expression builder: fix typos and warnings and follow selection (not just clicked)

Author: jef-n

src/app/qgsfieldcalculator.cpp

@@ -269,12 +269,7 @@ void QgsFieldCalculator::populateFields()
 
 void QgsFieldCalculator::setOkButtonState()
 {
-  bool okEnabled = true;
-  if (( mOutputFieldNameLineEdit->text().isEmpty()
-        && !mUpdateExistingGroupBox->isChecked()
-        || !builder->isExpressionVaild() ) )
-  {
-    okEnabled = false;
-  }
+  bool okEnabled = ( !mOutputFieldNameLineEdit->text().isEmpty() || mUpdateExistingGroupBox->isChecked() ) && builder->isExpressionValid();
+
   mButtonBox->button( QDialogButtonBox::Ok )->setEnabled( okEnabled );
 }

src/app/qgsfieldcalculator.h

@@ -59,7 +59,7 @@ class QgsFieldCalculator: public QDialog, private Ui::QgsFieldCalculatorBase
     /**idx of changed attribute*/
     int mAttributeId;
 
-    bool mExpressionVaild;
+    bool mExpressionValid;
 };
 
 #endif // QGSFIELDCALCULATOR_H

src/gui/qgsexpressionbuilderwidget.cpp

@@ -41,10 +41,12 @@ QgsExpressionBuilderWidget::QgsExpressionBuilderWidget( QWidget *parent )
   expressionTree->setModel( mProxyModel );
 
   expressionTree->setContextMenuPolicy( Qt::CustomContextMenu );
-  connect( this, SIGNAL( expressionParsed( bool ) ), this, SLOT( setExpressionState ) );
+  connect( this, SIGNAL( expressionParsed( bool ) ), this, SLOT( setExpressionState( bool ) ) );
   connect( expressionTree, SIGNAL( customContextMenuRequested( const QPoint & ) ), this, SLOT( showContextMenu( const QPoint & ) ) );
+  connect( expressionTree->selectionModel(), SIGNAL( currentChanged( const QModelIndex &, const QModelIndex & ) ),
+           this, SLOT( currentChanged( const QModelIndex &, const QModelIndex & ) ) );
 
-  foreach( QPushButton* button, this->mOperatorsGroupBox->findChildren<QPushButton *>() )
+  foreach( QPushButton* button, mOperatorsGroupBox->findChildren<QPushButton *>() )
   {
     connect( button, SIGNAL( pressed() ), this, SLOT( operatorButtonClicked() ) );
   }
@@ -99,7 +101,7 @@ void QgsExpressionBuilderWidget::setLayer( QgsVectorLayer *layer )
   mLayer = layer;
 }
 
-void QgsExpressionBuilderWidget::on_expressionTree_clicked( const QModelIndex &index )
+void QgsExpressionBuilderWidget::currentChanged( const QModelIndex &index, const QModelIndex & )
 {
   // Get the item
   QModelIndex idx = mProxyModel->mapToSource( index );
@@ -214,9 +216,9 @@ void QgsExpressionBuilderWidget::registerItem( QString group,
   }
 }
 
-bool QgsExpressionBuilderWidget::isExpressionVaild()
+bool QgsExpressionBuilderWidget::isExpressionValid()
 {
-  return mExpressionVaild;
+  return mExpressionValid;
 }
 
 QString QgsExpressionBuilderWidget::getExpressionString()
@@ -370,7 +372,7 @@ void QgsExpressionBuilderWidget::loadAllValues()
 
 void QgsExpressionBuilderWidget::setExpressionState( bool state )
 {
-  mExpressionVaild = state;
+  mExpressionValid = state;
 }
 
 QString QgsExpressionBuilderWidget::loadFunctionHelp( QgsExpressionItem* functionName )

src/gui/qgsexpressionbuilderwidget.h

@@ -140,10 +140,10 @@ class GUI_EXPORT QgsExpressionBuilderWidget : public QWidget, private Ui::QgsExp
                        QString helpText = "",
                        QgsExpressionItem::ItemType type = QgsExpressionItem::ExpressionNode );
 
-    bool isExpressionVaild();
+    bool isExpressionValid();
 
   public slots:
-    void on_expressionTree_clicked( const QModelIndex &index );
+    void currentChanged( const QModelIndex &index, const QModelIndex & );
     void on_expressionTree_doubleClicked( const QModelIndex &index );
     void on_txtExpressionString_textChanged();
     void on_txtSearchEdit_textChanged();
@@ -175,7 +175,7 @@ class GUI_EXPORT QgsExpressionBuilderWidget : public QWidget, private Ui::QgsExp
     QMap<QString, QgsExpressionItem*> mExpressionGroups;
     QgsFeature mFeature;
     QgsExpressionHighlighter* highlighter;
-    bool mExpressionVaild;
+    bool mExpressionValid;
 };
 
 #endif // QGSEXPRESSIONBUILDER_H

src/ui/qgsfieldcalculatorbase.ui

@@ -156,7 +156,6 @@
       <bool>false</bool>
      </property>
      <zorder>mButtonBox</zorder>
-     <zorder>mButtonBox</zorder>
     </widget>
    </item>
    <item row="3" column="0" colspan="2">