Prioritize moving unplaced labels in the move label tool

These are most likely the ones which users are trying to move when there's overlapping labels
qgis · Jul 21, 2019 · bae321a · bae321a
1 parent 87282e5
commit bae321a
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Showing 6 changed files with 29 additions and 6 deletions.
diff --git a/python/core/auto_generated/qgspallabeling.sip.in b/python/core/auto_generated/qgspallabeling.sip.in
@@ -20,7 +20,7 @@ class QgsLabelPosition
   public:
 
     QgsLabelPosition( QgsFeatureId id, double r, const QVector< QgsPointXY > &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(),
-                      const QgsGeometry &labelGeometry = QgsGeometry() );
+                      const QgsGeometry &labelGeometry = QgsGeometry(), bool isUnplaced = false );
 %Docstring
 Constructor for QgsLabelPosition.
 
@@ -38,6 +38,7 @@ Constructor for QgsLabelPosition.
 :param pinned: ``True`` if label has pinned placement
 :param providerId: ID of associated label provider
 :param labelGeometry: polygon geometry of label boundary
+:param isUnplaced: set to ``True`` if label was unplaced (e.g. due to collisions with other labels)
 %End
 
     QgsLabelPosition();
@@ -71,6 +72,8 @@ Constructor for QgsLabelPosition
     bool isPinned;
 
     QString providerID;
+
+    bool isUnplaced;
 };
 
 

diff --git a/src/app/qgsmaptoollabel.cpp b/src/app/qgsmaptoollabel.cpp
@@ -71,6 +71,18 @@ bool QgsMapToolLabel::labelAtPosition( QMouseEvent *e, QgsLabelPosition &p )
   if ( !activeLayerLabels.empty() )
     labelPosList = activeLayerLabels;
 
+  // prioritize unplaced labels
+  QList<QgsLabelPosition> unplacedLabels;
+  for ( const QgsLabelPosition &pos : qgis::as_const( labelPosList ) )
+  {
+    if ( pos.isUnplaced )
+    {
+      unplacedLabels.append( pos );
+    }
+  }
+  if ( !unplacedLabels.empty() )
+    labelPosList = unplacedLabels;
+
   if ( labelPosList.count() > 1 )
   {
     // multiple candidates found, so choose the smallest (i.e. most difficult to select otherwise)

diff --git a/src/core/qgslabelsearchtree.cpp b/src/core/qgslabelsearchtree.cpp
@@ -75,7 +75,7 @@ void QgsLabelSearchTree::labelsInRect( const QgsRectangle &r, QList<QgsLabelPosi
   }
 }
 
-bool QgsLabelSearchTree::insertLabel( pal::LabelPosition *labelPos, QgsFeatureId featureId, const QString &layerName, const QString &labeltext, const QFont &labelfont, bool diagram, bool pinned, const QString &providerId )
+bool QgsLabelSearchTree::insertLabel( pal::LabelPosition *labelPos, QgsFeatureId featureId, const QString &layerName, const QString &labeltext, const QFont &labelfont, bool diagram, bool pinned, const QString &providerId, bool isUnplaced )
 {
   if ( !labelPos )
   {
@@ -107,7 +107,7 @@ bool QgsLabelSearchTree::insertLabel( pal::LabelPosition *labelPos, QgsFeatureId
 
   QgsGeometry labelGeometry( QgsGeometry::fromPolygonXY( QVector<QgsPolylineXY>() << cornerPoints ) );
   std::unique_ptr< QgsLabelPosition > newEntry = qgis::make_unique< QgsLabelPosition >( featureId, labelPos->getAlpha() + mMapSettings.rotation(), 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, providerId, labelGeometry );
+      labelPos->getWidth(), labelPos->getHeight(), layerName, labeltext, labelfont, labelPos->getUpsideDown(), diagram, pinned, providerId, labelGeometry, isUnplaced );
   mSpatialIndex.Insert( c_min, c_max, newEntry.get() );
   mOwnedPositions.emplace_back( std::move( newEntry ) );
 

diff --git a/src/core/qgslabelsearchtree.h b/src/core/qgslabelsearchtree.h
@@ -79,7 +79,7 @@ class CORE_EXPORT QgsLabelSearchTree
      * \returns TRUE in case of success
      * \note not available in Python bindings
      */
-    bool insertLabel( pal::LabelPosition *labelPos, QgsFeatureId featureId, const QString &layerName, const QString &labeltext, const QFont &labelfont, bool diagram = false, bool pinned = false, const QString &providerId = QString() ) SIP_SKIP;
+    bool insertLabel( pal::LabelPosition *labelPos, QgsFeatureId featureId, const QString &layerName, const QString &labeltext, const QFont &labelfont, bool diagram = false, bool pinned = false, const QString &providerId = QString(), bool isUnplaced = false ) SIP_SKIP;
 
     /**
      * Sets the map \a settings associated with the labeling run.

diff --git a/src/core/qgspallabeling.h b/src/core/qgspallabeling.h
@@ -97,9 +97,10 @@ class CORE_EXPORT QgsLabelPosition
      * \param pinned TRUE if label has pinned placement
      * \param providerId ID of associated label provider
      * \param labelGeometry polygon geometry of label boundary
+     * \param isUnplaced set to TRUE if label was unplaced (e.g. due to collisions with other labels)
      */
     QgsLabelPosition( QgsFeatureId id, double r, const QVector< QgsPointXY > &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(),
-                      const QgsGeometry &labelGeometry = QgsGeometry() )
+                      const QgsGeometry &labelGeometry = QgsGeometry(), bool isUnplaced = false )
       : featureId( id )
       , rotation( r )
       , cornerPoints( corners )
@@ -114,6 +115,7 @@ class CORE_EXPORT QgsLabelPosition
       , isDiagram( diagram )
       , isPinned( pinned )
       , providerID( providerId )
+      , isUnplaced( isUnplaced )
     {}
 
     //! Constructor for QgsLabelPosition
@@ -183,6 +185,12 @@ class CORE_EXPORT QgsLabelPosition
      * \since QGIS 2.14
      */
     QString providerID;
+
+    /**
+     * TRUE if label position corresponds to an unplaced label.
+     * \since QGIS 3.10
+     */
+    bool isUnplaced = false;
 };
 
 

diff --git a/src/core/qgsvectorlayerlabelprovider.cpp b/src/core/qgsvectorlayerlabelprovider.cpp
@@ -439,7 +439,7 @@ void QgsVectorLayerLabelProvider::drawUnplacedLabel( QgsRenderContext &context,
 
   // add to the results
   QString labeltext = label->getFeaturePart()->feature()->labelText();
-  mEngine->results()->mLabelSearchTree->insertLabel( label, label->getFeaturePart()->featureId(), mLayerId, labeltext, tmpLyr.format().font(), false, lf->hasFixedPosition(), mProviderId );
+  mEngine->results()->mLabelSearchTree->insertLabel( label, label->getFeaturePart()->featureId(), mLayerId, labeltext, tmpLyr.format().font(), false, lf->hasFixedPosition(), mProviderId, true );
 }
 
 void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, QgsRenderContext &context, QgsPalLayerSettings &tmpLyr, QgsTextRenderer::TextPart drawType, double dpiRatio ) const