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<td >Qt 5.12</td><td ><a href="qtlocation-index.html">Qt Location</a></td><td ><a href="qtlocation-qmlmodule.html">QML Types</a></td><td >MapItemGroup QML Type</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right"><a href="qtlocation-index.html">Qt 5.12.6 Reference Documentation</a></td>
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<h3><a name="toc">Contents</a></h3>
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<li class="level1"><a href="#details">Detailed Description</a></li>
<li class="level2"><a href="#example-usage">Example Usage</a></li>
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<h1 class="title">MapItemGroup QML Type</h1>
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<!-- $$$MapItemGroup-brief -->
<p>The <a href="qml-qtlocation-mapitemgroup.html">MapItemGroup</a> type is a container for map items. <a href="#details">More...</a></p>
<!-- @@@MapItemGroup -->
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<tr><td class="memItemLeft rightAlign topAlign"> Import Statement:</td><td class="memItemRight bottomAlign"> import QtLocation 5.12</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> QtLocation 5.9</td></tr></table></div><ul>
<li><a href="qml-qtlocation-mapitemgroup-members.html">List of all members, including inherited members</a></li>
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<!-- $$$MapItemGroup-description -->
<a name="details"></a>
<h2 id="details">Detailed Description</h2>
<p>Its purpose is to enable code modularization by allowing the usage of qml files containing map elements related to each other, and the associated bindings.</p>
<p><b>Note: </b>The release of this API with Qt 5.9 is a Technology Preview.</p><a name="example-usage"></a>
<h3 id="example-usage">Example Usage</h3>
<p>The following snippet shows how to use a <a href="qml-qtlocation-mapitemgroup.html">MapItemGroup</a> to create a <a href="qml-qtlocation-mapcircle.html">MapCircle</a>, centered at the coordinate (63, -18) with a radius of 100km, filled in red, surrounded by an ondulated green border, both contained in a semitransparent blue circle with a MouseArea that moves the whole group. This group is defined in a separate file named PolygonGroup.qml:</p>
<pre class="cpp">
import <span class="type">QtQuick</span> <span class="number">2.4</span>
import <span class="type">QtPositioning</span> <span class="number">5.6</span>
import <span class="type">QtLocation</span> <span class="number">5.9</span>
MapItemGroup {
id: itemGroup
property alias position: mainCircle<span class="operator">.</span>center
property var radius: <span class="number">100</span> <span class="operator">*</span> <span class="number">1000</span>
property var borderHeightPct : <span class="number">0.3</span>
MapCircle {
id: mainCircle
center : <span class="type">QtPositioning</span><span class="operator">.</span>coordinate(<span class="number">40</span><span class="operator">,</span> <span class="number">0</span>)
radius: itemGroup<span class="operator">.</span>radius <span class="operator">*</span> (<span class="number">1.0</span> <span class="operator">+</span> borderHeightPct)
opacity: <span class="number">0.05</span>
visible: <span class="keyword">true</span>
color: <span class="char">'blue'</span>
MouseArea{
anchors<span class="operator">.</span>fill: parent
drag<span class="operator">.</span>target: parent
id: maItemGroup
}
}
MapCircle {
id: groupCircle
center: itemGroup<span class="operator">.</span>position
radius: itemGroup<span class="operator">.</span>radius
color: <span class="char">'crimson'</span>
onCenterChanged: {
groupPolyline<span class="operator">.</span>populateBorder();
}
}
MapPolyline {
id: groupPolyline
line<span class="operator">.</span>color: <span class="char">'green'</span>
line<span class="operator">.</span>width: <span class="number">3</span>
function populateBorder() {
groupPolyline<span class="operator">.</span>path <span class="operator">=</span> <span class="operator">[</span><span class="operator">]</span> <span class="comment">// clearing the path</span>
var waveLength <span class="operator">=</span> <span class="number">8.0</span>;
var waveAmplitude <span class="operator">=</span> groupCircle<span class="operator">.</span>radius <span class="operator">*</span> borderHeightPct;
<span class="keyword">for</span> (var i<span class="operator">=</span><span class="number">0</span>; i <span class="operator"><</span><span class="operator">=</span> <span class="number">360</span>; i<span class="operator">+</span><span class="operator">+</span>) {
var wavePhase <span class="operator">=</span> (i<span class="operator">/</span><span class="number">360.0</span> <span class="operator">*</span> <span class="number">2.0</span> <span class="operator">*</span> Math<span class="operator">.</span>PI )<span class="operator">*</span> waveLength
var waveHeight <span class="operator">=</span> (Math<span class="operator">.</span>cos(wavePhase) <span class="operator">+</span> <span class="number">1.0</span>) <span class="operator">/</span> <span class="number">2.0</span>
groupPolyline<span class="operator">.</span>addCoordinate(groupCircle<span class="operator">.</span>center<span class="operator">.</span>atDistanceAndAzimuth(groupCircle<span class="operator">.</span>radius <span class="operator">+</span> waveAmplitude <span class="operator">*</span> waveHeight <span class="operator">,</span> i))
}
}
Component<span class="operator">.</span>onCompleted: {
populateBorder()
}
}
}
</pre>
<p>PolygonGroup.qml is now a reusable component that can then be used in a Map as:</p>
<pre class="cpp">
Map {
id: map
PolygonGroup {
id: polygonGroup
position: <span class="type">QtPositioning</span><span class="operator">.</span>coordinate(<span class="number">63</span><span class="operator">,</span><span class="operator">-</span><span class="number">18</span>)
}
}
</pre>
<p class="centerAlign"><img src="images/api-mapitemgroup.png" alt="" /></p><!-- @@@MapItemGroup -->
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