Fixes crash when displaying relation editor

python/gui/auto_generated/editorwidgets/qgsrelationreferencewidget.sip.in

@@ -77,6 +77,14 @@ Returns the related feature foreign keys
 %End
 
     void setEditorContext( const QgsAttributeEditorContext &context, QgsMapCanvas *canvas, QgsMessageBar *messageBar );
+%Docstring
+Sets the editor ``context``
+
+.. note::
+
+   if context cadDockWidget is null, it won't be possible to digitize
+   the geometry of a referenced feature from this widget
+%End
 
     bool embedForm();
 %Docstring

python/gui/auto_generated/qgsrelationeditorwidget.sip.in

@@ -74,6 +74,11 @@ Sets the ``feature`` being edited and updates the UI unless ``update`` is set to
     void setEditorContext( const QgsAttributeEditorContext &context );
 %Docstring
 Sets the editor ``context``
+
+.. note::
+
+   if context cadDockWidget is null, it won't be possible to digitize
+   the geometry of a referencing feature from this widget
 %End
 
     QgsIFeatureSelectionManager *featureSelectionManager();

src/app/qgisapp.cpp

@@ -9286,7 +9286,7 @@ void QgisApp::modifyAttributesOfSelectedFeatures()
 
   //dummy feature
   QgsFeature f;
-  QgsAttributeEditorContext context;
+  QgsAttributeEditorContext context( createAttributeEditorContext() );
   context.setAllowCustomUi( false );
   context.setVectorLayerTools( mVectorLayerTools );
   context.setCadDockWidget( mAdvancedDigitizingDockWidget );
@@ -15572,3 +15572,13 @@ void QgisApp::triggerCrashHandler()
   RaiseException( 0x12345678, 0, 0, nullptr );
 #endif
 }
+
+QgsAttributeEditorContext QgisApp::createAttributeEditorContext()
+{
+  QgsAttributeEditorContext context;
+  context.setVectorLayerTools( vectorLayerTools() );
+  context.setMapCanvas( mapCanvas() );
+  context.setCadDockWidget( cadDockWidget() );
+  context.setMainMessageBar( messageBar() );
+  return context;
+}

src/app/qgisapp.h

@@ -1109,6 +1109,12 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     //! Create a new spatial bookmark
     void newBookmark( bool inProject = false );
 
+    /**
+     * Creates a default attribute editor context using the main map canvas and the main edit tools and message bar
+     * \since QGIS 3.12
+     */
+    QgsAttributeEditorContext createAttributeEditorContext();
+
   protected:
 
     //! Handle state changes (WindowTitleChange)

src/app/qgisappinterface.cpp

@@ -755,12 +755,8 @@ QgsAttributeDialog *QgisAppInterface::getFeatureForm( QgsVectorLayer *l, QgsFeat
   myDa.setSourceCrs( l->crs(), QgsProject::instance()->transformContext() );
   myDa.setEllipsoid( QgsProject::instance()->ellipsoid() );
 
-  QgsAttributeEditorContext context;
+  QgsAttributeEditorContext context( QgisApp::instance()->createAttributeEditorContext() );
   context.setDistanceArea( myDa );
-  context.setVectorLayerTools( qgis->vectorLayerTools() );
-  context.setMapCanvas( qgis->mapCanvas() );
-  context.setCadDockWidget( qgis->cadDockWidget() );
-  context.setMainMessageBar( qgis->messageBar() );
   QgsAttributeDialog *dialog = new QgsAttributeDialog( l, &feature, false, qgis, true, context );
   if ( !feature.isValid() )
   {

src/app/qgsattributetabledialog.cpp

@@ -152,12 +152,9 @@ QgsAttributeTableDialog::QgsAttributeTableDialog( QgsVectorLayer *layer, QgsAttr
   QgsDistanceArea da;
   da.setSourceCrs( mLayer->crs(), QgsProject::instance()->transformContext() );
   da.setEllipsoid( QgsProject::instance()->ellipsoid() );
-  mEditorContext.setDistanceArea( da );
 
-  mEditorContext.setVectorLayerTools( QgisApp::instance()->vectorLayerTools() );
-  mEditorContext.setMapCanvas( QgisApp::instance()->mapCanvas() );
-  mEditorContext.setMainMessageBar( QgisApp::instance()->messageBar() );
-  mEditorContext.setCadDockWidget( QgisApp::instance()->cadDockWidget() );
+  QgsAttributeEditorContext editorContext = QgisApp::instance()->createAttributeEditorContext();
+  editorContext.setDistanceArea( da );
 
   QgsFeatureRequest r;
   bool needsGeom = false;
@@ -177,12 +174,12 @@ QgsAttributeTableDialog::QgsAttributeTableDialog( QgsVectorLayer *layer, QgsAttr
     r.setFlags( QgsFeatureRequest::NoGeometry );
 
   // Initialize dual view
-  mMainView->init( mLayer, QgisApp::instance()->mapCanvas(), r, mEditorContext, false );
+  mMainView->init( mLayer, QgisApp::instance()->mapCanvas(), r, editorContext, false );
 
   QgsAttributeTableConfig config = mLayer->attributeTableConfig();
   mMainView->setAttributeTableConfig( config );
 
-  mFeatureFilterWidget->init( mLayer, mEditorContext, mMainView, QgisApp::instance()->messageBar(), QgisApp::instance()->messageTimeout() );
+  mFeatureFilterWidget->init( mLayer, editorContext, mMainView, QgisApp::instance()->messageBar(), QgisApp::instance()->messageTimeout() );
 
   mActionFeatureActions = new QToolButton();
   mActionFeatureActions->setAutoRaise( false );

src/app/qgsattributetabledialog.h

@@ -221,7 +221,6 @@ class APP_EXPORT QgsAttributeTableDialog : public QDialog, private Ui::QgsAttrib
 
     QPointer< QgsVectorLayer > mLayer = nullptr;
     QStringList mVisibleFields;
-    QgsAttributeEditorContext mEditorContext;
 
     void updateMultiEditButtonState();
     void deleteFeature( QgsFeatureId fid );

src/app/qgsfeatureaction.cpp

@@ -53,22 +53,19 @@ QgsAttributeDialog *QgsFeatureAction::newDialog( bool cloneFeature )
 {
   QgsFeature *f = cloneFeature ? new QgsFeature( *mFeature ) : mFeature;
 
-  QgsAttributeEditorContext context;
+  QgsAttributeEditorContext context( QgisApp::instance()->createAttributeEditorContext() );
 
   QgsDistanceArea myDa;
 
   myDa.setSourceCrs( mLayer->crs(), QgsProject::instance()->transformContext() );
   myDa.setEllipsoid( QgsProject::instance()->ellipsoid() );
 
   context.setDistanceArea( myDa );
-  context.setVectorLayerTools( QgisApp::instance()->vectorLayerTools() );
-  context.setMapCanvas( QgisApp::instance()->mapCanvas() );
-  context.setCadDockWidget( QgisApp::instance()->cadDockWidget() );
-  context.setMainMessageBar( QgisApp::instance()->messageBar() );
   context.setFormMode( QgsAttributeEditorContext::StandaloneDialog );
 
   QgsAttributeDialog *dialog = new QgsAttributeDialog( mLayer, f, cloneFeature, parentWidget(), true, context );
   dialog->setWindowFlags( dialog->windowFlags() | Qt::Tool );
+
   dialog->setObjectName( QStringLiteral( "featureactiondlg:%1:%2" ).arg( mLayer->id() ).arg( f->id() ) );
 
   QList<QgsAction> actions = mLayer->actions()->actions( QStringLiteral( "Feature" ) );

src/app/qgsmaptoolfillring.cpp

@@ -164,7 +164,11 @@ void QgsMapToolFillRing::cadCanvasReleaseEvent( QgsMapMouseEvent *e )
     }
     else
     {
-      QgsAttributeDialog *dialog = new QgsAttributeDialog( vlayer, &ft, false, nullptr, true );
+      QgsAttributeEditorContext context;
+      // don't set cadDockwidget in context because we don't want to be able to create geometries from this dialog
+      // there is one modified and one created feature, so it's a mess of we start to digitize a relation feature geometry
+      context.setVectorLayerTools( QgisApp::instance()->vectorLayerTools() );
+      QgsAttributeDialog *dialog = new QgsAttributeDialog( vlayer, &ft, false, nullptr, true, context );
       dialog->setMode( QgsAttributeEditorContext::AddFeatureMode );
       res = dialog->exec(); // will also add the feature
     }

src/gui/editorwidgets/qgsrelationreferencewidget.cpp

@@ -156,6 +156,7 @@ QgsRelationReferenceWidget::QgsRelationReferenceWidget( QWidget *parent )
   mHighlightFeatureButton->hide();
   mAttributeEditorFrame->hide();
   mInvalidLabel->hide();
+  mAddEntryButton->hide();
 
   // connect buttons
   connect( mOpenFormButton, &QAbstractButton::clicked, this, &QgsRelationReferenceWidget::openForm );
@@ -429,8 +430,12 @@ void QgsRelationReferenceWidget::setEditorContext( const QgsAttributeEditorConte
   mMapToolIdentify.reset( new QgsMapToolIdentifyFeature( mCanvas ) );
   mMapToolIdentify->setButton( mMapIdentificationButton );
 
-  mMapToolDigitize.reset( new QgsMapToolDigitizeFeature( mCanvas, context.cadDockWidget() ) );
-  mMapToolDigitize->setButton( mAddEntryButton );
+  if ( mEditorContext.cadDockWidget() )
+  {
+    mMapToolDigitize.reset( new QgsMapToolDigitizeFeature( mCanvas, mEditorContext.cadDockWidget() ) );
+    mMapToolDigitize->setButton( mAddEntryButton );
+    updateAddEntryButton();
+  }
 }
 
 void QgsRelationReferenceWidget::setEmbedForm( bool display )
@@ -1006,7 +1011,7 @@ void QgsRelationReferenceWidget::entryAdded( const QgsFeature &feat )
 
 void QgsRelationReferenceWidget::updateAddEntryButton()
 {
-  mAddEntryButton->setVisible( mAllowAddFeatures );
+  mAddEntryButton->setVisible( mAllowAddFeatures && mMapToolDigitize );
   mAddEntryButton->setEnabled( mReferencedLayer && mReferencedLayer->isEditable() );
 }
 

src/gui/editorwidgets/qgsrelationreferencewidget.h

@@ -112,6 +112,11 @@ class GUI_EXPORT QgsRelationReferenceWidget : public QWidget
     */
     QVariantList foreignKeys() const;
 
+    /**
+     * Sets the editor \a context
+     * \note if context cadDockWidget is null, it won't be possible to digitize
+     * the geometry of a referenced feature from this widget
+     */
     void setEditorContext( const QgsAttributeEditorContext &context, QgsMapCanvas *canvas, QgsMessageBar *messageBar );
 
     //! determines if the form of the related feature will be shown

src/gui/editorwidgets/qgsrelationreferencewidgetwrapper.cpp

@@ -88,6 +88,7 @@ void QgsRelationReferenceWidgetWrapper::initWidget( QWidget *editor )
       mWidget->setReadOnlySelector( true );
       mWidget->setAllowMapIdentification( false );
       mWidget->setOpenFormButtonVisible( false );
+      mWidget->setAllowAddFeatures( false );
       break;
     }
     ctx = ctx->parentContext();

src/gui/qgsrelationeditorwidget.cpp

@@ -285,7 +285,7 @@ void QgsRelationEditorWidget::initDualView( QgsVectorLayer *layer, const QgsFeat
     text = tr( "Add Polygon Feature" );
   }
 
-  if ( text.isEmpty() )
+  if ( text.isEmpty() || !mEditorContext.mapCanvas() || !mEditorContext.cadDockWidget() )
   {
     mAddFeatureGeometryButton->setVisible( false );
   }
@@ -368,8 +368,12 @@ void QgsRelationEditorWidget::setRelations( const QgsRelation &relation, const Q
 void QgsRelationEditorWidget::setEditorContext( const QgsAttributeEditorContext &context )
 {
   mEditorContext = context;
-  mMapToolDigitize.reset( new QgsMapToolDigitizeFeature( context.mapCanvas(), context.cadDockWidget() ) );
-  mMapToolDigitize->setButton( mAddFeatureGeometryButton );
+
+  if ( context.mapCanvas() && context.cadDockWidget() )
+  {
+    mMapToolDigitize.reset( new QgsMapToolDigitizeFeature( context.mapCanvas(), context.cadDockWidget() ) );
+    mMapToolDigitize->setButton( mAddFeatureGeometryButton );
+  }
 }
 
 QgsIFeatureSelectionManager *QgsRelationEditorWidget::featureSelectionManager()
@@ -448,6 +452,9 @@ void QgsRelationEditorWidget::addFeatureGeometry()
     layer = mRelation.referencingLayer();
 
   mMapToolDigitize->setLayer( layer );
+
+  // window is always on top, so we hide it to digitize without seeing it
+  window()->setVisible( false );
   setMapTool( mMapToolDigitize );
 
   connect( mMapToolDigitize, &QgsMapToolDigitizeFeature::digitizingCompleted, this, &QgsRelationEditorWidget::onDigitizingCompleted );
@@ -984,6 +991,7 @@ void QgsRelationEditorWidget::onKeyPressed( QKeyEvent *e )
 
 void QgsRelationEditorWidget::mapToolDeactivated()
 {
+  window()->setVisible( true );
   window()->raise();
   window()->activateWindow();
 

src/gui/qgsrelationeditorwidget.h

@@ -134,6 +134,8 @@ class GUI_EXPORT QgsRelationEditorWidget : public QgsCollapsibleGroupBox
 
     /**
      * Sets the editor \a context
+     * \note if context cadDockWidget is null, it won't be possible to digitize
+     * the geometry of a referencing feature from this widget
      */
     void setEditorContext( const QgsAttributeEditorContext &context );