[geopdf] Allow users to reorder layers in the generated layer tree

Fixes #36535

src/app/layout/qgslayoutdesignerdialog.cpp

@@ -4339,6 +4339,7 @@ bool QgsLayoutDesignerDialog::getPdfExportSettings( QgsLayoutExporter::PdfExport
   bool geoPdf = false;
   bool useOgcBestPracticeFormat = false;
   QStringList exportThemes;
+  QStringList geoPdfLayerOrder;
   if ( mLayout )
   {
     settings.flags = mLayout->renderContext().flags();
@@ -4352,6 +4353,10 @@ bool QgsLayoutDesignerDialog::getPdfExportSettings( QgsLayoutExporter::PdfExport
     const QString themes = mLayout->customProperty( QStringLiteral( "pdfExportThemes" ) ).toString();
     if ( !themes.isEmpty() )
       exportThemes = themes.split( QStringLiteral( "~~~" ) );
+    const QString layerOrder = mLayout->customProperty( QStringLiteral( "pdfLayerOrder" ) ).toString();
+    if ( !layerOrder.isEmpty() )
+      geoPdfLayerOrder = layerOrder.split( QStringLiteral( "~~~" ) );
+
     const int prevLayoutSettingLabelsAsOutlines = mLayout->customProperty( QStringLiteral( "pdfTextFormat" ), -1 ).toInt();
     if ( prevLayoutSettingLabelsAsOutlines >= 0 )
     {
@@ -4383,7 +4388,7 @@ bool QgsLayoutDesignerDialog::getPdfExportSettings( QgsLayoutExporter::PdfExport
     }
   }
 
-  QgsLayoutPdfExportOptionsDialog dialog( this, allowGeoPdfExport, dialogGeoPdfReason );
+  QgsLayoutPdfExportOptionsDialog dialog( this, allowGeoPdfExport, dialogGeoPdfReason, geoPdfLayerOrder );
 
   dialog.setTextRenderFormat( prevTextRenderFormat );
   dialog.setForceVector( forceVector );
@@ -4408,6 +4413,7 @@ bool QgsLayoutDesignerDialog::getPdfExportSettings( QgsLayoutExporter::PdfExport
   geoPdf = dialog.exportGeoPdf();
   useOgcBestPracticeFormat = dialog.useOgcBestPracticeFormat();
   exportThemes = dialog.exportThemes();
+  geoPdfLayerOrder = dialog.geoPdfLayerOrder();
 
   if ( mLayout )
   {
@@ -4421,6 +4427,7 @@ bool QgsLayoutDesignerDialog::getPdfExportSettings( QgsLayoutExporter::PdfExport
     mLayout->setCustomProperty( QStringLiteral( "pdfCreateGeoPdf" ), geoPdf ? 1 : 0 );
     mLayout->setCustomProperty( QStringLiteral( "pdfOgcBestPracticeFormat" ), useOgcBestPracticeFormat ? 1 : 0 );
     mLayout->setCustomProperty( QStringLiteral( "pdfExportThemes" ), exportThemes.join( QStringLiteral( "~~~" ) ) );
+    mLayout->setCustomProperty( QStringLiteral( "pdfLayerOrder" ), geoPdfLayerOrder.join( QStringLiteral( "~~~" ) ) );
   }
 
   settings.forceVectorOutput = forceVector;

src/core/layout/qgslayoutgeopdfexporter.cpp

@@ -145,7 +145,25 @@ QgsLayoutGeoPdfExporter::QgsLayoutGeoPdfExporter( QgsLayout *layout )
     map->addRenderedFeatureHandler( handler );
   }
 
-  const QList< QgsMapLayer * > layerOrder = mLayout->project()->layerTreeRoot()->layerOrder();
+  // start with project layer order, and then apply custom layer order if set
+  QStringList geoPdfLayerOrder;
+  const QString presetLayerOrder = mLayout->customProperty( QStringLiteral( "pdfLayerOrder" ) ).toString();
+  if ( !presetLayerOrder.isEmpty() )
+    geoPdfLayerOrder = presetLayerOrder.split( QStringLiteral( "~~~" ) );
+
+  QList< QgsMapLayer * > layerOrder = mLayout->project()->layerTreeRoot()->layerOrder();
+  for ( auto it = geoPdfLayerOrder.rbegin(); it != geoPdfLayerOrder.rend(); ++it )
+  {
+    for ( int i = 0; i < layerOrder.size(); ++i )
+    {
+      if ( layerOrder.at( i )->id() == *it )
+      {
+        layerOrder.move( i, 0 );
+        break;
+      }
+    }
+  }
+
   for ( const QgsMapLayer *layer : layerOrder )
     mLayerOrder << layer->id();
 }

src/gui/layout/qgsgeopdflayertreemodel.cpp

@@ -22,10 +22,10 @@
 #include "qgsvectorlayer.h"
 #include "qgsapplication.h"
 
-QgsGeoPdfLayerTreeModel::QgsGeoPdfLayerTreeModel( QgsLayerTree *rootNode, QObject *parent )
+QgsGeoPdfLayerTreeModel::QgsGeoPdfLayerTreeModel( const QList<QgsMapLayer *> &layers, QObject *parent )
-  : QgsLayerTreeModel( rootNode, parent )
+  : QgsMapLayerModel( layers, parent )
 {
-  setFlags( nullptr ); // ideally we'd just show embedded legend nodes - but the api doesn't exist for this
+  setItemsCanBeReordered( true );
 }
 
 int QgsGeoPdfLayerTreeModel::columnCount( const QModelIndex &parent ) const
@@ -36,37 +36,36 @@ int QgsGeoPdfLayerTreeModel::columnCount( const QModelIndex &parent ) const
 
 Qt::ItemFlags QgsGeoPdfLayerTreeModel::flags( const QModelIndex &idx ) const
 {
+  if ( !idx.isValid() )
+    return Qt::ItemIsDropEnabled;
+
   if ( idx.column() == IncludeVectorAttributes )
   {
     if ( vectorLayer( idx ) )
-      return QgsLayerTreeModel::flags( idx ) | Qt::ItemIsUserCheckable;
+      return QgsMapLayerModel::flags( idx ) | Qt::ItemIsUserCheckable;
     else
-      return QgsLayerTreeModel::flags( idx );
+      return QgsMapLayerModel::flags( idx );
   }
 
   if ( idx.column() == InitiallyVisible )
   {
-    return QgsLayerTreeModel::flags( idx ) | Qt::ItemIsUserCheckable;
+    return QgsMapLayerModel::flags( idx ) | Qt::ItemIsUserCheckable;
   }
 
   if ( !mapLayer( idx ) )
   {
-    return Qt::NoItemFlags;
+    return nullptr;
   }
   else
   {
-    return Qt::ItemIsEnabled | Qt::ItemIsEditable;
+    return Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsDragEnabled;
   }
   return Qt::NoItemFlags;
 }
 
 QgsMapLayer *QgsGeoPdfLayerTreeModel::mapLayer( const QModelIndex &idx ) const
 {
-  QgsLayerTreeNode *node = index2node( index( idx.row(), LayerColumn, idx.parent() ) );
+  return layerFromIndex( index( idx.row(), LayerColumn, idx.parent() ) );
-  if ( !node || !QgsLayerTree::isLayer( node ) )
-    return nullptr;
-
-  return QgsLayerTree::toLayer( node )->layer();
 }
 
 QgsVectorLayer *QgsGeoPdfLayerTreeModel::vectorLayer( const QModelIndex &idx ) const
@@ -95,7 +94,7 @@ QVariant QgsGeoPdfLayerTreeModel::headerData( int section, Qt::Orientation orien
       }
     }
   }
-  return QgsLayerTreeModel::headerData( section, orientation, role );
+  return QgsMapLayerModel::headerData( section, orientation, role );
 }
 
 QVariant QgsGeoPdfLayerTreeModel::data( const QModelIndex &idx, int role ) const
@@ -106,7 +105,7 @@ QVariant QgsGeoPdfLayerTreeModel::data( const QModelIndex &idx, int role ) const
       if ( role == Qt::CheckStateRole )
         return QVariant();
 
-      return QgsLayerTreeModel::data( idx, role );
+      return QgsMapLayerModel::data( idx, role );
 
     case GroupColumn:
     {
@@ -145,14 +144,13 @@ QVariant QgsGeoPdfLayerTreeModel::data( const QModelIndex &idx, int role ) const
         }
         return QVariant();
       }
-      return QgsLayerTreeModel::data( idx, role );
+      return QVariant();
     }
 
     case IncludeVectorAttributes:
     {
       if ( role == Qt::CheckStateRole )
       {
-        QgsLayerTreeNode *node = index2node( index( idx.row(), LayerColumn, idx.parent() ) );
         if ( QgsVectorLayer *vl = vectorLayer( idx ) )
         {
           const QVariant v = vl->customProperty( QStringLiteral( "geopdf/includeFeatures" ) );
@@ -162,8 +160,8 @@ QVariant QgsGeoPdfLayerTreeModel::data( const QModelIndex &idx, int role ) const
           }
           else
           {
-            // otherwise, we default to the layer's visibility
+            // otherwise, we default to true
-            return node->itemVisibilityChecked() ? Qt::Checked : Qt::Unchecked;
+            return Qt::Checked;
           }
         }
         return QVariant();
@@ -219,6 +217,9 @@ bool QgsGeoPdfLayerTreeModel::setData( const QModelIndex &index, const QVariant
       }
       break;
     }
+
+    case LayerColumn:
+      return QgsMapLayerModel::setData( index, value, role );
   }
   return false;
 }
@@ -244,10 +245,10 @@ QgsGeoPdfLayerFilteredTreeModel::QgsGeoPdfLayerFilteredTreeModel( QgsGeoPdfLayer
 
 bool QgsGeoPdfLayerFilteredTreeModel::filterAcceptsRow( int source_row, const QModelIndex &source_parent ) const
 {
-  if ( QgsLayerTreeNode *node = mLayerTreeModel->index2node( sourceModel()->index( source_row, 0, source_parent ) ) )
+  if ( QgsMapLayer *layer = mLayerTreeModel->layerFromIndex( sourceModel()->index( source_row, 0, source_parent ) ) )
   {
     // filter out non-spatial layers
-    if ( QgsLayerTree::isLayer( node ) && QgsLayerTree::toLayer( node ) && QgsLayerTree::toLayer( node )->layer() && !QgsLayerTree::toLayer( node )->layer()->isSpatial() )
+    if ( !layer->isSpatial() )
       return false;
 
   }

src/gui/layout/qgsgeopdflayertreemodel.h

@@ -22,10 +22,11 @@
 #include <QItemDelegate>
 
 #include "qgis_gui.h"
-#include "qgslayertreemodel.h"
+#include "qgsmaplayermodel.h"
 
 class QgsMapCanvas;
 class QgsProject;
+class QgsVectorLayer;
 
 
 /**
@@ -35,7 +36,7 @@ class QgsProject;
  * \note This class is not a part of public API
  * \since QGIS 3.12
  */
-class GUI_EXPORT QgsGeoPdfLayerTreeModel : public QgsLayerTreeModel
+class GUI_EXPORT QgsGeoPdfLayerTreeModel : public QgsMapLayerModel
 {
     Q_OBJECT
 
@@ -51,7 +52,7 @@ class GUI_EXPORT QgsGeoPdfLayerTreeModel : public QgsLayerTreeModel
     };
 
     //! constructor
-    QgsGeoPdfLayerTreeModel( QgsLayerTree *rootNode, QObject *parent = nullptr );
+    QgsGeoPdfLayerTreeModel( const QList< QgsMapLayer * > &layers, QObject *parent = nullptr );
 
     int columnCount( const QModelIndex &parent ) const override;
     QVariant headerData( int section, Qt::Orientation orientation, int role ) const override;

src/gui/layout/qgslayoutpdfexportoptionsdialog.cpp

@@ -23,12 +23,13 @@
 #include "qgsproject.h"
 #include "qgsmapthemecollection.h"
 #include "qgsgeopdflayertreemodel.h"
+#include "qgslayertree.h"
 
 #include <QCheckBox>
 #include <QPushButton>
 #include <QMenu>
 
-QgsLayoutPdfExportOptionsDialog::QgsLayoutPdfExportOptionsDialog( QWidget *parent, bool allowGeoPdfExport, const QString &geoPdfReason, Qt::WindowFlags flags )
+QgsLayoutPdfExportOptionsDialog::QgsLayoutPdfExportOptionsDialog( QWidget *parent, bool allowGeoPdfExport, const QString &geoPdfReason, const QStringList &geoPdfLayerOrder, Qt::WindowFlags flags )
   : QDialog( parent, flags )
 {
   setupUi( this );
@@ -67,12 +68,30 @@ QgsLayoutPdfExportOptionsDialog::QgsLayoutPdfExportOptionsDialog( QWidget *paren
     mThemesList->addItem( item );
   }
 
-  mGeoPdfStructureModel = new QgsGeoPdfLayerTreeModel( QgsProject::instance()->layerTreeRoot(), this );
+  QList< QgsMapLayer * > order = QgsProject::instance()->layerTreeRoot()->layerOrder();
+  for ( auto it = geoPdfLayerOrder.rbegin(); it != geoPdfLayerOrder.rend(); ++it )
+  {
+    for ( int i = 0; i < order.size(); ++i )
+    {
+      if ( order.at( i )->id() == *it )
+      {
+        order.move( i, 0 );
+        break;
+      }
+    }
+  }
+  mGeoPdfStructureModel = new QgsGeoPdfLayerTreeModel( order, this );
   mGeoPdfStructureProxyModel = new QgsGeoPdfLayerFilteredTreeModel( mGeoPdfStructureModel, this );
   mGeoPdfStructureTree->setModel( mGeoPdfStructureProxyModel );
   mGeoPdfStructureTree->resizeColumnToContents( 0 );
   mGeoPdfStructureTree->header()->show();
-  mGeoPdfStructureTree->setSelectionMode( QAbstractItemView::NoSelection );
+  mGeoPdfStructureTree->setSelectionMode( QAbstractItemView::SingleSelection );
+  mGeoPdfStructureTree->setSelectionBehavior( QAbstractItemView::SelectRows );
+
+  mGeoPdfStructureTree->setDragEnabled( true );
+  mGeoPdfStructureTree->setAcceptDrops( true );
+  mGeoPdfStructureTree->setDragDropMode( QAbstractItemView::InternalMove );
+  mGeoPdfStructureTree->setDefaultDropAction( Qt::MoveAction );
 
   mGeoPdfStructureTree->setContextMenuPolicy( Qt::CustomContextMenu );
   connect( mGeoPdfStructureTree, &QTreeView::customContextMenuRequested, this, [ = ]( const QPoint & point )
@@ -219,6 +238,16 @@ QStringList QgsLayoutPdfExportOptionsDialog::exportThemes() const
   return res;
 }
 
+QStringList QgsLayoutPdfExportOptionsDialog::geoPdfLayerOrder() const
+{
+  QStringList order;
+  for ( int row = 0; row < mGeoPdfStructureProxyModel->rowCount(); ++row )
+  {
+    order << mGeoPdfStructureProxyModel->data( mGeoPdfStructureProxyModel->index( row, 0 ), QgsGeoPdfLayerTreeModel::LayerIdRole ).toString();
+  }
+  return order;
+}
+
 void QgsLayoutPdfExportOptionsDialog::showHelp()
 {
   QgsHelp::openHelp( QStringLiteral( "print_composer/create_output.html" ) );

src/gui/layout/qgslayoutpdfexportoptionsdialog.h

@@ -48,11 +48,14 @@ class GUI_EXPORT QgsLayoutPdfExportOptionsDialog: public QDialog, private Ui::Qg
      * \param parent parent widget
      * \param allowGeoPdfExport set to FALSE if geoPdf export is blocked
      * \param geoPdfReason set to a descriptive translated string explaining why geopdf export is not available if applicable
+     * \param geoPdfLayerOrder optional layer ID order list for layers in the geopdf file. Any layers not present in this list
+     * will instead be appended to the end of the geopdf layer list
      * \param flags window flags
      */
     QgsLayoutPdfExportOptionsDialog( QWidget *parent = nullptr,
                                      bool allowGeoPdfExport = true,
                                      const QString &geoPdfReason = QString(),
+                                     const QStringList &geoPdfLayerOrder = QStringList(),
                                      Qt::WindowFlags flags = nullptr );
 
     //! Sets the text render format
@@ -97,6 +100,9 @@ class GUI_EXPORT QgsLayoutPdfExportOptionsDialog: public QDialog, private Ui::Qg
     //! Returns the list of export themes
     QStringList exportThemes() const;
 
+    //! Returns a list of map layer IDs in the desired order they should appear in a generated GeoPDF file
+    QStringList geoPdfLayerOrder() const;
+
   private slots:
 
     void showHelp();

src/ui/layout/qgspdfexportoptions.ui

@@ -101,7 +101,7 @@
            <x>0</x>
            <y>0</y>
            <width>451</width>
-           <height>630</height>
+           <height>612</height>
           </rect>
          </property>
          <layout class="QVBoxLayout" name="verticalLayout_6">
@@ -193,7 +193,7 @@
                  <item>
                   <widget class="QLabel" name="label_2">
                    <property name="text">
-                    <string>Uncheck layers to avoid exporting vector feature information for those layers, and optionally set the group name to allow multiple layers to be joined into a single logical PDF group</string>
+                    <string>Uncheck layers to avoid exporting vector feature information for those layers, and optionally set the group name to allow multiple layers to be joined into a single logical PDF group. Layers can be dragged and dropped to rearrange their order in the generated GeoPDF table of contents.</string>
                    </property>
                    <property name="wordWrap">
                     <bool>true</bool>

tests/src/core/testqgslayoutgeopdfexport.cpp

@@ -43,6 +43,7 @@ class TestQgsLayoutGeoPdfExport : public QObject
     void cleanup();// will be called after every testfunction.
     void testCollectingFeatures();
     void skipLayers();
+    void layerOrder();
 
   private:
 
@@ -405,5 +406,45 @@ void TestQgsLayoutGeoPdfExport::skipLayers()
   QCOMPARE( polyFeatures.count(), 10 ); // should be features, layer did not have any setting set
 }
 
+void TestQgsLayoutGeoPdfExport::layerOrder()
+{
+  QgsVectorLayer *linesLayer = new QgsVectorLayer( TEST_DATA_DIR + QStringLiteral( "/lines.shp" ),
+      QStringLiteral( "lines" ), QStringLiteral( "ogr" ) );
+  QVERIFY( linesLayer->isValid() );
+  QgsVectorLayer *pointsLayer = new QgsVectorLayer( TEST_DATA_DIR + QStringLiteral( "/points.shp" ),
+      QStringLiteral( "points" ), QStringLiteral( "ogr" ) );
+  QVERIFY( pointsLayer->isValid() );
+  QgsVectorLayer *polygonLayer = new QgsVectorLayer( TEST_DATA_DIR + QStringLiteral( "/polys.shp" ),
+      QStringLiteral( "polys" ), QStringLiteral( "ogr" ) );
+  QVERIFY( polygonLayer->isValid() );
+  pointsLayer->setDisplayExpression( QStringLiteral( "Staff" ) );
+
+  QgsProject p;
+  p.addMapLayer( linesLayer );
+  p.addMapLayer( pointsLayer );
+  p.addMapLayer( polygonLayer );
+
+  QgsLayout l( &p );
+  l.initializeDefaults();
+  QgsLayoutItemMap *map = new QgsLayoutItemMap( &l );
+  map->attemptSetSceneRect( QRectF( 20, 20, 200, 100 ) );
+  map->setFrameEnabled( true );
+  map->setLayers( QList<QgsMapLayer *>() << linesLayer << pointsLayer );
+  map->setCrs( linesLayer->crs() );
+  map->zoomToExtent( linesLayer->extent() );
+  map->setBackgroundColor( QColor( 200, 220, 230 ) );
+  map->setBackgroundEnabled( true );
+  l.addLayoutItem( map );
+
+  QgsLayoutGeoPdfExporter geoPdfExporter( &l );
+  // by default we should follow project layer order
+  QCOMPARE( geoPdfExporter.layerOrder(), QStringList() << polygonLayer->id() << pointsLayer->id() << linesLayer->id() );
+
+  // but if a custom order is specified, respected that
+  l.setCustomProperty( QStringLiteral( "pdfLayerOrder" ), QStringLiteral( "%1~~~%2" ).arg( linesLayer->id(), polygonLayer->id() ) );
+  QgsLayoutGeoPdfExporter geoPdfExporter2( &l );
+  QCOMPARE( geoPdfExporter2.layerOrder(), QStringList() << linesLayer->id() << polygonLayer->id() << pointsLayer->id() );
+}
+
 QGSTEST_MAIN( TestQgsLayoutGeoPdfExport )
 #include "testqgslayoutgeopdfexport.moc"