示例#1
0
bool QgsMapToolIdentify::identifyRasterLayer( QList<IdentifyResult> *results, QgsRasterLayer *layer, QgsPoint point, const QgsRectangle& viewExtent, double mapUnitsPerPixel )
{
  QgsDebugMsg( "point = " + point.toString() );
  if ( !layer )
    return false;

  QgsRasterDataProvider *dprovider = layer->dataProvider();
  if ( !dprovider )
    return false;

  int capabilities = dprovider->capabilities();
  if ( !( capabilities & QgsRasterDataProvider::Identify ) )
    return false;

  QgsPoint pointInCanvasCrs = point;
  try
  {
    point = toLayerCoordinates( layer, point );
  }
  catch ( QgsCsException &cse )
  {
    Q_UNUSED( cse );
    QgsDebugMsg( QString( "coordinate not reprojectable: %1" ).arg( cse.what() ) );
    return false;
  }
  QgsDebugMsg( QString( "point = %1 %2" ).arg( point.x() ).arg( point.y() ) );

  if ( !layer->extent().contains( point ) )
    return false;

  QMap< QString, QString > attributes, derivedAttributes;

  QgsRaster::IdentifyFormat format = QgsRasterDataProvider::identifyFormatFromName( layer->customProperty( "identify/format" ).toString() );

  // check if the format is really supported otherwise use first supported format
  if ( !( QgsRasterDataProvider::identifyFormatToCapability( format ) & capabilities ) )
  {
    if ( capabilities & QgsRasterInterface::IdentifyFeature ) format = QgsRaster::IdentifyFormatFeature;
    else if ( capabilities & QgsRasterInterface::IdentifyValue ) format = QgsRaster::IdentifyFormatValue;
    else if ( capabilities & QgsRasterInterface::IdentifyHtml ) format = QgsRaster::IdentifyFormatHtml;
    else if ( capabilities & QgsRasterInterface::IdentifyText ) format = QgsRaster::IdentifyFormatText;
    else return false;
  }

  QgsRasterIdentifyResult identifyResult;
  // We can only use current map canvas context (extent, width, height) if layer is not reprojected,
  if ( mCanvas->hasCrsTransformEnabled() && dprovider->crs() != mCanvas->mapSettings().destinationCrs() )
  {
    // To get some reasonable response for point/line WMS vector layers we must
    // use a context with approximately a resolution in layer CRS units
    // corresponding to current map canvas resolution (for examplei UMN Mapserver
    // in msWMSFeatureInfo() -> msQueryByRect() is using requested pixel
    // + TOLERANCE (layer param) for feature selection)
    //
    QgsRectangle r;
    r.setXMinimum( pointInCanvasCrs.x() - mapUnitsPerPixel / 2. );
    r.setXMaximum( pointInCanvasCrs.x() + mapUnitsPerPixel / 2. );
    r.setYMinimum( pointInCanvasCrs.y() - mapUnitsPerPixel / 2. );
    r.setYMaximum( pointInCanvasCrs.y() + mapUnitsPerPixel / 2. );
    r = toLayerCoordinates( layer, r ); // will be a bit larger
    // Mapserver (6.0.3, for example) does not work with 1x1 pixel box
    // but that is fixed (the rect is enlarged) in the WMS provider
    identifyResult = dprovider->identify( point, format, r, 1, 1 );
  }
  else
  {
    // It would be nice to use the same extent and size which was used for drawing,
    // so that WCS can use cache from last draw, unfortunately QgsRasterLayer::draw()
    // is doing some tricks with extent and size to allign raster to output which
    // would be difficult to replicate here.
    // Note: cutting the extent may result in slightly different x and y resolutions
    // and thus shifted point calculated back in QGIS WMS (using average resolution)
    //viewExtent = dprovider->extent().intersect( &viewExtent );

    // Width and height are calculated from not projected extent and we hope that
    // are similar to source width and height used to reproject layer for drawing.
    // TODO: may be very dangerous, because it may result in different resolutions
    // in source CRS, and WMS server (QGIS server) calcs wrong coor using average resolution.
    int width = qRound( viewExtent.width() / mapUnitsPerPixel );
    int height = qRound( viewExtent.height() / mapUnitsPerPixel );

    QgsDebugMsg( QString( "viewExtent.width = %1 viewExtent.height = %2" ).arg( viewExtent.width() ).arg( viewExtent.height() ) );
    QgsDebugMsg( QString( "width = %1 height = %2" ).arg( width ).arg( height ) );
    QgsDebugMsg( QString( "xRes = %1 yRes = %2 mapUnitsPerPixel = %3" ).arg( viewExtent.width() / width ).arg( viewExtent.height() / height ).arg( mapUnitsPerPixel ) );

    identifyResult = dprovider->identify( point, format, viewExtent, width, height );
  }

  derivedAttributes.insert( tr( "(clicked coordinate)" ), point.toString() );

  if ( identifyResult.isValid() )
  {
    QMap<int, QVariant> values = identifyResult.results();
    QgsGeometry geometry;
    if ( format == QgsRaster::IdentifyFormatValue )
    {
      Q_FOREACH ( int bandNo, values.keys() )
      {
        QString valueString;
        if ( values.value( bandNo ).isNull() )
        {
          valueString = tr( "no data" );
        }
        else
        {
          double value = values.value( bandNo ).toDouble();
          valueString = QgsRasterBlock::printValue( value );
        }
        attributes.insert( dprovider->generateBandName( bandNo ), valueString );
      }
      QString label = layer->name();
      results->append( IdentifyResult( qobject_cast<QgsMapLayer *>( layer ), label, attributes, derivedAttributes ) );
    }
bool QgsMapToolIdentify::identifyRasterLayer( QList<IdentifyResult> *results, QgsRasterLayer *layer, QgsPointXY point, const QgsRectangle &viewExtent, double mapUnitsPerPixel )
{
  QgsDebugMsg( "point = " + point.toString() );
  if ( !layer )
    return false;

  QgsRasterDataProvider *dprovider = layer->dataProvider();
  if ( !dprovider )
    return false;

  int capabilities = dprovider->capabilities();
  if ( !( capabilities & QgsRasterDataProvider::Identify ) )
    return false;

  QgsPointXY pointInCanvasCrs = point;
  try
  {
    point = toLayerCoordinates( layer, point );
  }
  catch ( QgsCsException &cse )
  {
    Q_UNUSED( cse );
    QgsDebugMsg( QString( "coordinate not reprojectable: %1" ).arg( cse.what() ) );
    return false;
  }
  QgsDebugMsg( QString( "point = %1 %2" ).arg( point.x() ).arg( point.y() ) );

  if ( !layer->extent().contains( point ) )
    return false;

  QMap< QString, QString > attributes, derivedAttributes;

  QgsRaster::IdentifyFormat format = QgsRasterDataProvider::identifyFormatFromName( layer->customProperty( QStringLiteral( "identify/format" ) ).toString() );

  // check if the format is really supported otherwise use first supported format
  if ( !( QgsRasterDataProvider::identifyFormatToCapability( format ) & capabilities ) )
  {
    if ( capabilities & QgsRasterInterface::IdentifyFeature ) format = QgsRaster::IdentifyFormatFeature;
    else if ( capabilities & QgsRasterInterface::IdentifyValue ) format = QgsRaster::IdentifyFormatValue;
    else if ( capabilities & QgsRasterInterface::IdentifyHtml ) format = QgsRaster::IdentifyFormatHtml;
    else if ( capabilities & QgsRasterInterface::IdentifyText ) format = QgsRaster::IdentifyFormatText;
    else return false;
  }

  QgsRasterIdentifyResult identifyResult;
  // We can only use current map canvas context (extent, width, height) if layer is not reprojected,
  if ( dprovider->crs() != mCanvas->mapSettings().destinationCrs() )
  {
    // To get some reasonable response for point/line WMS vector layers we must
    // use a context with approximately a resolution in layer CRS units
    // corresponding to current map canvas resolution (for examplei UMN Mapserver
    // in msWMSFeatureInfo() -> msQueryByRect() is using requested pixel
    // + TOLERANCE (layer param) for feature selection)
    //
    QgsRectangle r;
    r.setXMinimum( pointInCanvasCrs.x() - mapUnitsPerPixel / 2. );
    r.setXMaximum( pointInCanvasCrs.x() + mapUnitsPerPixel / 2. );
    r.setYMinimum( pointInCanvasCrs.y() - mapUnitsPerPixel / 2. );
    r.setYMaximum( pointInCanvasCrs.y() + mapUnitsPerPixel / 2. );
    r = toLayerCoordinates( layer, r ); // will be a bit larger
    // Mapserver (6.0.3, for example) does not work with 1x1 pixel box
    // but that is fixed (the rect is enlarged) in the WMS provider
    identifyResult = dprovider->identify( point, format, r, 1, 1 );
  }
  else
  {
    // It would be nice to use the same extent and size which was used for drawing,
    // so that WCS can use cache from last draw, unfortunately QgsRasterLayer::draw()
    // is doing some tricks with extent and size to align raster to output which
    // would be difficult to replicate here.
    // Note: cutting the extent may result in slightly different x and y resolutions
    // and thus shifted point calculated back in QGIS WMS (using average resolution)
    //viewExtent = dprovider->extent().intersect( &viewExtent );

    // Width and height are calculated from not projected extent and we hope that
    // are similar to source width and height used to reproject layer for drawing.
    // TODO: may be very dangerous, because it may result in different resolutions
    // in source CRS, and WMS server (QGIS server) calcs wrong coor using average resolution.
    int width = std::round( viewExtent.width() / mapUnitsPerPixel );
    int height = std::round( viewExtent.height() / mapUnitsPerPixel );

    QgsDebugMsg( QString( "viewExtent.width = %1 viewExtent.height = %2" ).arg( viewExtent.width() ).arg( viewExtent.height() ) );
    QgsDebugMsg( QString( "width = %1 height = %2" ).arg( width ).arg( height ) );
    QgsDebugMsg( QString( "xRes = %1 yRes = %2 mapUnitsPerPixel = %3" ).arg( viewExtent.width() / width ).arg( viewExtent.height() / height ).arg( mapUnitsPerPixel ) );

    identifyResult = dprovider->identify( point, format, viewExtent, width, height );
  }

  derivedAttributes.insert( tr( "(clicked coordinate X)" ), formatXCoordinate( pointInCanvasCrs ) );
  derivedAttributes.insert( tr( "(clicked coordinate Y)" ), formatYCoordinate( pointInCanvasCrs ) );

  if ( identifyResult.isValid() )
  {
    QMap<int, QVariant> values = identifyResult.results();
    QgsGeometry geometry;
    if ( format == QgsRaster::IdentifyFormatValue )
    {
      for ( auto it = values.constBegin(); it != values.constEnd(); ++it )
      {
        QString valueString;
        if ( it.value().isNull() )
        {
          valueString = tr( "no data" );
        }
        else
        {
          QVariant value( it.value() );
          // The cast is legit. Quoting QT doc :
          // "Although this function is declared as returning QVariant::Type,
          // the return value should be interpreted as QMetaType::Type"
          if ( static_cast<QMetaType::Type>( value.type() ) == QMetaType::Float )
          {
            valueString = QgsRasterBlock::printValue( value.toFloat() );
          }
          else
          {
            valueString = QgsRasterBlock::printValue( value.toDouble() );
          }
        }
        attributes.insert( dprovider->generateBandName( it.key() ), valueString );
      }
      QString label = layer->name();
      results->append( IdentifyResult( qobject_cast<QgsMapLayer *>( layer ), label, attributes, derivedAttributes ) );
    }
    else if ( format == QgsRaster::IdentifyFormatFeature )
    {
      for ( auto it = values.constBegin(); it != values.constEnd(); ++it )
      {
        QVariant value = it.value();
        if ( value.type() == QVariant::Bool && !value.toBool() )
        {
          // sublayer not visible or not queryable
          continue;
        }

        if ( value.type() == QVariant::String )
        {
          // error
          // TODO: better error reporting
          QString label = layer->subLayers().value( it.key() );
          attributes.clear();
          attributes.insert( tr( "Error" ), value.toString() );

          results->append( IdentifyResult( qobject_cast<QgsMapLayer *>( layer ), label, attributes, derivedAttributes ) );
          continue;
        }

        // list of feature stores for a single sublayer
        const QgsFeatureStoreList featureStoreList = it.value().value<QgsFeatureStoreList>();

        for ( const QgsFeatureStore &featureStore : featureStoreList )
        {
          const QgsFeatureList storeFeatures = featureStore.features();
          for ( QgsFeature feature : storeFeatures )
          {
            attributes.clear();
            // WMS sublayer and feature type, a sublayer may contain multiple feature types.
            // Sublayer name may be the same as layer name and feature type name
            // may be the same as sublayer. We try to avoid duplicities in label.
            QString sublayer = featureStore.params().value( QStringLiteral( "sublayer" ) ).toString();
            QString featureType = featureStore.params().value( QStringLiteral( "featureType" ) ).toString();
            // Strip UMN MapServer '_feature'
            featureType.remove( QStringLiteral( "_feature" ) );
            QStringList labels;
            if ( sublayer.compare( layer->name(), Qt::CaseInsensitive ) != 0 )
            {
              labels << sublayer;
            }
            if ( featureType.compare( sublayer, Qt::CaseInsensitive ) != 0 || labels.isEmpty() )
            {
              labels << featureType;
            }

            QMap< QString, QString > derAttributes = derivedAttributes;
            derAttributes.unite( featureDerivedAttributes( &feature, layer ) );

            IdentifyResult identifyResult( qobject_cast<QgsMapLayer *>( layer ), labels.join( QStringLiteral( " / " ) ), featureStore.fields(), feature, derAttributes );

            identifyResult.mParams.insert( QStringLiteral( "getFeatureInfoUrl" ), featureStore.params().value( QStringLiteral( "getFeatureInfoUrl" ) ) );
            results->append( identifyResult );
          }
        }
      }
    }
    else // text or html
    {
      QgsDebugMsg( QString( "%1 HTML or text values" ).arg( values.size() ) );
      for ( auto it = values.constBegin(); it != values.constEnd(); ++it )
      {
        QString value = it.value().toString();
        attributes.clear();
        attributes.insert( QLatin1String( "" ), value );

        QString label = layer->subLayers().value( it.key() );
        results->append( IdentifyResult( qobject_cast<QgsMapLayer *>( layer ), label, attributes, derivedAttributes ) );
      }
    }
  }
  else
  {
    attributes.clear();
    QString value = identifyResult.error().message( QgsErrorMessage::Text );
    attributes.insert( tr( "Error" ), value );
    QString label = tr( "Identify error" );
    results->append( IdentifyResult( qobject_cast<QgsMapLayer *>( layer ), label, attributes, derivedAttributes ) );
  }

  return true;
}