Properly update layer settings when an auxiliary field is deleted

python/core/qgsauxiliarystorage.sip

@@ -211,6 +211,19 @@ class QgsAuxiliaryLayer : QgsVectorLayer
  :rtype: int
 %End
 
+    int propertyFromField( int index ) const;
+%Docstring
+ Returns the underlying property key for the field index. The key may be
+ a PAL, diagram or symbology property according to the underlying
+ property definition of the field. The key -1 is returned if an error
+ happened.
+
+ \param index The index of the field
+
+.. versionadded:: 3.0
+ :rtype: int
+%End
+
     static int createProperty( QgsPalLayerSettings::Property property, const QString &providerId, QgsVectorLayer *vlayer );
 %Docstring
  Create if necessary a new auxiliary field for a PAL property and

python/gui/qgspropertyoverridebutton.sip

@@ -180,13 +180,6 @@ class QgsPropertyOverrideButton: QToolButton
 %Docstring
  Updates list of fields.
 
-.. versionadded:: 3.0
-%End
-
-    void updateGui();
-%Docstring
- Updates data defined button icon.
-
 .. versionadded:: 3.0
 %End
 

src/app/qgslabelinggui.cpp

@@ -50,6 +50,8 @@ void QgsLabelingGui::registerDataDefinedButton( QgsPropertyOverrideButton *butto
   connect( button, &QgsPropertyOverrideButton::changed, this, &QgsLabelingGui::updateProperty );
   connect( button, &QgsPropertyOverrideButton::createAuxiliaryField, this, &QgsLabelingGui::createAuxiliaryField );
   button->registerExpressionContextGenerator( this );
+
+  mButtons[key] = button;
 }
 
 void QgsLabelingGui::updateProperty()
@@ -611,15 +613,6 @@ void QgsLabelingGui::updateUi()
   {
     chkMergeLines->setToolTip( QString() );
   }
-
-  mCoordXDDBtn->updateFieldLists();
-  mCoordXDDBtn->updateGui();
-
-  mCoordYDDBtn->updateFieldLists();
-  mCoordYDDBtn->updateGui();
-
-  mCoordRotationDDBtn->updateFieldLists();
-  mCoordRotationDDBtn->updateGui();
 }
 
 void QgsLabelingGui::createAuxiliaryField()
@@ -653,3 +646,17 @@ void QgsLabelingGui::createAuxiliaryField()
 
   emit auxiliaryFieldCreated();
 }
+
+void QgsLabelingGui::deactivateField( QgsPalLayerSettings::Property key )
+{
+  if ( mButtons.contains( key ) )
+  {
+    QgsPropertyOverrideButton *button = mButtons[ key ];
+    QgsProperty p = button->toProperty();
+    p.setField( QString() );
+    p.setActive( false );
+    button->updateFieldLists();
+    button->setToProperty( p );
+    mDataDefinedProperties.setProperty( key, p );
+  }
+}

src/app/qgslabelinggui.h

@@ -43,6 +43,16 @@ class APP_EXPORT QgsLabelingGui : public QgsTextFormatWidget, private QgsExpress
 
     void setLayer( QgsMapLayer *layer );
 
+    /**
+     * Deactivate a field from data defined properties and update the
+     * corresponding button.
+     *
+     * \param key The property key to deactivate
+     *
+     * \since QGIS 3.0
+     */
+    void deactivateField( QgsPalLayerSettings::Property key );
+
   signals:
 
     void auxiliaryFieldCreated();
@@ -68,6 +78,8 @@ class APP_EXPORT QgsLabelingGui : public QgsTextFormatWidget, private QgsExpress
     void populateDataDefinedButtons();
     void registerDataDefinedButton( QgsPropertyOverrideButton *button, QgsPalLayerSettings::Property key );
 
+    QMap<QgsPalLayerSettings::Property, QgsPropertyOverrideButton *> mButtons;
+
   private slots:
 
     void updateProperty();

src/app/qgslabelingwidget.cpp

@@ -40,6 +40,11 @@ QgsLabelingWidget::QgsLabelingWidget( QgsVectorLayer *layer, QgsMapCanvas *canva
   setLayer( layer );
 }
 
+QgsLabelingGui *QgsLabelingWidget::labelingGui()
+{
+  return qobject_cast<QgsLabelingGui *>( mWidget );
+}
+
 void QgsLabelingWidget::resetSettings()
 {
   if ( mOldSettings )

src/app/qgslabelingwidget.h

@@ -38,6 +38,13 @@ class QgsLabelingWidget : public QgsMapLayerConfigWidget, private Ui::QgsLabelin
   public:
     QgsLabelingWidget( QgsVectorLayer *layer, QgsMapCanvas *canvas, QWidget *parent = nullptr );
 
+    /**
+     * Returns the labeling gui widget or a nullptr if none.
+     *
+     * \since QGIS 3.0
+     */
+    QgsLabelingGui *labelingGui();
+
   public slots:
     void setLayer( QgsMapLayer *layer );
     //! save config to layer

src/app/qgsvectorlayerproperties.cpp

@@ -57,6 +57,7 @@
 #include "qgsstyle.h"
 #include "qgsauxiliarystorage.h"
 #include "qgsnewauxiliarylayerdialog.h"
+#include "qgslabelinggui.h"
 
 #include "layertree/qgslayertreelayer.h"
 #include "qgslayertree.h"
@@ -1555,7 +1556,7 @@ void QgsVectorLayerProperties::updateAuxiliaryStoragePage( bool reset )
 
   if ( reset && labelingDialog )
   {
-    labelingDialog->resetSettings(); // update data defined buttons
+    labelingDialog->setLayer( mLayer );
   }
 }
 
@@ -1608,6 +1609,15 @@ void QgsVectorLayerProperties::onAuxiliaryLayerDelete()
   {
     QApplication::setOverrideCursor( Qt::WaitCursor );
     QgsDataSourceUri uri( alayer->source() );
+
+    // delete each attribute to correctly update layer settings and data
+    // defined buttons
+    while ( alayer->auxiliaryFields().size() > 0 )
+    {
+      QgsAuxiliaryField aField = alayer->auxiliaryFields()[0];
+      deleteAuxiliaryField( alayer->fields().indexOf( aField.name() ) );
+    }
+
     mLayer->setAuxiliaryLayer(); // remove auxiliary layer
     QgsAuxiliaryStorage::deleteTable( uri );
     QApplication::restoreOverrideCursor();
@@ -1659,11 +1669,27 @@ void QgsVectorLayerProperties::onAuxiliaryLayerDeleteField()
   if ( reply == QMessageBox::Yes )
   {
     QApplication::setOverrideCursor( Qt::WaitCursor );
-    mLayer->auxiliaryLayer()->deleteAttribute( index );
-    QApplication::restoreOverrideCursor();
-    mLayer->updateFields();
-    updateAuxiliaryStoragePage( true );
-    mFieldsPropertiesDialog->init();
+    deleteAuxiliaryField( index );
     mLayer->triggerRepaint();
+    QApplication::restoreOverrideCursor();
+  }
+}
+
+void QgsVectorLayerProperties::deleteAuxiliaryField( int index )
+{
+  if ( !mLayer->auxiliaryLayer() )
+    return;
+
+  int key = mLayer->auxiliaryLayer()->propertyFromField( index );
+  if ( mLayer->auxiliaryLayer()->deleteAttribute( index ) )
+  {
+    mLayer->updateFields();
+
+    // immediately deactivate data defined button
+    if ( labelingDialog && labelingDialog->labelingGui() )
+      labelingDialog->labelingGui()->deactivateField( ( QgsPalLayerSettings::Property ) key );
+
+    updateAuxiliaryStoragePage( true );
+    mFieldsPropertiesDialog->init();
   }
 }

src/app/qgsvectorlayerproperties.h

@@ -217,6 +217,7 @@ class APP_EXPORT QgsVectorLayerProperties : public QgsOptionsDialogBase, private
     void addJoinToTreeWidget( const QgsVectorLayerJoinInfo &join, const int insertIndex = -1 );
 
     void updateAuxiliaryStoragePage( bool reset = false );
+    void deleteAuxiliaryField( int index );
 
     QgsExpressionContext mContext;
 

src/core/qgsauxiliarystorage.cpp

@@ -405,6 +405,29 @@ bool QgsAuxiliaryLayer::isHiddenProperty( int index ) const
   return hidden;
 }
 
+int QgsAuxiliaryLayer::propertyFromField( int index ) const
+{
+  int p = -1;
+  QgsAuxiliaryField aField( fields().field( index ) );
+  QgsPropertyDefinition aDef = aField.propertyDefinition();
+
+  if ( aDef.origin().compare( "labeling" ) == 0 )
+  {
+    const QgsPropertiesDefinition defs = QgsPalLayerSettings::propertyDefinitions();
+    QgsPropertiesDefinition::const_iterator it = defs.constBegin();
+    for ( ; it != defs.constEnd(); ++it )
+    {
+      if ( it->name().compare( aDef.name(), Qt::CaseInsensitive ) == 0 )
+      {
+        p = it.key();
+        break;
+      }
+    }
+  }
+
+  return p;
+}
+
 int QgsAuxiliaryLayer::indexOfProperty( const QgsPropertyDefinition &def ) const
 {
   return fields().indexOf( QgsAuxiliaryField::nameFromProperty( def ) );

src/core/qgsauxiliarystorage.h

@@ -228,6 +228,18 @@ class CORE_EXPORT QgsAuxiliaryLayer : public QgsVectorLayer
      */
     int indexOfProperty( const QgsPropertyDefinition &definition ) const;
 
+    /**
+     * Returns the underlying property key for the field index. The key may be
+     * a PAL, diagram or symbology property according to the underlying
+     * property definition of the field. The key -1 is returned if an error
+     * happened.
+     *
+     * \param index The index of the field
+     *
+     * \since QGIS 3.0
+     */
+    int propertyFromField( int index ) const;
+
     /**
      * Create if necessary a new auxiliary field for a PAL property and
      * activate this property in settings.

src/gui/qgspropertyoverridebutton.h

@@ -192,13 +192,6 @@ class GUI_EXPORT QgsPropertyOverrideButton: public QToolButton
      */
     void updateFieldLists();
 
-    /**
-     * Updates data defined button icon.
-     *
-     * \since QGIS 3.0
-     */
-    void updateGui();
-
     /**
      * Sets a symbol which can be used for previews inside the widget or in any dialog created
      * by the widget. If not specified, a default created symbol will be used instead.
@@ -232,6 +225,7 @@ class GUI_EXPORT QgsPropertyOverrideButton: public QToolButton
     void showDescriptionDialog();
     void showExpressionDialog();
     void showAssistant();
+    void updateGui();
 
     /**
      * Sets the active status, emitting the activated signal where necessary (but never emitting the changed signal!).