heatmap plugin: fix labeling s/metre/layer units/ (fixes #11276)

(backports from commit c373d7b)

Author: jef-n

src/plugins/heatmap/heatmap.cpp

@@ -202,7 +202,7 @@ void Heatmap::run()
     QgsDebugMsg( QString( "Radius Field index received: %1" ).arg( rField ) );
 
     // If not using map units, then calculate a conversion factor to convert the radii to map units
-    if ( d.radiusUnit() == HeatmapGui::Meters )
+    if ( d.radiusUnit() == HeatmapGui::LayerUnits )
     {
       radiusToMapUnits = mapUnitsOf( 1, inputLayer->crs() );
     }
@@ -363,17 +363,17 @@ void Heatmap::run()
  *
  */
 
-double Heatmap::mapUnitsOf( double meters, QgsCoordinateReferenceSystem layerCrs )
+double Heatmap::mapUnitsOf( double layerdist, const QgsCoordinateReferenceSystem &layerCrs )
 {
-  // Worker to transform metres input to mapunits
+  // Worker to transform layer input to mapunits
   QgsDistanceArea da;
   da.setSourceCrs( layerCrs.srsid() );
   da.setEllipsoid( layerCrs.ellipsoidAcronym() );
   if ( da.geographic() )
   {
     da.setEllipsoidalMode( true );
   }
-  return meters / da.measureLine( QgsPoint( 0.0, 0.0 ), QgsPoint( 0.0, 1.0 ) );
+  return layerdist / da.measureLine( QgsPoint( 0.0, 0.0 ), QgsPoint( 0.0, 1.0 ) );
 }
 
 int Heatmap::bufferSize( double radius, double cellsize )

src/plugins/heatmap/heatmap.h

@@ -102,8 +102,8 @@ class Heatmap: public QObject, public QgisPlugin
   private:
     double mDecay;
 
-    //! Worker to convert meters to map units
-    double mapUnitsOf( double meters, QgsCoordinateReferenceSystem layerCrs );
+    //! Worker to convert layer to map units
+    double mapUnitsOf( double dist, const QgsCoordinateReferenceSystem& layerCrs );
     //! Worker to calculate buffer size in pixels
     int bufferSize( double radius, double cellsize );
     //! Calculate the value given to a point width a given distance for a specified kernel shape

src/plugins/heatmap/heatmapgui.cpp

@@ -361,11 +361,11 @@ double HeatmapGui::estimateRadius()
 
   double estimate = maxExtent / 30;
 
-  if ( mBufferUnitCombo->currentIndex() == HeatmapGui::Meters )
+  if ( mBufferUnitCombo->currentIndex() == HeatmapGui::LayerUnits )
   {
-    // metres selected, so convert estimate from map units
+    // layer units selected, so convert estimate from map units
     QgsCoordinateReferenceSystem layerCrs = inputLayer->crs();
-    estimate = estimate / mapUnitsOf( 1, layerCrs );
+    estimate /= mapUnitsOf( 1, layerCrs );
   }
 
   // Make estimate pretty by rounding off to first digit only (eg 356->300, 0.567->0.5)
@@ -447,7 +447,7 @@ void HeatmapGui::updateBBox()
     int idx = inputLayer->pendingFields().indexFromName( mRadiusFieldCombo->currentField() );
     double maxInField = inputLayer->maximumValue( idx ).toDouble();
 
-    if ( mRadiusFieldUnitCombo->currentIndex() == HeatmapGui::Meters )
+    if ( mRadiusFieldUnitCombo->currentIndex() == HeatmapGui::LayerUnits )
     {
       radiusInMapUnits = mapUnitsOf( maxInField, layerCrs );
     }
@@ -459,7 +459,7 @@ void HeatmapGui::updateBBox()
   else
   {
     double radiusValue = mBufferSizeLineEdit->text().toDouble();
-    if ( mBufferUnitCombo->currentIndex() == HeatmapGui::Meters )
+    if ( mBufferUnitCombo->currentIndex() == HeatmapGui::LayerUnits )
     {
       radiusInMapUnits = mapUnitsOf( radiusValue, layerCrs );
     }
@@ -481,9 +481,9 @@ void HeatmapGui::updateBBox()
   updateSize();
 }
 
-double HeatmapGui::mapUnitsOf( double meters, QgsCoordinateReferenceSystem layerCrs ) const
+double HeatmapGui::mapUnitsOf( double dist, const QgsCoordinateReferenceSystem& layerCrs ) const
 {
-  // converter function to transform metres input to mapunits
+  // converter function to transform layer input to mapunits
   // so that bounding box can be updated
   QgsDistanceArea da;
   da.setSourceCrs( layerCrs.srsid() );
@@ -493,8 +493,8 @@ double HeatmapGui::mapUnitsOf( double meters, QgsCoordinateReferenceSystem layer
     da.setEllipsoidalMode( true );
   }
   double unitDistance = da.measureLine( QgsPoint( 0.0, 0.0 ), QgsPoint( 0.0, 1.0 ) );
-  QgsDebugMsg( QString( "Converted %1 meters to %2 mapunits" ).arg( meters ).arg( meters / unitDistance ) );
-  return  meters / unitDistance;
+  QgsDebugMsg( QString( "Converted %1 layer to %2 map units" ).arg( dist ).arg( dist / unitDistance ) );
+  return  dist / unitDistance;
 }
 /*
  *
@@ -515,7 +515,7 @@ bool HeatmapGui::variableRadius() const
 double HeatmapGui::radius() const
 {
   double radius = mBufferSizeLineEdit->text().toDouble();
-  if ( mBufferUnitCombo->currentIndex() == HeatmapGui::Meters )
+  if ( mBufferUnitCombo->currentIndex() == HeatmapGui::LayerUnits )
   {
     radius = mapUnitsOf( radius, inputVectorLayer()->crs() );
   }

src/plugins/heatmap/heatmapgui.h

@@ -33,7 +33,7 @@ class HeatmapGui : public QDialog, private Ui::HeatmapGuiBase
     // Should have been private, made public to be used in heatmap.cpp
     enum mBufferType
     {
-      Meters,
+      LayerUnits,
       MapUnits
     };
 
@@ -46,7 +46,7 @@ class HeatmapGui : public QDialog, private Ui::HeatmapGuiBase
     /** Returns the fixed radius value */
     double radius() const;
 
-    /** Return the radius Unit (meters/map units) */
+    /** Return the radius unit (layer/map units) */
     int radiusUnit() const;
 
     /** Return the selected kernel shape */
@@ -119,8 +119,8 @@ class HeatmapGui : public QDialog, private Ui::HeatmapGuiBase
     /** Update the LineEdits cellsize and row&col values  */
     void updateSize();
 
-    /** Convert Maters value to the corresponding map units based on Layer projection */
-    double mapUnitsOf( double meters, QgsCoordinateReferenceSystem layerCrs ) const;
+    /** Convert layer distance value to the corresponding map units based on layer projection */
+    double mapUnitsOf( double dist, const QgsCoordinateReferenceSystem& layerCrs ) const;
 
     /** Estimate a reasonable starting value for the radius field */
     double estimateRadius();

src/plugins/heatmap/heatmapguibase.ui

@@ -89,7 +89,7 @@
       <widget class="QComboBox" name="mBufferUnitCombo">
        <item>
         <property name="text">
-         <string>meters</string>
+         <string>layer units</string>
         </property>
        </item>
        <item>
@@ -269,7 +269,7 @@
           </property>
           <item>
            <property name="text">
-            <string>meters</string>
+            <string>layer units</string>
            </property>
           </item>
           <item>