From 2c9fc2c1a197b84ba9ef3dc4e586a77a18c3dcc5 Mon Sep 17 00:00:00 2001
From: BogDan Vatra <bogdan@kde.org>
Date: Tue, 2 Apr 2019 14:00:37 +0300
Subject: Say hello to Qt Android Sensors based on NDK API

Until Qt 5.9, we had to use JNI way because the NDK sensors API was
introduced in API-16. Starting with Qt 5.9 we can safely use the NDK API
as API_16 is the minimum API supported by Qt.
Using the NDK API instead of JNI boost the performance a lot! The CPU
usage dropped 2 to 4 times, from over 60% using the JNI to less than
20%.

[ChangeLog][Android] Rewrite Qt Android Sensors using NDK
API.

Change-Id: If3e3f1e56973e2a189662912b2a6ebfbd71dee14
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>
---
 src/plugins/sensors/android/androidcompass.h | 72 ++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 src/plugins/sensors/android/androidcompass.h

(limited to 'src/plugins/sensors/android/androidcompass.h')

diff --git a/src/plugins/sensors/android/androidcompass.h b/src/plugins/sensors/android/androidcompass.h
new file mode 100644
index 00000000..1d20de72
--- /dev/null
+++ b/src/plugins/sensors/android/androidcompass.h
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 BogDan Vatra <bogdan@kde.org>
+** Contact: https://www.qt.io/licensing/
+**
+** 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef ANDROIDCOMPASS_H
+#define ANDROIDCOMPASS_H
+
+#include <QMutex>
+#include <qcompass.h>
+
+#include "sensoreventqueue.h"
+
+class AndroidCompass : public ThreadSafeSensorBackend
+{
+    Q_OBJECT
+
+public:
+    AndroidCompass(QSensor *sensor, QObject *parent = nullptr);
+    ~AndroidCompass() override;
+
+    void start() override;
+    void stop() override;
+private:
+    void readAllEvents();
+    static int looperCallback(int /*fd*/, int /*events*/, void* data);
+
+private:
+    QCompassReading m_reading;
+    const ASensor *m_accelerometer = nullptr;
+    const ASensor *m_magnetometer = nullptr;
+    ASensorEventQueue* m_sensorEventQueue = nullptr;
+    ASensorVector m_accelerometerEvent;
+    ASensorVector m_magneticEvent;
+    QMutex m_sensorsMutex;
+};
+
+#endif // ANDROIDCOMPASS_H
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