Simple prefetch scheme

Prefetches larger set of tiles when camera is stopped

QTBUG-25136

Prefetch implementation including zoom-level prefetching
Two prefetching options- pan buffer, or pan buffer for two nearest zoom levels
Code simplified by removing all three visibleTiles lists, so they can't go out of sync
Textures not promoted up the cache if they aren't visible when retrieved from server

Also: Prefetch on map initialize + optimisation

This ensures that the prefetch is called at the end of initialisation
Useful if the location is not already in disk cache. And makes no
difference if it is already in disk cache.
QTBUG-25786

Change-Id: Ife7c1d103f83695659f4534880268fa5afd8f7c7
Reviewed-by: Alex Wilson <alex.wilson@nokia.com>

14 files changed, 155 insertions, 45 deletions

diff --git a/src/location/maps/qgeocameratiles.cpp b/src/location/maps/qgeocameratiles.cpp
index 9258661b..a63420ed 100644
--- a/src/location/maps/qgeocameratiles.cpp
+++ b/src/location/maps/qgeocameratiles.cpp
@@ -58,6 +58,11 @@
 #include <cmath>
 
 QT_BEGIN_NAMESPACE
+#define ENABLE_PREFETCHING
+// larger values fetch a bigger set when the camera stops
+#define PREFETCH_FRUSTUM_SCALE 2.0
+// #define PREFETCH_NEIGHBOUR_LAYER
+#define PREFETCH_TWO_NEIGHBOUR_LAYERS
 
 struct Frustum
 {
@@ -91,9 +96,9 @@ public:
     int sideLength_;
 
     void updateMetadata();
-    void updateGeometry();
+    void updateGeometry(double viewExpansion = 1.0);
 
-    Frustum frustum() const;
+    Frustum frustum(double fieldOfViewGradient) const;
 
     class LengthSorter
     {
@@ -132,18 +137,78 @@ QGeoCameraTiles::~QGeoCameraTiles()
     delete d_ptr;
 }
 
+void QGeoCameraTiles::findPrefetchTiles()
+{
+#if defined(ENABLE_PREFETCHING)
+    Q_D(QGeoCameraTiles);
+
+    d->tiles_.clear();
+
+    // qDebug() << "prefetch called";
+    int zoom = static_cast<int>(floor(d->camera_.zoomLevel()));
+    d->intZoomLevel_ = zoom;
+    d->sideLength_ = 1 << d->intZoomLevel_;
+    d->updateGeometry(PREFETCH_FRUSTUM_SCALE);
+
+#if defined(PREFETCH_NEIGHBOUR_LAYER)
+    double zoomFraction = d->camera_.zoomLevel() - zoom;
+    int nearestNeighbourLayer = zoomFraction > 0.5 ? zoom + 1 : zoom - 1;
+    if (nearestNeighbourLayer <= d->maxZoom_ && nearestNeighbourLayer >= 0)
+    {
+        double oldZoom = d->camera_.zoomLevel();
+        d->intZoomLevel_ = nearestNeighbourLayer;
+        d->sideLength_ = 1 << d->intZoomLevel_;
+        d->camera_.setZoomLevel(d->intZoomLevel_);
+
+        // Approx heuristic, keeping total # prefetched tiles roughly independent of the
+        // fractional zoom level.
+        double neighbourScale = (1.0 + zoomFraction)/2.0;
+
+        d->updateGeometry(PREFETCH_FRUSTUM_SCALE * neighbourScale);
+        d->camera_.setZoomLevel(oldZoom);
+    }
+#elif defined(PREFETCH_TWO_NEIGHBOUR_LAYERS)
+ //   int size1 = d->tiles_.size();
+
+    // This is a simpler strategy, we just prefetch from layer above and below
+    // for the layer below we only use half the size as this fills the screen
+    double oldZoom = d->camera_.zoomLevel();
+    if (zoom > 0)
+    {
+        d->intZoomLevel_ = zoom-1;
+        d->sideLength_ = 1 << d->intZoomLevel_;
+        d->camera_.setZoomLevel(d->intZoomLevel_);
+        d->updateGeometry(0.5);
+    }
+ //   int size2 = d->tiles_.size();
+    if (zoom < d->maxZoom_)
+    {
+        d->intZoomLevel_ = zoom+1;
+        d->sideLength_ = 1 << d->intZoomLevel_;
+        d->camera_.setZoomLevel(d->intZoomLevel_);
+        d->updateGeometry(1.0);
+    }
+ //   qDebug() << "prefetched main tiles: " << size1 << " higher detail layer: " << d->tiles_.size() - size2 << " low detail layer: " << size2 - size1;
+    d->intZoomLevel_ = zoom;
+    d->sideLength_ = 1 << d->intZoomLevel_;
+    d->camera_.setZoomLevel(oldZoom);
+#endif
+#endif
+}
+
+
 void QGeoCameraTiles::setCamera(const QGeoCameraData &camera)
 {
     Q_D(QGeoCameraTiles);
 
     if (d->camera_ == camera)
         return;
-
     d->camera_ = camera;
 
     d->intZoomLevel_ = static_cast<int>(floor(d->camera_.zoomLevel()));
     d->sideLength_ = 1 << d->intZoomLevel_;
 
+    d->tiles_.clear();
     d->updateGeometry();
 }
 
@@ -155,6 +220,7 @@ void QGeoCameraTiles::setScreenSize(const QSize &size)
         return;
 
     d->screenSize_ = size;
+    d->tiles_.clear();
     d->updateGeometry();
 }
 
@@ -188,6 +254,7 @@ void QGeoCameraTiles::setTileSize(int tileSize)
         return;
 
     d->tileSize_ = tileSize;
+    d->tiles_.clear();
     d->updateGeometry();
 }
 
@@ -205,6 +272,7 @@ void QGeoCameraTiles::setMaximumZoomLevel(int maxZoom)
         return;
 
     d->maxZoom_ = maxZoom;
+    d->tiles_.clear();
     d->updateGeometry();
 }
 
@@ -239,12 +307,11 @@ void QGeoCameraTilesPrivate::updateMetadata()
     tiles_ = newTiles;
 }
 
-void QGeoCameraTilesPrivate::updateGeometry()
+void QGeoCameraTilesPrivate::updateGeometry(double viewExpansion)
 {
-    tiles_.clear();
-
     // Find the frustum from the camera / screen / viewport information
-    Frustum f = frustum();
+    // The larger frustum when stationary is a form of prefetching
+    Frustum f = frustum(viewExpansion);
 
     // Find the polygon where the frustum intersects the plane of the map
     Polygon footprint = frustumFootprint(f);
@@ -263,7 +330,7 @@ void QGeoCameraTilesPrivate::updateGeometry()
     }
 }
 
-Frustum QGeoCameraTilesPrivate::frustum() const
+Frustum QGeoCameraTilesPrivate::frustum(double fieldOfViewGradient) const
 {
     QDoubleVector3D center = sideLength_ * QGeoProjection::coordToMercator(camera_.center());
     center.setZ(0.0);
@@ -294,16 +361,16 @@ Frustum QGeoCameraTilesPrivate::frustum() const
     // this assumes that viewSize = 2*nearPlane x 2*nearPlane
 
     if (aspectRatio > 1.0) {
-        hn = 2 * nearPlane;
+        hn = 2 * fieldOfViewGradient * nearPlane;
         wn = hn * aspectRatio;
 
-        hf = 2 * farPlane;
+        hf = 2 * fieldOfViewGradient * farPlane;
         wf = hf * aspectRatio;
     } else {
-        wn = 2 * nearPlane;
+        wn = 2 * fieldOfViewGradient * nearPlane;
         hn = wn / aspectRatio;
 
-        wf = 2 * farPlane;
+        wf = 2 * fieldOfViewGradient * farPlane;
         hf = wf / aspectRatio;
     }
 
diff --git a/src/location/maps/qgeocameratiles_p.h b/src/location/maps/qgeocameratiles_p.h
index dfc8cdf3..30571f72 100644
--- a/src/location/maps/qgeocameratiles_p.h
+++ b/src/location/maps/qgeocameratiles_p.h
@@ -82,6 +82,7 @@ public:
     void setMapType(const QGeoMapType &mapType);
 
     QSet<QGeoTileSpec> tiles() const;
+    void findPrefetchTiles();
 
 private:
     QGeoCameraTilesPrivate *d_ptr;
diff --git a/src/location/maps/qgeomap.cpp b/src/location/maps/qgeomap.cpp
index 7001c7c7..ad81fd13 100644
--- a/src/location/maps/qgeomap.cpp
+++ b/src/location/maps/qgeomap.cpp
@@ -129,6 +129,11 @@ void QGeoMap::setCameraData(const QGeoCameraData &cameraData)
     mapData_->setCameraData(cameraData);
 }
 
+void QGeoMap::cameraStopped()
+{
+    mapData_->prefetchData();
+}
+
 QGeoCameraData QGeoMap::cameraData() const
 {
     return mapData_->cameraData();
diff --git a/src/location/maps/qgeomap_p.h b/src/location/maps/qgeomap_p.h
index 34771fe4..a16ad7d6 100644
--- a/src/location/maps/qgeomap_p.h
+++ b/src/location/maps/qgeomap_p.h
@@ -108,6 +108,7 @@ public:
 
 public Q_SLOTS:
     void update();
+    void cameraStopped(); // optional hint for prefetch
 
 Q_SIGNALS:
     void cameraDataChanged(const QGeoCameraData &cameraData);
diff --git a/src/location/maps/qgeomapdata.cpp b/src/location/maps/qgeomapdata.cpp
index 955b426b..1f0d5cc6 100644
--- a/src/location/maps/qgeomapdata.cpp
+++ b/src/location/maps/qgeomapdata.cpp
@@ -119,7 +119,6 @@ int QGeoMapData::height() const
 void QGeoMapData::setCameraData(const QGeoCameraData &cameraData)
 {
     Q_D(QGeoMapData);
-
     if (cameraData == d->cameraData())
         return;
 
@@ -270,7 +269,13 @@ void QGeoMapDataPrivate::setCameraData(const QGeoCameraData &cameraData)
     }
 
     cameraData_.setCoordinateInterpolator(coordinateInterpolator_.toWeakRef());
-    map_->changeCameraData(oldCameraData);
+
+    // Do not call this expensive function if the width is 0, since it will get called
+    // anyway when it is resized to a width > 0.
+    // this is mainly an optimisation to the initalization of the geomap, which would otherwise
+    // call changeCameraData four or more times
+    if (width() > 0)
+        map_->changeCameraData(oldCameraData);
 }
 
 QGeoCameraData QGeoMapDataPrivate::cameraData() const
diff --git a/src/location/maps/qgeomapdata_p.h b/src/location/maps/qgeomapdata_p.h
index 42367ced..f1304ff9 100644
--- a/src/location/maps/qgeomapdata_p.h
+++ b/src/location/maps/qgeomapdata_p.h
@@ -106,6 +106,7 @@ public:
     QString pluginString();
     QGeoCameraCapabilities cameraCapabilities();
     QGeoMappingManagerEngine *engine();
+    virtual void prefetchData() = 0;
 
 protected:
     void setCoordinateInterpolator(QSharedPointer<QGeoCoordinateInterpolator> interpolator);
diff --git a/src/location/maps/qgeomapscene.cpp b/src/location/maps/qgeomapscene.cpp
index c8b39232..7aea014d 100644
--- a/src/location/maps/qgeomapscene.cpp
+++ b/src/location/maps/qgeomapscene.cpp
@@ -231,6 +231,16 @@ void QGeoMapScene::paintGL(QGLPainter *painter)
     d->paintGL(painter);
 }
 
+QSet<QGeoTileSpec> QGeoMapScene::texturedTiles()
+{
+    Q_D(QGeoMapScene);
+    QSet<QGeoTileSpec> textured;
+    foreach (const QGeoTileSpec &tile, d->textures_.keys()) {
+        textured += tile;
+    }
+    return textured;
+}
+
 QGeoMapScenePrivate::QGeoMapScenePrivate(QGeoMapScene *scene)
     : tileSize_(0),
       camera_(new QGLCamera()),
@@ -400,6 +410,8 @@ void QGeoMapScenePrivate::setScalingOnTextures()
 
 void QGeoMapScenePrivate::addTile(const QGeoTileSpec &spec, QSharedPointer<QGeoTileTexture> texture)
 {
+    if (!visibleTiles_.contains(spec)) // Don't add the geometry if it isn't visible
+        return;
     if (linearScaling_) {
         texture->texture->setBindOptions(texture->texture->bindOptions() |
                                          (QGLTexture2D::LinearFilteringBindOption));
diff --git a/src/location/maps/qgeomapscene_p.h b/src/location/maps/qgeomapscene_p.h
index 9ff7969d..d2baa99e 100644
--- a/src/location/maps/qgeomapscene_p.h
+++ b/src/location/maps/qgeomapscene_p.h
@@ -101,6 +101,7 @@ public:
     void paintGL(QGLPainter *painter);
 
     bool verticalLock() const;
+    QSet<QGeoTileSpec> texturedTiles();
 
 Q_SIGNALS:
     void newTilesVisible(const QSet<QGeoTileSpec> &newTiles);
diff --git a/src/location/maps/qgeotiledmapdata.cpp b/src/location/maps/qgeotiledmapdata.cpp
index 0d331625..c1a6bdff 100644
--- a/src/location/maps/qgeotiledmapdata.cpp
+++ b/src/location/maps/qgeotiledmapdata.cpp
@@ -149,10 +149,10 @@ QGeoTileRequestManager *QGeoTiledMapData::getRequestManager()
     return d->tileRequests_;
 }
 
-void QGeoTiledMapData::newTileFetched(QSharedPointer<QGeoTileTexture> texture)
+void QGeoTiledMapData::newTileFetched(const QGeoTileSpec &spec)
 {
     Q_D(QGeoTiledMapData);
-    d->newTileFetched(texture);
+    d->newTileFetched(spec);
 }
 
 QGeoTileCache *QGeoTiledMapData::tileCache()
@@ -180,6 +180,12 @@ void QGeoTiledMapData::changeCameraData(const QGeoCameraData &oldCameraData)
     d->changeCameraData(oldCameraData);
 }
 
+void QGeoTiledMapData::prefetchData()
+{
+    Q_D(QGeoTiledMapData);
+    d->prefetchTiles();
+}
+
 void QGeoTiledMapData::changeActiveMapType(const QGeoMapType mapType)
 {
     Q_D(QGeoTiledMapData);
@@ -263,6 +269,14 @@ QGeoTiledMappingManagerEngine *QGeoTiledMapDataPrivate::engine() const
     return engine_;
 }
 
+void QGeoTiledMapDataPrivate::prefetchTiles()
+{
+    cameraTiles_->findPrefetchTiles();
+
+    if (tileRequests_)
+        tileRequests_->requestTiles(cameraTiles_->tiles() - mapScene_->texturedTiles());
+}
+
 void QGeoTiledMapDataPrivate::changeCameraData(const QGeoCameraData &oldCameraData)
 {
     double lat = oldCameraData.center().latitude();
@@ -288,14 +302,14 @@ void QGeoTiledMapDataPrivate::changeCameraData(const QGeoCameraData &oldCameraDa
     }
 
     cameraTiles_->setCamera(cam);
-    visibleTiles_ = cameraTiles_->tiles();
 
     mapScene_->setCameraData(cam);
-    mapScene_->setVisibleTiles(visibleTiles_);
+    mapScene_->setVisibleTiles(cameraTiles_->tiles());
 
     if (tileRequests_) {
+        // don't request tiles that are already built and textured
         QList<QSharedPointer<QGeoTileTexture> > cachedTiles =
-                tileRequests_->requestTiles(visibleTiles_);
+                tileRequests_->requestTiles(cameraTiles_->tiles() - mapScene_->texturedTiles());
 
         foreach (const QSharedPointer<QGeoTileTexture> &tex, cachedTiles) {
             mapScene_->addTile(tex->spec, tex);
@@ -303,14 +317,12 @@ void QGeoTiledMapDataPrivate::changeCameraData(const QGeoCameraData &oldCameraDa
 
         if (!cachedTiles.isEmpty())
             map_->update();
-
     }
 }
 
 void QGeoTiledMapDataPrivate::changeActiveMapType(const QGeoMapType mapType)
 {
     cameraTiles_->setMapType(mapType);
-    visibleTiles_ = cameraTiles_->tiles();
 }
 
 void QGeoTiledMapDataPrivate::resized(int width, int height)
@@ -337,15 +349,18 @@ void QGeoTiledMapDataPrivate::resized(int width, int height)
     }
 }
 
-void QGeoTiledMapDataPrivate::newTileFetched(QSharedPointer<QGeoTileTexture> texture)
+void QGeoTiledMapDataPrivate::newTileFetched(const QGeoTileSpec &spec)
 {
-    mapScene_->addTile(texture->spec, texture);
-    map_->update();
+    // Only promote the texture up to GPU if it is visible
+    if (cameraTiles_->tiles().contains(spec)){
+        mapScene_->addTile(spec, engine_->getTileTexture(spec));
+        map_->update();
+    }
 }
 
 QSet<QGeoTileSpec> QGeoTiledMapDataPrivate::visibleTiles()
 {
-    return visibleTiles_;
+    return cameraTiles_->tiles();
 }
 
 void QGeoTiledMapDataPrivate::paintGL(QGLPainter *painter)
diff --git a/src/location/maps/qgeotiledmapdata_p.h b/src/location/maps/qgeotiledmapdata_p.h
index 73fde8f1..db160fe9 100644
--- a/src/location/maps/qgeotiledmapdata_p.h
+++ b/src/location/maps/qgeotiledmapdata_p.h
@@ -82,10 +82,11 @@ public:
 
     void paintGL(QGLPainter *painter);
 
-    void newTileFetched(QSharedPointer<QGeoTileTexture> texture);
+    void newTileFetched(const QGeoTileSpec &spec);
 
     QGeoCoordinate screenPositionToCoordinate(const QPointF &pos, bool clipToViewport = true) const;
     QPointF coordinateToScreenPosition(const QGeoCoordinate &coordinate, bool clipToViewport = true) const;
+    void prefetchTiles();
 
     // Alternative to exposing this is to make tileFetched a slot, but then requestManager would
     // need to be a QObject
@@ -94,6 +95,7 @@ protected:
     void mapResized(int width, int height);
     void changeCameraData(const QGeoCameraData &oldCameraData);
     void changeActiveMapType(const QGeoMapType mapType);
+    void prefetchData();
 
 protected Q_SLOTS:
     virtual void evaluateCopyrights(const QSet<QGeoTileSpec> &visibleTiles);
diff --git a/src/location/maps/qgeotiledmapdata_p_p.h b/src/location/maps/qgeotiledmapdata_p_p.h
index e1d2d716..79af86fb 100644
--- a/src/location/maps/qgeotiledmapdata_p_p.h
+++ b/src/location/maps/qgeotiledmapdata_p_p.h
@@ -101,18 +101,17 @@ public:
     QGeoCoordinate screenPositionToCoordinate(const QPointF &pos) const;
     QPointF coordinateToScreenPosition(const QGeoCoordinate &coordinate) const;
 
-    void newTileFetched(QSharedPointer<QGeoTileTexture> texture);
+    void newTileFetched(const QGeoTileSpec &spec);
     QSet<QGeoTileSpec> visibleTiles();
 
     QGeoTiledMappingManagerEngine *engine() const;
+    void prefetchTiles();
 
 private:
     QGeoTiledMapData *map_;
     QGeoTileCache *cache_;
     QGeoTiledMappingManagerEngine *engine_;
 
-    QSet<QGeoTileSpec> visibleTiles_;
-
     QGeoCameraTiles *cameraTiles_;
     QGeoMapScene *mapScene_;
     Q_DISABLE_COPY(QGeoTiledMapDataPrivate)
diff --git a/src/location/maps/qgeotiledmappingmanagerengine.cpp b/src/location/maps/qgeotiledmappingmanagerengine.cpp
index 0a7b11b7..3dafc302 100644
--- a/src/location/maps/qgeotiledmappingmanagerengine.cpp
+++ b/src/location/maps/qgeotiledmappingmanagerengine.cpp
@@ -239,12 +239,10 @@ void QGeoTiledMappingManagerEngine::engineTileFinished(const QGeoTileSpec &spec,
 
     tileCache()->insert(spec, bytes, format, d->cacheHint_);
 
-    QSharedPointer<QGeoTileTexture> tile = tileCache()->get(spec);
-
     map = maps.constBegin();
     mapEnd = maps.constEnd();
     for (; map != mapEnd; ++map) {
-        (*map)->getRequestManager()->tileFetched(tile);
+        (*map)->getRequestManager()->tileFetched(spec);
     }
 }
 
diff --git a/src/location/maps/qgeotilerequestmanager.cpp b/src/location/maps/qgeotilerequestmanager.cpp
index 563df456..431a3c26 100644
--- a/src/location/maps/qgeotilerequestmanager.cpp
+++ b/src/location/maps/qgeotilerequestmanager.cpp
@@ -41,6 +41,7 @@
 #include "qgeotilerequestmanager_p.h"
 
 #include <QSharedPointer>
+#include <QDebug>
 #include "qgeotilespec.h"
 #include "qgeotiledmapdata_p.h"
 #include "qgeotiledmappingmanagerengine.h"
@@ -64,10 +65,9 @@ public:
 
     QHash<QGeoTileSpec, int> retries_;
     QHash<QGeoTileSpec, QSharedPointer<RetryFuture> > futures_;
-    QSet<QGeoTileSpec> visible_;
     QSet<QGeoTileSpec> requested_;
 
-    void tileFetched(QSharedPointer<QGeoTileTexture> texture);
+    void tileFetched(const QGeoTileSpec &spec);
 };
 
 QGeoTileRequestManager::QGeoTileRequestManager(QGeoTiledMapData *map)
@@ -86,10 +86,10 @@ QList<QSharedPointer<QGeoTileTexture> > QGeoTileRequestManager::requestTiles(con
     return d->requestTiles(tiles);
 }
 
-void QGeoTileRequestManager::tileFetched(QSharedPointer<QGeoTileTexture> texture)
+void QGeoTileRequestManager::tileFetched(const QGeoTileSpec &spec)
 {
     Q_D(QGeoTileRequestManager);
-    d->tileFetched(texture);
+    d->tileFetched(spec);
 }
 
 void QGeoTileRequestManager::tileError(const QGeoTileSpec &tile, const QString &errorString)
@@ -110,8 +110,10 @@ QGeoTileRequestManagerPrivate::~QGeoTileRequestManagerPrivate()
 QList<QSharedPointer<QGeoTileTexture> > QGeoTileRequestManagerPrivate::requestTiles(const QSet<QGeoTileSpec> &tiles)
 {
     QSet<QGeoTileSpec> cancelTiles = requested_ - tiles;
-    QSet<QGeoTileSpec> requestTiles = tiles - visible_ - requested_;
+    QSet<QGeoTileSpec> requestTiles = tiles - requested_;
     QSet<QGeoTileSpec> cached;
+//    int tileSize = tiles.size();
+//    int newTiles = requestTiles.size();
 
     typedef QSet<QGeoTileSpec>::const_iterator iter;
 
@@ -136,13 +138,14 @@ QList<QSharedPointer<QGeoTileTexture> > QGeoTileRequestManagerPrivate::requestTi
 
     requestTiles -= cached;
 
-    visible_ = tiles;
-
     requested_ -= cancelTiles;
     requested_ += requestTiles;
 
+//    qDebug() << "required # tiles: " << tileSize << ", new tiles: " << newTiles << ", total server requests: " << requested_.size();
+
     if (!requestTiles.isEmpty() || !cancelTiles.isEmpty()) {
         if (engine) {
+//            qDebug() << "new server requests: " << requestTiles.size() << ", server cancels: " << cancelTiles.size();
             engine->updateTileRequests(map_, requestTiles, cancelTiles);
 
             // Remove any cancelled tiles from the error retry hash to avoid
@@ -159,12 +162,12 @@ QList<QSharedPointer<QGeoTileTexture> > QGeoTileRequestManagerPrivate::requestTi
     return cachedTex;
 }
 
-void QGeoTileRequestManagerPrivate::tileFetched(QSharedPointer<QGeoTileTexture> texture)
+void QGeoTileRequestManagerPrivate::tileFetched(const QGeoTileSpec &spec)
 {
-    map_->newTileFetched(texture);
-    requested_.remove(texture->spec);
-    retries_.remove(texture->spec);
-    futures_.remove(texture->spec);
+    map_->newTileFetched(spec);
+    requested_.remove(spec);
+    retries_.remove(spec);
+    futures_.remove(spec);
 }
 
 // Represents a tile that needs to be retried after a certain period of time
diff --git a/src/location/maps/qgeotilerequestmanager_p.h b/src/location/maps/qgeotilerequestmanager_p.h
index 3f394de8..47d1b08a 100644
--- a/src/location/maps/qgeotilerequestmanager_p.h
+++ b/src/location/maps/qgeotilerequestmanager_p.h
@@ -76,7 +76,7 @@ public:
     QList<QSharedPointer<QGeoTileTexture> > requestTiles(const QSet<QGeoTileSpec> &tiles);
 
     void tileError(const QGeoTileSpec &tile, const QString &errorString);
-    void tileFetched(QSharedPointer<QGeoTileTexture> texture);
+    void tileFetched(const QGeoTileSpec &spec);
 private:
     QGeoTileRequestManagerPrivate *d_ptr;
     Q_DECLARE_PRIVATE(QGeoTileRequestManager)