Vector layer save as: usability tunings related to attribute selection

- The group is renamed as 'Select fields to export and their export options'
- It has no longer a checkbox. It is just collapsible. So
  QgsVectorLayerSaveAsDialog::attributeSelection() is deprecated and always
  return true.
- For most formats, all attributes are selected by default
- For CSV/XLSX/ODS, if they have edit widgets, the corresponding checkbox in
  "Replace with displayed values" column is also checked by default.
- For DXF, keep existing behaviour: attributes are unchecked and not checkable
- For KML, keep existing behaviour: attributes are unselected by default

src/app/ogr/qgsvectorlayersaveasdialog.cpp

@@ -223,22 +223,26 @@ void QgsVectorLayerSaveAsDialog::on_mFormatComboBox_currentIndexChanged( int idx
 
   browseFilename->setEnabled( true );
   leFilename->setEnabled( true );
+  bool selectAllFields = true;
+  bool fieldsAsDisplayedValues = false;
 
   if ( format() == "KML" )
   {
     mEncodingComboBox->setCurrentIndex( mEncodingComboBox->findText( "UTF-8" ) );
     mEncodingComboBox->setDisabled( true );
-    mAttributesSelection->setChecked( true );
+    mAttributesSelection->setEnabled( true );
+    selectAllFields = false;
   }
   else if ( format() == "DXF" )
   {
-    mAttributesSelection->setChecked( true );
-    mAttributesSelection->setDisabled( true );
+    mAttributesSelection->setEnabled( false );
+    selectAllFields = false;
   }
   else
   {
     mEncodingComboBox->setEnabled( true );
     mAttributesSelection->setEnabled( true );
+    fieldsAsDisplayedValues = ( format() == "CSV" || format() == "XLS" || format() == "XLSX" || format() == "ODS" );
   }
 
   if ( mLayer )
@@ -264,7 +268,6 @@ void QgsVectorLayerSaveAsDialog::on_mFormatComboBox_currentIndexChanged( int idx
     {
       mAttributeTable->setColumnCount( 2 );
       mAttributeTable->setHorizontalHeaderLabels( QStringList() << tr( "Name" ) << tr( "Type" ) );
-      mReplaceRawFieldValues->setVisible( false );
     }
 
     mAttributeTableItemChangedSlotEnabled = false;
@@ -276,7 +279,7 @@ void QgsVectorLayerSaveAsDialog::on_mFormatComboBox_currentIndexChanged( int idx
       QTableWidgetItem *item;
       item = new QTableWidgetItem( fld.name() );
       item->setFlags( flags | Qt::ItemIsUserCheckable );
-      item->setCheckState( Qt::Unchecked );
+      item->setCheckState(( selectAllFields ) ? Qt::Checked : Qt::Unchecked );
       mAttributeTable->setItem( i, COLUMN_IDX_NAME, item );
 
       item = new QTableWidgetItem( fld.typeName() );
@@ -286,12 +289,13 @@ void QgsVectorLayerSaveAsDialog::on_mFormatComboBox_currentIndexChanged( int idx
       if ( foundFieldThatCanBeExportedAsDisplayedValue )
       {
         QgsEditorWidgetFactory *factory;
-        if ( mLayer->editFormConfig()->widgetType( i ) != "TextEdit" &&
+        if ( flags == Qt::ItemIsEnabled &&
+             mLayer->editFormConfig()->widgetType( i ) != "TextEdit" &&
              ( factory = QgsEditorWidgetRegistry::instance()->factory( mLayer->editFormConfig()->widgetType( i ) ) ) )
         {
           item = new QTableWidgetItem( tr( "Use %1" ).arg( factory->name() ) );
-          item->setFlags( Qt::ItemIsUserCheckable );
-          item->setCheckState( Qt::Unchecked );
+          item->setFlags(( selectAllFields ) ? ( Qt::ItemIsEnabled | Qt::ItemIsUserCheckable ) : Qt::ItemIsUserCheckable );
+          item->setCheckState(( selectAllFields && fieldsAsDisplayedValues ) ? Qt::Checked : Qt::Unchecked );
           mAttributeTable->setItem( i, COLUMN_IDX_EXPORT_AS_DISPLAYED_VALUE, item );
         }
         else
@@ -305,7 +309,11 @@ void QgsVectorLayerSaveAsDialog::on_mFormatComboBox_currentIndexChanged( int idx
 
     mAttributeTableItemChangedSlotEnabled = true;
 
-    mReplaceRawFieldValues->setEnabled( false );
+    mReplaceRawFieldValuesStateChangedSlotEnabled = false;
+    mReplaceRawFieldValues->setChecked( selectAllFields && fieldsAsDisplayedValues );
+    mReplaceRawFieldValuesStateChangedSlotEnabled = true;
+    mReplaceRawFieldValues->setEnabled( selectAllFields );
+    mReplaceRawFieldValues->setVisible( foundFieldThatCanBeExportedAsDisplayedValue );
 
     mAttributeTable->resizeColumnsToContents();
   }
@@ -602,7 +610,7 @@ QStringList QgsVectorLayerSaveAsDialog::layerOptions() const
 
 bool QgsVectorLayerSaveAsDialog::attributeSelection() const
 {
-  return mAttributesSelection->isChecked();
+  return true;
 }
 
 QgsAttributeList QgsVectorLayerSaveAsDialog::selectedAttributes() const

src/app/ogr/qgsvectorlayersaveasdialog.h

@@ -48,6 +48,7 @@ class APP_EXPORT QgsVectorLayerSaveAsDialog : public QDialog, private Ui::QgsVec
     QStringList datasourceOptions() const;
     QStringList layerOptions() const;
     long crs() const;
+    /** @deprecated since 2.16. Now always return true since there is no longer any checkbox */
     bool attributeSelection() const;
     QgsAttributeList selectedAttributes() const;
     /** Return selected attributes that must be exported with their displayed values instead of their raw values. Added in QGIS 2.16 */

src/ui/qgsvectorlayersaveasdialogbase.ui

@@ -122,10 +122,10 @@
        <item>
         <widget class="QgsCollapsibleGroupBox" name="mAttributesSelection">
          <property name="title">
-          <string>Limit attributes to export</string>
+          <string>Select fields to export and their export options</string>
          </property>
          <property name="checkable">
-          <bool>true</bool>
+          <bool>false</bool>
          </property>
          <property name="checked">
           <bool>false</bool>

tests/src/app/testqgsvectorlayersaveasdialog.cpp

@@ -79,8 +79,8 @@ void TestQgsVectorLayerSaveAsDialog::testAttributesAsDisplayedValues()
 
   QgsVectorLayerSaveAsDialog d( tempLayer.data() );
 
-  QgsCollapsibleGroupBoxBasic* mAttributesSelection = d.findChild<QgsCollapsibleGroupBoxBasic*>( "mAttributesSelection" );
-  mAttributesSelection->setChecked( true );
+  QPushButton* mDeselectAllAttributes = d.findChild<QPushButton*>( "mDeselectAllAttributes" );
+  QTest::mouseClick( mDeselectAllAttributes, Qt::LeftButton );
 
   QTableWidget* mAttributeTable = d.findChild<QTableWidget*>( "mAttributeTable" );
   QCheckBox* mReplaceRawFieldValues = d.findChild<QCheckBox*>( "mReplaceRawFieldValues" );