Add alignCoordinateToPoint method

This method effectively extends the functionalities offered by
the center qml property, allowing to set a coordinate to an item
position other than the center of the item.
This is useful in those applications where the center of the scene
(e.g., a cursor) is not to be place exactly in the center of the map.

[ChangeLog][QtLocation][QDeclarativeGeoMap] Added alignCoordinateToPoint
method to QDeclarativeGeoMap.

Change-Id: I68a3d12e8376b83c4c1775a3af5e2125d3e71d63
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

3 files changed, 51 insertions, 0 deletions

diff --git a/src/location/declarativemaps/qdeclarativegeomap.cpp b/src/location/declarativemaps/qdeclarativegeomap.cpp
index 47283d85..67130bb9 100644
--- a/src/location/declarativemaps/qdeclarativegeomap.cpp
+++ b/src/location/declarativemaps/qdeclarativegeomap.cpp
@@ -1487,6 +1487,30 @@ void QDeclarativeGeoMap::setBearing(qreal bearing, const QGeoCoordinate &coordin
 }
 
 /*!
+    \qmlmethod void QtLocation::Map::alignCoordinateToPoint(coordinate coordinate, QPointF point)
+
+    Aligns \a coordinate to \a point.
+    This method effectively extends the functionality offered by the \l center qml property, allowing
+    to align a coordinate to point of the Map element other than its center.
+    This is useful in those applications where the center of the scene (e.g., a cursor) is not to be
+    placed exactly in the center of the map.
+
+    If the map is tilted, and \a coordinate happens to be behind the camera, or if the map is not ready
+    (see \l mapReady), calling this method will have no effect.
+
+    \sa center
+
+    \since 5.10
+*/
+void QDeclarativeGeoMap::alignCoordinateToPoint(const QGeoCoordinate &coordinate, const QPointF &point)
+{
+    if (!m_map)
+        return;
+
+    setCenter(m_map->geoProjection().anchorCoordinateToPoint(coordinate, point));
+}
+
+/*!
     \qmlmethod coordinate QtLocation::Map::toCoordinate(QPointF position, bool clipToViewPort)
 
     Returns the coordinate which corresponds to the \a position relative to the map item.
diff --git a/src/location/declarativemaps/qdeclarativegeomap_p.h b/src/location/declarativemaps/qdeclarativegeomap_p.h
index 2f20e3ae..f88eb03f 100644
--- a/src/location/declarativemaps/qdeclarativegeomap_p.h
+++ b/src/location/declarativemaps/qdeclarativegeomap_p.h
@@ -156,6 +156,7 @@ public:
     QQmlListProperty<QDeclarativeGeoMapType> supportedMapTypes();
 
     Q_INVOKABLE void setBearing(qreal bearing, const QGeoCoordinate &coordinate);
+    Q_INVOKABLE void alignCoordinateToPoint(const QGeoCoordinate &coordinate, const QPointF &point);
 
     Q_INVOKABLE void removeMapItem(QDeclarativeGeoMapItemBase *item);
     Q_INVOKABLE void addMapItem(QDeclarativeGeoMapItemBase *item);
diff --git a/tests/auto/declarative_ui/tst_map.qml b/tests/auto/declarative_ui/tst_map.qml
index 18d7c2d3..755da268 100644
--- a/tests/auto/declarative_ui/tst_map.qml
+++ b/tests/auto/declarative_ui/tst_map.qml
@@ -542,6 +542,32 @@ Item {
             mapTiltBearing.tilt = 25.0
         }
 
+        function test_map_align_coordinate_to_point()
+        {
+            var zeroCoord = QtPositioning.coordinate(0,0)
+            mapTiltBearing.bearing = 0.0
+            mapTiltBearing.tilt = 0.0
+            mapTiltBearing.zoomLevel = 3
+            mapTiltBearing.center = zeroCoord
+            compare(mapTiltBearing.bearing, 0.0)
+            compare(mapTiltBearing.tilt, 0.0)
+            compare(mapTiltBearing.zoomLevel, 3)
+            compare(mapTiltBearing.center, zeroCoord)
+
+            var coord = QtPositioning.coordinate(20,-20)
+            var point = Qt.point(400, 400)
+            mapTiltBearing.alignCoordinateToPoint(coord, point)
+            var coordAfter = mapTiltBearing.toCoordinate(point)
+            compare(coord.latitude, coordAfter.latitude)
+            compare(coord.longitude, coordAfter.longitude)
+
+            // resetting
+            mapTiltBearing.center = coordinate1
+            mapTiltBearing.zoomLevel = 4
+            mapTiltBearing.bearing = 45.0
+            mapTiltBearing.tilt = 25.0
+        }
+
         function test_coordinate_conversion()
         {
             wait(1000)