[api] add unplaced label handling to the QgsLabelSink class

qgis · Jan 6, 2022 · a0a6243 · a0a6243
1 parent 0982260
commit a0a6243
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Showing 2 changed files with 31 additions and 0 deletions.
diff --git a/src/core/labeling/qgslabelsink.cpp b/src/core/labeling/qgslabelsink.cpp
@@ -32,6 +32,12 @@ void QgsLabelSinkProvider::drawLabel( QgsRenderContext &context, pal::LabelPosit
   mLabelSink->drawLabel( layerId(), context, label, mSettings );
 }
 
+void QgsLabelSinkProvider::drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const
+{
+  Q_ASSERT( mLabelSink );
+  mLabelSink->drawUnplacedLabel( layerId(), context, label, mSettings );
+}
+
 QgsRuleBasedLabelSinkProvider::QgsRuleBasedLabelSinkProvider( const QgsRuleBasedLabeling &rules, QgsVectorLayer *layer, QgsLabelSink *sink )
   : QgsRuleBasedLabelProvider( rules, layer, false )
   , mLabelSink( sink )
@@ -55,3 +61,9 @@ void QgsRuleBasedLabelSinkProvider::drawLabel( QgsRenderContext &context, pal::L
   Q_ASSERT( mLabelSink );
   mLabelSink->drawLabel( layerId(), context, label, mSettings );
 }
+
+void QgsRuleBasedLabelSinkProvider::drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const
+{
+  Q_ASSERT( mLabelSink );
+  mLabelSink->drawUnplacedLabel( layerId(), context, label, mSettings );
+}
diff --git a/src/core/labeling/qgslabelsink.h b/src/core/labeling/qgslabelsink.h
@@ -45,6 +45,23 @@ class QgsLabelSink
      * to another desired location.
      */
     virtual void drawLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings ) = 0;
+
+    /**
+     * The drawLabel method is called for each unplaced label.
+     * \param layerId The layer ID associated to the label
+     * \param context The render context object
+     * \param label The label object
+     * \param settings The layer labeling settings
+     * \since QGIS 3.24
+     */
+    virtual void drawUnplacedLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings )
+    {
+      Q_UNUSED( layerId );
+      Q_UNUSED( context )
+      Q_UNUSED( label );
+      Q_UNUSED( settings );
+      return;
+    }
 };
 
 /**
@@ -61,6 +78,7 @@ class QgsLabelSinkProvider : public QgsVectorLayerLabelProvider
     explicit QgsLabelSinkProvider( QgsVectorLayer *layer, const QString &providerId, QgsLabelSink *sink, const QgsPalLayerSettings *settings );
 
     void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
+    void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
 
   private:
     QgsLabelSink *mLabelSink = nullptr;
@@ -86,6 +104,7 @@ class QgsRuleBasedLabelSinkProvider : public QgsRuleBasedLabelProvider
     Q_DECL_DEPRECATED void reinit( QgsVectorLayer *layer );
 
     void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
+    void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
 
     //! Creates a  QgsRuleBasedLabelSinkProvider
     QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings ) override;