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<td >Qt 5.12</td><td ><a href="qtbluetooth-index.html">Qt Bluetooth</a></td><td >QML Bluetooth Picture Push Example</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right"><a href="qtbluetooth-index.html">Qt 5.12.6 Reference Documentation</a></td>
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<h3><a name="toc">Contents</a></h3>
<ul>
<li class="level1"><a href="#running-the-example">Running the Example</a></li>
<li class="level1"><a href="#device-discovery">Device Discovery</a></li>
<li class="level1"><a href="#file-selection">File Selection</a></li>
<li class="level1"><a href="#root-element">Root Element</a></li>
<li class="level1"><a href="#file-transfer">File Transfer</a></li>
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<h1 class="title">QML Bluetooth Picture Push Example</h1>
<span class="subtitle"></span>
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<p>An example showing the use Bluetooth Object Push Profile (OPP).</p>
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<div class="descr"> <a name="details"></a>
<p>The Bluetooth Picture Push example shows how to use the <a href="qbluetoothtransfermanager.html">QBluetoothTransferManager</a> API. The example transfers a local image to a remote device. Unfortunately this example cannot be used on Android as Qt does not support the Object Push Profile (OPP) on this platform.</p>
<p>On the first user interface page the application scans for remote Bluetooth devices. The user must select the appropriate device to continue:</p>
<p class="centerAlign"><img src="images/opp-example-1.png" alt="" /></p><p>The next page presents a list of image files on the device. The files must be located under QStandardPaths::PicturesLocation}:</p>
<p class="centerAlign"><img src="images/opp-example-2.png" alt="" /></p><p>Once the picture was selected the UI shows the progress of the file transfer:</p>
<p class="centerAlign"><img src="images/opp-example-3.png" alt="" /></p><a name="running-the-example"></a>
<h2 id="running-the-example">Running the Example</h2>
<p>To run the example from Qt Creator, open the <b>Welcome</b> mode and select the example from <b>Examples</b>. For more information, visit Building and Running an Example.</p>
<a name="device-discovery"></a>
<h2 id="device-discovery">Device Discovery</h2>
<p>The device discovery uses the <a href="qml-qtbluetooth-bluetoothdiscoverymodel.html">BluetoothDiscoveryModel</a> to detect the remote devices. Each discovery is displayed as an entry in a list. Once a device was selected the device address is stored in the <code>root</code> element. More details about the <code>root</code> element will follow further below.</p>
<pre class="qml">
ListView {
model: BluetoothDiscoveryModel {
discoveryMode: BluetoothDiscoveryModel.DeviceDiscovery
onErrorChanged: {
if (error == BluetoothDiscoveryModel.NoError)
return;
if (error == BluetoothDiscoveryModel.PoweredOffError)
titleLabel.text = "Bluetooth turned off";
else
titleLabel.text = "Cannot find devices";
}
}
delegate: Button {
width: listView.width + 2
text: model.name
onClicked: root.remoteDevice = model.remoteAddress
}
}
</pre>
<a name="file-selection"></a>
<h2 id="file-selection">File Selection</h2>
<p>The file is selected with the help of FolderListModel. Once again the selected file is stored in the <code>root</code> element:</p>
<pre class="qml">
model: FolderListModel {
folder: "file://"+SystemPictureFolder
showDirs: false
}
delegate: Rectangle {
Text {
text: model.fileName
}
MouseArea {
id: mArea
anchors.fill: parent
onClicked: {
print ("path: " + model.filePath + " " + model.fileName)
root.fileName = model.filePath
}
}
}
</pre>
<a name="root-element"></a>
<h2 id="root-element">Root Element</h2>
<p>The already mentioned <code>root</code> element collects the necessary pieces of data for the picture transfer. Once the file name has been set it triggers the file transfer:</p>
<pre class="qml">
Image {
id: root
property string remoteDevice;
property string fileName;
onFileNameChanged: {
fileTransfer.initTransfer(remoteDevice, fileName);
loader.source = "FileSending.qml"
}
onFileNameChanged: {
fileTransfer.initTransfer(remoteDevice, fileName);
loader.source = "FileSending.qml"
}
</pre>
<a name="file-transfer"></a>
<h2 id="file-transfer">File Transfer</h2>
<p>The file transfer is implemented in C++:</p>
<pre class="cpp">
<span class="type">void</span> FileTransfer<span class="operator">::</span>initTransfer(<span class="type">QString</span> address<span class="operator">,</span> <span class="type">QString</span> fileName)
{
qDebug() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Begin sharing file: "</span> <span class="operator"><</span><span class="operator"><</span> address <span class="operator"><</span><span class="operator"><</span> fileName;
<span class="type"><a href="qbluetoothaddress.html">QBluetoothAddress</a></span> btAddress <span class="operator">=</span> <span class="type"><a href="qbluetoothaddress.html">QBluetoothAddress</a></span>(address);
<span class="type"><a href="qbluetoothtransferrequest.html">QBluetoothTransferRequest</a></span> request(btAddress);
<span class="type">QFile</span> <span class="operator">*</span>file <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QFile</span>(fileName);
reply <span class="operator">=</span> manager<span class="operator">.</span>put(request<span class="operator">,</span> file);
connect(reply<span class="operator">,</span> SIGNAL(transferProgress(<span class="type">qint64</span><span class="operator">,</span><span class="type">qint64</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(updateProgress(<span class="type">qint64</span><span class="operator">,</span><span class="type">qint64</span>)));
}
</pre>
<p>and exposed to QML via a context property:</p>
<pre class="cpp">
<span class="type">QQuickView</span> view;
FileTransfer fileTransfer;
view<span class="operator">.</span>rootContext()<span class="operator">-</span><span class="operator">></span>setContextProperty(<span class="string">"fileTransfer"</span><span class="operator">,</span> <span class="type">QVariant</span><span class="operator">::</span>fromValue(<span class="operator">&</span>fileTransfer));
</pre>
<p>Files:</p>
<ul>
<li><a href="qtbluetooth-picturetransfer-button-qml.html">picturetransfer/Button.qml</a></li>
<li><a href="qtbluetooth-picturetransfer-devicediscovery-qml.html">picturetransfer/DeviceDiscovery.qml</a></li>
<li><a href="qtbluetooth-picturetransfer-filesending-qml.html">picturetransfer/FileSending.qml</a></li>
<li><a href="qtbluetooth-picturetransfer-pictureselector-qml.html">picturetransfer/PictureSelector.qml</a></li>
<li><a href="qtbluetooth-picturetransfer-bttransfer-qml.html">picturetransfer/bttransfer.qml</a></li>
<li><a href="qtbluetooth-picturetransfer-filetransfer-cpp.html">picturetransfer/filetransfer.cpp</a></li>
<li><a href="qtbluetooth-picturetransfer-filetransfer-h.html">picturetransfer/filetransfer.h</a></li>
<li><a href="qtbluetooth-picturetransfer-main-cpp.html">picturetransfer/main.cpp</a></li>
<li><a href="qtbluetooth-picturetransfer-picturetransfer-pro.html">picturetransfer/picturetransfer.pro</a></li>
<li><a href="qtbluetooth-picturetransfer-qmltransfer-qrc.html">picturetransfer/qmltransfer.qrc</a></li>
</ul>
<p>Images:</p>
<ul>
<li><a href="images/used-in-examples/picturetransfer/background.png">picturetransfer/background.png</a></li>
<li><a href="images/used-in-examples/picturetransfer/icon.png">picturetransfer/icon.png</a></li>
</ul>
</div>
<p><b>See also </b><a href="qtbluetooth-index.html">Qt Bluetooth</a>.</p>
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