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  //reenable wfs with extent setting: pass canvas info to source select

  wfss->setProperty( "MapExtent", mMapCanvas->extent().toString() );

  if ( mMapCanvas->mapRenderer()->hasCrsTransformEnabled() )

  { //if "on the fly" reprojection is active, pass canvas CRS

    wfss->setProperty( "MapCRS", mMapCanvas->mapRenderer()->destinationCrs().authid() );

  }

    progressDialog = new QProgressDialog( tr( "Loading WFS data\n%1" ).arg( mTypeName ), tr( "Abort" ), 0, 0, mainWindow );

#include "qgsmaplayerregistry.h"

    mValid( true ),

    mLayer( 0 ),

    mGetRenderedOnly( false ),

    mInitGro( false )

  if ( rect.isEmpty() )

  { //select all features

    mSpatialFilter = mExtent;

  { //select features intersecting caller's extent

    QString dsURI = dataSourceUri();

    //first time through, initialize GetRenderedOnly args

    //ctor cannot initialize because layer object not available then

    if ( ! mInitGro )

    { //did user check "Cache Features" in WFS layer source selection?*

      if ( dsURI.contains( "BBOX" ) )

      { //no: initialize incremental getFeature

        if ( initGetRenderedOnly() )

        {

          mGetRenderedOnly = true;

        }

        else

        { //initialization failed;

          QgsDebugMsg( QString( "GetRenderOnly aborted; \"Cache Features\" in effect" ) );

        }

      }

      mInitGro = true;

    }

    if ( mGetRenderedOnly )

    { //"Cache Features" was not selected for this layer

      //has rendered extent expanded beyond last-retrieved WFS extent?

      //NB: "intersect" instead of "contains" to evade small rounding errors; avoids

      //    unnecessary double fetch on initial rendering or zoom-in/zoom-out sequences

      QgsRectangle olap( rect );

      olap = olap.intersect( &mGetExtent );

      double carea = rect.width() * rect.height();

      double oarea = olap.width() * olap.height();

      if ( .9999 < oarea/carea )

      { //do not re-fetch if previous get extent covers at least 99.99% of canvas extent

        QgsDebugMsg( QString( "Layer %1 GetRenderedOnly: no fetch required" ).arg( mLayer->name() ) );

      }

      else

      {

        mGetExtent.combineExtentWith( &rect );

        QgsDebugMsg( QString( "Layer %1 GetRenderedOnly: fetching extent %2" )

                   .arg( mLayer->name(), mGetExtent.asWktCoordinates() ) );

        dsURI = dsURI.replace( QRegExp( "BBOX=[.,0-9]*" ),

                               QString( "BBOX=%1,%2,%3,%4" )

                               .arg( mGetExtent.xMinimum(), 0, 'f' )

                               .arg( mGetExtent.yMinimum(), 0, 'f' )

                               .arg( mGetExtent.xMaximum(), 0, 'f' )

                               .arg( mGetExtent.yMaximum(), 0, 'f' ) );

        setDataSourceUri( dsURI );

        reloadData();

        mLayer->updateExtents();

      }

    mSpatialFilter = rect;

    mSelectedFeatures = mSpatialIndex->intersects( mSpatialFilter );

//initialization for getRenderedOnly option

//(formerly "Only request features overlapping the current view extent")

bool QgsWFSProvider::initGetRenderedOnly( )

{ //find our layer

  QMap<QString, QgsMapLayer*> layers = QgsMapLayerRegistry::instance()->mapLayers();

  QMap<QString, QgsMapLayer*>::const_iterator layersIt = layers.begin();

  for ( ; layersIt != layers.end() ; ++layersIt )

  {

    if ( ( mLayer = dynamic_cast<QgsVectorLayer*>( layersIt.value() ) ) )

    {

      if ( mLayer->dataProvider() == this )

      {

        QgsDebugMsg( QString( "found layer %1" ).arg( mLayer->name() ) );

        break;

      }

    }

  }

  if ( layersIt == layers.end() )

  {

    QgsDebugMsg( "SHOULD NOT OCCUR: initialize() did not find layer." );

    return false;

  }

  //set initial getFeatures extent from URI BBOX

  double m[4];

  bool ok = false;  //toDouble failure flag

  QRegExp rebbox( "BBOX=(([0-9.]+,?){4})" );

  QString dsURI = dataSourceUri();

  if ( dsURI.indexOf( rebbox ) >! 0 )

  {

    QStringList mlist = rebbox.cap( 1 ).split( "," );

    QStringList::const_iterator mlistIt = mlist.begin();

    ok = true;

    for (int i = 0 ; mlistIt != mlist.end() && ok ; ++mlistIt )

    {

      m[ i++ ] = ( *mlistIt ).toDouble( &ok );

    }

  }

  if ( ok )

  { //initial getFeatures extent

    mGetExtent = QgsRectangle( m[0], m[1], m[2], m[3] );

  }

  else

  {

    QgsDebugMsg( QString( "SHOULD NOT OCCUR: missing or malformed URI BBOX args \"%1\"" ).arg( dataSourceUri() ) );

    return false;

  }

  return true;

}

#include "qgsmaplayer.h"

#include "qgsvectorlayer.h"

    /**GetRenderedOnly: layer asociated with this provider*/

    QgsVectorLayer *mLayer;

    /**GetRenderedOnly: fetch only features within canvas extent to be rendered*/

    bool mGetRenderedOnly;

    /**GetRenderedOnly initializaiton flat*/

    bool mInitGro;

    /**if GetRenderedOnly, extent specified in WFS getFeatures; else empty (no constraint)*/

    QgsRectangle mGetExtent;

    /**Initializes "Cache Features" inactive processing*/

    bool initGetRenderedOnly();

#include "qgscoordinatetransform.h"

  QgsWFSConnection conn( cmbConnections->currentText() );

  QString pCrsString( labelCoordRefSys->text() );

  QgsCoordinateReferenceSystem pCrs( pCrsString );

  //prepare canvas extent info for layers with "cache features" option not set

  QgsRectangle extent;

  QVariant extentVariant = property( "MapExtent" );

  if ( extentVariant.isValid() )

    QString crs;

    QgsCoordinateTransform xform;

    QString extentString = extentVariant.toString();

    QStringList minMaxSplit = extentString.split( ":" );

    if ( minMaxSplit.size() > 1 )

      QStringList xyMinSplit = minMaxSplit[0].split( "," );

      QStringList xyMaxSplit = minMaxSplit[1].split( "," );

      if ( xyMinSplit.size() > 1 && xyMaxSplit.size() > 1 )

      {

        extent.set( xyMinSplit[0].toDouble(), xyMinSplit[1].toDouble(),

                    xyMaxSplit[0].toDouble(), xyMaxSplit[1].toDouble() );

      }

    //does canvas have "on the fly" reprojection set?

    QVariant crsVariant = property( "MapCRS" );

    if ( crsVariant.isValid() )

    { //transform between provider CRS set in source select dialog and canvas CRS

      QgsCoordinateReferenceSystem cCrs( crsVariant.toString() );

      if ( pCrs.isValid() && cCrs.isValid() )

      {

        QgsCoordinateTransform xform( pCrs, cCrs );

        extent = xform.transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );

        QgsDebugMsg( QString("canvas transform: Canvas CRS=%1, Provider CRS=%2, BBOX=%3")

                             .arg(cCrs.authid(), pCrs.authid(), extent.asWktCoordinates() ) );

      }

    }

  }

  //create layers that user selected from this WFS source

  for ( ; sIt != selectedItems.constEnd(); ++sIt )

  { //add a wfs layer to the map

    QString typeName = ( *sIt )->text( 1 );  //WFS repository's name for layer

    QString filter = ( *sIt )->text( 4 );    //optional filter specified by user

    //is "cache features" checked?

    if ( ( *sIt )->checkState( 3 ) == Qt::Checked )

    { //yes: entire WFS layer will be retrieved and cached

      mUri = conn.uriGetFeature( typeName, pCrsString, filter );

    }

    else

    { //no: include BBOX of current canvas extent in URI

      mUri = conn.uriGetFeature( typeName, pCrsString, filter, extent );

    }

    emit addWfsLayer( mUri, typeName );

    QString mUri;            // data source URI

    <width>592</width>

     <attribute name="headerMinimumSectionSize">

      <number>27</number>

     </attribute>

     <attribute name="headerMinimumSectionSize">

      <number>27</number>

     </attribute>

       <string>Cache

Features</string>

      </property>

      <property name="textAlignment">

       <set>AlignHCenter|AlignVCenter|AlignCenter</set>