Allow threaded tile provisioning

This change virtualizes four key methods of QGeoTiledMappingManagerEngine,
that need to be reimplemented in order to be able to run tile provisioning
in a separate thread.
QGeoTileRequestManager is also now privately exported, as it has to be
used in those methods.
Finally the patch includes some minor cleanup in QGeoTileFetcher.

Change-Id: I3063263120f935f0cde54abf00bd1caa476ab215
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

3 files changed, 9 insertions, 13 deletions

diff --git a/src/location/maps/qgeotiledmappingmanagerengine_p.h b/src/location/maps/qgeotiledmappingmanagerengine_p.h
index a7b4b1d0..3455655f 100644
--- a/src/location/maps/qgeotiledmappingmanagerengine_p.h
+++ b/src/location/maps/qgeotiledmappingmanagerengine_p.h
@@ -82,19 +82,18 @@ public:
     QSize tileSize() const;
     int tileVersion() const;
 
-    void updateTileRequests(QGeoTiledMap *map,
+    virtual void updateTileRequests(QGeoTiledMap *map,
                             const QSet<QGeoTileSpec> &tilesAdded,
                             const QSet<QGeoTileSpec> &tilesRemoved);
 
     QAbstractGeoTileCache *tileCache();
-    QSharedPointer<QGeoTileTexture> getTileTexture(const QGeoTileSpec &spec);
-
+    virtual QSharedPointer<QGeoTileTexture> getTileTexture(const QGeoTileSpec &spec);
 
     QAbstractGeoTileCache::CacheAreas cacheHint() const;
 
 private Q_SLOTS:
-    void engineTileFinished(const QGeoTileSpec &spec, const QByteArray &bytes, const QString &format);
-    void engineTileError(const QGeoTileSpec &spec, const QString &errorString);
+    virtual void engineTileFinished(const QGeoTileSpec &spec, const QByteArray &bytes, const QString &format);
+    virtual void engineTileError(const QGeoTileSpec &spec, const QString &errorString);
 
 Q_SIGNALS:
     void tileError(const QGeoTileSpec &spec, const QString &errorString);
@@ -108,7 +107,6 @@ protected:
     void setTileCache(QAbstractGeoTileCache *cache);
 
     QGeoTiledMap::PrefetchStyle m_prefetchStyle;
-private:
     QGeoTiledMappingManagerEnginePrivate *d_ptr;
 
     Q_DECLARE_PRIVATE(QGeoTiledMappingManagerEngine)
diff --git a/src/location/maps/qgeotilefetcher.cpp b/src/location/maps/qgeotilefetcher.cpp
index bab75034..b3f7021b 100644
--- a/src/location/maps/qgeotilefetcher.cpp
+++ b/src/location/maps/qgeotilefetcher.cpp
@@ -52,9 +52,6 @@ QGeoTileFetcher::QGeoTileFetcher(QGeoMappingManagerEngine *parent)
 
     d->enabled_ = true;
     d->engine_ = parent;
-
-//    if (!d->queue_.isEmpty())
-//        d->timer_.start(0, this);
 }
 
 QGeoTileFetcher::QGeoTileFetcher(QGeoTileFetcherPrivate &dd, QGeoMappingManagerEngine *parent)
@@ -63,9 +60,6 @@ QGeoTileFetcher::QGeoTileFetcher(QGeoTileFetcherPrivate &dd, QGeoMappingManagerE
     Q_D(QGeoTileFetcher);
     d->enabled_ = true;
     d->engine_ = parent;
-
-//    if (!d->queue_.isEmpty())
-//        d->timer_.start(0, this);
 }
 
 QGeoTileFetcher::~QGeoTileFetcher()
@@ -92,6 +86,7 @@ void QGeoTileFetcher::cancelTileRequests(const QSet<QGeoTileSpec> &tiles)
     Q_D(QGeoTileFetcher);
 
     typedef QSet<QGeoTileSpec>::const_iterator tile_iter;
+    // No need to lock: called only in updateTileRequests
     tile_iter tile = tiles.constBegin();
     tile_iter end = tiles.constEnd();
     for (; tile != end; ++tile) {
@@ -176,10 +171,12 @@ void QGeoTileFetcher::timerEvent(QTimerEvent *event)
         return;
     }
 
+    QMutexLocker ml(&d->queueMutex_);
     if (d->queue_.isEmpty() || !initialized()) {
         d->timer_.stop();
         return;
     }
+    ml.unlock();
 
     requestNextTile();
 }
diff --git a/src/location/maps/qgeotilerequestmanager_p.h b/src/location/maps/qgeotilerequestmanager_p.h
index f8ea4814..000e3f3a 100644
--- a/src/location/maps/qgeotilerequestmanager_p.h
+++ b/src/location/maps/qgeotilerequestmanager_p.h
@@ -48,6 +48,7 @@
 //
 
 #include <QtCore/QSharedPointer>
+#include <QtLocation/private/qlocationglobal_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -58,7 +59,7 @@ class QGeoTileTexture;
 
 class QGeoTileRequestManagerPrivate;
 
-class QGeoTileRequestManager
+class Q_LOCATION_PRIVATE_EXPORT QGeoTileRequestManager
 {
 public:
     explicit QGeoTileRequestManager(QGeoTiledMap *map, QGeoTiledMappingManagerEngine *engine);