[FEATURE] Allow renaming fields by double clicking name

in layer properties window

Available for supported data providers only (postgres,
memory layers and OGR layers, dependant on OGR data format
and version)

src/app/qgsfieldsproperties.cpp

@@ -257,6 +257,7 @@ void QgsFieldsProperties::loadRows()
 
   mFieldsList->resizeColumnsToContents();
   connect( mFieldsList, SIGNAL( cellChanged( int, int ) ), this, SLOT( attributesListCellChanged( int, int ) ) );
+  updateFieldRenamingStatus();
 }
 
 void QgsFieldsProperties::setRow( int row, int idx, const QgsField& field )
@@ -307,6 +308,12 @@ void QgsFieldsProperties::setRow( int row, int idx, const QgsField& field )
   for ( int i = 0; i < attrCommentCol; i++ )
     mFieldsList->item( row, i )->setFlags( mFieldsList->item( row, i )->flags() & ~Qt::ItemIsEditable );
 
+  bool canRenameFields = mLayer->isEditable() && ( mLayer->dataProvider()->capabilities() & QgsVectorDataProvider::RenameAttributes ) && !mLayer->readOnly();
+  if ( canRenameFields )
+    mFieldsList->item( row, attrNameCol )->setFlags( mFieldsList->item( row, attrNameCol )->flags() | Qt::ItemIsEditable );
+  else
+    mFieldsList->item( row, attrNameCol )->setFlags( mFieldsList->item( row, attrNameCol )->flags() & ~Qt::ItemIsEditable );
+
   FieldConfig cfg( mLayer, idx );
   QPushButton *pb;
   pb = new QPushButton( QgsEditorWidgetRegistry::instance()->name( cfg.mEditorWidgetV2Type ) );
@@ -602,6 +609,7 @@ bool QgsFieldsProperties::addAttribute( const QgsField &field )
 void QgsFieldsProperties::editingToggled()
 {
   updateButtons();
+  updateFieldRenamingStatus();
 }
 
 QgsFieldsProperties::FieldConfig QgsFieldsProperties::configForRow( int row )
@@ -715,7 +723,7 @@ void QgsFieldsProperties::updateButtons()
 
 void QgsFieldsProperties::attributesListCellChanged( int row, int column )
 {
-  if ( column == attrAliasCol && mLayer ) //only consider attribute aliases in this function
+  if ( column == attrAliasCol && mLayer )
   {
     int idx = mFieldsList->item( row, attrIdCol )->text().toInt();
 
@@ -739,6 +747,14 @@ void QgsFieldsProperties::attributesListCellChanged( int row, int column )
       }
     }
   }
+  else if ( column == attrNameCol && mLayer && mLayer->isEditable() )
+  {
+    QTableWidgetItem *nameItem = mFieldsList->item( row, column );
+    if ( nameItem && !nameItem->text().isEmpty() )
+    {
+      mLayer->renameAttribute( row,  nameItem->text() );
+    }
+  }
 }
 
 void QgsFieldsProperties::updateExpression()
@@ -814,6 +830,19 @@ QString QgsFieldsProperties::editTypeButtonText( QgsVectorLayer::EditType type )
   return editTypeMap[ type ];
 }
 
+void QgsFieldsProperties::updateFieldRenamingStatus()
+{
+  bool canRenameFields = mLayer->isEditable() && ( mLayer->dataProvider()->capabilities() & QgsVectorDataProvider::RenameAttributes ) && !mLayer->readOnly();
+
+  for ( int row = 0; row < mFieldsList->rowCount(); ++row )
+  {
+    if ( canRenameFields )
+      mFieldsList->item( row, attrNameCol )->setFlags( mFieldsList->item( row, attrNameCol )->flags() | Qt::ItemIsEditable );
+    else
+      mFieldsList->item( row, attrNameCol )->setFlags( mFieldsList->item( row, attrNameCol )->flags() & ~Qt::ItemIsEditable );
+  }
+}
+
 QgsAttributeEditorElement* QgsFieldsProperties::createAttributeEditorWidget( QTreeWidgetItem* item, QObject *parent )
 {
   QgsAttributeEditorElement *widgetDef = nullptr;

src/app/qgsfieldsproperties.h

@@ -217,6 +217,11 @@ class APP_EXPORT QgsFieldsProperties : public QWidget, private Ui_QgsFieldsPrope
     static QMap< QgsVectorLayer::EditType, QString > editTypeMap;
     static void setupEditTypes();
     static QString editTypeButtonText( QgsVectorLayer::EditType type );
+
+  private:
+
+    void updateFieldRenamingStatus();
+
 };
 
 QDataStream& operator<< ( QDataStream& stream, const QgsFieldsProperties::DesignerTreeItemData& data );