Add freefall sensorgesture.

I did this as a gesture, but could easily be a virtual QSensor.

Change-Id: I95ea97745f8537dd6d6940b290d470d0367383c2
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>

3 files changed, 209 insertions, 0 deletions

diff --git a/src/plugins/sensorgestures/qtsensors/qfreefallsensorgesturerecognizer.cpp b/src/plugins/sensorgestures/qtsensors/qfreefallsensorgesturerecognizer.cpp
new file mode 100644
index 00000000..7ea843a2
--- /dev/null
+++ b/src/plugins/sensorgestures/qtsensors/qfreefallsensorgesturerecognizer.cpp
@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Lorn Potter
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtSensors module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <qmath.h>
+
+#include "qfreefallsensorgesturerecognizer.h"
+
+QT_BEGIN_NAMESPACE
+
+QFreefallSensorGestureRecognizer::QFreefallSensorGestureRecognizer(QObject *parent)
+    : QSensorGestureRecognizer(parent)
+    , active(0)
+    , detecting(0)
+{
+}
+
+QFreefallSensorGestureRecognizer::~QFreefallSensorGestureRecognizer()
+{
+}
+
+void QFreefallSensorGestureRecognizer::create()
+{
+}
+
+QString QFreefallSensorGestureRecognizer::id() const
+{
+    return QString("QtSensors.freefall");
+}
+
+bool QFreefallSensorGestureRecognizer::start()
+{
+    if (QtSensorGestureSensorHandler::instance()->startSensor(QtSensorGestureSensorHandler::Accel)) {
+        active = true;
+        connect(QtSensorGestureSensorHandler::instance(),SIGNAL(accelReadingChanged(QAccelerometerReading *)),
+                this,SLOT(accelChanged(QAccelerometerReading *)));
+    } else {
+        active = false;
+    }
+    return active;
+
+}
+
+bool QFreefallSensorGestureRecognizer::stop()
+{
+    QtSensorGestureSensorHandler::instance()->stopSensor(QtSensorGestureSensorHandler::Accel);
+    disconnect(QtSensorGestureSensorHandler::instance(),SIGNAL(accelReadingChanged(QAccelerometerReading*)),
+            this,SLOT(accelChanged(QAccelerometerReading *)));
+    active = false;
+
+    return active;
+}
+
+bool QFreefallSensorGestureRecognizer::isActive()
+{
+    return active;
+}
+
+#define FREEFALL_THRESHOLD 1.0
+#define LANDED_THRESHOLD 20.0
+#define FREEFALL_MAX 4
+
+void QFreefallSensorGestureRecognizer::accelChanged(QAccelerometerReading *reading)
+{
+    const qreal x = reading->x();
+    const qreal y = reading->y();
+    const qreal z = reading->z();
+    qreal sum = qSqrt(x * x + y * y + z * z);
+
+    if (qAbs(sum) < FREEFALL_THRESHOLD) {
+        detecting = true;
+        freefallList.append(sum);
+    } else {
+        if (detecting && qAbs(sum) > LANDED_THRESHOLD) {
+            Q_EMIT landed();
+            Q_EMIT detected("landed");
+            freefallList.clear();
+        }
+    }
+
+    if (freefallList.count() > FREEFALL_MAX) {
+        Q_EMIT freefall();
+        Q_EMIT detected("freefall");
+    }
+}
+
+
+QT_END_NAMESPACE
+
diff --git a/src/plugins/sensorgestures/qtsensors/qfreefallsensorgesturerecognizer.h b/src/plugins/sensorgestures/qtsensors/qfreefallsensorgesturerecognizer.h
new file mode 100644
index 00000000..094d0c6e
--- /dev/null
+++ b/src/plugins/sensorgestures/qtsensors/qfreefallsensorgesturerecognizer.h
@@ -0,0 +1,82 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Lorn Potter
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtSensors module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+
+#ifndef QFREEFALLSENSORGESTURERECOGNIZER_H
+#define QFREEFALLSENSORGESTURERECOGNIZER_H
+
+#include <qsensorgesturerecognizer.h>
+
+#include "qtsensorgesturesensorhandler.h"
+
+QT_BEGIN_NAMESPACE
+
+class QFreefallSensorGestureRecognizer : public QSensorGestureRecognizer
+{
+    Q_OBJECT
+public:
+    explicit QFreefallSensorGestureRecognizer(QObject *parent = 0);
+    ~QFreefallSensorGestureRecognizer();
+
+    void create();
+
+    QString id() const;
+    bool start();
+    bool stop();
+    bool isActive();
+
+Q_SIGNALS:
+    void freefall();
+    void landed();
+
+private slots:
+    void accelChanged(QAccelerometerReading *reading);
+
+private:
+
+    bool active;
+    bool detecting;
+    QList <qreal> freefallList;
+
+};
+QT_END_NAMESPACE
+#endif // QPICKUPSENSORGESTURERECOGNIZER_H
diff --git a/src/plugins/sensorgestures/qtsensors/qtsensors.pro b/src/plugins/sensorgestures/qtsensors/qtsensors.pro
index 68831786..de6c2780 100644
--- a/src/plugins/sensorgestures/qtsensors/qtsensors.pro
+++ b/src/plugins/sensorgestures/qtsensors/qtsensors.pro
@@ -9,6 +9,7 @@ HEADERS += qtsensorgestureplugin.h \
     qcoversensorgesturerecognizer.h \
     qdoubletapsensorgesturerecognizer.h \
     qhoversensorgesturerecognizer.h \
+    qfreefallsensorgesturerecognizer.h \
     qpickupsensorgesturerecognizer.h \
     qshake2recognizer.h \
     qslamgesturerecognizer.h \
@@ -21,6 +22,7 @@ SOURCES += qtsensorgestureplugin.cpp \
     qcoversensorgesturerecognizer.cpp \
     qdoubletapsensorgesturerecognizer.cpp \
     qhoversensorgesturerecognizer.cpp \
+    qfreefallsensorgesturerecognizer.cpp \
     qpickupsensorgesturerecognizer.cpp \
     qshake2recognizer.cpp \
     qslamgesturerecognizer.cpp \