Add the alwaysOn property to QSensor

(This is a backport from qtsensors commits
f9672df5ea9872f911eb0011012f829309e11e71 and
4187d0baa96c4731abfcddfe2c24cf4ef4e72ac5)

Change-Id: I9b4adb6a97599dff7f8b0506e5800ed01abdd3b2
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>

3 files changed, 32 insertions, 0 deletions

diff --git a/src/sensors/qsensor.cpp b/src/sensors/qsensor.cpp
index 3e13eb69c4..0b22ad20f7 100644
--- a/src/sensors/qsensor.cpp
+++ b/src/sensors/qsensor.cpp
@@ -375,6 +375,30 @@ bool QSensor::isActive() const
 }
 
 /*!
+    \property QSensor::alwaysOn
+    \brief a value to indicate if the sensor should remain running when the screen is off.
+
+    Some platforms have a policy of suspending sensors when the screen turns off.
+    Setting this property to true will ensure the sensor continues to run.
+*/
+/*!
+    \fn QSensor::alwaysOnChanged()
+
+    This signal is emitted when the alwaysOn property changes.
+*/
+void QSensor::setAlwaysOn(bool alwaysOn)
+{
+    if (d->alwaysOn == alwaysOn) return;
+    d->alwaysOn = alwaysOn;
+    emit alwaysOnChanged();
+}
+
+bool QSensor::isAlwaysOn() const
+{
+    return d->alwaysOn;
+}
+
+/*!
     \property QSensor::availableDataRates
     \brief the data rates that the sensor supports.
 
diff --git a/src/sensors/qsensor.h b/src/sensors/qsensor.h
index dda9eb867b..02ef032e90 100644
--- a/src/sensors/qsensor.h
+++ b/src/sensors/qsensor.h
@@ -98,6 +98,7 @@ class Q_SENSORS_EXPORT QSensor : public QObject
     Q_PROPERTY(int outputRange READ outputRange WRITE setOutputRange)
     Q_PROPERTY(QString description READ description)
     Q_PROPERTY(int error READ error NOTIFY sensorError)
+    Q_PROPERTY(bool alwaysOn READ isAlwaysOn WRITE setAlwaysOn NOTIFY alwaysOnChanged REVISION 1)
 #ifdef Q_QDOC
     Q_PROPERTY(int maxBufferSize)
     Q_PROPERTY(int efficientBufferSize)
@@ -120,6 +121,9 @@ public:
     void setActive(bool active);
     bool isActive() const;
 
+    bool isAlwaysOn() const;
+    void setAlwaysOn(bool alwaysOn);
+
     qrangelist availableDataRates() const;
     int dataRate() const;
     void setDataRate(int rate);
@@ -158,6 +162,7 @@ Q_SIGNALS:
     void readingChanged();
     void sensorError(int error);
     void availableSensorsChanged();
+    void alwaysOnChanged();
 
 protected:
     // called by the back end
diff --git a/src/sensors/qsensor_p.h b/src/sensors/qsensor_p.h
index 6458a828ed..de34cd02df 100644
--- a/src/sensors/qsensor_p.h
+++ b/src/sensors/qsensor_p.h
@@ -74,6 +74,7 @@ public:
         , filter_reading(0)
         , cache_reading(0)
         , error(0)
+        , alwaysOn(false)
     {
     }
 
@@ -99,6 +100,8 @@ public:
     QSensorReading *cache_reading;
 
     int error;
+
+    bool alwaysOn;
 };
 
 class QSensorReadingPrivate