C++ QgsVectorLayer::labeling方法代码示例

bool QgsMapRendererJob::prepareLabelCache() const
{
  bool canCache = mCache;

  // calculate which layers will be labeled
  QSet< QgsMapLayer* > labeledLayers;
  Q_FOREACH ( const QgsMapLayer* ml, mSettings.layers() )
  {
    QgsVectorLayer* vl = const_cast< QgsVectorLayer* >( qobject_cast<const QgsVectorLayer *>( ml ) );
    if ( vl && QgsPalLabeling::staticWillUseLayer( vl ) )
      labeledLayers << vl;
    if ( vl && vl->labeling() && vl->labeling()->requiresAdvancedEffects( vl ) )
    {
      canCache = false;
      break;
    }
  }

  if ( mCache && mCache->hasCacheImage( LABEL_CACHE_ID ) )
  {
    // we may need to clear label cache and re-register labeled features - check for that here

    // can we reuse the cached label solution?
    bool canUseCache = canCache && mCache->dependentLayers( LABEL_CACHE_ID ).toSet() == labeledLayers;
    if ( !canUseCache )
    {
      // no - participating layers have changed
      mCache->clearCacheImage( LABEL_CACHE_ID );
    }
  }
  return canCache;
}

bool QgsMapToolLabel::createAuxiliaryFields( LabelDetails &details, QgsPalIndexes &indexes ) const
{
  bool newAuxiliaryLayer = false;
  QgsVectorLayer *vlayer = details.layer;
  QString providerId = details.pos.providerID;

  if ( !vlayer || !vlayer->labelsEnabled() )
    return false;

  if ( !vlayer->auxiliaryLayer() )
  {
    QgsNewAuxiliaryLayerDialog dlg( vlayer );
    dlg.exec();
    newAuxiliaryLayer = true;
  }

  if ( !vlayer->auxiliaryLayer() )
    return false;

  for ( const QgsPalLayerSettings::Property &p : qgis::as_const( mPalProperties ) )
  {
    int index = -1;

    // always use the default activated property
    QgsProperty prop = details.settings.dataDefinedProperties().property( p );
    if ( prop.propertyType() == QgsProperty::FieldBasedProperty && prop.isActive() )
    {
      index = vlayer->fields().lookupField( prop.field() );
    }
    else
    {
      index = QgsAuxiliaryLayer::createProperty( p, vlayer );
    }

    indexes[p] = index;
  }

  details.settings = vlayer->labeling()->settings( providerId );

  return newAuxiliaryLayer;
}

void QgsLabelPropertyDialog::init( const QString& layerId, const QString& providerId, int featureId, const QString& labelText )
{
  //get feature attributes
  QgsVectorLayer* vlayer = dynamic_cast<QgsVectorLayer*>( QgsMapLayerRegistry::instance()->mapLayer( layerId ) );
  if ( !vlayer )
  {
    return;
  }
  if ( !vlayer->labeling() )
  {
    return;
  }

  if ( !vlayer->getFeatures( QgsFeatureRequest().setFilterFid( featureId ).setFlags( QgsFeatureRequest::NoGeometry ) ).nextFeature( mCurLabelFeat ) )
  {
    return;
  }
  QgsAttributes attributeValues = mCurLabelFeat.attributes();

  //get layerproperties. Problem: only for pallabeling...

  blockElementSignals( true );

  QgsPalLayerSettings layerSettings = vlayer->labeling()->settings( vlayer, providerId );

  //get label field and fill line edit
  if ( layerSettings.isExpression && !labelText.isNull() )
  {
    mLabelTextLineEdit->setText( labelText );
    mLabelTextLineEdit->setEnabled( false );
    mLabelTextLabel->setText( tr( "Expression result" ) );
  }
  else
  {
    QString labelFieldName = vlayer->customProperty( "labeling/fieldName" ).toString();
    if ( !labelFieldName.isEmpty() )
    {
      mCurLabelField = vlayer->fieldNameIndex( labelFieldName );
      if ( mCurLabelField >= 0 )
      {
        mLabelTextLineEdit->setText( attributeValues.at( mCurLabelField ).toString() );
        const QgsFields& layerFields = vlayer->fields();
        switch ( layerFields.at( mCurLabelField ).type() )
        {
          case QVariant::Double:
            mLabelTextLineEdit->setValidator( new QDoubleValidator( this ) );
            break;
          case QVariant::Int:
          case QVariant::UInt:
          case QVariant::LongLong:
            mLabelTextLineEdit->setValidator( new QIntValidator( this ) );
            break;
          default:
            break;
        }
      }
      else
      {
        mLabelTextLineEdit->setEnabled( false );
      }
    }
  }

  //get attributes of the feature and fill data defined values

  // font is set directly from QgsLabelPosition
  updateFont( mLabelFont, false );

  //set all the gui elements to the default layer-level values
  mLabelDistanceSpinBox->clear();
  mLabelDistanceSpinBox->setSpecialValueText( tr( "Layer default (%1)" ).arg( QString::number( layerSettings.dist, 'f', mLabelDistanceSpinBox->decimals() ) ) );
  mBufferSizeSpinBox->clear();
  mBufferSizeSpinBox->setSpecialValueText( tr( "Layer default (%1)" ).arg( QString::number( layerSettings.bufferSize, 'f', mBufferSizeSpinBox->decimals() ) ) );
  mRotationSpinBox->clear();
  mXCoordSpinBox->clear();
  mYCoordSpinBox->clear();

  mShowLabelChkbx->setChecked( true );
  mFontColorButton->setColor( layerSettings.textColor );
  mBufferColorButton->setColor( layerSettings.bufferColor );
  mMinScaleSpinBox->setValue( layerSettings.scaleMin );
  mMaxScaleSpinBox->setValue( layerSettings.scaleMax );
  mHaliComboBox->setCurrentIndex( mHaliComboBox->findData( "Left" ) );
  mValiComboBox->setCurrentIndex( mValiComboBox->findData( "Bottom" ) );
  mFontColorButton->setColorDialogTitle( tr( "Font color" ) );
  mBufferColorButton->setColorDialogTitle( tr( "Buffer color" ) );

  disableGuiElements();

  QMap< QgsPalLayerSettings::DataDefinedProperties, QgsDataDefined* >::const_iterator it = layerSettings.dataDefinedProperties.constBegin();
  for ( ; it != layerSettings.dataDefinedProperties.constEnd(); ++it )
  {
    mDataDefinedProperties.insert( it.key(), it.value() ? new QgsDataDefined( *it.value() ) : nullptr );
  }

  //set widget values from data defined results
  setDataDefinedValues( layerSettings, vlayer );
  //enable widgets connected to data defined fields
  enableDataDefinedWidgets( vlayer );

//.........这里部分代码省略.........

void QgsLabelPropertyDialog::init( const QString &layerId, const QString &providerId, int featureId, const QString &labelText )
{
  //get feature attributes
  QgsVectorLayer *vlayer = QgsProject::instance()->mapLayer<QgsVectorLayer *>( layerId );
  if ( !vlayer )
  {
    return;
  }
  if ( !vlayer->labeling() )
  {
    return;
  }

  if ( !vlayer->getFeatures( QgsFeatureRequest().setFilterFid( featureId ).setFlags( QgsFeatureRequest::NoGeometry ) ).nextFeature( mCurLabelFeat ) )
  {
    return;
  }
  QgsAttributes attributeValues = mCurLabelFeat.attributes();

  //get layerproperties. Problem: only for pallabeling...

  blockElementSignals( true );

  QgsPalLayerSettings layerSettings = vlayer->labeling()->settings( providerId );

  //get label field and fill line edit
  if ( layerSettings.isExpression && !labelText.isNull() )
  {
    mLabelTextLineEdit->setText( labelText );
    mLabelTextLineEdit->setEnabled( false );
    mLabelTextLabel->setText( tr( "Expression result" ) );
  }
  else
  {
    QString labelFieldName = layerSettings.fieldName;
    if ( !labelFieldName.isEmpty() )
    {
      mCurLabelField = vlayer->fields().lookupField( labelFieldName );
      if ( mCurLabelField >= 0 )
      {
        mLabelTextLineEdit->setText( attributeValues.at( mCurLabelField ).toString() );

        if ( vlayer->isEditable() )
          mLabelTextLineEdit->setEnabled( true );
        else
          mLabelTextLineEdit->setEnabled( false );

        const QgsFields &layerFields = vlayer->fields();
        switch ( layerFields.at( mCurLabelField ).type() )
        {
          case QVariant::Double:
            mLabelTextLineEdit->setValidator( new QDoubleValidator( this ) );
            break;
          case QVariant::Int:
          case QVariant::UInt:
          case QVariant::LongLong:
            mLabelTextLineEdit->setValidator( new QIntValidator( this ) );
            break;
          default:
            break;
        }
      }
      else
      {
        mLabelTextLineEdit->setEnabled( false );
      }
    }
  }

  //get attributes of the feature and fill data defined values

  // font is set directly from QgsLabelPosition
  updateFont( mLabelFont, false );

  QgsTextFormat format = layerSettings.format();
  QgsTextBufferSettings buffer = format.buffer();

  //set all the gui elements to the default layer-level values
  mLabelDistanceSpinBox->clear();
  mLabelDistanceSpinBox->setSpecialValueText( tr( "Layer default (%1)" ).arg( QString::number( layerSettings.dist, 'f', mLabelDistanceSpinBox->decimals() ) ) );
  mBufferSizeSpinBox->clear();
  mBufferSizeSpinBox->setSpecialValueText( tr( "Layer default (%1)" ).arg( QString::number( buffer.size(), 'f', mBufferSizeSpinBox->decimals() ) ) );
  mRotationSpinBox->clear();
  mXCoordSpinBox->clear();
  mYCoordSpinBox->clear();

  mShowLabelChkbx->setChecked( true );
  mFontColorButton->setColor( format.color() );
  mBufferColorButton->setColor( buffer.color() );
  mMinScaleWidget->setScale( layerSettings.minimumScale );
  mMaxScaleWidget->setScale( layerSettings.maximumScale );
  mHaliComboBox->setCurrentIndex( mHaliComboBox->findData( "Left" ) );
  mValiComboBox->setCurrentIndex( mValiComboBox->findData( "Bottom" ) );
  mFontColorButton->setColorDialogTitle( tr( "Font Color" ) );
  mBufferColorButton->setColorDialogTitle( tr( "Buffer Color" ) );

  disableGuiElements();

  mDataDefinedProperties = layerSettings.dataDefinedProperties();

//.........这里部分代码省略.........