QGIS » QGIS Application

  //! called when starting rendering of a layer

  virtual int prepareLayer(QgsVectorLayer* layer, int& attrIndex, QgsRenderContext& ctx ) = 0;

  //! called for every feature

  //! called when the map is drawn and labels should be placed

  virtual void drawLabeling( QgsRenderContext& context ) = 0;

  //! called when we're done with rendering

   <rect>

    <x>0</x>

    <y>0</y>

    <height>610</height>

   </rect>

  </property>

    <normaloff/>

   </iconset>

  </property>

    <widget class="QCheckBox" name="chkEnableLabeling">

     <property name="text">

      <string>Label this layer</string>

     </property>

    </widget>

   </item>

    <layout class="QHBoxLayout" name="horizontalLayout_9">

     <item>

      <widget class="QLabel" name="label_6">

     </item>

    </layout>

   </item>

    <widget class="QGroupBox" name="groupBox_4">

     <property name="title">

      <string>Placement</string>

     </layout>

    </widget>

   </item>

    <layout class="QGridLayout" name="gridLayout_4">

     <item row="0" column="0" rowspan="2">

      <widget class="QGroupBox" name="groupBox">

     </item>

    </layout>

   </item>

    <widget class="QCheckBox" name="chkLabelPerFeaturePart">

     <property name="text">

      <string>label every part of multi-part features</string>

     </property>

    </widget>

   </item>

    <widget class="QCheckBox" name="chkMergeLines">

     <property name="text">

      <string>merge connected lines to avoid duplicate labels</string>

     </property>

    </widget>

   </item>

    <layout class="QHBoxLayout" name="horizontalLayout_2">

     <item>

      <widget class="QCheckBox" name="chkNoObstacle">

     </item>

    </layout>

   </item>

    <spacer name="verticalSpacer_2">

     <property name="orientation">

      <enum>Qt::Vertical</enum>

     </property>

    </spacer>

   </item>

    <widget class="QDialogButtonBox" name="buttonBox">

     <property name="orientation">

      <enum>Qt::Horizontal</enum>

  bufferColor = Qt::white;

  labelPerPart = false;

  mergeLines = false;

}

LayerSettings::LayerSettings( const LayerSettings& s )

  bufferColor = s.bufferColor;

  labelPerPart = s.labelPerPart;

  mergeLines = s.mergeLines;

  fontMetrics = NULL;

  ct = NULL;

  bufferColor = _readColor( layer, "labeling/bufferColor" );

  labelPerPart = layer->customProperty( "labeling/labelPerPart" ).toBool();

  mergeLines = layer->customProperty( "labeling/mergeLines" ).toBool();

}

void LayerSettings::writeToLayer( QgsVectorLayer* layer )

  _writeColor( layer, "labeling/bufferColor", bufferColor );

  layer->setCustomProperty( "labeling/labelPerPart", labelPerPart );

  layer->setCustomProperty( "labeling/mergeLines", mergeLines );

}

void LayerSettings::calculateLabelSize( QString text, double& labelX, double& labelY )

{

  //QFontMetrics fontMetrics(textFont);

}

{

  QString labelText = f.attributeMap()[fieldIndex].toString();

  double labelX, labelY; // will receive label size

  if ( ct != NULL ) // reproject the geometry if necessary

    geom->transform( *ct );

  MyLabel* lbl = new MyLabel( f.id(), labelText, GEOSGeom_clone( geom->asGeos() ) );

  // record the created geometry - it will be deleted at the end.

}

{

}

    QColor bufferColor;

    bool labelPerPart; // whether to label every feature's part or only the biggest one

    bool mergeLines;

    // called from register feature hook

    void calculateLabelSize( QString text, double& labelX, double& labelY );

    // implementation of register feature hook

    void readFromLayer( QgsVectorLayer* layer );

    void writeToLayer( QgsVectorLayer* layer );

    const QgsCoordinateTransform* ct;

    QgsPoint ptZero, ptOne;

    QList<MyLabel*> geometries;

};

class LabelCandidate

    //! hook called when drawing layer before issuing select()

    virtual int prepareLayer( QgsVectorLayer* layer, int& attrIndex, QgsRenderContext& ctx );

    //! hook called when drawing for every feature in a layer

    //! called when the map is drawn and labels should be placed

    virtual void drawLabeling( QgsRenderContext& context );

    //! called when we're done with rendering

    void initPal();

  protected:

    // temporary hashtable of layer settings, being filled during labeling, cleared once labeling's done

    QHash<QgsVectorLayer*, LayerSettings> mActiveLayers;

  chkNoObstacle->setChecked( !lyr.obstacle );

  chkLabelPerFeaturePart->setChecked( lyr.labelPerPart );

  chkMergeLines->setChecked( lyr.mergeLines );

  bool scaleBased = ( lyr.scaleMin != 0 && lyr.scaleMax != 0 );

  chkScaleBasedVisibility->setChecked( scaleBased );

  {

    lyr.bufferSize = 0;

  }

  return lyr;

}

      // labeling - register feature

      if ( labeling && mRendererV2->symbolForFeature( fet ) != NULL )

      if ( mEditable )

      {

    features[sym].append( fet );

    if ( labeling && mRendererV2->symbolForFeature( fet ) != NULL )

    if ( mEditable )

    {

        if ( labeling && mRenderer->willRenderFeature( &fet ) )

        {

        }

        ++featureCount;

    //! called when starting rendering of a layer

    virtual int prepareLayer( QgsVectorLayer* layer, int& attrIndex, QgsRenderContext& ctx ) = 0;

    //! called for every feature

    //! called when the map is drawn and labels should be placed

    virtual void drawLabeling( QgsRenderContext& context ) = 0;

    //! called when we're done with rendering