Update position when switching position sources.

The declarative position source only updates its position when an update
arrives. The position property is now updated when:

At construction time the position source may have a last known position
available.

When switching position sources, the position is updated to the last
known position of the new source or invalidated in the case that no
position source is selected.

Change-Id: Ib67407f252f2e60d8fd4e32179847f465c1aaf94
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>

3 files changed, 32 insertions, 16 deletions

diff --git a/src/imports/positioning/qdeclarativepositionsource.cpp b/src/imports/positioning/qdeclarativepositionsource.cpp
index 9f19b1e3..da439511 100644
--- a/src/imports/positioning/qdeclarativepositionsource.cpp
+++ b/src/imports/positioning/qdeclarativepositionsource.cpp
@@ -179,6 +179,8 @@ void QDeclarativePositionSource::setName(const QString &newName)
         m_positionSource->setUpdateInterval(m_updateInterval);
         m_positionSource->setPreferredPositioningMethods(
             static_cast<QGeoPositionInfoSource::PositioningMethods>(int(m_preferredPositioningMethods)));
+
+        setPosition(m_positionSource->lastKnownPosition());
     }
 
     if (previousUpdateInterval != updateInterval())
@@ -263,6 +265,7 @@ void QDeclarativePositionSource::setNmeaSource(const QUrl &nmeaSource)
         m_nmeaSocket = 0;
         delete m_positionSource;
         m_positionSource = 0;
+        setPosition(QGeoPositionInfo());
         // Create the NMEA source based on the given data. QML has automatically set QUrl
         // type to point to correct path. If the file is not found, check if the file actually
         // was an embedded resource file.
@@ -280,6 +283,7 @@ void QDeclarativePositionSource::setNmeaSource(const QUrl &nmeaSource)
             (qobject_cast<QNmeaPositionInfoSource *>(m_positionSource))->setDevice(m_nmeaFile);
             connect(m_positionSource, SIGNAL(positionUpdated(QGeoPositionInfo)),
                     this, SLOT(positionUpdateReceived(QGeoPositionInfo)));
+            setPosition(m_positionSource->lastKnownPosition());
             if (m_active && !m_singleUpdate) {
                 // Keep on updating even though source changed
                 QTimer::singleShot(0, this, SLOT(start()));
@@ -326,6 +330,8 @@ void QDeclarativePositionSource::socketConnected()
     connect(m_positionSource, &QNmeaPositionInfoSource::positionUpdated,
             this, &QDeclarativePositionSource::positionUpdateReceived);
 
+    setPosition(m_positionSource->lastKnownPosition());
+
     if (m_active && !m_singleUpdate) {
         // Keep on updating even though source changed
         QTimer::singleShot(0, this, SLOT(start()));
@@ -362,6 +368,24 @@ void QDeclarativePositionSource::socketError(QAbstractSocket::SocketError error)
     emit sourceErrorChanged();
 }
 
+void QDeclarativePositionSource::setPosition(const QGeoPositionInfo &pi)
+{
+    if (pi.isValid()) {
+        m_position.setTimestamp(pi.timestamp());
+        m_position.setCoordinate(pi.coordinate());
+        if (pi.hasAttribute(QGeoPositionInfo::GroundSpeed))
+            m_position.setSpeed(pi.attribute(QGeoPositionInfo::GroundSpeed));
+        if (pi.hasAttribute(QGeoPositionInfo::HorizontalAccuracy))
+            m_position.setHorizontalAccuracy(pi.attribute(QGeoPositionInfo::HorizontalAccuracy));
+        if (pi.hasAttribute(QGeoPositionInfo::VerticalAccuracy))
+            m_position.setVerticalAccuracy(pi.attribute(QGeoPositionInfo::VerticalAccuracy));
+    } else {
+        m_position.invalidate();
+    }
+
+    emit positionChanged();
+}
+
 /*!
     \internal
 */
@@ -623,22 +647,8 @@ QDeclarativePosition *QDeclarativePositionSource::position()
 
 void QDeclarativePositionSource::positionUpdateReceived(const QGeoPositionInfo &update)
 {
-    if (update.isValid()) {
-        m_position.setTimestamp(update.timestamp());
-        m_position.setCoordinate(update.coordinate());
-        if (update.hasAttribute(QGeoPositionInfo::GroundSpeed)) {
-            m_position.setSpeed(update.attribute(QGeoPositionInfo::GroundSpeed));
-        }
-        if (update.hasAttribute(QGeoPositionInfo::HorizontalAccuracy)) {
-            m_position.setHorizontalAccuracy(update.attribute(QGeoPositionInfo::HorizontalAccuracy));
-        }
-        if (update.hasAttribute(QGeoPositionInfo::VerticalAccuracy)) {
-            m_position.setVerticalAccuracy(update.attribute(QGeoPositionInfo::VerticalAccuracy));
-        }
-        emit positionChanged();
-    } else {
-        m_position.invalidate();
-    }
+    setPosition(update);
+
     if (m_singleUpdate && m_active) {
         m_active = false;
         m_singleUpdate = false;
@@ -686,6 +696,8 @@ void QDeclarativePositionSource::componentComplete()
             m_positionSource->setUpdateInterval(m_updateInterval);
             m_positionSource->setPreferredPositioningMethods(
                 static_cast<QGeoPositionInfoSource::PositioningMethods>(int(m_preferredPositioningMethods)));
+
+            setPosition(m_positionSource->lastKnownPosition());
         }
 
         if (previousUpdateInterval != updateInterval())
diff --git a/src/imports/positioning/qdeclarativepositionsource_p.h b/src/imports/positioning/qdeclarativepositionsource_p.h
index 61593a28..bb229d5e 100644
--- a/src/imports/positioning/qdeclarativepositionsource_p.h
+++ b/src/imports/positioning/qdeclarativepositionsource_p.h
@@ -136,7 +136,10 @@ private Q_SLOTS:
     void sourceErrorReceived(const QGeoPositionInfoSource::Error error);
     void socketConnected();
     void socketError(QAbstractSocket::SocketError error);
+
 private:
+    void setPosition(const QGeoPositionInfo &pi);
+
     QGeoPositionInfoSource *m_positionSource;
     QDeclarativePosition m_position;
     PositioningMethods m_preferredPositioningMethods;
diff --git a/tests/auto/declarative_core/tst_positionsource.qml b/tests/auto/declarative_core/tst_positionsource.qml
index c2b6b93e..e11408b6 100644
--- a/tests/auto/declarative_core/tst_positionsource.qml
+++ b/tests/auto/declarative_core/tst_positionsource.qml
@@ -77,6 +77,7 @@ TestCase {
     }
 
     function test_inactive() {
+        defaultSourceSpy.clear();
         compare(defaultSourceSpy.count, 0);
         wait(1000);
         compare(defaultSourceSpy.count, 0);