[Interest] Geoposition and Ubuntu 18.04

[Alex Blasche]

Hi,

Indeed the GeoClue 2 plugin was added to 5.12. However it is a plugin and the interfaces to plugins have not changed. You could simply build the plugin (src/plugins/position/geoclue2/) in your 5.9.x tree.

--
Alex

________________________________________
From: Interest <interest-bounces at lists.qt-project.org> on behalf of Denis Shienkov <denis.shienkov at gmail.com>
Sent: Sunday, 9 December 2018 9:02:41 PM
To: interest at lists.qt-project.org
Subject: Re: [Interest] Geoposition and Ubuntu 18.04

Hi,

That patch adds the support for Geoclue v2 only, which should be available since Qt 5.12 (but not since Qt 5.9.7, AFAIK).
You can try to check it with lookup the 'qtposition_geoclue2.so' file in the installed Qt's plugins path.
* Also, make sure that your distro has geoclue2 installed.
* Also it is unnecessary to use the QT_GEOCLUE_APP_DESKTOP_ID variable, it is enough to specify the
QCoreApplication::applicationName() property instead.
* Besides, I'm not sure that this QGeoPositionInfoSource::createDefaultSource(this) will work, because it may be not 'default' plugin.
Just try to use availableSources() && createSource() instead.

Denis.

09.12.2018 22:23, roland at logikalsolutions.com<mailto:roland at logikalsolutions.com> пишет:

All,

I've just started poking around with the GeopositionInfo stuff now that Ubuntu 18.04 has location services. Can't find good C++ examples. Everyone seems to focus on worthless QML.

First off:  Huge serious kudos to Denis Shienkov for https://codereview.qt-project.org/#/c/229911/
That bug report was better than any of the documentation. Well worth a read.


For purposes of this discussion we will call the application Fred to protect the guilty.

The application has the following snippet of code.

    syslog( LOG_MAKEPRI(LOG_USER, LOG_INFO), "%s", "Trying to create default GeoPositionInfoSource");
    qDebug() << "Trying to create default GeoPositionInfoSource";

    m_geoSource = QGeoPositionInfoSource::createDefaultSource(this);

    if (m_geoSource)
    {
        syslog( LOG_MAKEPRI(LOG_USER, LOG_INFO), "%s", "successfully created default GeopositionInfoSource");
        qDebug() << "successfully created default GeopositionInfoSource";
        connect(m_geoSource, SIGNAL(positionUpdated(QGeoPositionInfo)),
                this, SLOT(positionUpdated(QGeoPositionInfo)));
#ifdef QT_DEBUG
        m_geoSource->setUpdateInterval( 1000 * 60 * 2);  // 1000ms in a second
#else
        m_geoSource->setUpdateInterval( 1000 * 60 * 45);  // 1000ms in a second
#endif
        m_geoSource->startUpdates();
    }
    else
    {
        syslog( LOG_MAKEPRI(LOG_USER, LOG_ERR), "%s", "Unable to create default GeopositionInfoSource");
        qDebug() << "Unable to create default GeopositionInfoSource";
    }

I have enabled location services in Ubuntu 18.04 and am debugging inside of QtCreator. The .profile for my account contains:

export QT_GEOCLUE_APP_DESKTOP_ID=ipos

and I've added fred to /etc/geoclue/geoclue.conf

[fred]
allowed=true
system=false
users=

When I compiled 5.9.7 from source the following snippet is from the configuration summary.

Qt Positioning:
  Gypsy GPS Daemon ....................... no
  WinRT Geolocation API .................. no
Qt Location:
  Geoservice plugins:
    OpenStreetMap ........................ yes
    HERE ................................. yes
    Esri ................................. yes
    Mapbox ............................... yes
    MapboxGL ............................. no
    Itemsoverlay ......................... yes


When I step through in the debugger I see the following:

Debugging starts
QML debugging is enabled. Only use this in a safe environment.
Trying to create default GeoPositionInfoSource
successfully created default GeopositionInfoSource
Failed to set Geoclue positioning requirements. Geoclue error: org.qtproject.QtDBus.Error.InvalidObjectPath

My question here is: Have I skipped something stupid (quite possible as there are no good examples, the one C++ example reads from a file to emit a signal so is totally worthless) _or_ does the geoposition stuff not communicate with Ubuntu 18.04's version of geoclue?

Should I just install

geoclue-examples_0.12.99-4_amd64.deb     GeoClue example clients

and roll my own using the dbus interface?

Thanks,