Introduce label provider ID to uniquely identify label's settings

Before rule-based labeling, layer ID would identify label settings
of a label as there could be only one configuration per layer.

python/core/qgsmaprenderer.sip

@@ -6,7 +6,7 @@ class QgsLabelPosition
 #include <qgsmaprenderer.h>
 %End
   public:
-    QgsLabelPosition( int id, double r, const QVector< QgsPoint >& corners, const QgsRectangle& rect, double w, double h, const QString& layer, const QString& labeltext, const QFont& labelfont, bool upside_down, bool diagram = false, bool pinned = false );
+    QgsLabelPosition( int id, double r, const QVector< QgsPoint >& corners, const QgsRectangle& rect, double w, double h, const QString& layer, const QString& labeltext, const QFont& labelfont, bool upside_down, bool diagram = false, bool pinned = false, const QString& providerId = QString() );
     QgsLabelPosition();
     int featureId;
     double rotation;
@@ -20,6 +20,8 @@ class QgsLabelPosition
     bool upsideDown;
     bool isDiagram;
     bool isPinned;
+    //! @note added in 2.14
+    QString providerID;
 };
 
 /** Labeling engine interface. */

src/core/dxf/qgsdxfexport.cpp

@@ -978,7 +978,7 @@ void QgsDxfExport::writeEntities()
     }
     else
     {
-      lp = new QgsDxfLabelProvider( vl, this, nullptr );
+      lp = new QgsDxfLabelProvider( vl, QString(), this, nullptr );
       engine.addProvider( lp );
 
       if ( !lp->prepare( ctx, attributes ) )

src/core/dxf/qgsdxfpallabeling.cpp

@@ -22,8 +22,8 @@
 #include "qgslogger.h"
 
 
-QgsDxfLabelProvider::QgsDxfLabelProvider( QgsVectorLayer* layer, QgsDxfExport* dxf, const QgsPalLayerSettings *settings )
-    : QgsVectorLayerLabelProvider( layer, false, settings )
+QgsDxfLabelProvider::QgsDxfLabelProvider( QgsVectorLayer* layer, const QString& providerId, QgsDxfExport* dxf, const QgsPalLayerSettings *settings )
+    : QgsVectorLayerLabelProvider( layer, providerId, false, settings )
     , mDxfExport( dxf )
 {
 }
@@ -52,11 +52,11 @@ void QgsDxfRuleBasedLabelProvider::reinit( QgsVectorLayer* layer )
   mRules.rootRule()->createSubProviders( layer, mSubProviders, this );
 }
 
-QgsVectorLayerLabelProvider *QgsDxfRuleBasedLabelProvider::createProvider( QgsVectorLayer *layer, bool withFeatureLoop, const QgsPalLayerSettings *settings )
+QgsVectorLayerLabelProvider *QgsDxfRuleBasedLabelProvider::createProvider( QgsVectorLayer *layer, const QString& providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings )
 {
   QgsDebugMsg( "Entering." );
   Q_UNUSED( withFeatureLoop );
-  return new QgsDxfLabelProvider( layer, mDxfExport, settings );
+  return new QgsDxfLabelProvider( layer, providerId, mDxfExport, settings );
 }
 
 void QgsDxfRuleBasedLabelProvider::drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const

src/core/dxf/qgsdxfpallabeling.h

@@ -37,7 +37,7 @@ class QgsDxfLabelProvider : public QgsVectorLayerLabelProvider
 {
   public:
     //! construct the provider
-    explicit QgsDxfLabelProvider( QgsVectorLayer* layer, QgsDxfExport* dxf, const QgsPalLayerSettings *settings );
+    explicit QgsDxfLabelProvider( QgsVectorLayer* layer, const QString& providerId, QgsDxfExport* dxf, const QgsPalLayerSettings *settings );
 
     /** Re-implementation that writes to DXF file instead of drawing with QPainter
      * @param context render context
@@ -88,7 +88,7 @@ class QgsDxfRuleBasedLabelProvider : public QgsRuleBasedLabelProvider
     void registerDxfFeature( QgsFeature& feature, QgsRenderContext &context, const QString& dxfLayerName );
 
     //! create QgsDxfLabelProvider
-    virtual QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, bool withFeatureLoop, const QgsPalLayerSettings *settings ) override;
+    virtual QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, const QString& providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings ) override;
 
   protected:
     //! pointer to parent DXF export where this instance is used

src/core/qgslabelingenginev2.cpp

@@ -381,9 +381,10 @@ QgsAbstractLabelProvider*QgsLabelFeature::provider() const
 
 }
 
-QgsAbstractLabelProvider::QgsAbstractLabelProvider( const QString& layerId )
+QgsAbstractLabelProvider::QgsAbstractLabelProvider( const QString& layerId, const QString& providerId )
     : mEngine( nullptr )
     , mLayerId( layerId )
+    , mProviderId( providerId )
     , mFlags( DrawLabels )
     , mPlacement( QgsPalLayerSettings::AroundPoint )
     , mLinePlacementFlags( 0 )

src/core/qgslabelingenginev2.h

@@ -44,7 +44,7 @@ class CORE_EXPORT QgsAbstractLabelProvider
 
   public:
     //! Construct the provider with default values
-    QgsAbstractLabelProvider( const QString& layerId = QString() );
+    QgsAbstractLabelProvider( const QString& layerId = QString(), const QString& providerId = QString() );
     //! Vritual destructor
     virtual ~QgsAbstractLabelProvider() {}
 
@@ -77,6 +77,11 @@ class CORE_EXPORT QgsAbstractLabelProvider
     //! Returns ID of associated layer, or empty string if no layer is associated with the provider.
     QString layerId() const { return mLayerId; }
 
+    //! Returns provider ID - useful in case there is more than one label provider within a layer
+    //! (e.g. in case of rule-based labeling - provider ID = rule's key). May be empty string if
+    //! layer ID is sufficient for identification of provider's configuration.
+    QString providerId() const { return mProviderId; }
+
     //! Flags associated with the provider
     Flags flags() const { return mFlags; }
 
@@ -103,6 +108,8 @@ class CORE_EXPORT QgsAbstractLabelProvider
     QString mName;
     //! Associated layer's ID, if applicable
     QString mLayerId;
+    //! Associated provider ID (one layer may have multiple providers, e.g. in rule-based labeling)
+    QString mProviderId;
     //! Flags altering drawing and registration of features
     Flags mFlags;
     //! Placement strategy

src/core/qgslabelsearchtree.cpp

@@ -75,7 +75,7 @@ void QgsLabelSearchTree::labelsInRect( const QgsRectangle& r, QList<QgsLabelPosi
   }
 }
 
-bool QgsLabelSearchTree::insertLabel( pal::LabelPosition* labelPos, int featureId, const QString& layerName, const QString& labeltext, const QFont& labelfont, bool diagram, bool pinned )
+bool QgsLabelSearchTree::insertLabel( pal::LabelPosition* labelPos, int featureId, const QString& layerName, const QString& labeltext, const QFont& labelfont, bool diagram, bool pinned, const QString& providerId )
 {
   if ( !labelPos )
   {
@@ -93,7 +93,7 @@ bool QgsLabelSearchTree::insertLabel( pal::LabelPosition* labelPos, int featureI
     cornerPoints.push_back( QgsPoint( labelPos->getX( i ), labelPos->getY( i ) ) );
   }
   QgsLabelPosition* newEntry = new QgsLabelPosition( featureId, labelPos->getAlpha(), cornerPoints, QgsRectangle( c_min[0], c_min[1], c_max[0], c_max[1] ),
-      labelPos->getWidth(), labelPos->getHeight(), layerName, labeltext, labelfont, labelPos->getUpsideDown(), diagram, pinned );
+      labelPos->getWidth(), labelPos->getHeight(), layerName, labeltext, labelfont, labelPos->getUpsideDown(), diagram, pinned, providerId );
   mSpatialIndex.Insert( c_min, c_max, newEntry );
   mOwnedPositions << newEntry;
   return true;

src/core/qgslabelsearchtree.h

@@ -53,7 +53,7 @@ class CORE_EXPORT QgsLabelSearchTree
      * @return true in case of success
      * @note not available in python bindings
      */
-    bool insertLabel( pal::LabelPosition* labelPos, int featureId, const QString& layerName, const QString& labeltext, const QFont& labelfont, bool diagram = false, bool pinned = false );
+    bool insertLabel( pal::LabelPosition* labelPos, int featureId, const QString& layerName, const QString& labeltext, const QFont& labelfont, bool diagram = false, bool pinned = false, const QString& providerId = QString() );
 
   private:
     // set as mutable because RTree template is not const-correct

src/core/qgsmaprenderer.h

@@ -46,8 +46,8 @@ class QgsDiagramLayerSettings;
 class CORE_EXPORT QgsLabelPosition
 {
   public:
-    QgsLabelPosition( int id, double r, const QVector< QgsPoint >& corners, const QgsRectangle& rect, double w, double h, const QString& layer, const QString& labeltext, const QFont& labelfont, bool upside_down, bool diagram = false, bool pinned = false )
-        : featureId( id ), rotation( r ), cornerPoints( corners ), labelRect( rect ), width( w ), height( h ), layerID( layer ), labelText( labeltext ), labelFont( labelfont ), upsideDown( upside_down ), isDiagram( diagram ), isPinned( pinned ) {}
+    QgsLabelPosition( int id, double r, const QVector< QgsPoint >& corners, const QgsRectangle& rect, double w, double h, const QString& layer, const QString& labeltext, const QFont& labelfont, bool upside_down, bool diagram = false, bool pinned = false, const QString& providerId = QString() )
+        : featureId( id ), rotation( r ), cornerPoints( corners ), labelRect( rect ), width( w ), height( h ), layerID( layer ), labelText( labeltext ), labelFont( labelfont ), upsideDown( upside_down ), isDiagram( diagram ), isPinned( pinned ), providerID( providerId ) {}
     QgsLabelPosition()
         : featureId( -1 ), rotation( 0 ), labelRect( QgsRectangle() ), width( 0 ), height( 0 ), layerID( "" ), labelText( "" ), labelFont( QFont() ), upsideDown( false ), isDiagram( false ), isPinned( false ) {}
     int featureId;
@@ -62,6 +62,8 @@ class CORE_EXPORT QgsLabelPosition
     bool upsideDown;
     bool isDiagram;
     bool isPinned;
+    //! @note added in 2.14
+    QString providerID;
 };
 
 /** Labeling engine interface. */

src/core/qgsrulebasedlabeling.cpp

@@ -16,7 +16,7 @@
 
 
 QgsRuleBasedLabelProvider::QgsRuleBasedLabelProvider( const QgsRuleBasedLabeling& rules, QgsVectorLayer* layer, bool withFeatureLoop )
-    : QgsVectorLayerLabelProvider( layer, withFeatureLoop )
+    : QgsVectorLayerLabelProvider( layer, QString(), withFeatureLoop )
     , mRules( rules )
 {
   mRules.rootRule()->createSubProviders( layer, mSubProviders, this );
@@ -27,9 +27,9 @@ QgsRuleBasedLabelProvider::~QgsRuleBasedLabelProvider()
   // sub-providers owned by labeling engine
 }
 
-QgsVectorLayerLabelProvider *QgsRuleBasedLabelProvider::createProvider( QgsVectorLayer *layer, bool withFeatureLoop, const QgsPalLayerSettings *settings )
+QgsVectorLayerLabelProvider *QgsRuleBasedLabelProvider::createProvider( QgsVectorLayer *layer, const QString& providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings )
 {
-  return new QgsVectorLayerLabelProvider( layer, withFeatureLoop, settings );
+  return new QgsVectorLayerLabelProvider( layer, providerId, withFeatureLoop, settings );
 }
 
 bool QgsRuleBasedLabelProvider::prepare( const QgsRenderContext& context, QStringList& attributeNames )
@@ -67,6 +67,7 @@ QgsRuleBasedLabeling::Rule::Rule( QgsPalLayerSettings* settings, int scaleMinDen
     , mIsActive( true )
     , mFilter( nullptr )
 {
+  mRuleKey = QUuid::createUuid().toString();
   initFilter();
 }
 
@@ -162,11 +163,11 @@ QgsRuleBasedLabeling::Rule*QgsRuleBasedLabeling::Rule::create( const QDomElement
   QString description = ruleElem.attribute( "description" );
   int scaleMinDenom = ruleElem.attribute( "scalemindenom", "0" ).toInt();
   int scaleMaxDenom = ruleElem.attribute( "scalemaxdenom", "0" ).toInt();
-  //QString ruleKey = ruleElem.attribute( "key" );
+  QString ruleKey = ruleElem.attribute( "key" );
   Rule* rule = new Rule( settings, scaleMinDenom, scaleMaxDenom, filterExp, description );
 
-  //if ( !ruleKey.isEmpty() )
-  //  rule->mRuleKey = ruleKey;
+  if ( !ruleKey.isEmpty() )
+    rule->mRuleKey = ruleKey;
 
   rule->setActive( ruleElem.attribute( "active", "1" ).toInt() );
 
@@ -206,7 +207,7 @@ QDomElement QgsRuleBasedLabeling::Rule::save( QDomDocument& doc ) const
     ruleElem.setAttribute( "description", mDescription );
   if ( !mIsActive )
     ruleElem.setAttribute( "active", 0 );
-  //ruleElem.setAttribute( "key", mRuleKey );
+  ruleElem.setAttribute( "key", mRuleKey );
 
   for ( RuleList::const_iterator it = mChildren.constBegin(); it != mChildren.constEnd(); ++it )
   {
@@ -221,7 +222,7 @@ void QgsRuleBasedLabeling::Rule::createSubProviders( QgsVectorLayer* layer, QgsR
   if ( mSettings )
   {
     // add provider!
-    QgsVectorLayerLabelProvider *p = provider->createProvider( layer, false, mSettings );
+    QgsVectorLayerLabelProvider *p = provider->createProvider( layer, mRuleKey, false, mSettings );
     Q_ASSERT( !subProviders.contains( this ) );
     subProviders[this] = p;
   }

src/core/qgsrulebasedlabeling.h

@@ -119,6 +119,9 @@ class CORE_EXPORT QgsRuleBasedLabeling : public QgsAbstractVectorLayerLabeling
          */
         bool isElse() const { return mElseRule; }
 
+        //! Unique rule identifier (for identification of rule within labeling, used as provider ID)
+        QString ruleKey() const { return mRuleKey; }
+
         //! set new settings (or NULL). Deletes old settings if any.
         void setSettings( QgsPalLayerSettings* settings );
 
@@ -160,6 +163,8 @@ class CORE_EXPORT QgsRuleBasedLabeling : public QgsAbstractVectorLayerLabeling
          */
         void setIsElse( bool iselse ) { mElseRule = iselse; }
 
+        //! Override the assigned rule key (should be used just internally by rule-based labeling)
+        void setRuleKey( const QString& key ) { mRuleKey = key; }
 
         // parent / child operations
 
@@ -260,6 +265,8 @@ class CORE_EXPORT QgsRuleBasedLabeling : public QgsAbstractVectorLayerLabeling
         RuleList mElseRules;
         bool mIsActive; // whether it is enabled or not
 
+        QString mRuleKey; // string used for unique identification of rule within labeling
+
         // temporary
         QgsExpression* mFilter;
 
@@ -311,7 +318,7 @@ class CORE_EXPORT QgsRuleBasedLabelProvider : public QgsVectorLayerLabelProvider
     virtual void registerFeature( QgsFeature& feature, QgsRenderContext& context, QgsGeometry* obstacleGeometry = nullptr ) override;
 
     //! create a label provider
-    virtual QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, bool withFeatureLoop, const QgsPalLayerSettings *settings );
+    virtual QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, const QString& providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings );
 
     //! return subproviders
     virtual QList<QgsAbstractLabelProvider*> subProviders() override;

src/core/qgsvectorlayerdiagramprovider.cpp

@@ -35,7 +35,6 @@ QgsVectorLayerDiagramProvider::QgsVectorLayerDiagramProvider(
     : QgsAbstractLabelProvider( layerId )
     , mSettings( *diagSettings )
     , mDiagRenderer( diagRenderer->clone() )
-    , mLayerId( layerId )
     , mFields( fields )
     , mLayerCrs( crs )
     , mSource( source )
@@ -49,7 +48,6 @@ QgsVectorLayerDiagramProvider::QgsVectorLayerDiagramProvider( QgsVectorLayer* la
     : QgsAbstractLabelProvider( layer->id() )
     , mSettings( *layer->diagramLayerSettings() )
     , mDiagRenderer( layer->diagramRenderer()->clone() )
-    , mLayerId( layer->id() )
     , mFields( layer->fields() )
     , mLayerCrs( layer->crs() )
     , mSource( ownFeatureLoop ? new QgsVectorLayerFeatureSource( layer ) : nullptr )

src/core/qgsvectorlayerdiagramprovider.h

@@ -113,8 +113,6 @@ class CORE_EXPORT QgsVectorLayerDiagramProvider : public QgsAbstractLabelProvide
     QgsDiagramLayerSettings mSettings;
     //! Diagram renderer instance (owned by mSettings)
     QgsDiagramRendererV2* mDiagRenderer;
-    //! ID of the layer
-    QString mLayerId;
 
     // these are needed only if using own renderer loop
 

src/core/qgsvectorlayerlabeling.cpp

@@ -39,7 +39,7 @@ QgsAbstractVectorLayerLabeling* QgsAbstractVectorLayerLabeling::create( const QD
 QgsVectorLayerLabelProvider* QgsVectorLayerSimpleLabeling::provider( QgsVectorLayer* layer ) const
 {
   if ( layer->customProperty( "labeling" ).toString() == QLatin1String( "pal" ) && layer->labelsEnabled() )
-    return new QgsVectorLayerLabelProvider( layer, false );
+    return new QgsVectorLayerLabelProvider( layer, QString(), false );
 
   return nullptr;
 }

src/core/qgsvectorlayerlabelprovider.cpp

@@ -49,8 +49,8 @@ static void _fixQPictureDPI( QPainter* p )
 
 
 
-QgsVectorLayerLabelProvider::QgsVectorLayerLabelProvider( QgsVectorLayer* layer, bool withFeatureLoop, const QgsPalLayerSettings* settings, const QString& layerName )
-    : QgsAbstractLabelProvider( layer->id() )
+QgsVectorLayerLabelProvider::QgsVectorLayerLabelProvider( QgsVectorLayer* layer, const QString& providerId, bool withFeatureLoop, const QgsPalLayerSettings* settings, const QString& layerName )
+    : QgsAbstractLabelProvider( layer->id(), providerId )
     , mSettings( settings ? *settings : QgsPalLayerSettings::fromLayer( layer ) )
     , mLayerGeometryType( layer->geometryType() )
     , mRenderer( layer->rendererV2() )
@@ -490,7 +490,7 @@ void QgsVectorLayerLabelProvider::drawLabel( QgsRenderContext& context, pal::Lab
 
   // add to the results
   QString labeltext = label->getFeaturePart()->feature()->labelText();
-  mEngine->results()->mLabelSearchTree->insertLabel( label, label->getFeaturePart()->featureId(), mLayerId, labeltext, dFont, false, lf->hasFixedPosition() );
+  mEngine->results()->mLabelSearchTree->insertLabel( label, label->getFeaturePart()->featureId(), mLayerId, labeltext, dFont, false, lf->hasFixedPosition(), mProviderId );
 }
 
 

src/core/qgsvectorlayerlabelprovider.h

@@ -37,7 +37,11 @@ class CORE_EXPORT QgsVectorLayerLabelProvider : public QgsAbstractLabelProvider
   public:
 
     //! Convenience constructor to initialize the provider from given vector layer
-    explicit QgsVectorLayerLabelProvider( QgsVectorLayer* layer, bool withFeatureLoop = true, const QgsPalLayerSettings* settings = nullptr, const QString& layerName = QString() );
+    explicit QgsVectorLayerLabelProvider( QgsVectorLayer* layer,
+                                          const QString& providerId,
+                                          bool withFeatureLoop = true,
+                                          const QgsPalLayerSettings* settings = nullptr,
+                                          const QString& layerName = QString() );
 
     //! Construct diagram provider with all the necessary configuration parameters
     QgsVectorLayerLabelProvider( const QgsPalLayerSettings& settings,