Write operation for raster providers

Author: mhugent

src/core/qgsrasterdataprovider.h

@@ -435,6 +435,18 @@ class CORE_EXPORT QgsRasterDataProvider : public QgsDataProvider, public QgsRast
     /** Current time stamp of data source */
     virtual QDateTime dataTimestamp() const { return QDateTime(); }
 
+    /**Writes into the provider datasource*/
+    virtual bool write( void* data, int band, int width, int height, int xOffset, int yOffset )
+    {
+        Q_UNUSED( data );
+        Q_UNUSED( band );
+        Q_UNUSED( width );
+        Q_UNUSED( height );
+        Q_UNUSED( xOffset );
+        Q_UNUSED( yOffset );
+        return false;
+    }
+
     /** Creates a new dataset with mDataSourceURI
         @return true in case of success*/
     virtual bool create( const QString& format, int nBands,

src/providers/gdal/qgsgdalprovider.cpp

@@ -2089,6 +2089,16 @@ bool QgsGdalProvider::create( const QString& format, int nBands, QgsRasterDataPr
   return mValid;
 }
 
+bool QgsGdalProvider::write( void* data, int band, int width, int height, int xOffset, int yOffset )
+{
+    GDALRasterBandH rasterBand = GDALGetRasterBand( mGdalDataset, band );
+    if ( rasterBand == NULL )
+    {
+        return false;
+    }
+    return ( GDALRasterIO( rasterBand, GF_Write, xOffset, yOffset, width, height, data, width, height, GDALGetRasterDataType( rasterBand ), 0, 0 ) == CE_None );
+}
+
 QStringList QgsGdalProvider::createFormats() const
 {
   return QStringList();

src/providers/gdal/qgsgdalprovider.h

@@ -269,6 +269,9 @@ class QgsGdalProvider : public QgsRasterDataProvider
     bool create( const QString& format, int nBands, QgsRasterDataProvider::DataType type, int width, int height,
                  double* geoTransform, const QgsCoordinateReferenceSystem& crs );
 
+    /**Writes into the provider datasource*/
+    bool write( void* data, int band, int width, int height, int xOffset, int yOffset );
+
     /**Returns the formats supported by create()*/
     QStringList createFormats() const;