[FEATURE]: added reload method to map layers and provider interface. Like this, caching providers (currently WMS and WFS) can synchronize with changes in the datasource

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@14264 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

python/core/qgsdataprovider.sip

@@ -178,6 +178,10 @@ class QgsDataProvider : QObject
     */
     virtual QString fileRasterFilters() const;
 
+    /**Reloads the data from the the source. Needs to be implemented by providers with data caches to
+      synchronize with changes in the data source*/
+    virtual void reloadData();
+
   signals:
 
       /** 

python/core/qgsmaplayer.sip

@@ -70,6 +70,10 @@ public:
      */
     const QString & name() const;
 
+    /**Synchronises with changes in the datasource
+      @note added in version 1.6*/
+    virtual void reload();
+
     /** Render the layer, to be overridden in child classes
      */
     virtual bool draw(QgsRenderContext& rendererContext);

python/core/qgsmaplayerregistry.sip

@@ -67,6 +67,10 @@ public:
  */
  void clearAllLayerCaches();
 
+ /**Reload all provider data caches (currently used for WFS and WMS providers)
+ @note: this method was added in QGIS 1.6*/
+ void reloadAllLayers();
+
 signals:
 
     /** emitted when a layer is removed from the registry

python/core/qgsrasterlayer.sip

@@ -303,6 +303,10 @@ public:
     /** Returns the data provider in a const-correct manner */
     //const QgsRasterDataProvider* dataProvider() const;
 
+    /**Synchronises with changes in the datasource
+    @note added in version 1.6*/
+    virtual void reload();
+
     /** \brief This is called when the view on the raster layer needs to be redrawn */
     bool draw( QgsRenderContext& rendererContext );
 

python/core/qgsvectorlayer.sip

@@ -333,6 +333,10 @@ public:
   int snapWithContext(const QgsPoint& startPoint, double snappingTolerance, QMultiMap<double, QgsSnappingResult>& snappingResults /Out/,
                       QgsSnapper::SnappingType snap_to);
 
+  /**Synchronises with changes in the datasource
+  @note added in version 1.6*/
+  virtual void reload();
+
   /** Draws the layer using coordinate transformation
    *  @return FALSE if an error occurred during drawing
    */

src/app/qgisapp.cpp

@@ -4706,6 +4706,8 @@ void QgisApp::refreshMapCanvas()
 {
   //clear all caches first
   QgsMapLayerRegistry::instance()->clearAllLayerCaches();
+  //reload cached provider data
+  QgsMapLayerRegistry::instance()->reloadAllLayers();
   //then refresh
   mMapCanvas->refresh();
 }

src/core/qgsdataprovider.h

@@ -267,6 +267,10 @@ class CORE_EXPORT QgsDataProvider : public QObject
       return "";
     }
 
+    /**Reloads the data from the the source. Needs to be implemented by providers with data caches to
+      synchronize with changes in the data source*/
+    virtual void reloadData() {}
+
   signals:
 
     /**

src/core/qgsmaplayer.h

@@ -79,6 +79,10 @@ class CORE_EXPORT QgsMapLayer : public QObject
      */
     QString const & name() const;
 
+    /**Synchronises with changes in the datasource
+        @note added in version 1.6*/
+    virtual void reload() {}
+
     /** This is the method that does the actual work of
      * drawing the layer onto a paint device.
      * @param QgsRenderContext - describes the extents,

src/core/qgsmaplayerregistry.cpp

@@ -22,7 +22,6 @@
 #include "qgsmaplayer.h"
 #include "qgslogger.h"
 
-
 //
 // Static calls to enforce singleton behaviour
 //
@@ -128,6 +127,19 @@ void QgsMapLayerRegistry::clearAllLayerCaches()
   }
 } // QgsMapLayerRegistry::clearAllLayerCaches()
 
+void QgsMapLayerRegistry::reloadAllLayers()
+{
+  QMap<QString, QgsMapLayer *>::iterator it;
+  for ( it = mMapLayers.begin(); it != mMapLayers.end() ; ++it )
+  {
+    QgsMapLayer* layer = it.value();
+    if ( layer )
+    {
+      layer->reload();
+    }
+  }
+}
+
 QMap<QString, QgsMapLayer*> & QgsMapLayerRegistry::mapLayers()
 {
   return mMapLayers;

src/core/qgsmaplayerregistry.h

@@ -89,6 +89,11 @@ class CORE_EXPORT QgsMapLayerRegistry : public QObject
      * @note this method was added in QGIS 1.4
      */
     void clearAllLayerCaches();
+
+    /**Reload all provider data caches (currently used for WFS and WMS providers)
+      @note: this method was added in QGIS 1.6*/
+    void reloadAllLayers();
+
   signals:
 
     /** emitted when a layer is removed from the registry

src/core/qgsvectorlayer.cpp

@@ -888,6 +888,14 @@ void QgsVectorLayer::drawRendererV2Levels( QgsRenderContext& rendererContext, bo
   stopRendererV2( rendererContext, selRenderer );
 }
 
+void QgsVectorLayer::reload()
+{
+  if ( mDataProvider )
+  {
+    mDataProvider->reloadData();
+  }
+}
+
 bool QgsVectorLayer::draw( QgsRenderContext& rendererContext )
 {
   //set update threshold before each draw to make sure the current setting is picked up

src/core/qgsvectorlayer.h

@@ -380,6 +380,10 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
                          QgsSnappingResult > & snappingResults,
                          QgsSnapper::SnappingType snap_to );
 
+    /**Synchronises with changes in the datasource
+      @note added in version 1.6*/
+    virtual void reload();
+
     /** Draws the layer
      *  @return false if an error occurred during drawing
      */

src/core/raster/qgsrasterlayer.cpp

@@ -1,4 +1,4 @@
-/* **************************************************************************
+/***************************************************************************
         qgsrasterlayer.cpp -  description
    -------------------
 begin                : Sat Jun 22 2002
@@ -824,7 +824,7 @@ const QgsRasterBandStats QgsRasterLayer::bandStatistics( int theBandNo )
             continue; // NULL
           }
 
-          myRasterBandStats.sum += myValue;          
+          myRasterBandStats.sum += myValue;
           ++myRasterBandStats.elementCount;
           //only use this element if we have a non null element
           if ( myFirstIterationFlag )
@@ -1385,6 +1385,14 @@ const QgsRasterDataProvider* QgsRasterLayer::dataProvider() const
   return mDataProvider;
 }
 
+void QgsRasterLayer::reload()
+{
+  if ( mDataProvider )
+  {
+    mDataProvider->reloadData();
+  }
+}
+
 bool QgsRasterLayer::draw( QgsRenderContext& rendererContext )
 {
   QgsDebugMsg( "entered. (renderContext)" );

src/core/raster/qgsrasterlayer.h

@@ -471,6 +471,10 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     /** Returns the data provider in a const-correct manner */
     const QgsRasterDataProvider* dataProvider() const;
 
+    /**Synchronises with changes in the datasource
+    @note added in version 1.6*/
+    virtual void reload();
+
     /** \brief This is called when the view on the raster layer needs to be redrawn */
     bool draw( QgsRenderContext& rendererContext );
 

src/providers/wfs/qgswfsdata.cpp

@@ -138,6 +138,7 @@ int QgsWFSData::getWFSData()
     }
   }
 
+  XML_ParserFree( p );
   return 0;
 }
 

src/providers/wfs/qgswfsprovider.cpp

@@ -52,28 +52,36 @@ QgsWFSProvider::QgsWFSProvider( const QString& uri )
     mFeatureCount( 0 ),
     mValid( true )
 {
-  mSpatialIndex = new QgsSpatialIndex;
-  if ( getFeature( uri ) == 0 )
+  mSpatialIndex = 0;
+  reloadData();
+  if ( mValid )
   {
-    mValid = true;
     getLayerCapabilities();
-
-    //set spatial filter to the whole extent
-    //select(mExtent, false); //MH TODO: fix this in provider0_9-branch
-  }
-  else
-  {
-    mValid = false;
   }
 }
 
 QgsWFSProvider::~QgsWFSProvider()
+{
+  deleteData();
+  delete mSpatialIndex;
+}
+
+void QgsWFSProvider::reloadData()
+{
+  deleteData();
+  delete mSpatialIndex;
+  mSpatialIndex = new QgsSpatialIndex;
+  mValid = !getFeature( dataSourceUri() );
+}
+
+void QgsWFSProvider::deleteData()
 {
   mSelectedFeatures.clear();
   for ( int i = 0; i < mFeatures.size(); i++ )
+  {
     delete mFeatures[i];
+  }
   mFeatures.clear();
-  delete mSpatialIndex;
 }
 
 void QgsWFSProvider::copyFeature( QgsFeature* f, QgsFeature& feature, bool fetchGeometry, QgsAttributeList fetchAttributes )
@@ -626,6 +634,7 @@ bool QgsWFSProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
 
 int QgsWFSProvider::describeFeatureType( const QString& uri, QString& geometryAttribute, QgsFieldMap& fields )
 {
+  fields.clear();
   switch ( mEncoding )
   {
     case QgsWFSProvider::GET:

src/providers/wfs/qgswfsprovider.h

@@ -136,6 +136,10 @@ class QgsWFSProvider: public QgsVectorDataProvider
      */
     virtual bool changeAttributeValues( const QgsChangedAttributesMap &attr_map );
 
+    /**Reloads the data from the the source. Needs to be implemented by providers with data caches to
+      synchronize with changes in the data source*/
+    virtual void reloadData();
+
   signals:
     void dataReadProgressMessage( QString message );
 
@@ -282,6 +286,8 @@ class QgsWFSProvider: public QgsVectorDataProvider
     void appendSupportedOperations( const QDomElement& operationsElem, int& capabilities ) const;
     /**Shows a message box with the exception string (or does nothing if the xml document is not an exception)*/
     void handleException( const QDomDocument& serverResponse ) const;
+
+    void deleteData();
 };
 
 #endif

src/providers/wms/qgswmsprovider.cpp

@@ -2813,6 +2813,11 @@ QString  QgsWmsProvider::description() const
   return WMS_DESCRIPTION;
 } //  QgsWmsProvider::description()
 
+void QgsWmsProvider::reloadData()
+{
+  delete cachedImage;
+  cachedImage = 0;
+}
 
 /**
  * Class factory to return a pointer to a newly created

src/providers/wms/qgswmsprovider.h

@@ -616,6 +616,10 @@ class QgsWmsProvider : public QgsRasterDataProvider
     */
     QString description() const;
 
+    /**Reloads the data from the the source. Needs to be implemented by providers with data caches to
+      synchronize with changes in the data source*/
+    virtual void reloadData();
+
 
   signals: