Add API for duplicate skipping

Duplicate skipping enables omitting reading values
that are very similar to the previous one, thus saving
processing power.

Implement this for the Blackberry backend.

Change-Id: Ic608d8ca795b5a2e0bca5a75a62e8005c283c620
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>

3 files changed, 14 insertions, 14 deletions

diff --git a/src/plugins/sensors/blackberry/bborientationsensor.cpp b/src/plugins/sensors/blackberry/bborientationsensor.cpp
index 68ed735b..3d9d120c 100644
--- a/src/plugins/sensors/blackberry/bborientationsensor.cpp
+++ b/src/plugins/sensors/blackberry/bborientationsensor.cpp
@@ -44,6 +44,9 @@ BbOrientationSensor::BbOrientationSensor(QSensor *sensor)
     : BbSensorBackend<QOrientationReading>(devicePath(), SENSOR_TYPE_ORIENTATION, sensor)
 {
     setDescription(QLatin1String("Device orientation"));
+
+    // Orientation rarely changes, so enable skipping of duplicates by default
+    sensor->setSkipDuplicates(true);
 }
 
 QString BbOrientationSensor::devicePath()
@@ -51,19 +54,6 @@ QString BbOrientationSensor::devicePath()
     return QLatin1String("/dev/sensor/orientation");
 }
 
-void BbOrientationSensor::start()
-{
-    BbSensorBackend<QOrientationReading>::start();
-
-    // Orientation rarely changes, so enable skiping of duplicates
-    sensor_devctl_skipdupevent_u deviceSkip;
-    deviceSkip.tx.enable = 1;
-    const int result = devctl(deviceFile().handle(), DCMD_SENSOR_SKIPDUPEVENT, &deviceSkip,
-                              sizeof(deviceSkip), NULL);
-    if (result != EOK)
-        perror("Enabling duplicate skipping for orientation sensor failed");
-}
-
 void BbOrientationSensor::additionalDeviceInit()
 {
     // When querying the OS service for the range, it gives us the angles, which we don't need.
diff --git a/src/plugins/sensors/blackberry/bborientationsensor.h b/src/plugins/sensors/blackberry/bborientationsensor.h
index 07dc3d0f..85c7bd67 100644
--- a/src/plugins/sensors/blackberry/bborientationsensor.h
+++ b/src/plugins/sensors/blackberry/bborientationsensor.h
@@ -53,7 +53,6 @@ public:
 
     static QString devicePath();
 
-    void start() Q_DECL_OVERRIDE;
     void additionalDeviceInit() Q_DECL_OVERRIDE;
     bool addDefaultRange() Q_DECL_OVERRIDE;
 
diff --git a/src/plugins/sensors/blackberry/bbsensorbackend.cpp b/src/plugins/sensors/blackberry/bbsensorbackend.cpp
index 324929fd..9850d4dd 100644
--- a/src/plugins/sensors/blackberry/bbsensorbackend.cpp
+++ b/src/plugins/sensors/blackberry/bbsensorbackend.cpp
@@ -254,6 +254,16 @@ void BbSensorBackendBase::start()
         }
     }
 
+    // Enable/disable duplicate skipping
+    sensor_devctl_skipdupevent_u deviceSkip;
+    deviceSkip.tx.enable = sensor()->skipDuplicates();
+    const int result = devctl(deviceFile().handle(), DCMD_SENSOR_SKIPDUPEVENT, &deviceSkip,
+                              sizeof(deviceSkip), NULL);
+    if (result != EOK) {
+        perror(QString::fromLatin1("Setting duplicate skipping for %1 failed")
+               .arg(m_deviceFile.fileName()).toLocal8Bit());
+    }
+
     // Explicitly switch to non-blocking mode, otherwise read() will wait until new sensor
     // data is available, and we have no way to check if there is more data or not (bytesAvailable()
     // does not work for unbuffered mode)
@@ -299,6 +309,7 @@ bool BbSensorBackendBase::isFeatureSupported(QSensor::Feature feature) const
     case QSensor::AlwaysOn:
     case QSensor::Buffering:
     case QSensor::AccelerationMode:
+    case QSensor::SkipDuplicates:
         return true;
     case QSensor::Reserved:
     case QSensor::GeoValues: