explorer-qml-qrc.html">sensor_explorer/qml.qrc</a></li>
<li><a href="qtsensors-sensor-explorer-sensor-explorer-pro.html">sensor_explorer/sensor_explorer.pro</a></li>
<li><a href="qtsensors-sensor-explorer-explorer-qmldir.html">sensor_explorer/Explorer/qmldir</a></li>
<li><a href="qtsensors-sensor-explorer-import-import-pro.html">sensor_explorer/import/import.pro</a></li>
<li><a href="qtsensors-sensor-explorer-import-qmldir.html">sensor_explorer/import/qmldir</a></li>
</ul>
</div>
<!-- @@@sensor_explorer -->
</div>
</div>
</div>
</div>
</div>
<div class="footer">
<p>
<acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd.
Documentation contributions included herein are the copyrights of
their respective owners.<br> 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.<br> 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. </p>
</div>
</body>
</html>
