Fix and simplify sensor_explorer example

This commit strives to both fix and simplify the application
and bring its intended demonstrative purpose more forward,
consequently hopefully also making the example easier to
understand and maintain.

First, the sensor_explorer example used QQC1 functionalities
which are no longer available in Qt6. The removed elements were
such that the datamodels needed to be redesigned. This commit
changes the example to use bit more standard Qt model-view
approach.

Second, the sensor_explorer application has not worked in years
on Android due to missing QML plugin installation. While this
could be fixed, in the name of simplicity the example is
now a single binary.

Third, the explorer allowed editing of sensor values. While
this could be a feature of the example, it perhaps deviates
from the gist of the example making it more difficult to
understand. Thus the editing was not added as part of the
example rewrite. It can be added later though.

Task-number: QTBUG-92514
Task-number: QTBUG-92505
Task-number: QTBUG-63054
Change-Id: Icd620ea605a87ba74a42cd1309a3c02d05b146ac
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>

1 files changed, 238 insertions, 0 deletions

diff --git a/examples/sensors/sensor_explorer/sensormodels.cpp b/examples/sensors/sensor_explorer/sensormodels.cpp
new file mode 100644
index 00000000..4766fc58
--- /dev/null
+++ b/examples/sensors/sensor_explorer/sensormodels.cpp
@@ -0,0 +1,238 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtSensors module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "sensormodels.h"
+#include "qsensor.h"
+#include "qorientationsensor.h"
+#include <QtCore/QDebug>
+#include <qsensor.h>
+#include <QMetaObject>
+#include <QMetaProperty>
+
+QT_BEGIN_NAMESPACE
+
+QByteArray rangelistToByteArray(const qrangelist& list)
+{
+    QStringList ranges;
+    for (const qrange &r : list) {
+        if (r.first == r.second)
+            ranges << QString("%1 Hz").arg(r.first);
+        else
+            ranges << QString("%1-%2 Hz").arg(r.first).arg(r.second);
+    }
+    if (ranges.count() > 0)
+        return ranges.join(", ").toLatin1();
+    return "-";
+}
+
+QByteArray outputrangelistToByteArray(const qoutputrangelist& list)
+{
+    QStringList ranges;
+    for (const qoutputrange &r : list) {
+        ranges << QString("(%1, %2) += %3").arg(r.minimum).arg(r.maximum).arg(r.accuracy);
+    }
+    if (ranges.count() > 0)
+        return ranges.join(", ").toLatin1();
+    return "-";
+}
+
+AvailableSensorsModel::AvailableSensorsModel(QObject* parent) : QAbstractListModel(parent)
+{
+    // Some valuetypes do not convert nicely to presentable strings, add converters for them
+    QMetaType::registerConverter<qrangelist, QByteArray>(rangelistToByteArray);
+    QMetaType::registerConverter<qoutputrangelist, QByteArray>(outputrangelistToByteArray);
+
+    // Populate the available sensors list
+    loadSensors();
+}
+
+/*
+    Load all available sensors and store them in a list.
+*/
+void AvailableSensorsModel::loadSensors()
+{
+    //! [0]
+    beginResetModel();
+    m_availableSensors.clear();
+
+    for (const QByteArray &type : QSensor::sensorTypes()) {
+        for (const QByteArray &identifier : QSensor::sensorsForType(type)) {
+            QSensor* sensor = new QSensor(type, this);
+            sensor->setIdentifier(identifier);
+            // Don't put in sensors we can't connect to
+            if (!sensor->connectToBackend())
+                continue;
+            m_availableSensors.append(sensor);
+        }
+    }
+    endResetModel();
+    //! [0]
+}
+
+int AvailableSensorsModel::rowCount(const QModelIndex&) const
+{
+    return m_availableSensors.count();
+}
+
+//! [1]
+QVariant AvailableSensorsModel::data(const QModelIndex &index, int role) const
+{
+    if (role != Qt::DisplayRole)
+        return QVariant();
+    return QVariant::fromValue<QSensor*>(m_availableSensors.at(index.row()));
+}
+//! [1]
+
+QSensor* AvailableSensorsModel::get(int index) const
+{
+    if (index < 0 || index >= m_availableSensors.count())
+        return nullptr;
+    return m_availableSensors[index];
+}
+
+// -- SensorPropertyModel
+
+static QSet<QByteArray> ignoredProperties = {"reading", "identifier", "active",
+                                             "connectedToBackend", "busy"};
+
+SensorPropertyModel::SensorPropertyModel(QObject* parent) : QAbstractTableModel(parent)
+{
+}
+
+int SensorPropertyModel::rowCount(const QModelIndex&) const
+{
+    if (!m_sensor)
+        return 0;
+    return m_values.count();
+}
+
+int SensorPropertyModel::columnCount(const QModelIndex&) const
+{
+    return 2; // 2 = property name + value columns
+}
+
+QVariant SensorPropertyModel::data(const QModelIndex &index, int role) const
+{
+    if (role != Qt::DisplayRole)
+        return QVariant();
+    return (index.column() == 0) ? std::get<0>(m_values.at(index.row()))
+                                 : std::get<1>(m_values.at(index.row()));
+}
+
+void SensorPropertyModel::setSensor(QSensor *sensor)
+{
+    if (m_sensor == sensor)
+        return;
+    if (m_sensor)
+        m_sensor->disconnect(this);
+    m_sensor = sensor;
+
+    beginResetModel();
+    m_values.clear();
+    if (m_sensor) {
+        // Use metobject to read the available properties. This allows the model to support all
+        // available sensors without knowing their properties in advance / compile-time.
+
+        // 1. Read properties of the 'reading' object if available
+        //! [2]
+        int firstProperty = QSensorReading::staticMetaObject.propertyOffset();
+        QSensorReading *reading = m_sensor->reading();
+        if (reading) {
+            const QMetaObject *mo = reading->metaObject();
+            for (int i = firstProperty; i < mo->propertyCount(); ++i) {
+                QByteArray name = mo->property(i).name();
+                m_values.append(std::tuple<QByteArray, QByteArray>
+                                (name, reading->property(name).toByteArray()));
+            }
+        }
+        //! [2]
+
+        // 2. Read properties of the 'sensor' object
+        const QMetaObject *mo1 = m_sensor->metaObject();
+        firstProperty = QSensorReading::staticMetaObject.propertyOffset();
+        for (int i = firstProperty; i < mo1->propertyCount(); ++i) {
+            QByteArray name = mo1->property(i).name();
+            if (ignoredProperties.contains(name))
+                continue;
+            m_values.append(std::tuple<QByteArray, QByteArray>
+                            (name, m_sensor->property(name).toByteArray()));
+        }
+        QObject::connect(m_sensor, &QSensor::readingChanged,
+                         this, &SensorPropertyModel::onReadingChanged);
+    }
+    endResetModel();
+    emit sensorChanged();
+}
+
+QSensor* SensorPropertyModel::sensor() const
+{
+    return m_sensor;
+}
+
+void SensorPropertyModel::onReadingChanged()
+{
+    QSensorReading *reading = m_sensor->reading();
+    const QMetaObject *mo = reading->metaObject();
+    int firstProperty = QSensorReading::staticMetaObject.propertyOffset();
+
+    int valueMapIndex = 0;
+    for (int i = firstProperty; i < mo->propertyCount(); ++i) {
+        QByteArray name = mo->property(i).name();
+        // Update the value and signal the change. Note: here we rely that the "reading"
+        // properties are first on the m_values, and in same order as after the initial
+        // population. This should be true as we access the static metabobject (dynamic
+        // property changes shouldn't impact)
+        m_values[valueMapIndex++] = std::tuple<QByteArray, QByteArray>
+                (name, reading->property(name).toByteArray());
+    }
+    emit dataChanged(createIndex(0,1), createIndex(valueMapIndex,1), {Qt::DisplayRole});
+}
+
+QT_END_NAMESPACE