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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant reason:default
#include "qdeclarativepositionsource_p.h"
#include "qdeclarativeposition_p.h"
#include <QtCore/QCoreApplication>
#include <QtQml/qqmlinfo.h>
#include <QtQml/qqml.h>
#include <qdeclarativepluginparameter_p.h>
#include <QFile>
#include <QtNetwork/QTcpSocket>
#include <QTimer>
QT_BEGIN_NAMESPACE
/*!
\qmltype PositionSource
//! \nativetype QDeclarativePositionSource
\inqmlmodule QtPositioning
\since 5.2
\brief The PositionSource type provides the device's current position.
The PositionSource type provides information about the user device's
current position. The position is available as a \l{Position} type, which
contains all the standard parameters typically available from GPS and other
similar systems, including longitude, latitude, speed and accuracy details.
As different position sources are available on different platforms and
devices, these are categorized by their basic type (Satellite, NonSatellite,
and AllPositioningMethods). The available methods for the current platform
can be enumerated in the \l{supportedPositioningMethods} property.
To indicate which methods are suitable for your application, set the
\l{preferredPositioningMethods} property. If the preferred methods are not
available, the default source of location data for the platform will be
chosen instead. If no default source is available (because none are installed
for the runtime platform, or because it is disabled), the \l{valid} property
will be set to false.
The \l updateInterval property can then be used to indicate how often your
application wishes to receive position updates. The \l{start}(),
\l{stop}() and \l{update}() methods can be used to control the operation
of the PositionSource, as well as the \l{active} property, which when set
is equivalent to calling \l{start}() or \l{stop}().
When the PositionSource is active, position updates can be retrieved
either by simply using the \l{position} property in a binding (as the
value of another item's property), or by providing an implementation of
the \c {onPositionChanged} signal-handler.
\section2 Example Usage
The following example shows a simple PositionSource used to receive
updates every second and print the longitude and latitude out to
the console.
\code
PositionSource {
id: src
updateInterval: 1000
active: true
onPositionChanged: {
var coord = src.position.coordinate;
console.log("Coordinate:", coord.longitude, coord.latitude);
}
}
\endcode
\section2 Controlling Operation State
As it's mentioned above, PositionSource provides two ways to control its
operation state:
\list
\li By using the \l active \l {Qt Bindable Properties}{bindable} property.
\li By using \l start() and \l stop() methods.
\endlist
\note It's very important not to mix these approaches. If a bindable
\l active property is used to control the PositionSource object, but later
\l start() or \l stop() is called from the other part of the code, the
binding is broken, which may result in, for example, a UI element that is
not connected to any underlying object anymore.
Consider the following example of \b {bad code} where the \c active property
is bound to the CheckBox state, and calling \l stop() in the \c onClicked
signal handler breaks that binding.
\qml
Window {
width: 640
height: 480
visible: true
PositionSource {
id: posSource
name: "geoclue2"
active: cb.checked
}
Column {
anchors.centerIn: parent
spacing: 20
CheckBox {
id: cb
}
Button {
id: btn
text: "Stop"
onClicked: {
posSource.stop()
}
}
}
}
\endqml
Once the \e Stop button is clicked, \l stop() is executed, and the binding
for the \l active property is broken. At this point the CheckBox UI element
is no longer controlling the PositionSource object.
A straightforward fix in this case is to update the CheckBox state from
the \c onClicked handler. As soon as the CheckBox is unchecked, the
\l active property will be notified, and the PositionSource object's state
will update accordingly. The UI will also be in a consistent state.
\qml
Button {
id: btn
text: "Stop"
onClicked: {
cb.checked = false
}
}
\endqml
\note Using \l update() to request a single position update \e {does not}
have any effect on the \l active property's bindings, so they can be used
together without any problems.
\sa {QtPositioning::Position}, {QGeoPositionInfoSource}, {PluginParameter},
{Qt Bindable Properties}
*/
QDeclarativePositionSource::QDeclarativePositionSource()
: m_singleUpdate(0), m_regularUpdates(0), m_componentComplete(0),
m_parametersInitialized(0), m_startRequested(0), m_defaultSourceUsed(0)
{
m_position.setValueBypassingBindings(new QDeclarativePosition(this));
}
QDeclarativePositionSource::~QDeclarativePositionSource()
{
delete m_positionSource;
}
/*!
\qmlproperty string PositionSource::name
This property holds the unique internal name for the plugin currently
providing position information.
Setting the property causes the PositionSource to use a particular positioning provider. If
the PositionSource is active at the time that the name property is changed, it will become
inactive. If the specified positioning provider cannot be loaded the position source will
become invalid.
Changing the name property may cause the \l {updateInterval}, \l {supportedPositioningMethods}
and \l {preferredPositioningMethods} properties to change as well.
*/
QString QDeclarativePositionSource::name() const
{
return m_sourceName;
}
void QDeclarativePositionSource::setName(const QString &newName)
{
m_sourceName.removeBindingUnlessInWrapper();
if (m_positionSource && m_positionSource->sourceName() == newName)
return;
if (newName.isEmpty() && m_defaultSourceUsed)
return; // previously attached to a default source, now requesting the same.
const QString previousName = m_sourceName.valueBypassingBindings();
if (!m_componentComplete || !m_parametersInitialized) {
if (previousName != newName) {
m_sourceName.setValueBypassingBindings(newName);
m_sourceName.notify();
}
return;
}
// tryAttach() will update the m_sourceName correctly
tryAttach(newName, false);
}
QBindable<QString> QDeclarativePositionSource::bindableName()
{
return QBindable<QString>(&m_sourceName);
}
QBindable<QDeclarativePosition *> QDeclarativePositionSource::bindablePosition() const
{
return QBindable<QDeclarativePosition *>(&m_position);
}
/*!
\internal
*/
void QDeclarativePositionSource::tryAttach(const QString &newName, bool useFallback)
{
const QString previousName = name();
const bool sourceExisted = (m_positionSource != nullptr);
int previousUpdateInterval = updateInterval();
PositioningMethods previousPositioningMethods = supportedPositioningMethods();
PositioningMethods previousPreferredPositioningMethods = preferredPositioningMethods();
m_defaultSourceUsed = false;
if (newName.isEmpty()) {
setSource(QGeoPositionInfoSource::createDefaultSource(parameterMap(), this));
m_defaultSourceUsed = true;
} else {
setSource(QGeoPositionInfoSource::createSource(newName, parameterMap(), this));
if (!m_positionSource && useFallback) {
setSource(QGeoPositionInfoSource::createDefaultSource(parameterMap(), this));
m_defaultSourceUsed = true;
}
}
if (m_positionSource) {
m_sourceName.setValueBypassingBindings(m_positionSource->sourceName());
connect(m_positionSource, SIGNAL(positionUpdated(QGeoPositionInfo)),
this, SLOT(positionUpdateReceived(QGeoPositionInfo)));
connect(m_positionSource, SIGNAL(errorOccurred(QGeoPositionInfoSource::Error)),
this, SLOT(sourceErrorReceived(QGeoPositionInfoSource::Error)));
m_positionSource->setUpdateInterval(m_updateInterval);
m_positionSource->setPreferredPositioningMethods(
static_cast<QGeoPositionInfoSource::PositioningMethods>(int(m_preferredPositioningMethods)));
if (m_startRequested) {
const QGeoPositionInfo &lastKnown = m_positionSource->lastKnownPosition();
if (lastKnown.isValid())
setPosition(lastKnown);
}
} else {
m_sourceName.setValueBypassingBindings(newName);
m_defaultSourceUsed = false;
if (m_active) {
// We do not want to break the binding here, because we just want to
// give the user an opportunity to select another plugin and keep
// working.
m_active.setValueBypassingBindings(false);
m_active.notify();
}
}
if (previousUpdateInterval != updateInterval())
emit updateIntervalChanged();
if (previousPreferredPositioningMethods != preferredPositioningMethods())
emit preferredPositioningMethodsChanged();
if (previousPositioningMethods != supportedPositioningMethods())
notifySupportedPositioningMethodsChanged();
const bool sourceCurrentlyExists = (m_positionSource != nullptr);
if (sourceExisted != sourceCurrentlyExists) {
m_isValid.notify();
emit validityChanged();
}
if (m_active) { // implies m_positionSource
// If m_active is true, then the previous position source existed!
Q_ASSERT(sourceExisted);
// New source is set. It should be inactive by default.
// But we do not want to break the binding.
m_active.setValueBypassingBindings(false);
m_active.notify();
} else if (m_startRequested) {
m_startRequested = false;
executeStart();
}
if (previousName != m_sourceName)
m_sourceName.notify();
}
/*!
\qmlproperty bool PositionSource::valid
This property is true if the PositionSource object has acquired a valid
backend plugin to provide data. If false, other methods on the PositionSource
will have no effect.
Applications should check this property to determine whether positioning is
available and enabled on the runtime platform, and react accordingly.
*/
bool QDeclarativePositionSource::isValid() const
{
return m_isValid.value();
}
QBindable<bool> QDeclarativePositionSource::bindableIsValid() const
{
return QBindable<bool>(&m_isValid);
}
bool QDeclarativePositionSource::isValidActualComputation() const
{
return m_positionSource != nullptr;
}
/*!
\internal
*/
void QDeclarativePositionSource::onParameterInitialized()
{
m_parametersInitialized = true;
for (QDeclarativePluginParameter *p: std::as_const(m_parameters)) {
if (!p->isInitialized()) {
m_parametersInitialized = false;
break;
}
}
// If here, componentComplete has been called.
if (m_parametersInitialized)
tryAttach(m_sourceName.value());
}
void QDeclarativePositionSource::notifySupportedPositioningMethodsChanged()
{
m_supportedPositioningMethods.notify();
emit supportedPositioningMethodsChanged();
}
void QDeclarativePositionSource::setPosition(const QGeoPositionInfo &pi)
{
m_position.value()->setPosition(pi);
m_position.notify();
emit positionChanged();
}
void QDeclarativePositionSource::setSource(QGeoPositionInfoSource *source)
{
if (m_positionSource)
delete m_positionSource;
if (!source) {
m_positionSource = nullptr;
} else {
m_positionSource = source;
connect(m_positionSource, &QGeoPositionInfoSource::supportedPositioningMethodsChanged,
this, &QDeclarativePositionSource::notifySupportedPositioningMethodsChanged);
}
}
bool QDeclarativePositionSource::parametersReady()
{
for (const QDeclarativePluginParameter *p: std::as_const(m_parameters)) {
if (!p->isInitialized())
return false;
}
return true;
}
/*!
\internal
*/
QVariantMap QDeclarativePositionSource::parameterMap() const
{
QVariantMap map;
for (const auto *parameter : m_parameters)
map.insert(parameter->name(), parameter->value());
return map;
}
/*!
\internal
*/
void QDeclarativePositionSource::setUpdateInterval(int updateInterval)
{
if (m_positionSource) {
int previousUpdateInterval = m_positionSource->updateInterval();
m_updateInterval = updateInterval;
if (previousUpdateInterval != updateInterval) {
m_positionSource->setUpdateInterval(updateInterval);
if (previousUpdateInterval != m_positionSource->updateInterval())
emit updateIntervalChanged();
}
} else {
if (m_updateInterval != updateInterval) {
m_updateInterval = updateInterval;
emit updateIntervalChanged();
}
}
}
/*!
\qmlproperty int PositionSource::updateInterval
This property holds the desired interval between updates (milliseconds).
\sa {QGeoPositionInfoSource::updateInterval()}
*/
int QDeclarativePositionSource::updateInterval() const
{
if (!m_positionSource)
return m_updateInterval;
return m_positionSource->updateInterval();
}
/*!
\qmlproperty enumeration PositionSource::supportedPositioningMethods
This property holds the supported positioning methods of the
current source.
\value PositionSource.NoPositioningMethods
No positioning methods supported (no source).
\value PositionSource.SatellitePositioningMethods
Satellite-based positioning methods such as GPS are supported.
\value PositionSource.NonSatellitePositioningMethods
Non-satellite-based methods are supported.
\value PositionSource.AllPositioningMethods
Both satellite-based and non-satellite positioning methods are supported.
*/
QDeclarativePositionSource::PositioningMethods
QDeclarativePositionSource::supportedPositioningMethods() const
{
return m_supportedPositioningMethods.value();
}
QDeclarativePositionSource::PositioningMethods
QDeclarativePositionSource::supportedMethodsActualComputation() const
{
if (m_positionSource) {
return static_cast<QDeclarativePositionSource::PositioningMethods>(
int(m_positionSource->supportedPositioningMethods()));
}
return QDeclarativePositionSource::NoPositioningMethods;
}
QBindable<QDeclarativePositionSource::PositioningMethods>
QDeclarativePositionSource::bindableSupportedPositioningMethods() const
{
return QBindable<PositioningMethods>(&m_supportedPositioningMethods);
}
/*!
\qmlproperty enumeration PositionSource::preferredPositioningMethods
This property holds the preferred positioning methods of the
current source.
\value PositionSource.NoPositioningMethods
No positioning method is preferred.
\value PositionSource.SatellitePositioningMethods
Satellite-based positioning methods such as GPS should be preferred.
\value PositionSource.NonSatellitePositioningMethods
Non-satellite-based methods should be preferred.
\value PositionSource.AllPositioningMethods
Any positioning methods are acceptable.
*/
void QDeclarativePositionSource::setPreferredPositioningMethods(PositioningMethods methods)
{
if (m_positionSource) {
PositioningMethods previousPreferredPositioningMethods = preferredPositioningMethods();
m_preferredPositioningMethods = methods;
if (previousPreferredPositioningMethods != methods) {
m_positionSource->setPreferredPositioningMethods(
static_cast<QGeoPositionInfoSource::PositioningMethods>(int(methods)));
if (previousPreferredPositioningMethods != m_positionSource->preferredPositioningMethods())
emit preferredPositioningMethodsChanged();
}
} else {
if (m_preferredPositioningMethods != methods) {
m_preferredPositioningMethods = methods;
emit preferredPositioningMethodsChanged();
}
}
}
QDeclarativePositionSource::PositioningMethods QDeclarativePositionSource::preferredPositioningMethods() const
{
if (m_positionSource) {
return static_cast<QDeclarativePositionSource::PositioningMethods>(
int(m_positionSource->preferredPositioningMethods()));
}
return m_preferredPositioningMethods;
}
/*!
\qmlmethod void PositionSource::start()
Requests updates from the location source.
Uses \l updateInterval if set, default interval otherwise.
If there is no source available, this method has no effect.
\note Calling this method breaks the bindings of
\l {PositionSource::}{active} property.
\sa stop(), update(), active
*/
void QDeclarativePositionSource::start()
{
if (m_positionSource) {
m_active.removeBindingUnlessInWrapper();
executeStart();
}
}
/*!
\qmlmethod void PositionSource::update(int timeout)
A convenience method to request single update from the location source.
If there is no source available, this method has no effect.
If the position source is not active, it will be activated for as
long as it takes to receive an update, or until the request times
out. The request timeout period is source-specific.
The \a timeout is specified in milliseconds. If the \a timeout is zero
(the default value), it defaults to a reasonable timeout period as
appropriate for the source.
\sa start(), stop(), active
*/
void QDeclarativePositionSource::update(int timeout)
{
if (m_positionSource) {
m_singleUpdate = true;
if (!m_active) {
// Questionable: we do not want this method to break the binding.
// Mostly because it can be called while the updates are already
// running.
m_active.setValueBypassingBindings(true);
m_active.notify();
}
// Use default timeout value. Set active before calling the
// update request because on some platforms there may
// be results immediately.
m_positionSource->requestUpdate(timeout);
}
}
/*!
\qmlmethod void PositionSource::stop()
Stops updates from the location source.
If there is no source available or it is not active,
this method has no effect.
\note Calling this method breaks the bindings of
\l {PositionSource::}{active} property.
\sa start(), update(), active
*/
void QDeclarativePositionSource::stop()
{
if (m_positionSource) {
m_positionSource->stopUpdates();
m_regularUpdates = false;
// Try to break the binding even if we do not actually need to update
// the active state. The m_active can be updated later, when the
// single update request finishes.
m_active.removeBindingUnlessInWrapper();
if (m_active && !m_singleUpdate) {
m_active.setValueBypassingBindings(false);
m_active.notify();
}
}
}
/*!
\qmlproperty bool PositionSource::active
This property indicates whether the position source is active.
Setting this property to false equals calling \l stop, and
setting this property true equals calling \l start.
\sa start, stop, update
*/
void QDeclarativePositionSource::setActive(bool active)
{
// We need to remove binding, if this method is called explicitly.
// Other changes to m_active are done inside start() and stop() methods.
m_active.removeBindingUnlessInWrapper();
if (active == m_active)
return;
if (active) {
// If the component is not completed yet, we need to defer the
// actual executeStart() call until everything is set up.
if (m_componentComplete && m_parametersInitialized)
executeStart();
else
m_startRequested = true;
} else {
stop();
}
}
bool QDeclarativePositionSource::isActive() const
{
return m_active;
}
/*!
\qmlproperty Position PositionSource::position
This property holds the last known positional data.
It is a read-only property.
The Position type has different positional member variables,
whose validity can be checked with appropriate validity functions
(for example sometimes an update does not have speed or altitude data).
However, whenever a \c {positionChanged} signal has been received, at least
position::coordinate::latitude, position::coordinate::longitude, and position::timestamp can
be assumed to be valid.
\sa start, stop, update
*/
QDeclarativePosition *QDeclarativePositionSource::position()
{
return m_position.value();
}
void QDeclarativePositionSource::positionUpdateReceived(const QGeoPositionInfo &update)
{
setPosition(update);
if (m_singleUpdate && m_active) {
// we need to reset m_singleUpdate because we got one
m_singleUpdate = false;
if (!m_regularUpdates) {
// but we change the active state only if the regular updates are
// also stopped
m_active.setValueBypassingBindings(false);
m_active.notify();
}
}
}
/*!
\qmlproperty enumeration PositionSource::sourceError
This property holds the error which last occurred with the PositionSource.
\value PositionSource.AccessError
The connection setup to the remote positioning backend failed because the
application lacked the required privileges.
\value PositionSource.ClosedError
The positioning backend closed the connection, which happens for example in case
the user is switching location services to off. As soon as the location service is re-enabled
regular updates will resume.
\value PositionSource.NoError No error has occurred.
\value PositionSource.UnknownSourceError An unidentified error occurred.
\value PositionSource.UpdateTimeoutError
The current position could not be
retrieved within the specified timeout, or this PositionSource determined
that it will not be able to provide further regular updates.
*/
QDeclarativePositionSource::SourceError QDeclarativePositionSource::sourceError() const
{
return m_sourceError;
}
QBindable<QDeclarativePositionSource::SourceError>
QDeclarativePositionSource::bindableSourceError() const
{
return QBindable<QDeclarativePositionSource::SourceError>(&m_sourceError);
}
QGeoPositionInfoSource *QDeclarativePositionSource::positionSource() const
{
return m_positionSource;
}
/*!
\qmlproperty list<PluginParameter> PositionSource::parameters
\qmldefault
This property holds the list of plugin parameters.
\since QtPositioning 5.14
*/
QQmlListProperty<QDeclarativePluginParameter> QDeclarativePositionSource::parameters()
{
return QQmlListProperty<QDeclarativePluginParameter>(this,
0,
parameter_append,
parameter_count,
parameter_at,
parameter_clear);
}
/*!
\internal
*/
void QDeclarativePositionSource::parameter_append(QQmlListProperty<QDeclarativePluginParameter> *prop, QDeclarativePluginParameter *parameter)
{
QDeclarativePositionSource *p = static_cast<QDeclarativePositionSource *>(prop->object);
p->m_parameters.append(parameter);
}
/*!
\internal
*/
qsizetype QDeclarativePositionSource::parameter_count(QQmlListProperty<QDeclarativePluginParameter> *prop)
{
return static_cast<QDeclarativePositionSource *>(prop->object)->m_parameters.size();
}
/*!
\internal
*/
QDeclarativePluginParameter *QDeclarativePositionSource::parameter_at(QQmlListProperty<QDeclarativePluginParameter> *prop, qsizetype index)
{
return static_cast<QDeclarativePositionSource *>(prop->object)->m_parameters[index];
}
/*!
\internal
*/
void QDeclarativePositionSource::parameter_clear(QQmlListProperty<QDeclarativePluginParameter> *prop)
{
QDeclarativePositionSource *p = static_cast<QDeclarativePositionSource *>(prop->object);
p->m_parameters.clear();
}
void QDeclarativePositionSource::executeStart()
{
if (m_positionSource) {
m_positionSource->startUpdates();
// If this method is called directly from start(), the binding is
// already broken there (for the consistency with stop()).
// If this method is called by a timer, started in setActive(), we do
// not need to break the binding, because it was already done (if
// needed).
m_regularUpdates = true;
if (!m_active) {
m_active.setValueBypassingBindings(true);
m_active.notify();
}
}
}
void QDeclarativePositionSource::componentComplete()
{
m_componentComplete = true;
m_parametersInitialized = true;
for (QDeclarativePluginParameter *p: std::as_const(m_parameters)) {
if (!p->isInitialized()) {
m_parametersInitialized = false;
connect(p, &QDeclarativePluginParameter::initialized,
this, &QDeclarativePositionSource::onParameterInitialized,
Qt::SingleShotConnection);
}
}
if (m_parametersInitialized)
tryAttach(m_sourceName.value());
}
/*!
\qmlmethod bool PositionSource::setBackendProperty(string name, var value)
Sets the backend-specific property named \a name to \a value.
Returns true on success, false otherwise, including if called on an uninitialized PositionSource.
Supported backend-specific properties are listed and described in
\l {Qt Positioning plugins#Default plugins}.
\since Qt Positioning 5.14
\sa backendProperty, QGeoPositionInfoSource::setBackendProperty
*/
bool QDeclarativePositionSource::setBackendProperty(const QString &name, const QVariant &value)
{
if (m_positionSource)
return m_positionSource->setBackendProperty(name, value);
return false;
}
/*!
\qmlmethod var PositionSource::backendProperty(string name)
Returns the value of the backend-specific property named \a name, if present.
Otherwise, including if called on an uninitialized PositionSource, the return value will be invalid.
Supported backend-specific properties are listed and described in
\l {Qt Positioning plugins#Default plugins}.
\since Qt Positioning 5.14
\sa setBackendProperty, QGeoPositionInfoSource::setBackendProperty
*/
QVariant QDeclarativePositionSource::backendProperty(const QString &name) const
{
if (m_positionSource)
return m_positionSource->backendProperty(name);
return QVariant();
}
QBindable<bool> QDeclarativePositionSource::bindableActive()
{
return QBindable<bool>(&m_active);
}
/*!
\internal
*/
void QDeclarativePositionSource::sourceErrorReceived(const QGeoPositionInfoSource::Error error)
{
if (error == QGeoPositionInfoSource::AccessError)
m_sourceError.setValueBypassingBindings(QDeclarativePositionSource::AccessError);
else if (error == QGeoPositionInfoSource::ClosedError)
m_sourceError.setValueBypassingBindings(QDeclarativePositionSource::ClosedError);
else if (error == QGeoPositionInfoSource::UpdateTimeoutError)
m_sourceError.setValueBypassingBindings(QDeclarativePositionSource::UpdateTimeoutError);
else if (error == QGeoPositionInfoSource::NoError)
return; //nothing to do
else
m_sourceError.setValueBypassingBindings(QDeclarativePositionSource::UnknownSourceError);
m_sourceError.notify();
emit sourceErrorChanged();
// if an error occurred during single update, the update is stopped, so we
// need to change the active state.
if (m_active && m_singleUpdate) {
m_singleUpdate = false;
if (!m_regularUpdates) {
m_active.setValueBypassingBindings(false);
m_active.notify();
}
}
}
QT_END_NAMESPACE
#include "moc_qdeclarativepositionsource_p.cpp"