Merge pull request #9841 from signedav/default_symbol_scale_bp_34

[server] Default scale/mupmm on GetLegendGraphics

python/server/auto_generated/qgsserverprojectutils.sip.in

@@ -152,6 +152,17 @@ Returns the quality for WMS images defined in a QGIS project.
 :param project: the QGIS project
 
 :return: quality if defined in project, -1 otherwise.
+%End
+
+  double wmsDefaultMapUnitsPerMm( const QgsProject &project );
+%Docstring
+Returns the default number of map units per millimeters in case of the scale is not given
+
+:param project: the QGIS project
+
+:return: the default number of map units per millimeter
+
+.. versionadded:: 3.4
 %End
 
   bool wmsUseLayerIds( const QgsProject &project );

src/app/qgsprojectproperties.cpp

@@ -637,6 +637,25 @@ QgsProjectProperties::QgsProjectProperties( QgsMapCanvas *mapCanvas, QWidget *pa
     mWMSImageQualitySpinBox->setValue( imageQuality );
   }
 
+  QString defaultValueToolTip = tr( "In case of no other information to evaluate the map unit sized symbols, it uses default scale (on projected CRS) or default map units per mm (on geographic CRS)." );
+  mWMSDefaultMapUnitsPerMm = new QDoubleSpinBox();
+  mWMSDefaultMapUnitsPerMm->setDecimals( 4 );
+  mWMSDefaultMapUnitsPerMm->setSingleStep( 0.001 );
+  mWMSDefaultMapUnitsPerMm->setValue( QgsProject::instance()->readDoubleEntry( QStringLiteral( "WMSDefaultMapUnitsPerMm" ), QStringLiteral( "/" ), 1 ) );
+  mWMSDefaultMapUnitsPerMm->setToolTip( defaultValueToolTip );
+  mWMSDefaultMapUnitScale = new QgsScaleWidget();
+  mWMSDefaultMapUnitScale->setScale( QgsProject::instance()->readDoubleEntry( QStringLiteral( "WMSDefaultMapUnitsPerMm" ), QStringLiteral( "/" ), 1 ) * QgsUnitTypes::fromUnitToUnitFactor( QgsProject::instance()->crs().mapUnits(), QgsUnitTypes::DistanceMillimeters ) );
+  mWMSDefaultMapUnitScale->setToolTip( defaultValueToolTip );
+  if ( QgsProject::instance()->crs().isGeographic() )
+  {
+    mWMSDefaultMapUnitsPerMmLayout->addWidget( mWMSDefaultMapUnitsPerMm );
+  }
+  else
+  {
+    mWMSDefaultMapUnitsPerMmLayout->addWidget( mWMSDefaultMapUnitScale );
+    mWMSDefaultMapUnitsPerMmLabel->setText( tr( "Default scale for legend" ) );
+  }
+
   mWMTSUrlLineEdit->setText( QgsProject::instance()->readEntry( QStringLiteral( "WMTSUrl" ), QStringLiteral( "/" ), QString() ) );
   mWMTSMinScaleLineEdit->setValue( QgsProject::instance()->readNumEntry( QStringLiteral( "WMTSMinScale" ), QStringLiteral( "/" ), 5000 ) );
 
@@ -1257,6 +1276,18 @@ void QgsProjectProperties::apply()
     QgsProject::instance()->writeEntry( QStringLiteral( "WMSImageQuality" ), QStringLiteral( "/" ), imageQualityValue );
   }
 
+  double defaultMapUnitsPerMm;
+  if ( QgsProject::instance()->crs().isGeographic() )
+  {
+    defaultMapUnitsPerMm = mWMSDefaultMapUnitsPerMm->value();
+  }
+  else
+  {
+    defaultMapUnitsPerMm = mWMSDefaultMapUnitScale->scale() / QgsUnitTypes::fromUnitToUnitFactor( QgsProject::instance()->crs().mapUnits(), QgsUnitTypes::DistanceMillimeters );
+  }
+
+  QgsProject::instance()->writeEntry( QStringLiteral( "WMSDefaultMapUnitsPerMm" ), QStringLiteral( "/" ), defaultMapUnitsPerMm );
+
   QgsProject::instance()->writeEntry( QStringLiteral( "WMTSUrl" ), QStringLiteral( "/" ), mWMTSUrlLineEdit->text() );
   QgsProject::instance()->writeEntry( QStringLiteral( "WMTSMinScale" ), QStringLiteral( "/" ), mWMTSMinScaleLineEdit->value() );
   bool wmtsProject = false;

src/app/qgsprojectproperties.h

@@ -22,6 +22,7 @@
 #include "qgis.h"
 #include "qgsunittypes.h"
 #include "qgsguiutils.h"
+#include "qgsscalewidget.h"
 #include "qgshelp.h"
 #include "qgis_app.h"
 
@@ -188,6 +189,9 @@ class APP_EXPORT QgsProjectProperties : public QgsOptionsDialogBase, private Ui:
     QgsMetadataWidget *mMetadataWidget = nullptr;
     QgsLayerCapabilitiesModel *mLayerCapabilitiesModel = nullptr;
 
+    QDoubleSpinBox *mWMSDefaultMapUnitsPerMm = nullptr;
+    QgsScaleWidget *mWMSDefaultMapUnitScale = nullptr;
+
     QgsCoordinateReferenceSystem mCrs;
 
     void checkPageWidgetNameMap();

src/server/qgsserverprojectutils.cpp

@@ -111,6 +111,11 @@ int QgsServerProjectUtils::wmsImageQuality( const QgsProject &project )
   return project.readNumEntry( QStringLiteral( "WMSImageQuality" ), QStringLiteral( "/" ), -1 );
 }
 
+double QgsServerProjectUtils::wmsDefaultMapUnitsPerMm( const QgsProject &project )
+{
+  return project.readDoubleEntry( QStringLiteral( "WMSDefaultMapUnitsPerMm" ), QStringLiteral( "/" ), 1 );
+}
+
 bool QgsServerProjectUtils::wmsInfoFormatSia2045( const QgsProject &project )
 {
   QString sia2045 = project.readEntry( QStringLiteral( "WMSInfoFormatSIA2045" ), QStringLiteral( "/" ), "" );

src/server/qgsserverprojectutils.h

@@ -147,6 +147,14 @@ namespace QgsServerProjectUtils
    */
   SERVER_EXPORT int wmsImageQuality( const QgsProject &project );
 
+  /**
+   * Returns the default number of map units per millimeters in case of the scale is not given
+   * \param project the QGIS project
+   * \returns the default number of map units per millimeter
+   * \since QGIS 3.4
+   */
+  SERVER_EXPORT double wmsDefaultMapUnitsPerMm( const QgsProject &project );
+
   /**
    * Returns if layer ids are used as name in WMS.
    * \param project the QGIS project

src/server/services/wms/qgswmsrenderer.cpp

@@ -193,15 +193,20 @@ namespace QgsWms
     std::unique_ptr<QImage> image;
     std::unique_ptr<QPainter> painter;
 
-    // getting scale from bbox
+    // getting scale from bbox or default size
     if ( !mWmsParameters.bbox().isEmpty() )
     {
       QgsMapSettings mapSettings;
-      image.reset( createImage( width(), height(), false ) );
-      configureMapSettings( image.get(), mapSettings );
+      std::unique_ptr<QImage> tmp( createImage( width(), height(), false ) );
+      configureMapSettings( tmp.get(), mapSettings );
       legendSettings.setMapScale( mapSettings.scale() );
       legendSettings.setMapUnitsPerPixel( mapSettings.mapUnitsPerPixel() );
     }
+    else
+    {
+      double defaultMapUnitsPerPixel = QgsServerProjectUtils::wmsDefaultMapUnitsPerMm( *mProject ) / dpmm;
+      legendSettings.setMapUnitsPerPixel( defaultMapUnitsPerPixel );
+    }
 
     if ( !mWmsParameters.rule().isEmpty() )
     {