Start restoring SVG export

python/core/layout/qgslayoutexporter.sip

@@ -236,6 +236,55 @@ Layout context flags, which control how the export will be created.
 %Docstring
 Exports the layout as a PDF to the a ``filePath``, using the specified export ``settings``.
 
+Returns a result code indicating whether the export was successful or an
+error was encountered.
+%End
+
+
+    struct SvgExportSettings
+    {
+      SvgExportSettings();
+%Docstring
+Constructor for SvgExportSettings
+%End
+
+      double dpi;
+%Docstring
+Resolution to export layout at. If dpi <= 0 the default layout dpi will be used.
+%End
+
+      bool forceVectorOutput;
+%Docstring
+Set to true to force vector object exports, even when the resultant appearance will differ
+from the layout. If false, some items may be rasterized in order to maintain their
+correct appearance in the output.
+
+This option is mutually exclusive with rasterizeWholeImage.
+%End
+
+      bool cropToContents;
+%Docstring
+Set to true if image should be cropped so only parts of the layout
+containing items are exported.
+%End
+
+      QgsMargins cropMargins;
+%Docstring
+Crop to content margins, in layout units. These margins will be added
+to the bounds of the exported layout if cropToContents is true.
+%End
+
+      QgsLayoutContext::Flags flags;
+%Docstring
+Layout context flags, which control how the export will be created.
+%End
+
+    };
+
+    ExportResult exportToSvg( const QString &filePath, const QgsLayoutExporter::SvgExportSettings &settings );
+%Docstring
+Exports the layout as an SVG to the a ``filePath``, using the specified export ``settings``.
+
 Returns a result code indicating whether the export was successful or an
 error was encountered.
 %End

src/app/layout/qgslayoutdesignerdialog.cpp

@@ -53,6 +53,7 @@
 #include "qgsbusyindicatordialog.h"
 #include "qgslayoutundostack.h"
 #include "qgslayoutpagecollection.h"
+#include "ui_qgssvgexportoptions.h"
 #include <QShortcut>
 #include <QComboBox>
 #include <QLineEdit>
@@ -182,6 +183,7 @@ QgsLayoutDesignerDialog::QgsLayoutDesignerDialog( QWidget *parent, Qt::WindowFla
 
   connect( mActionExportAsImage, &QAction::triggered, this, &QgsLayoutDesignerDialog::exportToRaster );
   connect( mActionExportAsPDF, &QAction::triggered, this, &QgsLayoutDesignerDialog::exportToPdf );
+  connect( mActionExportAsSVG, &QAction::triggered, this, &QgsLayoutDesignerDialog::exportToSvg );
 
   connect( mActionShowGrid, &QAction::triggered, this, &QgsLayoutDesignerDialog::showGrid );
   connect( mActionSnapGrid, &QAction::triggered, this, &QgsLayoutDesignerDialog::snapToGrid );
@@ -1671,6 +1673,152 @@ void QgsLayoutDesignerDialog::exportToPdf()
   QApplication::restoreOverrideCursor();
 }
 
+void QgsLayoutDesignerDialog::exportToSvg()
+{
+  if ( containsWmsLayers() )
+  {
+    showWmsPrintingWarning();
+  }
+
+  showSvgExportWarning();
+
+  QgsSettings settings;
+  QString lastUsedFile = settings.value( QStringLiteral( "UI/lastSaveAsSvgFile" ), QStringLiteral( "qgis.svg" ) ).toString();
+  QFileInfo file( lastUsedFile );
+  QString outputFileName;
+
+#if 0// TODO
+  if ( hasAnAtlas && !atlasOnASingleFile &&
+       ( mode == QgsComposer::Atlas || mComposition->atlasMode() == QgsComposition::PreviewAtlas ) )
+  {
+    outputFileName = QDir( file.path() ).filePath( atlasMap->currentFilename() ) + ".pdf";
+  }
+  else
+  {
+#endif
+    outputFileName = file.path();
+#if 0 //TODO
+  }
+#endif
+
+#ifdef Q_OS_MAC
+  QgisApp::instance()->activateWindow();
+  this->raise();
+#endif
+  outputFileName = QFileDialog::getSaveFileName(
+                     this,
+                     tr( "Export to SVG" ),
+                     outputFileName,
+                     tr( "SVG Format" ) + " (*.svg *.SVG)" );
+  this->activateWindow();
+  if ( outputFileName.isEmpty() )
+  {
+    return;
+  }
+
+  if ( !outputFileName.endsWith( QLatin1String( ".svg" ), Qt::CaseInsensitive ) )
+  {
+    outputFileName += QLatin1String( ".svg" );
+  }
+
+  settings.setValue( QStringLiteral( "UI/lastSaveAsSvgFile" ), outputFileName );
+
+  bool groupLayers = false;
+  bool prevSettingLabelsAsOutlines = mLayout->project()->readBoolEntry( QStringLiteral( "PAL" ), QStringLiteral( "/DrawOutlineLabels" ), true );
+  bool clipToContent = false;
+  double marginTop = 0.0;
+  double marginRight = 0.0;
+  double marginBottom = 0.0;
+  double marginLeft = 0.0;
+  bool previousForceVector = mLayout->customProperty( QStringLiteral( "forceVector" ), false ).toBool();
+
+  // open options dialog
+  QDialog dialog;
+  Ui::QgsSvgExportOptionsDialog options;
+  options.setupUi( &dialog );
+  options.chkTextAsOutline->setChecked( prevSettingLabelsAsOutlines );
+  options.chkMapLayersAsGroup->setChecked( mLayout->customProperty( QStringLiteral( "svgGroupLayers" ), false ).toBool() );
+  options.mClipToContentGroupBox->setChecked( mLayout->customProperty( QStringLiteral( "svgCropToContents" ), false ).toBool() );
+  options.mForceVectorCheckBox->setChecked( previousForceVector );
+  options.mTopMarginSpinBox->setValue( mLayout->customProperty( QStringLiteral( "svgCropMarginTop" ), 0 ).toInt() );
+  options.mRightMarginSpinBox->setValue( mLayout->customProperty( QStringLiteral( "svgCropMarginRight" ), 0 ).toInt() );
+  options.mBottomMarginSpinBox->setValue( mLayout->customProperty( QStringLiteral( "svgCropMarginBottom" ), 0 ).toInt() );
+  options.mLeftMarginSpinBox->setValue( mLayout->customProperty( QStringLiteral( "svgCropMarginLeft" ), 0 ).toInt() );
+
+  if ( dialog.exec() != QDialog::Accepted )
+    return;
+
+  groupLayers = options.chkMapLayersAsGroup->isChecked();
+  clipToContent = options.mClipToContentGroupBox->isChecked();
+  marginTop = options.mTopMarginSpinBox->value();
+  marginRight = options.mRightMarginSpinBox->value();
+  marginBottom = options.mBottomMarginSpinBox->value();
+  marginLeft = options.mLeftMarginSpinBox->value();
+
+  //save dialog settings
+  mLayout->setCustomProperty( QStringLiteral( "svgGroupLayers" ), groupLayers );
+  mLayout->setCustomProperty( QStringLiteral( "svgCropToContents" ), clipToContent );
+  mLayout->setCustomProperty( QStringLiteral( "svgCropMarginTop" ), marginTop );
+  mLayout->setCustomProperty( QStringLiteral( "svgCropMarginRight" ), marginRight );
+  mLayout->setCustomProperty( QStringLiteral( "svgCropMarginBottom" ), marginBottom );
+  mLayout->setCustomProperty( QStringLiteral( "svgCropMarginLeft" ), marginLeft );
+
+  //temporarily override label draw outlines setting
+  mLayout->project()->writeEntry( QStringLiteral( "PAL" ), QStringLiteral( "/DrawOutlineLabels" ), options.chkTextAsOutline->isChecked() );
+
+  mView->setPaintingEnabled( false );
+  QApplication::setOverrideCursor( Qt::BusyCursor );
+
+  QgsLayoutExporter::SvgExportSettings svgSettings;
+  svgSettings.forceVectorOutput = mLayout->customProperty( QStringLiteral( "forceVector" ), false ).toBool();
+  svgSettings.cropToContents = clipToContent;
+  svgSettings.cropMargins = QgsMargins( marginLeft, marginTop, marginRight, marginBottom );
+  svgSettings.forceVectorOutput = options.mForceVectorCheckBox->isChecked();
+
+  // force a refresh, to e.g. update data defined properties, tables, etc
+  mLayout->refresh();
+
+  QFileInfo fi( outputFileName );
+  QgsLayoutExporter exporter( mLayout );
+  switch ( exporter.exportToSvg( outputFileName, svgSettings ) )
+  {
+    case QgsLayoutExporter::Success:
+    {
+      mMessageBar->pushMessage( tr( "Export layout" ),
+                                tr( "Successfully exported layout to <a href=\"%1\">%2</a>" ).arg( QUrl::fromLocalFile( fi.path() ).toString(), outputFileName ),
+                                QgsMessageBar::INFO, 0 );
+      break;
+    }
+
+    case QgsLayoutExporter::FileError:
+      QMessageBox::warning( this, tr( "Export to SVG" ),
+                            tr( "Cannot write to %1.\n\nThis file may be open in another application." ).arg( outputFileName ),
+                            QMessageBox::Ok,
+                            QMessageBox::Ok );
+      break;
+
+    case QgsLayoutExporter::PrintError:
+      QMessageBox::warning( this, tr( "Export to SVG" ),
+                            tr( "Could not create print device." ),
+                            QMessageBox::Ok,
+                            QMessageBox::Ok );
+      break;
+
+
+    case QgsLayoutExporter::MemoryError:
+      QMessageBox::warning( this, tr( "Memory Allocation Error" ),
+                            tr( "Exporting the SVG "
+                                "resulted in a memory overflow.\n\n"
+                                "Please try a lower resolution or a smaller paper size." ),
+                            QMessageBox::Ok, QMessageBox::Ok );
+      break;
+  }
+
+  mView->setPaintingEnabled( true );
+  mLayout->project()->writeEntry( QStringLiteral( "PAL" ), QStringLiteral( "/DrawOutlineLabels" ), prevSettingLabelsAsOutlines );
+  QApplication::restoreOverrideCursor();
+}
+
 void QgsLayoutDesignerDialog::paste()
 {
   QPointF pt = mView->mapFromGlobal( QCursor::pos() );
@@ -1816,6 +1964,34 @@ void QgsLayoutDesignerDialog::showWmsPrintingWarning()
   }
 }
 
+void QgsLayoutDesignerDialog::showSvgExportWarning()
+{
+  QgsSettings settings;
+
+  bool displaySVGWarning = settings.value( QStringLiteral( "/UI/displaySVGWarning" ), true ).toBool();
+
+  if ( displaySVGWarning )
+  {
+    QgsMessageViewer m( this );
+    m.setWindowTitle( tr( "Export as SVG" ) );
+    m.setCheckBoxText( tr( "Don't show this message again" ) );
+    m.setCheckBoxState( Qt::Unchecked );
+    m.setCheckBoxVisible( true );
+    m.setCheckBoxQgsSettingsLabel( QStringLiteral( "/UI/displaySVGWarning" ) );
+    m.setMessageAsHtml( tr( "<p>The SVG export function in QGIS has several "
+                            "problems due to bugs and deficiencies in the " )
+                        + tr( "underlying Qt SVG library. In particular, there are problems "
+                              "with layers not being clipped to the map "
+                              "bounding box.</p>" )
+                        + tr( "If you require a vector-based output file from "
+                              "QGIS it is suggested that you try exporting "
+                              "to PDF if the SVG output is not "
+                              "satisfactory."
+                              "</p>" ) );
+    m.exec();
+  }
+}
+
 bool QgsLayoutDesignerDialog::requiresRasterization() const
 {
   QList< QgsLayoutItem *> items;

src/app/layout/qgslayoutdesignerdialog.h

@@ -284,6 +284,7 @@ class QgsLayoutDesignerDialog: public QMainWindow, private Ui::QgsLayoutDesigner
     void deleteLayout();
     void exportToRaster();
     void exportToPdf();
+    void exportToSvg();
 
   private:
 
@@ -379,6 +380,8 @@ class QgsLayoutDesignerDialog: public QMainWindow, private Ui::QgsLayoutDesigner
     //! Displays a warning because of possible min/max size in WMS
     void showWmsPrintingWarning();
 
+    void showSvgExportWarning();
+
     //! True if the layout contains advanced effects, such as blend modes
     bool requiresRasterization() const;
 

src/core/layout/qgslayoutexporter.cpp

@@ -23,6 +23,7 @@
 #include "qgslayoutguidecollection.h"
 #include <QImageWriter>
 #include <QSize>
+#include <QSvgGenerator>
 
 #include "gdal.h"
 #include "cpl_conv.h"
@@ -401,6 +402,103 @@ QgsLayoutExporter::ExportResult QgsLayoutExporter::exportToPdf( const QString &f
   return result;
 }
 
+QgsLayoutExporter::ExportResult QgsLayoutExporter::exportToSvg( const QString &filePath, const QgsLayoutExporter::SvgExportSettings &s )
+{
+  if ( !mLayout )
+    return PrintError;
+
+  SvgExportSettings settings = s;
+  if ( settings.dpi <= 0 )
+    settings.dpi = mLayout->context().dpi();
+
+  mErrorFileName.clear();
+
+  LayoutContextPreviewSettingRestorer restorer( mLayout );
+  ( void )restorer;
+  LayoutContextSettingsRestorer contextRestorer( mLayout );
+  ( void )contextRestorer;
+  mLayout->context().setDpi( settings.dpi );
+
+  mLayout->context().setFlag( QgsLayoutContext::FlagForceVectorOutput, settings.forceVectorOutput );
+
+  QFileInfo fi( filePath );
+  PageExportDetails pageDetails;
+  pageDetails.directory = fi.path();
+  pageDetails.baseName = fi.baseName();
+  pageDetails.extension = fi.completeSuffix();
+
+  double inchesToLayoutUnits = mLayout->convertToLayoutUnits( QgsLayoutMeasurement( 1, QgsUnitTypes::LayoutInches ) );
+
+  for ( int i = 0; i < mLayout->pageCollection()->pageCount(); ++i )
+  {
+    if ( !mLayout->pageCollection()->shouldExportPage( i ) )
+    {
+      continue;
+    }
+
+    pageDetails.page = i;
+    QString fileName = generateFileName( pageDetails );
+
+    QSvgGenerator generator;
+    generator.setTitle( mLayout->project()->title() );
+    generator.setFileName( fileName );
+
+    QRectF bounds;
+    if ( settings.cropToContents )
+    {
+      if ( mLayout->pageCollection()->pageCount() == 1 )
+      {
+        // single page, so include everything
+        bounds = mLayout->layoutBounds( true );
+      }
+      else
+      {
+        // multi page, so just clip to items on current page
+        bounds = mLayout->pageItemBounds( i, true );
+      }
+      bounds = bounds.adjusted( -settings.cropMargins.left(),
+                                -settings.cropMargins.top(),
+                                settings.cropMargins.right(),
+                                settings.cropMargins.bottom() );
+    }
+    else
+    {
+      QgsLayoutItemPage *pageItem = mLayout->pageCollection()->page( i );
+      bounds = QRectF( pageItem->pos().x(), pageItem->pos().y(), pageItem->rect().width(), pageItem->rect().height() );
+    }
+
+    //width in pixel
+    int width = ( int )( bounds.width() * settings.dpi / inchesToLayoutUnits );
+    //height in pixel
+    int height = ( int )( bounds.height() * settings.dpi / inchesToLayoutUnits );
+    if ( width == 0 || height == 0 )
+    {
+      //invalid size, skip this page
+      continue;
+    }
+    generator.setSize( QSize( width, height ) );
+    generator.setViewBox( QRect( 0, 0, width, height ) );
+    generator.setResolution( settings.dpi );
+
+    QPainter p;
+    bool createOk = p.begin( &generator );
+    if ( !createOk )
+    {
+      mErrorFileName = fileName;
+      return FileError;
+    }
+
+    if ( settings.cropToContents )
+      renderRegion( &p, bounds );
+    else
+      renderPage( &p, i );
+
+    p.end();
+  }
+
+  return Success;
+}
+
 void QgsLayoutExporter::preparePrintAsPdf( QPrinter &printer, const QString &filePath )
 {
   printer.setOutputFileName( filePath );