Improved zooming and map movement behavior.

Improved: Double tapping/mouse wheel based zooming keeps the map at the current geo location.
Added: Left/Right/Up/Down keys can be used to move the map.

Task-number: QTBUG-47020
Task-number: QTBUG-47019
Change-Id: I63859319b282e7738a173b0d3917433860fc8969
Reviewed-by: Michal Klocek <michal.klocek@theqtcompany.com>
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

3 files changed, 28 insertions, 10 deletions

diff --git a/src/imports/location/qdeclarativegeomap.cpp b/src/imports/location/qdeclarativegeomap.cpp
index f948b0c3..1de22a50 100644
--- a/src/imports/location/qdeclarativegeomap.cpp
+++ b/src/imports/location/qdeclarativegeomap.cpp
@@ -821,31 +821,33 @@ QQmlListProperty<QDeclarativeGeoMapType> QDeclarativeGeoMap::supportedMapTypes()
 }
 
 /*!
-    \qmlmethod coordinate QtLocation::Map::toCoordinate(QPointF position)
+    \qmlmethod coordinate QtLocation::Map::toCoordinate(QPointF position, bool clipToViewPort)
 
     Returns the coordinate which corresponds to the \a position relative to the map item.
 
-    Returns an invalid coordinate if \a position is not within the current viewport.
+    If \a cliptoViewPort is \c true, or not supplied then returns an invalid coordinate if
+    \a position is not within the current viewport.
 */
-QGeoCoordinate QDeclarativeGeoMap::toCoordinate(const QPointF &position) const
+QGeoCoordinate QDeclarativeGeoMap::toCoordinate(const QPointF &position, bool clipToViewPort) const
 {
     if (m_map)
-        return m_map->itemPositionToCoordinate(QDoubleVector2D(position));
+        return m_map->itemPositionToCoordinate(QDoubleVector2D(position), clipToViewPort);
     else
         return QGeoCoordinate();
 }
 
 /*!
-    \qmlmethod point QtLocation::Map::fromCoordinate(coordinate coordinate)
+    \qmlmethod point QtLocation::Map::fromCoordinate(coordinate coordinate, bool clipToViewPort)
 
     Returns the position relative to the map item which corresponds to the \a coordinate.
 
-    Returns an invalid QPointF if \a coordinate is not within the current viewport.
+    If \a cliptoViewPort is \c true, or not supplied then returns an invalid QPointF if
+    \a coordinate is not within the current viewport.
 */
-QPointF QDeclarativeGeoMap::fromCoordinate(const QGeoCoordinate &coordinate) const
+QPointF QDeclarativeGeoMap::fromCoordinate(const QGeoCoordinate &coordinate, bool clipToViewPort) const
 {
     if (m_map)
-        return m_map->coordinateToItemPosition(coordinate).toPointF();
+        return m_map->coordinateToItemPosition(coordinate, clipToViewPort).toPointF();
     else
         return QPointF(qQNaN(), qQNaN());
 }
diff --git a/src/imports/location/qdeclarativegeomap_p.h b/src/imports/location/qdeclarativegeomap_p.h
index 58c07b1b..ddbb8018 100644
--- a/src/imports/location/qdeclarativegeomap_p.h
+++ b/src/imports/location/qdeclarativegeomap_p.h
@@ -103,8 +103,8 @@ public:
     Q_INVOKABLE void clearMapItems();
     QList<QObject *> mapItems();
 
-    Q_INVOKABLE QGeoCoordinate toCoordinate(const QPointF &position) const;
-    Q_INVOKABLE QPointF fromCoordinate(const QGeoCoordinate &coordinate) const;
+    Q_INVOKABLE QGeoCoordinate toCoordinate(const QPointF &position, bool clipToViewPort = true) const;
+    Q_INVOKABLE QPointF fromCoordinate(const QGeoCoordinate &coordinate, bool clipToViewPort = true) const;
 
 #if QT_DEPRECATED_SINCE(5,5)
     QT_DEPRECATED Q_INVOKABLE QPointF toScreenPosition(const QGeoCoordinate &coordinate) const;
diff --git a/src/imports/location/qdeclarativegeomapgesturearea.cpp b/src/imports/location/qdeclarativegeomapgesturearea.cpp
index 5a74d231..7d34b729 100644
--- a/src/imports/location/qdeclarativegeomapgesturearea.cpp
+++ b/src/imports/location/qdeclarativegeomapgesturearea.cpp
@@ -658,7 +658,23 @@ void QDeclarativeGeoMapGestureArea::handleTouchEvent(QTouchEvent *event)
 
 void QDeclarativeGeoMapGestureArea::handleWheelEvent(QWheelEvent *event)
 {
+    QGeoCoordinate wheelGeoPos = map_->itemPositionToCoordinate(QDoubleVector2D(event->posF()), false);
+    QPointF preZoomPoint = map_->coordinateToItemPosition(wheelGeoPos, false).toPointF();
+
     declarativeMap_->setZoomLevel(qBound(minimumZoomLevel(), declarativeMap_->zoomLevel() + event->angleDelta().y() * qreal(0.001), maximumZoomLevel()));
+
+    QPointF postZoomPoint = map_->coordinateToItemPosition(wheelGeoPos, false).toPointF();
+
+    if (preZoomPoint != postZoomPoint)
+    {
+        qreal dx = postZoomPoint.x() - preZoomPoint.x();
+        qreal dy = postZoomPoint.y() - preZoomPoint.y();
+        QPointF mapCenterPoint(map_->width() / 2.0 + dx, map_->height() / 2.0  + dy);
+
+        QGeoCoordinate mapCenterCoordinate = map_->itemPositionToCoordinate(QDoubleVector2D(mapCenterPoint), false);
+        map_->mapController()->setCenter(mapCenterCoordinate);
+    }
+
     event->accept();
 }