dxf export: support rule based labeling (fixes #13757)

Author: jef-n

python/core/qgsmaprenderer.sip

@@ -35,7 +35,7 @@ class QgsLabelingEngineInterface
 
     //! called when we're going to start with rendering
     //! @deprecated since 2.4 - use override with QgsMapSettings
-    virtual void init( QgsMapRenderer* mp ) = 0 /Deprecated/;
+    virtual void init( QgsMapRenderer *mp ) = 0 /Deprecated/;
     //! called when we're going to start with rendering
     virtual void init( const QgsMapSettings& mapSettings ) = 0;
     //! called to find out whether the layer is used for labeling
@@ -48,17 +48,17 @@ class QgsLabelingEngineInterface
     virtual int prepareLayer( QgsVectorLayer* layer, QStringList& attrNames, QgsRenderContext& ctx ) = 0;
     //! returns PAL layer settings for a registered layer
     //! @deprecated since 2.12 - if direct access to QgsPalLayerSettings is necessary, use QgsPalLayerSettings::fromLayer()
-    virtual QgsPalLayerSettings& layer( const QString& layerName ) = 0 /Deprecated/;
+    virtual QgsPalLayerSettings &layer( const QString &layerName ) = 0 /Deprecated/;
     //! adds a diagram layer to the labeling engine
     //! @note added in QGIS 2.12
-    virtual int prepareDiagramLayer( QgsVectorLayer* layer, QStringList& attrNames, QgsRenderContext& ctx );
+    virtual int prepareDiagramLayer( QgsVectorLayer *layer, QStringList &attrNames, QgsRenderContext &ctx );
     //! adds a diagram layer to the labeling engine
     //! @deprecated since 2.12 - use prepareDiagramLayer()
-    virtual int addDiagramLayer( QgsVectorLayer* layer, const QgsDiagramLayerSettings* s ) /Deprecated/;
+    virtual int addDiagramLayer( QgsVectorLayer *layer, const QgsDiagramLayerSettings *s ) /Deprecated/;
     //! called for every feature
-    virtual void registerFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context, const QString& dxfLayer = QString::null ) = 0;
+    virtual void registerFeature( const QString &layerID, QgsFeature &feat, QgsRenderContext &context ) = 0;
     //! called for every diagram feature
-    virtual void registerDiagramFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context );
+    virtual void registerDiagramFeature( const QString &layerID, QgsFeature &feat, QgsRenderContext &context );
     //! called when the map is drawn and labels should be placed
     virtual void drawLabeling( QgsRenderContext& context ) = 0;
     //! called when we're done with rendering
@@ -268,7 +268,7 @@ class QgsMapRenderer : QObject
     //! Accessor for render context
     QgsRenderContext* rendererContext();
 
-    //! Labeling engine (NULL if there's no custom engine)
+    //! Labeling engine (nullptr if there's no custom engine)
     QgsLabelingEngineInterface* labelingEngine();
 
     //! Set labeling engine. Previous engine (if any) is deleted.

python/core/qgspallabeling.sip

@@ -551,7 +551,6 @@ class QgsPalLayerSettings
      * @param f feature to label
      * @param context render context. The QgsExpressionContext contained within the render context
      * must have already had the feature and fields sets prior to calling this method.
-     * @param dxfLayer dxfLayer name
      * @param labelFeature if using QgsLabelingEngineV2, this will receive the label feature. Not available
      * in Python bindings.
      * @param obstacleGeometry optional obstacle geometry, if a different geometry to the feature's geometry
@@ -560,7 +559,7 @@ class QgsPalLayerSettings
      * the feature's original geometry will be used as an obstacle for labels. Not available
      * in Python bindings.
      */
-    void registerFeature( QgsFeature& f, QgsRenderContext& context, const QString& dxfLayer );
+    void registerFeature( QgsFeature& f, QgsRenderContext& context );
 
     void readFromLayer( QgsVectorLayer* layer );
     void writeToLayer( QgsVectorLayer* layer );
@@ -867,9 +866,8 @@ class QgsPalLabeling : QgsLabelingEngineInterface
      * @param feat feature to label
      * @param context render context. The QgsExpressionContext contained within the render context
      * must have already had the feature and fields sets prior to calling this method.
-     * @param dxfLayer dxfLayer name
      */
-    virtual void registerFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context, const QString& dxfLayer = QString::null );
+    virtual void registerFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context );
 
     virtual void registerDiagramFeature( const QString& layerID, QgsFeature& feat, QgsRenderContext& context );
     //! called when the map is drawn and labels should be placed

src/core/dxf/qgsdxfexport.cpp

@@ -37,6 +37,11 @@
 #include "qgsvectorlayer.h"
 #include "qgsmaplayerregistry.h"
 #include "qgsunittypes.h"
+#include "qgstextlabelfeature.h"
+
+#include "pal/feature.h"
+#include "pal/pointset.h"
+#include "pal/labelposition.h"
 
 #include <QIODevice>
 
@@ -942,12 +947,32 @@ void QgsDxfExport::writeEntities()
         attributes << layerAttr;
     }
 
-    QgsDxfLabelProvider* lp = new QgsDxfLabelProvider( vl, this );
-    engine.addProvider( lp );
-    if ( !lp->prepare( ctx, attributes ) )
+    const QgsAbstractVectorLayerLabeling *labeling = vl->labeling();
+    QgsDxfLabelProvider *lp = nullptr;
+    QgsDxfRuleBasedLabelProvider *rblp = nullptr;
+    if ( dynamic_cast<const QgsRuleBasedLabeling*>( labeling ) )
+    {
+      const QgsRuleBasedLabeling *rbl = dynamic_cast<const QgsRuleBasedLabeling*>( labeling );
+      rblp = new QgsDxfRuleBasedLabelProvider( *rbl, vl, this );
+      rblp->reinit( vl );
+      engine.addProvider( rblp );
+
+      if ( !rblp->prepare( ctx, attributes ) )
+      {
+        engine.removeProvider( rblp );
+        rblp = nullptr;
+      }
+    }
+    else
     {
-      engine.removeProvider( lp );
-      lp = nullptr;
+      lp = new QgsDxfLabelProvider( vl, this, nullptr );
+      engine.addProvider( lp );
+
+      if ( !lp->prepare( ctx, attributes ) )
+      {
+        engine.removeProvider( lp );
+        lp = nullptr;
+      }
     }
 
     if ( mSymbologyExport == QgsDxfExport::SymbolLayerSymbology &&
@@ -1012,6 +1037,10 @@ void QgsDxfExport::writeEntities()
         {
           lp->registerDxfFeature( fet, ctx, lName );
         }
+        else if ( rblp )
+        {
+          rblp->registerDxfFeature( fet, ctx, lName );
+        }
       }
     }
 
@@ -4169,3 +4198,112 @@ QString QgsDxfExport::layerName( QgsVectorLayer *vl ) const
   Q_ASSERT( vl );
   return mLayerTitleAsName && !vl->title().isEmpty() ? vl->title() : vl->name();
 }
+
+void QgsDxfExport::drawLabel( QString layerId, QgsRenderContext& context, pal::LabelPosition* label, const QgsPalLayerSettings &settings )
+{
+  Q_UNUSED( context );
+  QgsTextLabelFeature* lf = dynamic_cast<QgsTextLabelFeature*>( label->getFeaturePart()->feature() );
+  if ( !lf )
+    return;
+
+  //label text
+  QString txt = lf->text( label->getPartId() );
+
+  //angle
+  double angle = label->getAlpha() * 180 / M_PI;
+
+  QgsFeatureId fid = label->getFeaturePart()->featureId();
+  QString dxfLayer = mDxfLayerNames[layerId][fid];
+
+  //debug: show label rectangle
+#if 0
+  QgsPolyline line;
+  for ( int i = 0; i < 4; ++i )
+  {
+    line.append( QgsPoint( label->getX( i ), label->getY( i ) ) );
+  }
+  writePolyline( line, dxfLayer, "CONTINUOUS", 1, 0.01, true );
+#endif
+
+  QString wrapchr = settings.wrapChar.isEmpty() ? "\n" : settings.wrapChar;
+
+  //add the direction symbol if needed
+  if ( !txt.isEmpty() && settings.placement == QgsPalLayerSettings::Line && settings.addDirectionSymbol )
+  {
+    bool prependSymb = false;
+    QString symb = settings.rightDirectionSymbol;
+
+    if ( label->getReversed() )
+    {
+      prependSymb = true;
+      symb = settings.leftDirectionSymbol;
+    }
+
+    if ( settings.reverseDirectionSymbol )
+    {
+      if ( symb == settings.rightDirectionSymbol )
+      {
+        prependSymb = true;
+        symb = settings.leftDirectionSymbol;
+      }
+      else
+      {
+        prependSymb = false;
+        symb = settings.rightDirectionSymbol;
+      }
+    }
+
+    if ( settings.placeDirectionSymbol == QgsPalLayerSettings::SymbolAbove )
+    {
+      prependSymb = true;
+      symb = symb + wrapchr;
+    }
+    else if ( settings.placeDirectionSymbol == QgsPalLayerSettings::SymbolBelow )
+    {
+      prependSymb = false;
+      symb = wrapchr + symb;
+    }
+
+    if ( prependSymb )
+    {
+      txt.prepend( symb );
+    }
+    else
+    {
+      txt.append( symb );
+    }
+  }
+
+  txt = txt.replace( wrapchr, "\\P" );
+
+  if ( settings.textFont.underline() )
+  {
+    txt.prepend( "\\L" ).append( "\\l" );
+  }
+
+  if ( settings.textFont.overline() )
+  {
+    txt.prepend( "\\O" ).append( "\\o" );
+  }
+
+  if ( settings.textFont.strikeOut() )
+  {
+    txt.prepend( "\\K" ).append( "\\k" );
+  }
+
+  txt.prepend( QString( "\\f%1|i%2|b%3;\\H%4;\\W0.75;" )
+               .arg( settings.textFont.family() )
+               .arg( settings.textFont.italic() ? 1 : 0 )
+               .arg( settings.textFont.bold() ? 1 : 0 )
+               .arg( label->getHeight() / ( 1 + txt.count( "\\P" ) ) * 0.75 ) );
+
+  writeMText( dxfLayer, txt, QgsPoint( label->getX(), label->getY() ), label->getWidth() * 1.1, angle, settings.textColor );
+}
+
+void QgsDxfExport::registerDxfLayer( QString layerId, QgsFeatureId fid, QString layerName )
+{
+  if ( !mDxfLayerNames.contains( layerId ) )
+    mDxfLayerNames[ layerId ] = QMap<QgsFeatureId, QString>();
+
+  mDxfLayerNames[layerId][fid] = layerName;
+}

src/core/dxf/qgsdxfexport.h

@@ -20,6 +20,7 @@
 
 #include "qgsgeometry.h"
 #include "qgssymbolv2.h"
+
 #include <QColor>
 #include <QList>
 #include <QTextStream>
@@ -28,6 +29,12 @@ class QgsMapLayer;
 class QgsPoint;
 class QgsSymbolLayerV2;
 class QIODevice;
+class QgsPalLayerSettings;
+
+namespace pal
+{
+  class LabelPosition;
+};
 
 class CORE_EXPORT QgsDxfExport
 {
@@ -283,6 +290,9 @@ class CORE_EXPORT QgsDxfExport
     //! return list of available DXF encodings
     static QStringList encodings();
 
+    void drawLabel( QString layerId, QgsRenderContext& context, pal::LabelPosition* label, const QgsPalLayerSettings &settings );
+    void registerDxfLayer( QString layerId, QgsFeatureId fid, QString layer );
+
   private:
     QList< QPair<QgsVectorLayer*, int> > mLayers;
 
@@ -350,6 +360,9 @@ class CORE_EXPORT QgsDxfExport
 
     QHash<QString, int> mBlockHandles;
     QString mBlockHandle;
+
+    //! DXF layer name for each label feature
+    QMap< QString, QMap<QgsFeatureId, QString> > mDxfLayerNames;
 };
 
 #endif // QGSDXFEXPORT_H