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<td >Qt 5.9</td><td ><a href="qtsensors-index.html">Qt Sensors</a></td><td ><a href="qtsensors-module.html">C++ Classes</a></td><td >QSensorFilter</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td>
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<h3><a name="toc">Contents</a></h3>
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<li class="level1"><a href="#public-functions">Public Functions</a></li>
<li class="level1"><a href="#protected-functions">Protected Functions</a></li>
<li class="level1"><a href="#details">Detailed Description</a></li>
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<h1 class="title">QSensorFilter Class</h1>
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<p>The <a href="qsensorfilter.html">QSensorFilter</a> class provides an efficient callback facility for asynchronous notifications of sensor changes. <a href="#details">More...</a></p>
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<tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QSensorFilter></span>
</td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += sensors</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherited By:</td><td class="memItemRight bottomAlign"> <p><a href="qaccelerometerfilter.html">QAccelerometerFilter</a>, <a href="qaltimeterfilter.html">QAltimeterFilter</a>, <a href="qambientlightfilter.html">QAmbientLightFilter</a>, <a href="qambienttemperaturefilter.html">QAmbientTemperatureFilter</a>, <a href="qcompassfilter.html">QCompassFilter</a>, <a href="qdistancefilter.html">QDistanceFilter</a>, <a href="qgyroscopefilter.html">QGyroscopeFilter</a>, <a href="qholsterfilter.html">QHolsterFilter</a>, <a href="qhumidityfilter.html">QHumidityFilter</a>, <a href="qirproximityfilter.html">QIRProximityFilter</a>, <a href="qlidfilter.html">QLidFilter</a>, <a href="qlightfilter.html">QLightFilter</a>, <a href="qmagnetometerfilter.html">QMagnetometerFilter</a>, <a href="qorientationfilter.html">QOrientationFilter</a>, <a href="qpressurefilter.html">QPressureFilter</a>, <a href="qproximityfilter.html">QProximityFilter</a>, <a href="qrotationfilter.html">QRotationFilter</a>, <a href="qtapfilter.html">QTapFilter</a>, and <a href="qtiltfilter.html">QTiltFilter</a></p>
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<li><a href="qsensorfilter-members.html">List of all members, including inherited members</a></li>
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<h2 id="public-functions">Public Functions</h2>
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<tr><td class="memItemLeft rightAlign topAlign"> virtual bool </td><td class="memItemRight bottomAlign"><b><a href="qsensorfilter.html#filter">filter</a></b>(QSensorReading *<i>reading</i>) = 0</td></tr>
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<h2 id="protected-functions">Protected Functions</h2>
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<tr><td class="memItemLeft rightAlign topAlign"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qsensorfilter.html#dtor.QSensorFilter">~QSensorFilter</a></b>()</td></tr>
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<h2 id="details">Detailed Description</h2>
<p>The <a href="qsensorfilter.html">QSensorFilter</a> class provides an efficient callback facility for asynchronous notifications of sensor changes.</p>
<p>Some sensors (eg. the accelerometer) are often accessed very frequently. This may be slowed down by the use of signals and slots. The <a href="qsensorfilter.html">QSensorFilter</a> interface provides a more efficient way for the sensor to notify your class that the sensor has changed.</p>
<p>Additionally, multiple filters can be added to a sensor. They are called in order and each filter has the option to modify the values in the reading or to suppress the reading altogether.</p>
<p>Note that the values in the class returned by <a href="qsensor.html#reading-prop">QSensor::reading</a>() will not be updated until after the filters have been run.</p>
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<p><b>See also </b><a href="qsensorfilter.html#filter">filter</a>().</p>
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<h2>Member Function Documentation</h2>
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<h3 class="fn" id="dtor.QSensorFilter"><a name="dtor.QSensorFilter"></a><code>[virtual protected] </code>QSensorFilter::<span class="name">~QSensorFilter</span>()</h3>
<p>Notifies the attached sensor (if any) that the filter is being destroyed.</p>
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<h3 class="fn" id="filter"><a name="filter"></a><code>[pure virtual] </code><span class="type">bool</span> QSensorFilter::<span class="name">filter</span>(<span class="type"><a href="qsensorreading.html">QSensorReading</a></span> *<i>reading</i>)</h3>
<p>This function is called when the sensor <i>reading</i> changes.</p>
<p>The filter can modify the reading.</p>
<p>Returns true to allow the next filter to receive the value. If this is the last filter, returning true causes the signal to be emitted and the value is stored in the sensor.</p>
<p>Returns false to drop the reading.</p>
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