Add item from value list on double click

Author: NathanW2

src/gui/qgsexpressionbuilder.cpp

@@ -202,6 +202,7 @@ void QgsExpressionBuilderWidget::on_txtExpressionString_textChanged()
     // we don't show the user an error as it will be confusing.
     if ( text.isEmpty() )
     {
+        this->lblPreview->setText("");
         this->lblPreview->setStyleSheet("");
         this->txtExpressionString->setToolTip("");
         this->lblPreview->setToolTip("");
@@ -264,6 +265,11 @@ void QgsExpressionBuilderWidget::on_lblPreview_linkActivated(QString link)
     mv->exec();
 }
 
+void QgsExpressionBuilderWidget::on_mValueListWidget_itemDoubleClicked(QListWidgetItem *item)
+{
+    txtExpressionString->insertPlainText( " " + item->text() + " " );
+}
+
 void QgsExpressionBuilderWidget::operatorButtonClicked()
 {
     QPushButton* button = dynamic_cast<QPushButton*>( sender() );

src/gui/qgsexpressionbuilder.h

@@ -136,6 +136,7 @@ public slots:
     void on_txtExpressionString_textChanged();
     void on_txtSearchEdit_textChanged();
     void on_lblPreview_linkActivated(QString link);
+    void on_mValueListWidget_itemDoubleClicked(QListWidgetItem* item);
     void operatorButtonClicked();
     void showContextMenu( const QPoint & );
     void loadSampleValues();