Generalise editor widget config saving/restoring props from gui

Author: nyalldawson

python/gui/editorwidgets/core/qgseditorconfigwidget.sip

@@ -32,5 +32,7 @@ class QgsEditorConfigWidget : QWidget
 
   protected:
     void initializeDataDefinedButton( QgsPropertyOverrideButton *button, QgsWidgetWrapper::Property key );
+    void updateDataDefinedButtons();
+    void updateDataDefinedButton( QgsPropertyOverrideButton *button );
 };
 

src/gui/editorwidgets/core/qgseditorconfigwidget.cpp

@@ -43,8 +43,36 @@ void QgsEditorConfigWidget::initializeDataDefinedButton( QgsPropertyOverrideButt
 {
   button->blockSignals( true );
   button->init( key, mPropertyCollection, QgsWidgetWrapper::propertyDefinitions(), mLayer );
-  connect( button, &QgsPropertyOverrideButton::changed, this, &QgsEditorConfigWidget::changed );
+  connect( button, &QgsPropertyOverrideButton::changed, this, &QgsEditorConfigWidget::updateProperty );
   button->registerExpressionContextGenerator( this );
   button->blockSignals( false );
 }
 
+void QgsEditorConfigWidget::updateDataDefinedButtons()
+{
+  Q_FOREACH ( QgsPropertyOverrideButton *button, findChildren< QgsPropertyOverrideButton * >() )
+  {
+    updateDataDefinedButton( button );
+  }
+}
+
+void QgsEditorConfigWidget::updateDataDefinedButton( QgsPropertyOverrideButton *button )
+{
+  if ( !button )
+    return;
+
+  if ( button->propertyKey() < 0 )
+    return;
+
+  QgsWidgetWrapper::Property key = static_cast< QgsWidgetWrapper::Property >( button->propertyKey() );
+  whileBlocking( button )->setToProperty( mPropertyCollection.property( key ) );
+}
+
+void QgsEditorConfigWidget::updateProperty()
+{
+  QgsPropertyOverrideButton *button = qobject_cast<QgsPropertyOverrideButton *>( sender() );
+  QgsWidgetWrapper::Property key = static_cast<  QgsWidgetWrapper::Property >( button->propertyKey() );
+  mPropertyCollection.setProperty( key, button->toProperty() );
+  emit changed();
+}
+

src/gui/editorwidgets/core/qgseditorconfigwidget.h

@@ -92,9 +92,23 @@ class GUI_EXPORT QgsEditorConfigWidget : public QWidget, public QgsExpressionCon
      */
     void initializeDataDefinedButton( QgsPropertyOverrideButton *button, QgsWidgetWrapper::Property key );
 
+    /**
+     * Updates all property override buttons to reflect the widgets's current properties.
+     */
+    void updateDataDefinedButtons();
+
+    /**
+     * Updates a specific property override \a button to reflect the widgets's current properties.
+     */
+    void updateDataDefinedButton( QgsPropertyOverrideButton *button );
+
     //! Temporary property collection for config widgets
     QgsPropertyCollection mPropertyCollection;
 
+  private slots:
+
+    void updateProperty();
+
   private:
     QgsVectorLayer *mLayer = nullptr;
     int mField;

src/gui/editorwidgets/qgsexternalresourceconfigdlg.cpp

@@ -100,7 +100,6 @@ void QgsExternalResourceConfigDlg::chooseDefaultPath()
 void QgsExternalResourceConfigDlg::rootPathPropertyChanged()
 {
   QgsProperty prop = mRootPathPropertyOverrideButton->toProperty();
-  mPropertyCollection.setProperty( QgsWidgetWrapper::RootPath, prop );
   setRootPathExpression( prop );
 
   mRootPathExpression->setVisible( prop.isActive() );
@@ -152,8 +151,6 @@ QVariantMap QgsExternalResourceConfigDlg::config()
   if ( !mRootPath->text().isEmpty() )
     cfg.insert( QStringLiteral( "DefaultRoot" ), mRootPath->text() );
 
-  cfg.insert( QStringLiteral( "RootPathProperty" ), mRootPathPropertyOverrideButton->toProperty().toVariant() );
-
   // Save Storage Mode
   cfg.insert( QStringLiteral( "StorageMode" ), mStorageButtonGroup->checkedId() );
 
@@ -205,6 +202,8 @@ void QgsExternalResourceConfigDlg::setConfig( const QVariantMap &config )
   }
 
   mPropertyCollection.loadVariant( config.value( QStringLiteral( "PropertyCollection" ) ), QgsWidgetWrapper::propertyDefinitions() );
+  updateDataDefinedButtons();
+
   setRootPathExpression( mPropertyCollection.property( QgsWidgetWrapper::RootPath ) );
   mRootPath->setText( config.value( QStringLiteral( "DefaultRoot" ) ).toString() );
 
@@ -255,7 +254,6 @@ void QgsExternalResourceConfigDlg::setConfig( const QVariantMap &config )
 
 void QgsExternalResourceConfigDlg::setRootPathExpression( const QgsProperty &property )
 {
-  mRootPathPropertyOverrideButton->setToProperty( property );
   mRootPathExpression->setToolTip( property.asExpression() );
 
   QgsExpressionContext ctx = layer()->createExpressionContext();