[FEATURE]: add option to export all lines with minimal width in dxf export

python/PyQt6/core/auto_additions/qgsdxfexport.py

@@ -1,6 +1,7 @@
 # The following has been generated automatically from src/core/dxf/qgsdxfexport.h
 QgsDxfExport.FlagNoMText = QgsDxfExport.Flag.FlagNoMText
 QgsDxfExport.FlagOnlySelectedFeatures = QgsDxfExport.Flag.FlagOnlySelectedFeatures
+QgsDxfExport.FlagHairlineWidthExport = QgsDxfExport.Flag.FlagHairlineWidthExport
 QgsDxfExport.Flags = lambda flags=0: QgsDxfExport.Flag(flags)
 # monkey patching scoped based enum
 QgsDxfExport.ExportResult.Success.__doc__ = "Successful export"

python/PyQt6/core/auto_generated/dxf/qgsdxfexport.sip.in

@@ -82,6 +82,7 @@ Returns the overridden layer name to be used in the exported DXF.
     {
       FlagNoMText,
       FlagOnlySelectedFeatures,
+      FlagHairlineWidthExport
     };
     typedef QFlags<QgsDxfExport::Flag> Flags;
 

python/core/auto_generated/dxf/qgsdxfexport.sip.in

@@ -82,6 +82,7 @@ Returns the overridden layer name to be used in the exported DXF.
     {
       FlagNoMText,
       FlagOnlySelectedFeatures,
+      FlagHairlineWidthExport
     };
     typedef QFlags<QgsDxfExport::Flag> Flags;
 

src/app/qgisapp.cpp

@@ -6871,6 +6871,8 @@ void QgisApp::dxfExport()
       flags = flags | QgsDxfExport::FlagNoMText;
     if ( d.selectedFeaturesOnly() )
       flags = flags | QgsDxfExport::FlagOnlySelectedFeatures;
+    if ( d.hairlineWidthExport() )
+      flags = flags | QgsDxfExport::FlagHairlineWidthExport;
     dxfExport.setFlags( flags );
 
     if ( auto *lMapCanvas = mapCanvas() )

src/app/qgsdxfexportdialog.cpp

@@ -804,6 +804,7 @@ QgsDxfExportDialog::QgsDxfExportDialog( QWidget *parent, Qt::WindowFlags f )
   mSelectedFeaturesOnly->setChecked( QgsProject::instance()->readEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfSelectedFeaturesOnly" ), settings.value( QStringLiteral( "qgis/lastDxfSelectedFeaturesOnly" ), "false" ).toString() ) != QLatin1String( "false" ) );
   mMTextCheckBox->setChecked( QgsProject::instance()->readEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfUseMText" ), settings.value( QStringLiteral( "qgis/lastDxfUseMText" ), "true" ).toString() ) != QLatin1String( "false" ) );
   mForce2d->setChecked( QgsProject::instance()->readEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfForce2d" ), settings.value( QStringLiteral( "qgis/lastDxfForce2d" ), "false" ).toString() ) != QLatin1String( "false" ) );
+  mHairlineWidthExportCheckBox->setChecked( QgsProject::instance()->readEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfHairlineWidthExport" ), settings.value( QStringLiteral( "qgis/lastDxfHairlineWidthExport" ), "false" ).toString() ) !=  QLatin1String( "false" ) );
 
   QStringList ids = QgsProject::instance()->mapThemeCollection()->mapThemes();
   ids.prepend( QString() );
@@ -1054,6 +1055,11 @@ bool QgsDxfExportDialog::loadSettingsFromXML( QDomDocument &doc, QString &errorM
   if ( !value.isNull() )
     mSelectedFeaturesOnly->setChecked( value == true );
 
+  element = dxfElement.namedItem( QStringLiteral( "hairline_width_export" ) ).toElement();
+  value = QgsXmlUtils::readVariant( element.firstChildElement() );
+  if ( !value.isNull() )
+    mHairlineWidthExportCheckBox->setChecked( value == true );
+
   return true;
 }
 
@@ -1177,6 +1183,11 @@ void QgsDxfExportDialog::saveSettingsToXML( QDomDocument &doc ) const
   selectedFeatures.appendChild( QgsXmlUtils::writeVariant( selectedFeaturesOnly(), doc ) );
   dxfElement.appendChild( selectedFeatures );
 
+  QDomElement hairlineWidthExportElem = domDocument.createElement( QStringLiteral( "hairline_width_export" ) );
+  hairlineWidthExportElem.appendChild( QgsXmlUtils::writeVariant( hairlineWidthExport(), doc ) );
+  dxfElement.appendChild( hairlineWidthExportElem );
+
+
   doc = domDocument;
 }
 
@@ -1252,6 +1263,11 @@ bool QgsDxfExportDialog::useMText() const
   return mMTextCheckBox->isChecked();
 }
 
+bool QgsDxfExportDialog::hairlineWidthExport() const
+{
+  return mHairlineWidthExportCheckBox->isChecked();
+}
+
 void QgsDxfExportDialog::saveSettings()
 {
   QgsSettings settings;
@@ -1266,6 +1282,7 @@ void QgsDxfExportDialog::saveSettings()
   settings.setValue( QStringLiteral( "qgis/lastDxfCrs" ), QString::number( mCRS.srsid() ) );
   settings.setValue( QStringLiteral( "qgis/lastDxfUseMText" ), mMTextCheckBox->isChecked() );
   settings.setValue( QStringLiteral( "qgis/lastDxfForce2d" ), mForce2d->isChecked() );
+  settings.setValue( QStringLiteral( "qgis/lastDxfHairlineWidthExport" ), mHairlineWidthExportCheckBox->isChecked() );
 
   QgsProject::instance()->writeEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfSymbologyMode" ), mSymbologyModeComboBox->currentIndex() );
   QgsProject::instance()->writeEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastSymbologyExportScale" ), mScaleWidget->scale() != 0 ? 1.0 / mScaleWidget->scale() : 0 );
@@ -1277,6 +1294,7 @@ void QgsDxfExportDialog::saveSettings()
   QgsProject::instance()->writeEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfCrs" ), QString::number( mCRS.srsid() ) );
   QgsProject::instance()->writeEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfUseMText" ), mMTextCheckBox->isChecked() );
   QgsProject::instance()->writeEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfForce2d" ), mForce2d->isChecked() );
+  QgsProject::instance()->writeEntry( QStringLiteral( "dxf" ), QStringLiteral( "/lastDxfHairlineWidthExport" ), mHairlineWidthExportCheckBox->isChecked() );
 
   mModel->saveLayersOutputAttribute( mModel->rootGroup() );
 }

src/app/qgsdxfexportdialog.h

@@ -119,6 +119,7 @@ class QgsDxfExportDialog : public QDialog, private Ui::QgsDxfExportDialogBase
     bool layerTitleAsName() const;
     bool force2d() const;
     bool useMText() const;
+    bool hairlineWidthExport() const;
     QString mapTheme() const;
     QString encoding() const;
     QgsCoordinateReferenceSystem crs() const;

src/core/dxf/qgsdxfexport.cpp

@@ -1763,6 +1763,11 @@ void QgsDxfExport::addFeature( QgsSymbolRenderContext &ctx, const QgsCoordinateT
       offset = 0.0;
   }
 
+  if ( mFlags & FlagHairlineWidthExport )
+  {
+    width = 0;
+  }
+
   QString lineStyleName = QStringLiteral( "CONTINUOUS" );
   if ( mSymbologyExport != Qgis::FeatureSymbologyExport::NoSymbology )
   {

src/core/dxf/qgsdxfexport.h

@@ -147,6 +147,7 @@ class CORE_EXPORT QgsDxfExport : public QgsLabelSink
     {
       FlagNoMText = 1 << 1, //!< Export text as TEXT elements. If not set, text will be exported as MTEXT elements.
       FlagOnlySelectedFeatures = 1 << 2, //!< Use only selected features for the export.
+      FlagHairlineWidthExport = 1 << 3 //!Export all lines with minimum width and don't fill polygons. Since QGIS 3.38
     };
     Q_DECLARE_FLAGS( Flags, Flag )
 

src/ui/qgsdxfexportdialogbase.ui

@@ -30,7 +30,7 @@
       </widget>
      </item>
      <item row="0" column="1">
-      <widget class="QgsFileWidget" name="mFileName"/>
+      <widget class="QgsFileWidget" name="mFileName" native="true"/>
      </item>
      <item row="1" column="0">
       <widget class="QLabel" name="mSymbologyModeLabel">
@@ -62,11 +62,11 @@
       </widget>
      </item>
      <item row="2" column="1">
-      <widget class="QgsScaleWidget" name="mScaleWidget">
+      <widget class="QgsScaleWidget" name="mScaleWidget" native="true">
        <property name="focusPolicy">
         <enum>Qt::StrongFocus</enum>
        </property>
-       <property name="showCurrentScaleButton">
+       <property name="showCurrentScaleButton" stdset="0">
         <bool>true</bool>
        </property>
       </widget>
@@ -101,7 +101,7 @@
       </widget>
      </item>
      <item row="4" column="1">
-      <widget class="QgsProjectionSelectionWidget" name="mCrsSelector">
+      <widget class="QgsProjectionSelectionWidget" name="mCrsSelector" native="true">
        <property name="focusPolicy">
         <enum>Qt::StrongFocus</enum>
        </property>
@@ -216,6 +216,13 @@
          </property>
         </widget>
        </item>
+       <item row="2" column="1">
+        <widget class="QCheckBox" name="mHairlineWidthExportCheckBox">
+         <property name="text">
+          <string>Export minimum line width</string>
+         </property>
+        </widget>
+       </item>
       </layout>
      </item>
      <item row="15" column="0" colspan="2">